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  • 1. Abbasi, Arshad Mehmood
    et al.
    Khan, Mir Ajab
    Khan, Nadeem
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Shah, Munir H
    Ethnobotanical survey of medicinally important wild edible fruits species used by tribal communities of Lesser Himalayas-Pakistan2013Ingår i: Journal of Ethnopharmacology, ISSN 0378-8741, E-ISSN 1872-7573, Vol. 148, nr 2, s. 528-536Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Ethnopharmacological relevance: Present survey was conducted to explore ethnomedicinal uses and cultural importance of wild edible fruits species by the inhabitants of Lesser Himalayas-Pakistan. Materials and methods: Information was obtained through informed consent semi-structured interviews, questionnaires, market survey, focus group conversation, unceremonious dialogue and village walks with key informants. Cultural significance of each species was calculated based on use report by participants at each study site. Results: A total of 35 wild edible fruits belonging to 21 genera and 17 families were used for the treatment of various ailments and consumed. Rosaceae was found dominating family with (8 spp.), followed by Moraceae (6 spp.), Rhamnaceae (5 spp.), Palmae and Vitaceae (2 spp. each) and remaining families were represented by one species each. Fruits (48%) were found highly utilized plant parts, followed by leaves (34%), bark, flowers and seeds (4% each), branches, latex and roots (2% each). Water was used as a medium for preparation while milk, ghee, oil, egg and butter are used for application. Modes of preparation were fall into seven categories like fresh parts eaten raw (38%), powder (24%), decoction (20%), extract (12 %), paste (4%), juice and latex (2% each). Based on cultural important index (CI) Morus nigra was found most significant species within top ten fruit plants followed by Morus alba, Olea ferruginea, Berberis lycium, Pyrus pashia, Ficus carica, Ficus palmata, Ziziphus mauritiana, Diospyros lotus and Ziziphus nummularia. Conclusions: Traditional uses of wild edible plant depend mainly on socio-economic factors rather than climatic conditions or wealth of flora. Use reports and citation demonstrated that there is a common cultural heritage regarding the gathered food plants. Further investigation is required for Antioxidant study, essential and toxic components, pharmacological applications; dietary requirements and biotechnological techniques to improve yields.

    (C) 2013 Elsevier Ireland Ltd. All rights reserved.

  • 2. Abraham, Edit
    et al.
    Miskolczi, Pal
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Ayaydin, Ferhan
    Yu, Ping
    Kotogany, Edit
    Bako, Laszlo
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Oetvoes, Krisztina
    Horvath, Gabor V.
    Dudits, Denes
    Immunodetection of retinoblastoma-related protein and its phosphorylated form in interphase and mitotic alfalfa cells2011Ingår i: Journal of Experimental Botany, ISSN 0022-0957, E-ISSN 1460-2431, Vol. 62, nr 6, s. 2155-2168Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Plant retinoblastoma-related (RBR) proteins are primarily considered as key regulators of G(1)/S phase transition, with functional roles in a variety of cellular events during plant growth and organ development. Polyclonal antibody against the C-terminal region of the Arabidopsis RBR1 protein also specifically recognizes the alfalfa 115 kDa MsRBR protein, as shown by the antigen competition assay. The MsRBR protein was detected in all cell cycle phases, with a moderate increase in samples representing G(2)/M cells. Antibody against the human phospho-pRb peptide (Ser807/811) cross-reacted with the same 115 kDa MsRBR protein and with the in vitro phosphorylated MsRBR protein C-terminal fragment. Phospho-MsRBR protein was low in G(1) cells. Its amount increased upon entry into the S phase and remained high during the G(2)/M phases. Roscovitine treatment abolished the activity of alfalfa MsCDKA1;1 and MsCDKB2;1, and the phospho-MsRBR protein level was significantly decreased in the treated cells. Colchicine block increased the detected levels of both forms of MsRBR protein. Reduced levels of the MsRBR protein in cells at stationary phase or grown in hormone-free medium can be a sign of the division-dependent presence of plant RBR proteins. Immunolocalization of the phospho-MsRBR protein indicated spots of variable number and size in the labelled interphase nuclei and high signal intensity of nuclear granules in prophase. Structures similar to phospho-MsRBR proteins cannot be recognized in later mitotic phases. Based on the presented western blot and immunolocalization data, the possible involvement of RBR proteins in G(2)/M phase regulation in plant cells is discussed.

  • 3. Abreu, Ilka N.
    et al.
    Aksmann, Anna
    Bajhaiya, Amit K.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen. Algal Biotechnology Lab, Department of Microbiology, School of Life Sciences, Central University of Tamil Nadu, Thiruvarur, Tamil Nadu, India.
    Benlloch, Reyes
    Giordano, Mario
    Pokora, Wojciech
    Selstam, Eva
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Moritz, Thomas
    Changes in lipid and carotenoid metabolism in Chlamydomonas reinhardtii during induction of CO2-concentrating mechanism: Cellular response to low CO2 stress2020Ingår i: Algal Research, ISSN 2211-9264, Vol. 52, artikel-id 102099Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Photosynthetic organisms strictly depend on CO2 availability and the CO2:O2 ratio, as both CO2/O2 compete for catalytic site of Rubisco. Green alga Chlamydomonas reinhardtii, can overcome CO2 shortage by inducing CO2-concentrating mechanism (CCM). Cells transferred to low-CO2 are subjected to light-driven oxidative stress due to decrease in the electron sink. Response to environmental perturbations is mediated to some extent by changes in the lipid and carotenoid metabolism. We thus hypothesize that when cells are challenged with changes in CO2 availability, changes in the lipidome and carotenoids profile occur. These changes expected to be transient, when CCM is activated, CO2 limitation will be substantially ameliorated. In our experiments, cells were transferred from high (5%) to low (air equilibrium) CO2. qPCR analysis of genes related to CCM and lipid metabolism was carried out. Lipidome was analyzed both in whole cells and in isolated lipid droplets. We characterized the changes in polar lipids, fatty acids and ketocarotenoids. In general, polar lipids significantly and transiently increased in lipid droplets during CCM. Similar pattern was observed for xanthophylls, ketocarotenoids and their esters. The data supports our hypothesis about the roles of lipids and carotenoids in tackling the oxidative stress associated with acclimation to sub-saturating CO2.

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  • 4. Abreu, Ilka N.
    et al.
    Johansson, Annika I.
    Sokolowska, Katarzyna
    Niittylä, Totte
    Sundberg, Björn
    Hvidsten, Torgeir R.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC). Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway.
    Street, Nathaniel R.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Moritz, Thomas
    A metabolite roadmap of the wood-forming tissue in Populus tremula2020Ingår i: New Phytologist, ISSN 0028-646X, E-ISSN 1469-8137, Vol. 228, nr 5, s. 1559-1572Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Wood, or secondary xylem, is the product of xylogenesis, a developmental process that begins with the proliferation of cambial derivatives and ends with mature xylem fibers and vessels with lignified secondary cell walls. Fully mature xylem has undergone a series of cellular processes, including cell division, cell expansion, secondary wall formation, lignification and programmed cell death. A complex network of interactions between transcriptional regulators and signal transduction pathways controls wood formation. However, the role of metabolites during this developmental process has not been comprehensively characterized. To evaluate the role of metabolites during wood formation, we performed a high spatial resolution metabolomics study of the wood-forming zone of Populus tremula, including laser dissected aspen ray and fiber cells. We show that metabolites show specific patterns within the wood-forming zone, following the differentiation process from cell division to cell death. The data from profiled laser dissected aspen ray and fiber cells suggests that these two cell types host distinctly different metabolic processes. Furthermore, by integrating previously published transcriptomic and proteomic profiles generated from the same trees, we provide an integrative picture of molecular processes, for example, deamination of phenylalanine during lignification is of critical importance for nitrogen metabolism during wood formation.

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  • 5.
    Abreu, Ilka Nacif
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC). Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik.
    Ahnlund, Maria
    Moritz, Thomas
    Albrectsen, Benedicte R.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    UHPLC-ESI/TOFMS Determination of Salicylate-like Phenolic Gycosides in Populus tremula Leaves2011Ingår i: Journal of Chemical Ecology, ISSN 0098-0331, E-ISSN 1573-1561, Vol. 37, nr 8, s. 857-70Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Associations of salicylate-like phenolic glycosides (PGs) with biological activity have been reported in Salix and Populus trees, but only for a few compounds, and in relation to a limited number of herbivores. By considering the full diversity of PGs, we may improve our ability to recognize genotypes or chemotype groups and enhance our understanding of their ecological function. Here, we present a fast and efficient general method for salicylate determination in leaves of Eurasian aspen that uses ultra-high performance liquid chromatography-electrospray ionization/time-of-flight mass spectrometry (UHPLC-ESI/TOFMS). The time required for the liquid chromatography separations was 13.5 min per sample, compared to around 60 min per sample for most HPLC protocols. In leaf samples from identical P. tremula genotypes with diverse propagation and treatment histories, we identified nine PGs. We found the compound-specific mass chromatograms to be more informative than the UV-visible chromatograms for compound identification and when quantitating samples with large variability in PG content. Signature compounds previously reported for P. tremoloides (tremulacin, tremuloidin, salicin, and salicortin) always were present, and five PGs (2'-O-cinnamoyl-salicortin, 2'-O-acetyl-salicortin, 2'-O-acetyl-salicin, acetyl-tremulacin, and salicyloyl-salicin) were detected for the first time in P. tremula. By using information about the formic acid adduct that appeared for PGs in the LTQ-Orbitrap MS environment, novel compounds like acetyl-tremulacin could be tentatively identified without the use of standards. The novel PGs were consistently either present in genotypes regardless of propagation and damage treatment or were not detectable. In some genotypes, concentrations of 2'-O-acetyl-salicortin and 2'-O-cinnamoyl-salicortin were similar to levels of biologically active PGs in other Salicaceous trees. Our study suggests that we may expect a wide variation in PG content in aspen populations which is of interest both for studies of interactions with herbivores and for mapping population structure.

