umu.sePublications
Change search
Link to record
Permanent link

Direct link
BETA
Schmid, Markus
Alternative names
Publications (10 of 62) Show all publications
Goretti, D., Silvestre, M., Collani, S., Langenecker, T., Mendez, C., Madueno, F. & Schmid, M. (2020). TERMINAL FLOWER1 Functions as a Mobile Transcriptional Cofactor in the Shoot Apical Meristem. Plant Physiology, 182(4), 2081-2095
Open this publication in new window or tab >>TERMINAL FLOWER1 Functions as a Mobile Transcriptional Cofactor in the Shoot Apical Meristem
Show others...
2020 (English)In: Plant Physiology, ISSN 0032-0889, E-ISSN 1532-2548, Vol. 182, no 4, p. 2081-2095Article in journal (Refereed) Published
Abstract [en]

TERMINAL FLOWER1 acts in the shoot apical meristem as a mobile cell-non-autonomous transcriptional cofactor that associates with DNA to regulate meristem indeterminacy and flowering. The floral transition is a critical step in the life cycle of flowering plants, and several mechanisms control this finely orchestrated process. TERMINAL FLOWER1 (TFL1) is a floral repressor and close relative of the florigen, FLOWERING LOCUS T (FT). During the floral transition, TFL1 expression is up-regulated in the inflorescence apex to maintain the indeterminate growth of the shoot apical meristem (SAM). Both TFL1 and FT are mobile proteins, but they move in different ways. FT moves from the leaves to the SAM, while TFL1 appears to move within the SAM. The importance of TFL1 movement for its function in the regulation of flowering time and shoot indeterminacy and its molecular function are still largely unclear. Our results using Arabidopsis (Arabidopsis thaliana) indicate that TFL1 moves from its place of expression in the center of the SAM to the meristem layer L1 and that the movement in the SAM is required for the regulation of the floral transition. Chromatin immunoprecipitation sequencing and RNA sequencing demonstrated that TFL1 functions as a cotranscription factor that associates with and regulates the expression of hundreds of genes. These newly identified direct TFL1 targets provide the possibility to discover new roles for TFL1 in the regulation of floral transition and inflorescence development.

Place, publisher, year, edition, pages
American Society of Plant Biologists, 2020
National Category
Botany
Identifiers
urn:nbn:se:umu:diva-170524 (URN)10.1104/pp.19.00867 (DOI)000526827500057 ()31996406 (PubMedID)
Available from: 2020-05-07 Created: 2020-05-07 Last updated: 2020-05-07Bibliographically approved
Brunoni, F., Collani, S., Simura, J., Schmid, M., Bellini, C. & Ljung, K. (2019). A bacterial assay for rapid screening of IAA catabolic enzymes. Plant Methods, 15(1), Article ID 126.
Open this publication in new window or tab >>A bacterial assay for rapid screening of IAA catabolic enzymes
Show others...
2019 (English)In: Plant Methods, ISSN 1746-4811, E-ISSN 1746-4811, Vol. 15, no 1, article id 126Article in journal (Refereed) Published
Abstract [en]

Background: Plants rely on concentration gradients of the native auxin, indole-3-acetic acid (IAA), to modulate plant growth and development. Both metabolic and transport processes participate in the dynamic regulation of IAA homeostasis. Free IAA levels can be reduced by inactivation mechanisms, such as conjugation and degradation. IAA can be conjugated via ester linkage to glucose, or via amide linkage to amino acids, and degraded via oxidation. Members of the UDP glucosyl transferase (UGT) family catalyze the conversion of IAA to indole-3-acetyl-1-glucosyl ester (IAGlc); by contrast, IAA is irreversibly converted to indole-3-acetyl-L-aspartic acid (IAAsp) and indole-3-acetyl glutamic acid (IAGlu) by Group II of the GRETCHEN HAGEN3 (GH3) family of acyl amido synthetases. Dioxygenase for auxin oxidation (DAO) irreversibly oxidizes IAA to oxindole-3-acetic acid (oxIAA) and, in turn, oxIAA can be further glucosylated to oxindole-3-acetyl-1-glucosyl ester (oxIAGlc) by UGTs. These metabolic pathways have been identified based on mutant analyses, in vitro activity measurements, and in planta feeding assays. In vitro assays for studying protein activity are based on producing Arabidopsis enzymes in a recombinant form in bacteria or yeast followed by recombinant protein purification. However, the need to extract and purify the recombinant proteins represents a major obstacle when performing in vitro assays.

Results: In this work we report a rapid, reproducible and cheap method to screen the enzymatic activity of recombinant proteins that are known to inactivate IAA. The enzymatic reactions are carried out directly in bacteria that produce the recombinant protein. The enzymatic products can be measured by direct injection of a small supernatant fraction from the bacterial culture on ultrahigh-performance liquid chromatography coupled to electrospray ionization tandem spectrometry (UHPLC–ESI-MS/MS). Experimental procedures were optimized for testing the activity of different classes of IAA-modifying enzymes without the need to purify recombinant protein.

Conclusions: This new method represents an alternative to existing in vitro assays. It can be applied to the analysis of IAA metabolites that are produced upon supplementation of substrate to engineered bacterial cultures and can be used for a rapid screening of orthologous candidate genes from non-model species.

Place, publisher, year, edition, pages
BioMed Central, 2019
Keywords
IAA metabolism, UHPLC-ESI-MS, MS, Enzyme assay, Arabidopsis, Conjugation, Degradation
National Category
Biochemistry and Molecular Biology
Identifiers
urn:nbn:se:umu:diva-165335 (URN)10.1186/s13007-019-0509-6 (DOI)000494725300001 ()31700527 (PubMedID)
Funder
Swedish Research CouncilSwedish Research Council FormasVinnovaKnut and Alice Wallenberg Foundation
Available from: 2019-11-26 Created: 2019-11-26 Last updated: 2019-11-26Bibliographically approved
Lee, J. E., Neumann, M., Duro, D. I. & Schmid, M. (2019). CRISPR-based tools for targeted transcriptional and epigenetic regulation in plants. PLoS ONE, 14(9), Article ID e0222778.
Open this publication in new window or tab >>CRISPR-based tools for targeted transcriptional and epigenetic regulation in plants
2019 (English)In: PLoS ONE, E-ISSN 1932-6203, Vol. 14, no 9, article id e0222778Article in journal (Refereed) Published
Abstract [en]

Programmable gene regulators that can modulate the activity of selected targets in trans are a useful tool for probing and manipulating gene function. CRISPR technology provides a convenient method for gene targeting that can also be adapted for multiplexing and other modifications to enable strong regulation by a range of different effectors. We generated a vector toolbox for CRISPR/dCas9-based targeted gene regulation in plants, modified with the previously described MS2 system to amplify the strength of regulation, and using Golden Gate-based cloning to enable rapid vector assembly with a high degree of flexibility in the choice of promoters, effectors and targets. We tested the system using the floral regulator FLOWERING LOCUS T (FT) as a target and a range of different effector domains including the transcriptional activator VP64, the H3K27 acetyltransferase p300 and the H3K9 methyltransferase KRYPTONITE. When transformed into Arabidopsis thaliana, several of the constructs caused altered flowering time phenotypes that were associated with changes in FT expression and/or epigenetic status, thus demonstrating the effectiveness of the system. The MS2-CRISPR/dCas9 system can be used to modulate transcriptional activity and epigenetic status of specific target genes in plants, and provides a versatile tool that can easily be used with different targets and types of regulation for a range of applications.

Place, publisher, year, edition, pages
Public Library of Science, 2019
National Category
Botany
Identifiers
urn:nbn:se:umu:diva-166461 (URN)10.1371/journal.pone.0222778 (DOI)000489744000001 ()31557222 (PubMedID)2-s2.0-85072661389 (Scopus ID)
Funder
Knut and Alice Wallenberg Foundation, KAW 2016.0025
Available from: 2019-12-17 Created: 2019-12-17 Last updated: 2019-12-17Bibliographically approved
Collani, S., Neumann, M., Yant, L. & Schmid, M. (2019). FT Modulates Genome-Wide DNA-Binding of the bZIP Transcription Factor FD. Plant Physiology, 180(1), 367-380
Open this publication in new window or tab >>FT Modulates Genome-Wide DNA-Binding of the bZIP Transcription Factor FD
2019 (English)In: Plant Physiology, ISSN 0032-0889, E-ISSN 1532-2548, Vol. 180, no 1, p. 367-380Article in journal (Refereed) Published
Abstract [en]

The transition to flowering is a crucial step in the plant life cycle that is controlled by multiple endogenous and environmental cues, including hormones, sugars, temperature, and photoperiod. Permissive photoperiod induces the expression of FLOWERING LOCUS T (FT) in the phloem companion cells of leaves. The FT protein then acts as a florigen that is transported to the shoot apical meristem, where it physically interacts with the Basic Leucine Zipper Domain transcription factor FD and 14-3-3 proteins. However, despite the importance of FD in promoting flowering, its direct transcriptional targets are largely unknown. Here, we combined chromatin immunoprecipitation sequencing and RNA sequencing to identify targets of FD at the genome scale and assessed the contribution of FT to DNA binding. We further investigated the ability of FD to form protein complexes with FT and TERMINAL FLOWER1 through interaction with 14-3-3 proteins. Importantly, we observed direct binding of FD to targets involved in several aspects of plant development. These target genes were previously unknown to be directly related to the regulation of flowering time. Our results confirm FD as a central regulator of floral transition at the shoot meristem and provide evidence for crosstalk between the regulation of flowering and other signaling pathways, such as pathways involved in hormone signaling.