  • 6. Adam, Zach
    et al.
    Adamska, Iwona
    Nakabayashi, Kazumi
    Ostersetzer, Oren
    Haussuhl, Kirsten
    Manuell, Andrea
    Zheng, Bo
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Vallon, Olivier
    Rodermel, Steven
    Shinozaki, Kazuo
    Chloroplast and mitochondrial proteases in Arabidopsis: a proposed nomenclature2001Ingår i: Plant Physiology, ISSN 0032-0889, E-ISSN 1532-2548, Vol. 125, nr 4, s. 1912-1918Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The identity and scope of chloroplast and mitochondrial proteases in higher plants has only started to become apparent in recent years. Biochemical and molecular studies suggested the existence of Clp, FtsH, and DegP proteases in chloroplasts, and a Lon protease in mitochondria, although currently the full extent of their role in organellar biogenesis and function remains poorly understood. Rapidly accumulating DNA sequence data, especially from Arabidopsis, has revealed that these proteolytic enzymes are found in plant cells in multiple isomeric forms. As a consequence, a systematic approach was taken to catalog all these isomers, to predict their intracellular location and putative processing sites, and to propose a standard nomenclature to avoid confusion and facilitate scientific communication. For the Clp protease most of the ClpP isomers are found in chloroplasts, whereas one is mitochondrial. Of the ATPase subunits, the one ClpD and two ClpC isomers are located in chloroplasts, whereas both ClpX isomers are present in mitochondria. Isomers of the Lon protease are predicted in both compartments, as are the different forms of FtsH protease. DegP, the least characterized protease in plant cells, has the most number of isomers and they are predicted to localize in several cell compartments. These predictions, along with the proposed nomenclature, will serve as a framework for future studies of all four families of proteases and their individual isomers.

  • 7. Agostinelli, Marta
    et al.
    Cleary, Michelle
    Martin, Juan A.
    Albrectsen, Benedicte R.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Witzell, Johanna
    Pedunculate Oaks (Quercus robur L.) Differing in Vitality as Reservoirs for Fungal Biodiversity2018Ingår i: Frontiers in Microbiology, E-ISSN 1664-302X, Vol. 9, artikel-id 1758Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Ecological significance of trees growing in urban and peri-urban settings is likely to increase in future land-use regimes, calling for better understanding of their role as potential reservoirs or stepping stones for associated biodiversity. We studied the diversity of fungal endophytes in woody tissues of asymptomatic even aged pedunculate oak trees, growing as amenity trees in a peri-urban setting. The trees were classified into three groups according to their phenotypic vitality (high, medium, and low). Endophytes were cultured on potato dextrose media from surface sterilized twigs and DNA sequencing was performed to reveal the taxonomic identity of the morphotypes. In xylem tissues, the frequency and diversity of endophytes was highest in oak trees showing reduced vitality. This difference was not found for bark samples, in which the endophyte infections were more frequent and communities more diverse than in xylem. In general, most taxa were shared across the samples with few morphotypes being recovered in unique samples. Leaf phenolic profiles were found to accurately classify the trees according to their phenotypic vitality. Our results confirm that xylem is more selective substrate for endophytes than bark and that endophyte assemblages in xylem are correlated to the degree of host vitality. Thus, high vitality of trees may be associated with reduced habitat quality to wood-associated endophytes.

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  • 8. Ahad, Abdul
    et al.
    Keech, Olivier
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Sjödin, Andreas
    Lindén, Pernilla
    Brouwer, Bastiaan
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Stenlund, Hans
    Moritz, Thomas
    Jansson, Stefan
    Gardeström, Per
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Comparison between leaves from darkened plants and individually-darkened leaves reveals differential metabolic strategies in response to darknessManuskript (preprint) (Övrigt vetenskapligt)
  • 9.
    Ahad, Abdul
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Nick, Peter
    Actin is bundled in activation-tagged tobacco mutants that tolerate aluminum2007Ingår i: Planta, ISSN 0032-0935, E-ISSN 1432-2048, Vol. 225, nr 2, s. 451-468Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A panel of aluminum-tolerant (AlRes) mutants was isolated by protoplast-based T-DNA activation tagging in the tobacco cultivar SR1. The mutants fell into two phenotypic classes: a minority of the mutants were fertile and developed similarly to the wild type (type I), the majority was male-sterile and grew as semi-dwarfs (type II). These traits, along with the aluminum tolerance, were inherited in a monogenic dominant manner. Both types of mutants were characterized by excessive bundling of actin microfilaments and by a strongly increased abundance of actin, a phenotype that could be partially phenocopied in the wild type by treatment with aluminum chloride. The actin bundles could be dissociated into finer strands by addition of exogenous auxin in both types of mutants. However, actin microfilaments and leaf expansion were sensitive to blockers of actin assembly in the wild type and in the mutants of type I, whereas they were more tolerant in the mutants of type II. The mutants of type II displayed a hypertrophic development of vasculature, manifest in form of supernumerary leaf veins and extended xylem layers in stems and petioles. Whereas mutants of type I were characterized by a normal, but aluminum-tolerant polar auxin-transport, auxin-transport was strongly promoted in the mutants of type II. The phenotype of these mutants is discussed in terms of reduced endocytosis leading, concomitantly with aluminum tolerance, to changes in polar auxin transport.

  • 10. Ahlfors, Reetta
    et al.
    Lång, Saara
    Overmyer, Kirk
    Jaspers, Pinja
    Brosché, Mikael
    Tauriainen, Airi
    Kollist, Hannes
    Tuominen, Hannele
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Belles-Boix, Enric
    Piippo, Mirva
    Inzé, Dirk
    Palva, E Tapio
    Kangasjärvi, Jaakko
    Arabidopsis RADICAL-INDUCED CELL DEATH1 belongs to the WWE protein-protein interaction domain protein family and modulates abscisic acid, ethylene, and methyl jasmonate responses.2004Ingår i: The Plant Cell, ISSN 1040-4651, Vol. 16, nr 7, s. 1925-37Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Experiments with several Arabidopsis thaliana mutants have revealed a web of interactions between hormonal signaling. Here, we show that the Arabidopsis mutant radical-induced cell death1 (rcd1), although hypersensitive to apoplastic superoxide and ozone, is more resistant to chloroplastic superoxide formation, exhibits reduced sensitivity to abscisic acid, ethylene, and methyl jasmonate, and has altered expression of several hormonally regulated genes. Furthermore, rcd1 has higher stomatal conductance than the wild type. The rcd1-1 mutation was mapped to the gene At1g32230 where it disrupts an intron splice site resulting in a truncated protein. RCD1 belongs to the (ADP-ribosyl)transferase domain–containing subfamily of the WWE protein–protein interaction domain protein family. The results suggest that RCD1 could act as an integrative node in hormonal signaling and in the regulation of several stress-responsive genes.

  • 11.
    Ahmad, Iftikhar
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Fysiologisk botanik.
    Screening for mutants with delayed leaf senescence in Arabidopsis2009Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Senescence is the last stage of development in plants. During foliar senescence, theleaves experience changes in metabolism, cell structures and gene expression. In thisprocess the limiting nutrients of leaves are relocated from senescing organs to thedeveloping leaves, fruits and buds. The genetic screening to identify senescence mutantsis of utmost importance both for scientific research and for future biotechnology becausethe stay green mutants could increase crop yields.In our experimental setup, the senescence was induced by darkening the individual leavesof Arabidopsis thaliana plants with “mittens” for six days. We have screened 1064Arabidopsis plants for the mutants with delayed senescence phenotypes (stay-green,light-green and slightly light green plants) by measuring chlorophyll content, proteincontent and change in protein levels of the rubisco LSU, COXII, GS1 and GS2 duringdark induced senescence. After senescence induction, the wild type plants had showntypical yellowing and drying of leaves coupled with chlorophyll and protein degradation,while the foliar senescence progresses more slowly in selected stay green mutants. Theselected stay green mutants (19/29, 19/1043 and 19/531) delayed the degradation ofchlorophyll and protein contents even after 6 days of dark treatment. Furthermore, theretention of chloroplast and mitochondrial protein (rubisco LSU and GS2, and COXIIrespectively) and their higher chlorophyll contents may suggest that 19/29, 19/531and19/1043 plants may maintain their photosynthetic and respiratory activities. Thesemutants delay the functional leaf senescence and could be candidates for functional staygreen mutants for upcoming experiments.

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  • 12. Ahn, Ji Hoon
    et al.
    Schmid, Markus
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik.
    Editorial overview: Growth and development: Change is in the air: how plants modulate development in response to the environment2017Ingår i: Current opinion in plant biology, ISSN 1369-5266, E-ISSN 1879-0356, Vol. 35, s. IV-VIArtikel i tidskrift (Refereegranskat)
  • 13.
    Ailizati, Aili
    et al.
    Graduate School of Science and Engineering, Saitama University, Saitama, Japan.
    Nagahage, Isura Sumeda Priyadarshana
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik.
    Miyagi, Atsuko
    Graduate School of Science and Engineering, Saitama University, Saitama, Japan.
    Ishikawa, Toshiki
    Graduate School of Science and Engineering, Saitama University, Saitama, Japan.
    Kawai-Yamada, Maki
    Graduate School of Science and Engineering, Saitama University, Saitama, Japan.
    Demura, Taku
    Graduate School of Biological Sciences, Nara Institute of Science and Technology (NAIST), Nara, Japan.
    Yamaguchi, Masatoshi
    Graduate School of Science and Engineering, Saitama University, Saitama, Japan.
    An Arabidopsis NAC domain transcriptional activator VND7 negatively regulates VNI2 expression2021Ingår i: Plant Biotechnology, ISSN 1342-4580, E-ISSN 1347-6114, Vol. 38, nr 4, s. 415-420Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A NAC domain transcription factor, VND-INTERACTING2 (VNI2) is originally isolated as an interacting protein with another NAC domain transcription factor, VASCULAR-RELATED NAC-DOMAIN7 (VND7), a master regulator of xylem vessel element differentiation. VND7 directly or indirectly induces expression of a number of genes associated with xylem vessel element differentiation, while VNI2 inhibits the transcriptional activation activities of VND7 by forming a protein complex. VNI2 is expressed at an earlier stage of xylem vessel element differentiation than VND7. Here, to investigate whether VND7 also affects VNI2, a transient expression assay was performed. We demonstrated that VND7 downregulated VNI2 expression. Other transcription factors involved in xylem vessel formation did not show the negative regulation of VNI2 expression. Rather, MYB83, a downstream target of VND7, upregulated VNI2 expression. By using the deletion series of the VNI2 promoter, a 400 bp region was identified as being responsible for downregulation by VND7. These data suggested that VND7 and VNI2 mutually regulate each other, and VNI2 expression is both positively and negatively regulated in the transcriptional cascade.