Place, publisher, year, edition, pages
American Society of Plant Biologists, 2019
National Category
Botany
Identifiers
urn:nbn:se:umu:diva-159400 (URN)10.1104/pp.18.01505 (DOI)000466860800033 ()30770462 (PubMedID)
Available from: 2019-06-10 Created: 2019-06-10 Last updated: 2019-06-10Bibliographically approved
You, Y., Sawikowska, A., Lee, J. E., Benstein, R. M., Neumann, M., Krajewski, P. & Schmid, M. (2019). Phloem Companion Cell-Specific Transcriptomic and Epigenomic Analyses Identify MRF1, a Regulator of Flowering. The Plant Cell, 31(2), 325-345
Open this publication in new window or tab >>Phloem Companion Cell-Specific Transcriptomic and Epigenomic Analyses Identify MRF1, a Regulator of Flowering
Show others...
2019 (English)In: The Plant Cell, ISSN 1040-4651, E-ISSN 1532-298X, Vol. 31, no 2, p. 325-345Article in journal (Refereed) Published
Abstract [en]

The phloem plays essential roles in the source-to-sink relationship and in long-distance communication, and thereby coordinates growth and development throughout the plant. Here we employed isolation of nuclei tagged in specific cell types coupled with low-input, high-throughput sequencing approaches to analyze the changes of the chromatin modifications H3K4me3 and H3K27me3 and their correlation with gene expression in the phloem companion cells (PCCs) of Arabidopsis (Arabidopsis thaliana) shoots in response to changes in photoperiod. We observed a positive correlation between changes in expression and H3K4me3 levels of genes that are involved in essential PCC functions, including regulation of metabolism, circadian rhythm, development, and epigenetic modifications. By contrast, changes in H3K27me3 signal appeared to contribute little to gene expression changes. These genomic data illustrate the complex gene-regulatory networks that integrate plant developmental and physiological processes in the PCCs. Emphasizing the importance of cell-specific analyses, we identified a previously uncharacterized MORN-motif repeat protein, MORN-MOTIF REPEAT PROTEIN REGULATING FLOWERING1 (MRF1), that was strongly up-regulated in the PCCs in response to inductive photoperiod. The mrf1 mutation delayed flowering, whereas MRF1 overexpression had the opposite effect, indicating that MRF1 acts as a floral promoter.

Place, publisher, year, edition, pages
Rockville: American Society of Plant Biologists, 2019
National Category
Cell Biology Botany
Identifiers
urn:nbn:se:umu:diva-157972 (URN)10.1105/tpc.17.00714 (DOI)000462028400009 ()30670485 (PubMedID)
Available from: 2019-04-16 Created: 2019-04-16 Last updated: 2019-04-16Bibliographically approved
Speth, C., Szabo, E. X., Martinho, C., Collani, S., zur Oven-Krockhaus, S., Richter, S., . . . Laubinger, S. (2018). Arabidopsis RNA processing factor SERRATE regulates the transcription of intronless genes. eLIFE, 7, Article ID e37078.
Open this publication in new window or tab >>Arabidopsis RNA processing factor SERRATE regulates the transcription of intronless genes
Show others...
2018 (English)In: eLIFE, E-ISSN 2050-084X, Vol. 7, article id e37078Article in journal (Refereed) Published
Abstract [en]

Intron splicing increases proteome complexity, promotes RNA stability, and enhances transcription. However, introns and the concomitant need for splicing extend the time required for gene expression and can cause an undesirable delay in the activation of genes. Here, we show that the plant microRNA processing factor SERRATE (SE) plays an unexpected and pivotal role in the regulation of intronless genes. Arabidopsis SE associated with more than 1000, mainly intronless, genes in a transcription-dependent manner. Chromatin-bound SE liaised with paused and elongating polymerase II complexes and promoted their association with intronless target genes. Our results indicate that stress-responsive genes contain no or few introns, which negatively affects their expression strength, but that some genes circumvent this limitation via a novel SE-dependent transcriptional activation mechanism. Transcriptome analysis of a Drosophila mutant defective in ARS2, the metazoan homologue of SE, suggests that SE/ARS2 function in regulating intronless genes might be conserved across kingdoms.

Place, publisher, year, edition, pages
Elife Sciences Publications ltd, 2018
National Category
Biochemistry and Molecular Biology
Identifiers
urn:nbn:se:umu:diva-152270 (URN)10.7554/eLife.37078 (DOI)000444379000001 ()30152752 (PubMedID)
Available from: 2018-10-03 Created: 2018-10-03 Last updated: 2018-10-03Bibliographically approved
Capovilla, G., Delhomme, N., Collani, S., Shutava, I., Bezrukov, I., Symeonidi, E., . . . Schmid, M. (2018). PORCUPINE regulates development in response to temperature through alternative splicing. Nature plants, 4(8), 534-539
Open this publication in new window or tab >>PORCUPINE regulates development in response to temperature through alternative splicing
Show others...
2018 (English)In: Nature plants, ISSN 2055-026X, Vol. 4, no 8, p. 534-539Article in journal (Refereed) Published
Abstract [en]

Recent findings suggest that alternative splicing has a critical role in controlling the responses of plants to temperature variations. However, alternative splicing factors in plants are largely uncharacterized. Here we establish the putative splice regulator, PORCUPINE (PCP), as temperature-specific regulator of development in Arabidopsis thaliana. Our findings point to the misregulation of WUSCHEL and CLAVATA3 as the possible cause for the meristem defects affecting the pcp-1 loss-of-function mutants at low temperatures.

Place, publisher, year, edition, pages
Nature Publishing Group, 2018
National Category
Biochemistry and Molecular Biology Botany
Identifiers
urn:nbn:se:umu:diva-152230 (URN)10.1038/s41477-018-0176-z (DOI)000443861300009 ()29988152 (PubMedID)
Available from: 2018-10-25 Created: 2018-10-25 Last updated: 2018-10-25Bibliographically approved
Shanks, C. M., Hecker, A., Cheng, C.-Y., Brand, L., Collani, S., Schmid, M., . . . Kieber, J. J. (2018). Role of BASIC PENTACYSTEINE transcription factors in a subset of cytokinin signaling responses. The Plant Journal, 95(3), 458-473
Open this publication in new window or tab >>Role of BASIC PENTACYSTEINE transcription factors in a subset of cytokinin signaling responses
Show others...
2018 (English)In: The Plant Journal, ISSN 0960-7412, E-ISSN 1365-313X, Vol. 95, no 3, p. 458-473Article in journal (Refereed) Published
Abstract [en]

Cytokinin plays diverse roles in plant growth and development, generally acting by modulating gene transcription in target tissues. The type-B Arabidopsis response regulators (ARR) transcription factors have emerged as primary targets of cytokinin signaling and are required for essentially all cytokinin-mediated changes in gene expression. The diversity of cytokinin function is likely imparted by the activity of various transcription factors working with the type-B ARRs to alter specific sets of target genes. One potential set of co-regulators modulating the cytokinin response are the BARLEY B-RECOMBINANT/BASIC PENTACYSTEINE (BBR/BPC) family of plant-specific transcription factors. Here, we show that disruption of multiple BPCs results in reduced sensitivity to cytokinin. Further, the BPCs are necessary for the induction of a subset of genes in response to cytokinin. We identified direct invivo targets of BPC6 using ChIP-Seq and found an enrichment of promoters of genes differentially expressed in response to cytokinin. Further, a significant number of BPC6 regulated genes are also direct targets of the type-B ARRs. Potential cis-binding elements for a number of other transcription factors linked to cytokinin action are enriched in the BPC binding fragments, including those for the cytokinin response factors (CRFs). In addition, several BPCs interact with a subset of type-A ARRs. Consistent with these results, a significant number of genes whose expression is altered in bpc mutant roots are also mis-expressed in crf1,3,5,6 and type-A arr3,4,5,6,7,8,9,15 mutant roots. These results suggest that the BPCs are part of a complex network of transcription factors that are involved in the response to cytokinin.