  • 14.
    Ailizati, Aili
    et al.
    Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama, Saitama, Japan.
    Nagahage, Isura Sumeda Priyadarshana
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik.
    Miyagi, Atsuko
    Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama, Saitama, Japan.
    Ishikawa, Toshiki
    Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama, Saitama, Japan.
    Kawai-Yamada, Maki
    Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama, Saitama, Japan.
    Demura, Taku
    Graduate School of Biological Sciences, Nara Institute of Science and Technology (NAIST), 8916-5 Takayama, Nara, Ikoma, Japan.
    Yamaguchi, Masatoshi
    Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama, Saitama, Japan.
    VND-INTERACTING2 effectively inhibits transcriptional activities of VASCULAR-RELATED NAC-DOMAIN7 through a conserved sequence2022Ingår i: Plant Biotechnology, ISSN 1342-4580, E-ISSN 1347-6114, Vol. 39, nr 2, s. 147-153Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    An Arabidopsis NAC domain transcription factor VND-INTERACTING2 (VNI2) was originally isolated as an interacting protein with another NAC domain transcription factor, VASCULAR-RELATED NAC-DOMAIN7 (VND7), a master regulator of xylem vessel element differentiation. VNI2 inhibits transcriptional activation activity of VND7 by forming a protein complex. Here, to obtain insights into how VNI2 regulates VND7, we tried to identify the amino acid region of VNI2 required for inhibition of VND7. VNI2 has an amino acid sequence similar to the ETHYLENE-RESPONSIVE ELEMENT BINDING FACTOR (ERF)-associated amphiphilic repression (EAR) motif, conserved in transcriptional repressors, at the C-terminus. A transient expression assay showed that the EAR-like motif of VNI2 was not required for inhibition of VND7. The C-terminal deletion series of VNI2 revealed that 10 amino acid residues, highly conserved in the VNI2 orthologs contributed to effective repression of the transcriptional activation activity of VND7. Observation of transgenic plants ectopically expressing VNI2 showed that the identified 10 amino acid sequence strongly affected xylem vessel formation and plant growth. These data indicated that the 10 amino acid sequence of VNI2 has an important role in its transcriptional repression activity and negative regulation of xylem vessel formation.

  • 15. Akhter, Shirin
    et al.
    Kretzschmar, Warren W.
    Nordal, Veronika
    Delhomme, Nicolas
    Street, Nathaniel
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Nilsson, Ove
    Emanuelsson, Olof
    Sundström, Jens F.
    Integrative analysis of three RNA sequencing methods identifies mutually exclusive exons of MADS-box isoforms during early bud development in Picea abies2018Ingår i: Frontiers in Plant Science, E-ISSN 1664-462X, Vol. 9, artikel-id 1625Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Recent efforts to sequence the genomes and transcriptomes of several gymnosperm species have revealed an increased complexity in certain gene families in gymnosperms as compared to angiosperms. One example of this is the gymnosperm sister Glade to angiosperm TM3-like MADS-box genes, which at least in the conifer lineage has expanded in number of genes. We have previously identified a member of this subclade, the conifer gene DEFICIENS AGAMOUS LIKE 19 (DAL19), as being specifically upregulated in cone-setting shoots. Here, we show through Sanger sequencing of mRNA-derived cDNA and mapping to assembled conifer genomic sequences that DAL19 produces six mature mRNA splice variants in Picea abies. These splice variants use alternate first and last exons, while their four central exons constitute a core region present in all six transcripts. Thus, they are likely to be transcript isoforms. Quantitative Real-Time PCR revealed that two mutually exclusive first DAL19 exons are differentially expressed across meristems that will form either male or female cones, or vegetative shoots. Furthermore, mRNA in situ hybridization revealed that two mutually exclusive last DAL19 exons were expressed in a cell-specific pattern within bud meristems. Based on these findings in DAL19, we developed a sensitive approach to transcript isoform assembly from short-read sequencing of mRNA. We applied this method to 42 putative MADS-box core regions in P abies, from which we assembled 1084 putative transcripts. We manually curated these transcripts to arrive at 933 assembled transcript isoforms of 38 putative MADS-box genes. 152 of these isoforms, which we assign to 28 putative MADS-box genes, were differentially expressed across eight female, male, and vegetative buds. We further provide evidence of the expression of 16 out of the 38 putative MADS-box genes by mapping PacBio Iso-Seq circular consensus reads derived from pooled sample sequencing to assembled transcripts. In summary, our analyses reveal the use of mutually exclusive exons of MADS-box gene isoforms during early bud development in P. abies, and we find that the large number of identified MADS-box transcripts in P. abies results not only from expansion of the gene family through gene duplication events but also from the generation of numerous splice variants.

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  • 16.
    Akhter, Shirin
    et al.
    Department of Plant Biology, Linnean Center for Plant Biology, Uppsala BioCentre, Swedish University of Agricultural Sciences (SLU), Uppsala, Sweden.
    Westrin, Karl Johan
    Science for Life Laboratory, Department of Gene Technology, KTH Royal Institute of Technology, Solna, Sweden.
    Zivi, Nathan
    Department of Plant Biology, Linnean Center for Plant Biology, Uppsala BioCentre, Swedish University of Agricultural Sciences (SLU), Uppsala, Sweden; Skogforsk, Uppsala Science Park, Uppsala, Sweden.
    Nordal, Veronika
    Department of Plant Biology, Linnean Center for Plant Biology, Uppsala BioCentre, Swedish University of Agricultural Sciences (SLU), Uppsala, Sweden.
    Kretzschmar, Warren W.
    Science for Life Laboratory, Department of Gene Technology, KTH Royal Institute of Technology, Solna, Sweden.
    Delhomme, Nicolas
    Department of Forest Genetics and Plant Physiology, Umeå Plant Science Centre, Swedish University of Agricultural Sciences (SLU), Umeå, Sweden.
    Street, Nathaniel R.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Nilsson, Ove
    Department of Forest Genetics and Plant Physiology, Umeå Plant Science Centre, Swedish University of Agricultural Sciences (SLU), Umeå, Sweden.
    Emanuelsson, Olof
    Science for Life Laboratory, Department of Gene Technology, KTH Royal Institute of Technology, Solna, Sweden.
    Sundström, Jens F.
    Department of Plant Biology, Linnean Center for Plant Biology, Uppsala BioCentre, Swedish University of Agricultural Sciences (SLU), Uppsala, Sweden.
    Cone-setting in spruce is regulated by conserved elements of the age-dependent flowering pathway2022Ingår i: New Phytologist, ISSN 0028-646X, E-ISSN 1469-8137, Vol. 236, nr 5, s. 1951-1963Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Reproductive phase change is well characterized in angiosperm model species, but less studied in gymnosperms. We utilize the early cone-setting acrocona mutant to study reproductive phase change in the conifer Picea abies (Norway spruce), a gymnosperm. The acrocona mutant frequently initiates cone-like structures, called transition shoots, in positions where wild-type P. abies always produces vegetative shoots.

    We collect acrocona and wild-type samples, and RNA-sequence their messenger RNA (mRNA) and microRNA (miRNA) fractions. We establish gene expression patterns and then use allele-specific transcript assembly to identify mutations in acrocona. We genotype a segregating population of inbred acrocona trees.

    A member of the SQUAMOSA BINDING PROTEIN-LIKE (SPL) gene family, PaSPL1, is active in reproductive meristems, whereas two putative negative regulators of PaSPL1, miRNA156 and the conifer specific miRNA529, are upregulated in vegetative and transition shoot meristems. We identify a mutation in a putative miRNA156/529 binding site of the acrocona PaSPL1 allele and show that the mutation renders the acrocona allele tolerant to these miRNAs. We show co-segregation between the early cone-setting phenotype and trees homozygous for the acrocona mutation.

    In conclusion, we demonstrate evolutionary conservation of the age-dependent flowering pathway and involvement of this pathway in regulating reproductive phase change in the conifer P. abies.

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  • 17. Aksmann, Anna
    et al.
    Shutova, Tatiana
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC). Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik.
    Samuelsson, Göran
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC). Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik.
    Tukaj, Zbigniew
    The mechanism of anthracene interaction with photosynthetic apparatus: A study using intact cells, thylakoid membranes and PS II complexes isolated from Chlamydomonas reinhardtii2011Ingår i: Aquatic Toxicology, ISSN 0166-445X, E-ISSN 1879-1514, Vol. 104, nr 3-4, s. 205-210Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Intact cells of Chlamydomonas reinhardtii as well as isolated thylakoid membranes and photosystem II complexes were used to examine a possible mechanism of anthracene (ANT) interaction with the photosynthetic apparatus. Since ANT concentrations above 1 mM were required to significantly inhibit the rate of oxygen evolution in PS II membrane fragments it may indicate that the toxicant did not directly interact with this photosystem. On the other hand, stimulation of oxygen uptake by ANT-treated thylakoids suggested that ANT could either act as an artificial electron acceptor in the photosynthetic electron transport chain or function as an uncoupler. Electron transfer from excited chlorophyll to ANT is impossible due to the very low reduction potential of ANT and therefore we propose that toxic concentrations of ANT increase the thylakoid membrane permeability and thereby function as an uncoupler, enhancing electron transport in vitro. Hence, its unspecific interference with photosynthetic membranes in vitro suggests that the inhibitory effect observed on intact cell photosynthesis is caused by uncoupling of phosphorylation. 

  • 18. Alagna, F.
    et al.
    Caceres, M. E.
    Pandolfi, S.
    Collani, Silvio
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC). Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik.
    Mousavi, S.
    Mariotti, R.
    Cultrera, N. G. M.
    Baldoni, L.
    Barcaccia, G.
    The Paradox of Self-Fertile Varieties in the Context of Self-Incompatible Genotypes in Olive2019Ingår i: Frontiers in Plant Science, E-ISSN 1664-462X, Vol. 10, artikel-id 725Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    Olive, representing one of the most important fruit crops of the Mediterranean area, is characterized by a general low fruit yield, due to numerous constraints, including alternate bearing, low flower viability, male-sterility, inter-incompatibility, and self-incompatibility (SI). Early efforts to clarify the genetic control of SI in olive gave conflicting results, and only recently, the genetic control of SI has been disclosed, revealing that olive possesses an unconventional homomorphic sporophytic diallelic system of SI, dissimilar from other described plants. This system, characterized by the presence of two SI groups, prevents self-fertilization and regulates inter-compatibility between cultivars, such that cultivars bearing the same incompatibility group are incompatible. Despite the presence of a functional SI, some varieties, in particular conditions, are able to set seeds following self-fertilization, a mechanism known as pseudo-self-compatibility (PSC), as widely reported in previous literature. Here, we summarize the results of previous works on SI in olive, particularly focusing on the occurrence of self-fertility, and offer a new perspective in view of the recent elucidation of the genetic architecture of the SI system in olive. Recent advances in research aimed at unraveling the molecular bases of SI and its breakdown in olive are also presented. The clarification of these mechanisms may have a huge impact on orchard management and will provide fundamental information for the future of olive breeding programs.