Place, publisher, year, edition, pages
John Wiley & Sons, 2018
Keywords
Arabidopsis thaliana, ChIP-Seq, cytokinin, phytohormones, transcription factor
National Category
Biochemistry and Molecular Biology
Identifiers
urn:nbn:se:umu:diva-150658 (URN)10.1111/tpj.13962 (DOI)000438224100006 ()29763523 (PubMedID)
Available from: 2018-08-28 Created: 2018-08-28 Last updated: 2018-08-28Bibliographically approved
Prát, T., Hajný, J., Grunewald, W., Vasileva, M., Molnár, G., Tejos, R., . . . Friml, J. (2018). WRKY23 is a component of the transcriptional network mediating auxin feedback on PIN polarity. PLoS Genetics, 14(1), Article ID e1007177.
Open this publication in new window or tab >>WRKY23 is a component of the transcriptional network mediating auxin feedback on PIN polarity
Show others...
2018 (English)In: PLoS Genetics, ISSN 1553-7390, E-ISSN 1553-7404, Vol. 14, no 1, article id e1007177Article in journal (Refereed) Published
Abstract [en]

Auxin is unique among plant hormones due to its directional transport that is mediated by the polarly distributed PIN auxin transporters at the plasma membrane. The canalization hypothesis proposes that the auxin feedback on its polar flow is a crucial, plant-specific mechanism mediating multiple self-organizing developmental processes. Here, we used the auxin effect on the PIN polar localization in Arabidopsis thaliana roots as a proxy for the auxin feedback on the PIN polarity during canalization. We performed microarray experiments to find regulators of this process that act downstream of auxin. We identified genes that were transcriptionally regulated by auxin in an AXR3/IAA17-and ARF7/ARF19-dependent manner. Besides the known components of the PIN polarity, such as PID and PIP5K kinases, a number of potential new regulators were detected, among which the WRKY23 transcription factor, which was characterized in more detail. Gain-and loss-of-function mutants confirmed a role for WRKY23 in mediating the auxin effect on the PIN polarity. Accordingly, processes requiring auxin-mediated PIN polarity rearrangements, such as vascular tissue development during leaf venation, showed a higher WRKY23 expression and required the WRKY23 activity. Our results provide initial insights into the auxin transcriptional network acting upstream of PIN polarization and, potentially, canalization-mediated plant development.

Place, publisher, year, edition, pages
PUBLIC LIBRARY SCIENCE, 2018
National Category
Developmental Biology
Identifiers
urn:nbn:se:umu:diva-144963 (URN)10.1371/journal.pgen.1007177 (DOI)000423718600034 ()
Available from: 2018-02-21 Created: 2018-02-21 Last updated: 2018-06-09Bibliographically approved
Conn, V. M., Hugouvieux, V., Nayak, A., Conos, S. A., Capovilla, G., Cildir, G., . . . Conn, S. J. (2017). A circRNA from SEPALLATA3 regulates splicing of its cognate mRNA through R-loop formation. Nature Plants, 3(5), Article ID 17053.
Open this publication in new window or tab >>A circRNA from SEPALLATA3 regulates splicing of its cognate mRNA through R-loop formation
Show others...
2017 (English)In: Nature Plants, ISSN 2055-026X, Vol. 3, no 5, article id 17053Article in journal (Refereed) Published
Abstract [en]

Circular RNAs (circRNAs) are a diverse and abundant class of hyper-stable, non-canonical RNAs that arise through a form of alternative splicing (AS) called back-splicing. These single-stranded, covalently-closed circRNA molecules have been identified in all eukaryotic kingdoms of life(1), yet their functions have remained elusive. Here, we report that circRNAs can be used as bona fide biomarkers of functional, exon-skipped AS variants in Arabidopsis, including in the homeotic MADS-box transcription factor family. Furthermore, we demonstrate that circRNAs derived from exon 6 of the SEPALLATA3 (SEP3) gene increase abundance of the cognate exon-skipped AS variant (SEP3.3 which lacks exon 6), in turn driving floral homeotic phenotypes. Toward demonstrating the underlying mechanism, we show that the SEP3 exon 6 circRNA can bind strongly to its cognate DNA locus, forming an RNA: DNA hybrid, or R-loop, whereas the linear RNA equivalent bound significantly more weakly to DNA. R-loop formation results in transcriptional pausing, which has been shown to coincide with splicing factor recruitment and AS(2-4). This report presents a novel mechanistic insight for how at least a subset of circRNAs probably contribute to increased splicing efficiency of their cognate exon-skipped messenger RNA and provides the first evidence of an organismal-level phenotype mediated by circRNA manipulation.

Place, publisher, year, edition, pages
Nature Publishing Group, 2017
National Category
Biochemistry and Molecular Biology
Identifiers
urn:nbn:se:umu:diva-137882 (URN)10.1038/nplants.2017.53 (DOI)000404896700006 ()28418376 (PubMedID)
Available from: 2017-08-10 Created: 2017-08-10 Last updated: 2018-06-09Bibliographically approved
Organisations

Search in DiVA

Show all publications