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  • 19.
    Alallaq, Sanaria
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Characterization of adventitious root formation in Populus species and Norway spruce2021Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Adventitious root (AR) formation is a form of post-embryonic development and is a key adaptive trait in plants. De novo adventitious root regeneration represents an elegant evolutionary innovation that allows many plant species to multiply through vegetative propagation; it is widely used in forestry and horticulture to multiply elite genotypes. However, several tree species with high economic and ecological value are difficult to root, and the genetic and molecular bases underlying AR regeneration remain largely elusive. Recently our laboratory showed that jasmonate (JA) and cytokinins (CK) act cooperatively to repress AR initiation (ARI) in Arabidopsishypocotyls, while auxin positively controls ARI by repressing this negative effect. With the recent availability of the reference genomes of Populus spp. and Norway spruce (Picea abies), the aim of this thesis is to explore the molecular and mechanistic foundations of AR formation in woody species and check whether or not there is conservation of the molecular mechanisms identified in Arabidopsis. First, physiological, molecular and hormonic approaches coupled with extensive anatomical analysis were combined to explore the role of light spectral quality in the control of ARI in P. abies de-rooted seedlings. We showed that constant red light (cRL) promotes ARI by reducing the content of the wound-induced phytohormones JA and JA-isoleucine and repressing the accumulation of the isopentyl-adenine-type cytokinins. These results suggest that the cooperative role of JA and CK signaling in the repression of ARI is evolutionarily conserved.Next we compared transcriptomic data from the cambium tissue of woody stem cuttings of the hybrid aspen T89, which is difficult-to-root, and from the hybrid poplar OP42, which is easy-to-root, under hydroponic conditions. The analyses revealed high transcriptional activity in OP42, with twice as many transcription factors differentially expressed in OP42 24 hours after cutting compared to T89. Although we did not observe significant differences in the expression of Auxin response factor (ARF) genes between the two genotypes, the production of transgenic plants downregulating or over-expressing ARF6, 8 or 17 confirmed that PtARF6 and PtARF8 positively and PtARF17 negatively regulate AR development in transgenic hybrid aspen T89. Interestingly, the expression of MYC2 orthologs as well as the expression of several genes involved in JA signaling increased more in T89 than in OP42, suggesting that JA could be a negative regulator of ARI in Populus spp. We also showed that overexpressing PtMYC2 led to a reduced number of ARs in hybrid aspen T89 cuttings. In addition, many genes encoding ROS scavenging proteins such as peroxidases or GSTs were significantly differentially expressed in OP42 24 h after cutting but not in T89, which is interesting since peroxidase activity has often been positively correlated with ARI. In parallel to this research, we characterized the rooting phenotype of clones from the Swedish Aspen (SwAsp) collection usingin vitro cuttings. We observed a significant variation in the rooting ability as well as different root system establishment between the clones. We analyzed the expression of some genes known to be involved in AR development in selected clones with contrasting AR phenotypes but could not identify any correlation between gene expression and rooting phenotype. A transcriptomic analysis of selected clones, with contrasting AR phenotypes, could be a useful tool in the identification of marker genes, which can be used for future selection of the best rooting clones of Populus or other economically important trees in breeding programs.

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  • 20.
    Alallaq, Sanaria
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Bannoud, Florencia
    Bellini, Catherine
    Characterization of AR formation in aspen clones from the Swedish Aspen collectionManuskript (preprint) (Övrig (populärvetenskap, debatt, mm))
  • 21.
    Alallaq, Sanaria
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC). Department of Biology, College of Science for Women, Baghdad University, Baghdad, Iraq.
    Ranjan, Alok
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Brunoni, Federica
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Novak, Ondrej
    Lakehal, Abdellah
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Bellini, Catherine
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC). Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Institut Jean-Pierre Bourgin, INRAE, AgroParisTech, Universite´ Paris-Saclay, Versailles, France.
    Red Light Controls Adventitious Root Regeneration by Modulating Hormone Homeostasis in Picea abies Seedlings2020Ingår i: Frontiers in Plant Science, E-ISSN 1664-462X, Vol. 11, artikel-id 586140Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Vegetative propagation relies on the capacity of plants to regeneratede novoadventitious roots (ARs), a quantitative trait controlled by the interaction of endogenous factors, such as hormones and environmental cues among which light plays a central role. However, the physiological and molecular components mediating light cues during AR initiation (ARI) remain largely elusive. Here, we explored the role of red light (RL) on ARI in de-rooted Norway spruce seedlings. We combined investigation of hormone metabolism and gene expression analysis to identify potential signaling pathways. We also performed extensive anatomical characterization to investigate ARI at the cellular level. We showed that in contrast to white light, red light promoted ARI likely by reducing jasmonate (JA) and JA-isoleucine biosynthesis and repressing the accumulation of isopentyl-adenine-type cytokinins. We demonstrated that exogenously applied JA and/or CK inhibit ARI in a dose-dependent manner and found that they possibly act in the same pathway. The negative effect of JA on ARI was confirmed at the histological level. We showed that JA represses the early events of ARI. In conclusion, RL promotes ARI by repressing the accumulation of the wound-induced phytohormones JA and CK.

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  • 22.
    Albrectsen, Benedicte
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Gutierrez, Laura
    Fritz, Robert S
    Fritz, Robert D
    Orians, Colin M
    Does the differential seedling mortality caused by slugs alter the foliar traits and subsequent susceptibility of hybrid willows to a generalist herbivore?2007Ingår i: Ecological Entomology, Vol. 32, s. 211-220Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Abstract. 1. Many Salicaceae species naturally form hybrid swarms with parental and hybrid taxa that differ in secondary chemical profile and in resistance to herbivores. Theoretically, the differential mortality in the seedling stage can lead to changes in trait expression and alter subsequent interactions between plants and herbivores. This study examines whether herbivory by the generalist slug Arion subfuscus, which causes extensive mortality in young willow seedlings, causes shifts in (a) the foliar chemistry of F2 willow hybrids (Salix sericea and Salix eriocephala), and (b) the subsequent susceptibility to Japanese Beetles, Popillia japonica.

    2. In 2001, two populations of F2 seedlings were generated: those that survived slug herbivory (80–90% of seedlings placed in the field were killed by the slugs) were designated as S-plants, whereas C-plants (controls) experienced no mortality.

    3. Common garden experiments with cuttings from these populations, in 2001 and 2002, revealed extensive variation in the phenolic chemistry of F2 hybrids, but revealed no significant difference between S- and C-plants, although the levels of foliar nutrients, proteins and nitrogen tended to be higher in S-plants.

    4. Concentrations of salicortin and 2'-cinnamoylsalicortin explained 55 and 38% of the the variation in leaf damage caused by Japanese beetles, and secondary chemistry was highly correlated within replicate clones (salicortin R2 = 0.85, 2-cinnamoylsalicortin R2 = 0.77, condensed tannins R2 = 0.68).

    5. Interestingly, Japanese beetle damage and condensed tannins were positively correlated within the S-plants, but not in the C-plants, suggesting that slugs had selected for plants with a positive relationship between tannins and P. japonica damage. This is unlikely to be a consequence of a preference for tannins, but is suggested to be related to the elevated nutrient levels in the S-plants, perhaps in combination with the complex-binding properties of tannins.

    6. The damage was highly correlated within replicate clones and a model choice analysis suggested that Japanese beetle damage may be explained by four factors: concentrations of salicortin, condensed tannins, and nitrogen, as well as the specific leaf area (thick leaves were damaged less).

  • 23.
    Albrectsen, Benedicte
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Jansson, Stefan
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    From micro towards the macro scale2006Ingår i: New Phytologist, Vol. 172, s. 7-10Artikel i tidskrift (Refereegranskat)
  • 24.
    Albrectsen, Benedicte R.
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Björkén, Lars
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Varad, Akkamahadevi
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Hagner, Åsa
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Wedin, Mats
    Karlsson, Jan
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Jansson, Stefan
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Endophytic fungi in European aspen (Populus tremula) leaves - diversity, detection, and a suggested correlation with herbivory resistance2010Ingår i: Fungal diversity, ISSN 1560-2745, E-ISSN 1878-9129, Vol. 41, nr 1, s. 17-28Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    According to the geographic mosaic theory of coevolution (GMTC), clines of traits reflecting local co-adaptation (including resistance genes) should be common between a host and its parasite and should persist across time. To test the GMTC-assumption of persistent clinal patterns we compared the natural prevalence of two parasites on aspen Populus tremula trees: mining moths of the genus Phyllocnistis and leaf rust Melampsora spp. Damage data were collated from the Swedish National Forest Damage Inventory (2004–2006). In addition, occurrence of the parasites was scored in field conditions in two common gardens in the north and south of Sweden over five growing seasons (2004–2008), then related to biomass (stem height and diameter) and to concentrations of eleven leaf phenolics. Phyllocnistis mainly occurred in the northern garden, a distribution range which was confirmed by the countrywide inventory, although Phyllocnistis was more abundant on southern clones, providing evidence for possible local maladaptation. Melampsora occurred all over the country and in both gardens, but built up more quickly on northern clones, which suggests a centre of local clone maladaptation in the north. Stem growth also followed a clinal pattern as did the concentration of three phenolic compounds: benzoic acid, catechin and cinnamic acid. However, only benzoic acid was related to parasite presence: negatively to Phyllocnistis and positively to Melampsora and it could thus be a potential trait under selection.

    In conclusion, clines of Phyllocnistis were stronger and more persistent compared to Melampsora, which showed contrasting clines of varying strength. Our data thus support the assumption of the GMTC model that clines exist in the border between hot and cold spots and that they may be less persistent for parasites with an elevated gene flow, and/or for parasites which cover relatively larger hot spots surrounded by fewer cold spots.

  • 25.
    Albrectsen, Benedicte R.
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Ericson, Lars
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Lundberg, Per
    Nutrient addition extends flowering display, which gets tracked by seed predators, but not by their parasitoids2008Ingår i: Oikos, ISSN 0030-1299, E-ISSN 1600-0706, Vol. 117, s. 473-480Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Although phenological matching between two and three trophic interactions has received some attention, it has largely been disregarded in explaining the lack of strong cascade dynamics in terrestrial systems. We studied the response of the specialist seed predator, Paroxyna plantaginis (Tephritidae) and associated generalist parasitoids (Chalcidoidea) to controlled fertilisation of individuals of naturally growing Tripolium vulgare (Asteraceae) on four island populations (Skeppsvik Archipelago, Sweden). We consistently found evidence of nutrient limitation: fertilised plants increased their biomass, produced more capitula (the oviposition units for tephritid flies), were more at risk of attack by the tephritids, and puparia were heavier in fertilised plants. During some parts of the season tephritids became more heavily parasitized, supporting the presence of cascade dynamics, however net parasitism over season decreased in response to nutrient addition. We found no evidence that capitulum size complicated parasitoid access to the tephritids, however the extended bud production prolonged the flowering season. Thus, tephritids utilized the surplus production of capitula throughout the entire season, while parasitoids did not expand their oviposition time window accordingly. Implications for top down regulation and cascade dynamics in the system are discussed.

  • 26.
    Albrectsen, Benedicte R
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Witzell, Johanna
    Robinson, Kathryn M
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Wulff, Sören
    Luquez, Virginia MC
    Ågren, Rickard
    Jansson, Stefan
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Large scale geographic clines of parasite damage to Populus tremula L2010Ingår i: Ecography, ISSN 0906-7590, E-ISSN 1600-0587, Vol. 33, nr 3, s. 483-493Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In conclusion, clines of Phyllocnistis were stronger and more persistent compared to Melampsora, which showed contrasting clines of varying strength. Our data thus support the assumption of the GMTC model that clines exist in the border between hot and cold spots and that they may be less persistent for parasites with an elevated gene flow, and/or for parasites which cover relatively larger hot spots surrounded by fewer cold spots.

  • 27.
    Albrectsen, Benedicte Riber
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Siddique, Abu Bakar
    Ernst-Moritz-Arndt Universität Greifswald, Institut für Botanik und Landschaftsökologie, Greifswald, Germany.
    Decker, Vicki Huizu Guo
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC). Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik.
    Unterseher, Martin
    Robinson, Kathryn M
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Both plant genotype and herbivory shape aspen endophyte communities2018Ingår i: Oecologia, ISSN 0029-8549, E-ISSN 1432-1939, Vol. 187, nr 2, s. 535-545Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Salicinoid phenolic glycosides are common defence substances in salicaceous trees and specialist leaf beetles use these compounds for their own defence against predators. Salicinoids vary qualitatively and qualitatively in aspen (Populus tremula) and this variation has a genetic basis. The foliar endophyte mycobiome is plentiful and we hypothesised that it is related to plant genotype, potentially mediated by salicinoid composition, and that interactions with the leaf beetle Chrysomela tremula may alter this relationship. We studied these three-way interactions in controlled greenhouse experiments. Endophytic fungi were isolated from sterilised leaf tissues with and without beetle damage, and from beetles. We confirmed that endophyte composition was influenced by host genotype. Beetle activity added generalist morphs to the mycobiome that overrode the initial host association. Yeast-like genera (Cryptococcus and Rhodotorula) were isolated only from beetle-damaged tissues and from beetles, whereas fast-growing filamentous fungi dominated beetle-free control plants. Competition experiments between filamentous fungi of plant origin and beetle-related yeasts suggested interaction of both stimulating and inhibiting modes of action amongst the fungi. As a result, we detected examples of amensalism, commensalism, parasitism and competition between the morphs tested, but we found no evidence of mutualism, and consequently no co-evolutionary relationship could be demonstrated, between yeasts carried by beetles, host genotype and associated filamentous morphs. Endophyte studies are method-dependent and high-throughput sequencing technology best define the fungal mycobiome, culturing however continues to be a cheap way to provide fundamental ecological insights and it is also required for experimental studies.

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  • 28.
    Albrectsen, Benedicte Riber
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Witzell, J.
    Swedish University of Agricultural Sciences, Faculty of Forest Sciences, Southern Swedish Forest Research Centre, Alnarp, Sweden.
    Disentangling functions of fungal endophytes in forest trees2012Ingår i: Fungi: types, environmental impact and role in disease / [ed] Adolfo Paz-Silva; María Sol Arias Vázquez, Nova Science Publishers, Inc., 2012, s. 235-246Kapitel i bok, del av antologi (Refereegranskat)
    Abstract [en]

    Endophytic fungi are known to be abundant colonizers of the internal tissues of forest trees, but their ecological functions are still largely unknown. Recent studies indicate that endophytes may associate with tree's resistance and tolerance properties, and they are thus potential bio-agents that could be utilized in sustainable forest protection and management. To gain a better understanding of the endophytes' potential role in shaping forest health we need more evidence in the form of ecological studies of endophyte communities, in various tissues, across space, and time. The recent advances in molecular methods have given us new and effective tools to obtain such data. Studies of endophyte functions are further facilitated with the development of new high through-put screening methods for substrate use and competitive ability. Fungi are known as chemical factories of natural compounds with biological properties. Beside their potential as antagonists against pests and diseases, the tree-associated endophytic fungi therefore also appear as an emerging source of novel biomolecules for industrial or clinical applications outside forestry. This chapter presents some of the current methodological approaches that are likely to be valuable in studies on endophyte diversity in forest trees, and discusses the goals and impacts of the studies that aim at disentangling the beneficial potential of fungal endophytes in trees. A new concept, bioactive symbiosis, is suggested as a general framework for these studies.

  • 29.
    Aliashkevich, Alena
    et al.
    Umeå universitet, Medicinska fakulteten, Molekylär Infektionsmedicin, Sverige (MIMS). Umeå universitet, Medicinska fakulteten, Institutionen för molekylärbiologi (Medicinska fakulteten). Umeå universitet, Medicinska fakulteten, Umeå Centre for Microbial Research (UCMR).
    Schiffthaler, Bastian
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC). Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik.
    Cava, Felipe
    Umeå universitet, Medicinska fakulteten, Molekylär Infektionsmedicin, Sverige (MIMS). Umeå universitet, Medicinska fakulteten, Institutionen för molekylärbiologi (Medicinska fakulteten). Umeå universitet, Medicinska fakulteten, Umeå Centre for Microbial Research (UCMR).
    Genetic dissection of LD-transpeptidation in Agrobacterium tumefaciensManuskript (preprint) (Övrigt vetenskapligt)
  • 30. Allakhverdiev, Suleyman I.
    et al.
    Zharmukhamedov, Sergey K.
    Rodionova, Margarita V.
    Shuvalov, Vladimir A.
    Dismukes, Charles
    Shen, Jian-Ren
    Barber, James
    Samuelsson, Göran
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Govindjee,
    Vyacheslav (Slava) Klimov (1945-2017): A scientist par excellence, a great human being, a friend, and a Renaissance man2018Ingår i: Photosynthesis Research, ISSN 0166-8595, E-ISSN 1573-5079, Vol. 136, nr 1, s. 1-16Artikel i tidskrift (Övrigt vetenskapligt)
    Abstract [en]

    Vyacheslav Vasilevich (V.V.) Klimov (or Slava, as most of us called him) was born on January 12, 1945 and passed away on May 9, 2017. He began his scientific career at the Bach Institute of Biochemistry of the USSR Academy of Sciences (Akademy Nauk (AN) SSSR), Moscow, Russia, and then, he was associated with the Institute of Photosynthesis, Pushchino, Moscow Region, for about 50 years. He worked in the field of biochemistry and biophysics of photosynthesis. He is known for his studies on the molecular organization of photosystem II (PSII). He was an eminent scientist in the field of photobiology, a well-respected professor, and, above all, an outstanding researcher. Further, he was one of the founding members of the Institute of Photosynthesis in Pushchino, Russia. To most, Slava Klimov was a great human being. He was one of the pioneers of research on the understanding of the mechanism of light energy conversion and of water oxidation in photosynthesis. Slava had many collaborations all over the world, and he is (and will be) very much missed by the scientific community and friends in Russia as well as around the World. We present here a brief biography and some comments on his research in photosynthesis. We remember him as a friendly and enthusiastic person who had an unflagging curiosity and energy to conduct outstanding research in many aspects of photosynthesis, especially that related to PSII.

  • 31. Amstutz, Cynthia L.
    et al.
    Fristedt, Rikard
    Schultink, Alex
    Merchant, Sabeeha S.
    Niyogi, Krishna K.
    Malnoë, Alizée
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC). Howard Hughes Medical Institute, University of California, Berkeley, CA, USA; Department of Plant and Microbial Biology, University of California, Berkeley, CA, USA; Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
    An atypical short-chain dehydrogenase–reductase functions in the relaxation of photoprotective qH in Arabidopsis2020Ingår i: Nature Plants, ISSN 2055-026X, Vol. 6, s. 154-166Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Photosynthetic organisms experience wide fluctuations in light intensity and regulate light harvesting accordingly to prevent damage from excess energy. The antenna quenching component qH is a sustained form of energy dissipation that protects the photosynthetic apparatus under stress conditions. This photoprotective mechanism requires the plastid lipocalin LCNP and is prevented by SUPPRESSOR OF QUENCHING1 (SOQ1) under non-stress conditions. However, the molecular mechanism of qH relaxation has yet to be resolved. Here, we isolated and characterized RELAXATION OF QH1 (ROQH1), an atypical short-chain dehydrogenase–reductase that functions as a qH-relaxation factor in Arabidopsis. The ROQH1 gene belongs to the GreenCut2 inventory specific to photosynthetic organisms, and the ROQH1 protein localizes to the chloroplast stroma lamellae membrane. After a cold and high-light treatment, qH does not relax in roqh1 mutants and qH does not occur in leaves overexpressing ROQH1. When the soq1 and roqh1 mutations are combined, qH can neither be prevented nor relaxed and soq1 roqh1 displays constitutive qH and light-limited growth. We propose that LCNP and ROQH1 perform dosage-dependent, antagonistic functions to protect the photosynthetic apparatus and maintain light-harvesting efficiency in plants.

  • 32. Anderson, James V.
    Ramos-Sánchez, José M.
    Conde, Daniel
    Ibáñez, Christian
    Takata, Naoki
    Allona, Isabel
    Eriksson, Maria E.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Role of the Circadian Clock in Cold Acclimation and Winter Dormancy in Perennial Plants2015Samlingsverk (redaktörskap) (Refereegranskat)
    Abstract [en]

    Seasonal variation is a strong cue directing the growth and development of plants. It is particularly important for perennials growing in temperate and boreal regions where woody plants must become dormant to survive freezing winter temperatures. Shortening of the photoperiod induces growth cessation, bud set and a first degree of cold acclimation in most woody plants. The subsequent drop in temperature then produces a greater tolerance to cold and, in deciduous trees, leaf senescence and fall. Trees must time their periods of dormancy accurately with their environment. Circadian clocks underlie this ability, allowing organisms to predict regular, daily changes in their environment as well as longer term seasonal changes. This chapter provides an update on the plant clock in a model annual, thale cress (Arabidopsis thaliana), and further summarizes recent advances about the clock in perennial plants and its involvement in their annual growth cycles, which allows trees to withstand cold and freezing temperatures. Moreover, we outline our views on areas where future work on the circadian clock is necessary to gain insight into the life of a tree.

  • 33. ANDERSSON, A
    et al.
    FALK, S
    Samuelsson, Göran
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    HAGSTROM, A
    NUTRITIONAL CHARACTERISTICS OF A MIXOTROPHIC NANOFLAGELLATE, OCHROMONAS SP1989Ingår i: Microbial Ecology, ISSN 0095-3628, E-ISSN 1432-184X, Vol. 17, nr 3, s. 251-262Artikel i tidskrift (Refereegranskat)
  • 34. Andersson, A
    et al.
    Wallberg, P
    Nordback, J
    Bergqvist, P A
    Selstam, Eva
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Effect of nutrient enrichment on the distribution and sedimentation of polychlorinated biphenyls (PCBs) in seawater1998Ingår i: Hydrobiologia, ISSN 0018-8158, E-ISSN 1573-5117, Vol. 377, s. 45-56Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The effect of nutrient enrichment on the distribution of polychlorinated biphenyl's (PCBs) in the microbial food web and the residence time of PCBs in seawater was studied in an experimental mesocosm system. Two 5 m high temperature and light controlled mesocosm tubes (empty set = 0.5 m) were filled with seawater from the northern Baltic Sea. Inorganic phosphorus and nitrogen were added daily to one mesocosm, while the other served as a control. Experiments were conducted at 5, 10 and 20 degrees C. Three C-14-labelled PCBs of different degree of chlorination were added to subsamples of the mesocosms: 4-chlorobiphenyl (MCB), IUPAC # 3, 2,2',5,5'-tetrachlorobiphenyl (TCB), IUPAC # 52 and 2,2',4,4',5,5'-hexachlorobiphenyl (HCB) IUPAC # 153. The biomasses and growth rates of the microorganisms as well as the sedimentation rate of particulate organic material increased with nutrient enrichment. The size distribution of the microorganisms changed with nutrient status, from dominance of picoplankton (< 2 mu m) in the control towards increased importance of micro (> 10 mu m) and nanoplankton (2-10 mu m) in nutrient enrichment. The specific growth rate of the bacterial community was found to be more temperature dependent than that of the phytoplankton community. The relative proportion of PCBs in the > 2 mu m fraction was observed to be in the order MCB < TCB < HCB, while the opposite distribution prevailed in the < 2 mu m fraction. We hypothesize that this is due to the combined effect of the different K-ow values of the PCBs and a different composition of the particulate organic carbon in the > 2 mu m and < 2 mu m fractions (e.g. different lipid composition). The residence time of the PCBs in the mesocosm generally decreased with nutrient enrichment, but was dependent on the degree of chlorination of the PCB. Our results indicate that the transport of organic pollutants up through the food web is more important in nutrient poor than in nutrient rich waters and that the importance of sedimentation is higher in eutrophic ecosystems.

  • 35.
    Andersson, Agneta
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå marina forskningscentrum (UMF). Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Selstam, Eva
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Hagström, Åke
    Vertical transport of lipid in seawater1993Ingår i: Marine Ecology Progress Series, ISSN 0171-8630, E-ISSN 1616-1599, Vol. 98, nr 1-2, s. 149-155Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Lipids in seawater act as solvents and transporters of lipophilic organic pollutants. To investigate a possible transport route of lipophilic pollutants, the vertical flux of lipid was quantified during an annual cycle in the northern Baltic Sea. The lipid content in both sedimenting material and different size fractions of seawater was analyzed. During the year, 8 g lipid m-2 sedimented out from the photic zone to the benthic system. The sedimentation of lipid accounted for 300 to 400 % of the average standing stock of pelagic lipid and was concentrated in the spring bloom period (April-June) when 70 % of the total lipid sedimentation occurred. About 30 % of the produced pelagic lipid settled out from the system. In seawater the lipid maximum occurred at the end of the spring bloom, shortly after nutrient depletion, indicating a stress response in the algae. Since lipid sedimentation is concentrated in the spring bloom, removal of lipophilic organic pollutants may be important during this period.

  • 36. Andersson, Anders
    et al.
    Keskitalo, Johanna
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC). Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik.
    Sjödin, Andreas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC). Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik.
    Bhalerao, Rupali
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC). Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik.
    Sterky, Fredrik
    Wissel, Kirsten
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC). Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik.
    Tandre, Karolina
    Aspeborg, Henrik
    Moyle, Richard
    Ohmiya, Yasunori
    Bhalerao, Rishikesh
    Brunner, Amy
    Gustafsson, Petter
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik.
    Karlsson, Jan
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Lundeberg, Joakim
    Nilsson, Ove
    Sandberg, Göran
    Strauss, Steven
    Sundberg, Björn
    Uhlen, Mathias
    Jansson, Stefan
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Nilsson, Peter
    A transcriptional timetable of autumn senescence2004Ingår i: Genome Biology, ISSN 1465-6906, E-ISSN 1474-760X, Vol. 5, nr 4, s. R24-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background We have developed genomic tools to allow the genus Populus (aspens and cottonwoods) to be exploited as a full-featured model for investigating fundamental aspects of tree biology. We have undertaken large-scale expressed sequence tag (EST) sequencing programs and created Populus microarrays with significant gene coverage. One of the important aspects of plant biology that cannot be studied in annual plants is the gene activity involved in the induction of autumn leaf senescence. Results On the basis of 36,354 Populus ESTs, obtained from seven cDNA libraries, we have created a DNA microarray consisting of 13,490 clones, spotted in duplicate. Of these clones, 12,376 (92%) were confirmed by resequencing and all sequences were annotated and functionally classified. Here we have used the microarray to study transcript abundance in leaves of a free-growing aspen tree (Populus tremula) in northern Sweden during natural autumn senescence. Of the 13,490 spotted clones, 3,792 represented genes with significant expression in all leaf samples from the seven studied dates. Conclusions We observed a major shift in gene expression, coinciding with massive chlorophyll degradation, that reflected a shift from photosynthetic competence to energy generation by mitochondrial respiration, oxidation of fatty acids and nutrient mobilization. Autumn senescence had much in common with senescence in annual plants; for example many proteases were induced. We also found evidence for increased transcriptional activity before the appearance of visible signs of senescence, presumably preparing the leaf for degradation of its components.

  • 37.
    Andersson, Jenny
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik.
    Dissecting the photosystem II light-harvesting antenna2003Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    In photosynthesis, sunlight is converted into chemical energy that is stored mainly as carbohydrates and supplies basically all life on Earth with energy.

    In order to efficiently absorb the light energy, plants have developed the outer light harvesting antenna, which is composed of ten different protein subunits (LHC) that bind chlorophyll a and b as well as different carotenoids. In addition to the light harvesting function, the antenna has the capacity to dissipate excess energy as heat (feedback de-excitation or qE), which is crucial to avoid oxidative damage under conditions of high excitation pressure. Another regulatory function in the antenna is the state transitions in which the distribution of the trimeric LHC II between photosystem I (PS I) and II is controlled. The same ten antenna proteins are conserved in all higher plants and based on evolutionary arguments this has led to the suggestion that each protein has a specific function.

    I have investigated the functions of individual antenna proteins of PS II (Lhcb proteins) by antisense inhibition in the model plant Arabidopsis thaliana. Four antisense lines were obtained, in which the target proteins were reduced, in some cases beyond detection level, in other cases small amounts remained.

    The results show that CP29 has a unique function as organising the antenna. CP26 can form trimers that substitute for Lhcb1 and Lhcb2 in the antenna structure, but the trimers that accumulate as a response to the lack of Lhcb1 and Lhcb2 cannot take over the LHC II function in state transitions. It has been argued that LHC II is essential for grana stacking, but antisense plants without Lhcb1 and Lhcb2 do form grana. Furthermore, LHC II is necessary to maintain growth rates in very low light.

    Numerous biochemical evidences have suggested that CP29 and/or CP26 were crucial for feedback de-excitation. Analysis of two antisense lines each lacking one of these proteins clearly shows that there is no direct involvement of either CP29 or CP26 in this process. Investigation of the other antisense lines shows that no Lhcb protein is indispensable for qE. A model for feedback de-excitation is presented in which PsbS plays a major role.

    The positions of the minor antenna proteins in the PS II supercomplex were established by comparisons of transmission electron micrographs of supercomplexes from the wild type and antisense plants.

    A fitness experiment was conducted where the antisense plants were grown in the field and seed production was used to estimate the fitness of the different genotypes. Based on the results from this experiment it is concluded that each Lhcb protein is important, because all antisense lines show reduced fitness in the field.

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  • 38.
    Andersson, Jenny
    et al.
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Fysiologisk botanik.
    Jansson, S.
    Loss of Lhcb1 and Lhcb2 decreases growth in extreme low light.Manuskript (Övrigt vetenskapligt)
  • 39.
    Andersson, Jenny
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Walters, Robin G
    Horton, Peter
    Jansson, Stefan
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Antisense inhibition of the photosynthetic antenna proteins CP29 and CP26: implications for the mechanism of protective energy dissipation2001Ingår i: The Plant Cell, ISSN 1040-4651, E-ISSN 1532-298X, Vol. 13, nr 5, s. 1193-1204Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The specific roles of the chlorophyll a/b binding proteins CP29 and CP26 in light harvesting and energy dissipation within the photosynthetic apparatus have been investigated. Arabidopsis was transformed with antisense constructs against the genes encoding the CP29 or CP26 apoprotein, which gave rise to several transgenic lines with remarkably low amounts of the antisense target proteins. The decrease in the level of CP24 protein in the CP29 antisense lines indicates a physical interaction between these complexes. Analysis of chlorophyll fluorescence showed that removal of the proteins affected photosystem II function, probably as a result of changes in the organization of the light-harvesting antenna. However, whole plant measurements showed that overall photosynthetic rates were similar to those in the wild type. Both antisense lines were capable of the qE type of nonphotochemical fluorescence quenching, although there were minor changes in the capacity for quenching and in its induction kinetics. High-light-induced violaxanthin deepoxidation to zeaxanthin was not affected, although the pool size of these pigments was decreased slightly. We conclude that CP29 and CP26 are unlikely to be sites for nonphotochemical quenching.

  • 40.
    Andersson, Jenny
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik.
    Wentworth, M.
    Walters, R. G.
    Howard, C. A.
    Ruban, A. V.
    Horton, P.
    Jansson, S.
    Absence of the main light-harvesting complex of photosystem II affects photosynthetic function.Manuskript (preprint) (Övrigt vetenskapligt)
  • 41.
    Andersson, Jenny
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Wentworth, Mark
    Walters, Robin G
    Howard, Caroline A
    Ruban, Alexander V
    Horton, Peter
    Jansson, Stefan
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Absence of the Lhcb1 and Lhcb2 proteins of the light-harvesting complex of photosystem II - effects on photosynthesis, grana stacking and fitness2003Ingår i: The Plant Journal, ISSN 0960-7412, E-ISSN 1365-313X, Vol. 35, nr 3, s. 350-361Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We have constructed Arabidopsis thaliana plants that are virtually devoid of the major light-harvesting complex, LHC II. This was accomplished by introducing the Lhcb2.1 coding region in the antisense orientation into the genome by Agrobacterium-mediated transformation. Lhcb1 and Lhcb2 were absent, while Lhcb3, a protein present in LHC II associated with photosystem (PS) II, was retained. Plants had a pale green appearance and showed reduced chlorophyll content and an elevated chlorophyll a/b ratio. The content of PS II reaction centres was unchanged on a leaf area basis, but there was evidence for increases in the relative levels of other light harvesting proteins, notably CP26, associated with PS II, and Lhca4, associated with PS I. Electron microscopy showed the presence of grana. Photosynthetic rates at saturating irradiance were the same in wild-type and antisense plants, but there was a 10-15% reduction in quantum yield that reflected the decrease in light absorption by the leaf. The antisense plants were not able to perform state transitions, and their capacity for non-photochemical quenching was reduced. There was no difference in growth between wild-type and antisense plants under controlled climate conditions, but the antisense plants performed worse compared to the wild type in the field, with decreases in seed production of up to 70%.

  • 42. Andreazza, N
    et al.
    Abreu, Ilka Nacif
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Sawaya, A
    Eberlin, M
    Mazzafera, P
    Production of imidazole alkaloids in cell cultures of jaborandi as affected by the medium pH2009Ingår i: Biotechnology letters, ISSN 0141-5492, E-ISSN 1573-6776, Vol. 31, nr 4, s. 607-614Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The effect of pH (from 4.8 to 9.8) on the production of pilosine and pilocarpine and on their partition between cell and medium was studied in two lineages (P and PP) of Pilocarpus microphyllus cell suspension cultures. Highest mass accumulation was observed at high pHs and both lineages produced pilocarpine while only lineage PP produced pilosine. Both alkaloids were released in the medium but higher accumulation occurred in the cells. The highest production of pilocarpine was at pH 8.8-9.8 in both cell lineages. Other imidazole alkaloids were also identified in both lineages. At all pHs tested, the pH in the media cultures tended to stabilize around 6 after 10-15 days of cultivation. NO(3) (-) and NH(4) (+) variation in the media might partially explain the pH stabilization.

  • 43.
    André, Domenique
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    The role of the Populus FT genes in the regulation of tree growth.2014Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    In annual plants, flowering related genes were initially thought to have the only function to coordinate and execute reproductive development. In perennial species like poplar, however, it became clear that these genes seem to have acquired additional functions in the regulation of the yearly growth cycle. The two poplar orthologs of the Arabidopsis “florigen” FLOWERING LOCUS T (FT), PtFT1 and PtFT2, are associated with flowering as well as other aspects of phenology. After duplication they have diverged in expression pattern, and maybe also in function and their gene regulatory networks. In this study I have characterized the role of PtFT1 and PtFT2 during the yearly growth cyle, as well as the interaction between, FT-like genes, poplar homologs of the Arabidopsis flowering time repressor TFL1 and PHYTOCHROME A in the regulation of tree flowering. The preliminary data show new unexpected functional relations between these genes and new previously undescribed effects on plant growth and development.

  • 44.
    André, Domenique
    et al.
    Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, Umeå, Sweden.
    Marcon, Alice
    Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, Umeå, Sweden.
    Lee, Keh Chien
    Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, Umeå, Sweden.
    Goretti, Daniela
    Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, Umeå, Sweden.
    Zhang, Bo
    Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, Umeå, Sweden.
    Delhomme, Nicolas
    Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, Umeå, Sweden.
    Schmid, Markus
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Nilsson, Ove
    Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, Umeå, Sweden.
    FLOWERING LOCUS T paralogs control the annual growth cycle in Populus trees2022Ingår i: Current Biology, ISSN 0960-9822, E-ISSN 1879-0445, Vol. 32, nr 13, s. 2988-2996.e4Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In temperate and boreal regions, perennials adapt their annual growth cycle to the change of seasons. These adaptations ensure survival in harsh environmental conditions, allowing growth at different latitudes and altitudes, and are therefore tightly regulated. Populus tree species cease growth and form terminal buds in autumn when photoperiod falls below a certain threshold.1 This is followed by establishment of dormancy and cold hardiness over the winter. At the center of the photoperiodic pathway in Populus is the gene FLOWERING LOCUS T2 (FT2), which is expressed during summer and harbors significant SNPs in its locus associated with timing of bud set.1–4 The paralogous gene FT1, on the other hand, is hyper-induced in chilling buds during winter.3,5 Even though its function is so far unknown, it has been suggested to be involved in the regulation of flowering and the release of winter dormancy.3,5 In this study, we employ CRISPR-Cas9-mediated gene editing to individually study the function of the FT-like genes in Populus trees. We show that while FT2 is required for vegetative growth during spring and summer and regulates the entry into dormancy, expression of FT1 is absolutely required for bud flush in spring. Gene expression profiling suggests that this function of FT1 is linked to the release of winter dormancy rather than to the regulation of bud flush per se. These data show how FT duplication and sub-functionalization have allowed Populus trees to regulate two completely different and major developmental control points during the yearly growth cycle.

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  • 45. Ankele, Elisabeth
    et al.
    Kindgren, Peter
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Pesquet, Edouard
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC). Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik.
    Strand, Åsa
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    In vivo visualization of Mg-ProtoporphyrinIX, a coordinator of photosynthetic gene expression in the nucleus and the chloroplast2007Ingår i: Plant Cell, ISSN 1040-4651, Vol. 19, nr 6, s. 1964-1979Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The photosynthetic apparatus is composed of proteins encoded by genes from both the nucleus and the chloroplast. To ensure that the photosynthetic complexes are assembled stoichiometrically and to enable their rapid reorganization in response to a changing environment, the plastids emit signals that regulate nuclear gene expression to match the status of the plastids. One of the plastid signals, the chlorophyll intermediate Mg-ProtoporphyrinIX (Mg-ProtoIX) accumulates under stress conditions and acts as a negative regulator of photosynthetic gene expression. By taking advantage of the photoreactive property of tetrapyrroles, Mg-ProtoIX could be visualized in the cells using confocal laser scanning spectroscopy. Our results demonstrate that Mg-ProtoIX accumulated both in the chloroplast and in the cytosol during stress conditions. Thus, the signaling metabolite is exported from the chloroplast, transmitting the plastid signal to the cytosol. Our results from the Mg-ProtoIX over- and underaccumulating mutants copper response defect and genome uncoupled5, respectively, demonstrate that the expression of both nuclear- and plastid-encoded photosynthesis genes is regulated by the accumulation of Mg-ProtoIX. Thus, stress-induced accumulation of the signaling metabolite Mg-ProtoIX coordinates nuclear and plastidic photosynthetic gene expression.

  • 46. Anoman, Armand D.
    et al.
    Flores-Tornero, Maria
    Benstein, Ruben M.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC). Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Biocenter–Botanical Institute II, University of Cologne, Cologne, Germany.
    Blau, Samira
    Rosa-Tellez, Sara
    Braeutigam, Andrea
    Fernie, Alisdair R.
    Munoz-Bertomeu, Jesus
    Schilasky, Soeren
    Meyer, Andreas J.
    Kopriva, Stanislav
    Segura, Juan
    Krueger, Stephan
    Ros, Roc
    Deficiency in the Phosphorylated Pathway of Serine Biosynthesis Perturbs Sulfur Assimilation2019Ingår i: Plant Physiology, ISSN 0032-0889, E-ISSN 1532-2548, Vol. 180, nr 1, s. 153-170Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Although the plant Phosphorylated Pathway of L-Ser Biosynthesis (PPSB) is essential for embryo and pollen development, and for root growth, its metabolic implications have not been fully investigated. A transcriptomics analysis of Arabidopsis (Arabidopsis thaliana) PPSB-deficient mutants at night, when PPSB activity is thought to be more important, suggested interaction with the sulfate assimilation process. Because sulfate assimilation occurs mainly in the light, we also investigated it in PPSB-deficient lines in the day. Key genes in the sulfate starvation response, such as the adenosine 5'phosphosulfate reductase genes, along with sulfate transporters, especially those involved in sulfate translocation in the plant, were induced in the PPSB-deficient lines. However, sulfate content was not reduced in these lines as compared with wild-type plants; besides the glutathione (GSH) steady-state levels in roots of PPSB-deficient lines were even higher than in wild type. This suggested that PPSB deficiency perturbs the sulfate assimilation process between tissues/organs. Alteration of thiol distribution in leaves from different developmental stages, and between aerial parts and roots in plants with reduced PPSB activity, provided evidence supporting this idea. Diminished PPSB activity caused an enhanced flux of S-35 into thiol biosynthesis, especially in roots. GSH turnover also accelerated in the PPSB-deficient lines, supporting the notion that not only biosynthesis, but also transport and allocation, of thiols were perturbed in the PPSB mutants. Our results suggest that PPSB is required for sulfide assimilation in specific heterotrophic tissues and that a lack of PPSB activity perturbs sulfur homeostasis between photosynthetic and nonphotosynthetic tissues.

  • 47. Apuli, Rami-Petteri
    et al.
    Bernhardsson, Carolina
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC). Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Schiffthaler, Bastian
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC). Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik.
    Robinson, Kathryn M
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Jansson, Stefan
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC). Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik.
    Street, Nathaniel
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Ingvarsson, Pär K.
    Inferring the Genomic Landscape of Recombination Rate Variation in European Aspen (Populus tremula)2020Ingår i: G3: Genes, Genomes, Genetics, E-ISSN 2160-1836, Vol. 10, nr 1, s. 299-309Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The rate of meiotic recombination is one of the central factors determining genome-wide levels of linkage disequilibrium which has important consequences for the efficiency of natural selection and for the dissection of quantitative traits. Here we present a new, high-resolution linkage map for Populus tremula that we use to anchor approximately two thirds of the P. tremula draft genome assembly on to the expected 19 chromosomes, providing us with the first chromosome-scale assembly for P. tremula (Table 2). We then use this resource to estimate variation in recombination rates across the P. tremula genome and compare these results to recombination rates based on linkage disequilibrium in a large number of unrelated individuals. We also assess how variation in recombination rates is associated with a number of genomic features, such as gene density, repeat density and methylation levels. We find that recombination rates obtained from the two methods largely agree, although the LD-based method identifies a number of genomic regions with very high recombination rates that the map-based method fails to detect. Linkage map and LD-based estimates of recombination rates are positively correlated and show similar correlations with other genomic features, showing that both methods can accurately infer recombination rate variation across the genome. Recombination rates are positively correlated with gene density and negatively correlated with repeat density and methylation levels, suggesting that recombination is largely directed toward gene regions in P. tremula.

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  • 48.
    Arias, Carolina
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC). Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik.
    Obudulu, Ogonna
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen. Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, SE-90183 Umeå, Sweden.
    Zhao, Xiaoling
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC). Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik.
    Ansolia, Preeti
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC). Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik.
    Zhang, Xueyang
    Paul, Suman
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Bygdell, Joakim
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Pirmoradian, Mohammad
    Zubarev, Roman A.
    Samuelsson, Göran
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC). Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik.
    Wingsle, Gunnar
    Bajhaiya, Amit K.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Nuclear proteome analysis of Chlamydomonas with response to CO2 limitation2020Ingår i: Algal Research, ISSN 2211-9264, Vol. 46, artikel-id 101765Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Chlamydomonas reinhardtii is a unicellular green alga that can survive at a wide range of inorganic carbon (Ci) concentrations by regulating the activity of a CO2-concentrating mechanism (CCM) as well as other cellular functions. Under CO2 limited conditions, C. reinhardtii cells display a wide range of adaptive responses including changes in photosynthetic electron transport, mitochondria localization in the cells, the structure of the pyrenoid starch sheath, and primary metabolism. In addition to these functional and structural changes, gene and protein expression are also affected. Several physiological aspects of the CO2 response mechanism have been studied in detail. However, the regulatory components (transcription factors and transcriptional regulators) involved in this process are not fully characterized. Here we report a comprehensive analysis of the C. reinhardtii nuclear proteome using liquid chromatography electrospray ionization spectrometry (LC-ESI-MS). The study aims to identify the proteins that govern adaptation to varying CO2 concentrations in Chlamydomonas. The nuclear proteome of C. reinhardtii cells grown in the air at high (5%) and low (0.04%) CO2 concentrations were analyzed. Using this approach, we identified 1378 proteins in total, including 90 putative transcription factors and 27 transcriptional regulators. Characterization of these new regulatory components could shed light on the molecular mechanisms underlying acclimation to CO2 stress.

  • 49.
    Arshad, Rameez
    et al.
    Department of Biophysics, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Olomouc, Czech Republic; Electron microscopy group, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, The Netherlands.
    Saccon, Francesco
    Queen Mary University of London, School of Biological and Behavioural Sciences, London, UK.
    Bag, Pushan
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Biswas, Avratanu
    Department of Physics and Astronomy and LaserLaB, Faculty of Science, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
    Calvaruso, Claudio
    Institute for Molecular Biosciences,Goethe University of Frankfurt, Frankfurt, Germany.
    Bhatti, Ahmad Farhan
    Laboratory of Biophysics, Wageningen University, Wageningen, the Netherlands.
    Grebe, Steffen
    Department of Life Technologies, MolecularPlant Biology, University of Turku, Turku, Finland.
    Mascoli, Vincenzo
    Department of Physics and Astronomy and LaserLaB, Faculty of Science, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
    Mahbub, Moontaha
    Queen Mary University of London, School of Biological and Behavioural Sciences, London, UK; Department of Botany, Jagannath University, Dhaka, Bangladesh.
    Muzzopappa, Fernando
    Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, Gif sur Yvette, France.
    Polyzois, Alexandros
    Université de Paris, Faculté de pharmacie de Paris, CiTCoM UMR 8038 CNRS, Paris, France.
    Schiphorst, Christo
    Dipartimento di Biotecnologie, Università di Verona, Verona, Italy.
    Sorrentino, Mirella
    Photon Systems Instruments, spol. s.r.o., Drásov, Czechia; Department of Agricultural Sciences, University of Naples Federico II, Napoli, Italy.
    Streckaité, Simona
    Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, Gif sur Yvette, France.
    van Amerongen, Herbert
    Laboratory of Biophysics, Wageningen University, Wageningen, the Netherlands.
    Aro, Eva-Mari
    Department of Life Technologies, MolecularPlant Biology, University of Turku, Turku, Finland.
    Bassi, Roberto
    Dipartimento di Biotecnologie, Università di Verona, Verona, Italy.
    Boekema, Egbert J.
    Electron microscopy group, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, The Netherlands.
    Croce, Roberta
    Department of Physics and Astronomy and LaserLaB, Faculty of Science, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
    Dekker, Jan
    Department of Physics and Astronomy and LaserLaB, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands.
    van Grondelle, Rienk
    Department of Physics and Astronomy and LaserLaB, Faculty of Science, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
    Jansson, Stefan
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC). Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik.
    Kirilovsky, Diana
    Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, Gif sur Yvette, France.
    Kouřil, Roman
    Department of Biophysics, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Olomouc, Czech Republic.
    Michel, Sylvie
    Université de Paris, Faculté de pharmacie de Paris, CiTCoM UMR 8038 CNRS, Paris, France.
    Mullineaux, Conrad W.
    Queen Mary University of London, School of Biological and Behavioural Sciences, London, UK.
    Panzarová, Klára
    Photon Systems Instruments, spol. s.r.o., Drásov, Czechia.
    Robert, Bruno
    Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, Gif sur Yvette, France.
    Ruban, Alexander V.
    Queen Mary University of London, School of Biological and Behavioural Sciences, London, UK.
    van Stokkum, Ivo
    Department of Physics and Astronomy and LaserLaB, Faculty of Science, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
    Wientjes, Emilie
    Laboratory of Biophysics, Wageningen University, Wageningen, the Netherlands.
    Büchel, Claudia
    Institute for Molecular Biosciences,Goethe University of Frankfurt, Frankfurt, Germany.
    A kaleidoscope of photosynthetic antenna proteins and their emerging roles2022Ingår i: Plant Physiology, ISSN 0032-0889, E-ISSN 1532-2548, Vol. 189, nr 3, s. 1204-1219Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Photosynthetic light-harvesting antennae are pigment-binding proteins that perform one of the most fundamental tasks on Earth, capturing light and transferring energy that enables life in our biosphere. Adaptation to different light environments led to the evolution of an astonishing diversity of light-harvesting systems. At the same time, several strategies have been developed to optimize the light energy input into photosynthetic membranes in response to fluctuating conditions. The basic feature of these prompt responses is the dynamic nature of antenna complexes, whose function readily adapts to the light available. High-resolution microscopy and spectroscopic studies on membrane dynamics demonstrate the crosstalk between antennae and other thylakoid membrane components. With the increased understanding of light-harvesting mechanisms and their regulation, efforts are focusing on the development of sustainable processes for effective conversion of sunlight into functional bio-products. The major challenge in this approach lies in the application of fundamental discoveries in light-harvesting systems for the improvement of plant or algal photosynthesis. Here, we underline some of the latest fundamental discoveries on the molecular mechanisms and regulation of light harvesting that can potentially be exploited for the optimization of photosynthesis.

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  • 50. Arshadi, Mehrdad
    et al.
    Sellstedt, Anita
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Biomass-based energy production2015Ingår i: Introduction to chemicals from biomass / [ed] James Clark, Fabien Deswarte, John Wiley & Sons, 2015, 2, s. 249-284Kapitel i bok, del av antologi (Refereegranskat)
    Abstract [en]

    Today, bioenergy is a practical and increasingly widely available option for heating that is being adopted by many industries and households that are looking to use more sustainable energy sources. Biomass‐derived fuels may be solids, liquids, or gases. They can be classified based on the processes used in their production, which include physical upgrading, microbiological processes, thermochemical processes, and chemical processes. The production of solid fuels from renewable resources has become more important due to the growing global demand for energy and environmental concerns. Various microbial processes can be exploited to utilize energy that has been stored in biomass by photosynthesis. Methanol, ethanol, and butanol are liquid biofuels that can be synthesized from biomass and used in both four‐stroke gasoline and diesel engines. These alcohols can be prepared from sugarcane, sugar beet, wheat, barley, corn, switch grass, agricultural residues, wood, and many other industrial wastes.

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