Crosstalk of ethylene and gibberellins during wood formation in hybridaspen
Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
Both gibberellins (GAs) and ethylene (ET) or its in planta precursor 1‐Aminocyclopropane-1‐carboxylic acid (ACC) stimulate cambial cell division and modify wood development when exogenously applied to wood forming tissues of trees. Furthermore both hormones are involved in tension wood (TW) formation in leaned trees. In Arabidopsis a cross‐talk of ET and GA on a molecular level has been demonstrated. We have examined here the effects of GA and ACC, alone and in combination, on wood development in hybrid aspen (Populus tremula x tremuloides) to investigate their potential of cross-talk during wood development. The response of selected transcripts involved in GA, ET and auxin signaling, biosynthesis and transport was inspected in the total stem of T89 trees after 10 hours of treatment with quantitative real‐time PCR (qPCR). Analysis of the phenotype, anatomy and chemistry of wild-type, ethylene-insensitive and GA‐deficient trees after 2 weeks of treatment emphasized that a cross‐talk between GA and ACC is plausible. Based on primary growth characteristics, GA and ACC seemed to be partially redundant. Lignin stainings suggest antagonistic interactions, while fiber to vessel ratios and the distribution of G‐layers put forward a collaborating action. Diffuse reflectance FT‐IR demonstrates that functional GA and ACC signalling are needed to induce differences in chemical composition.
Place, publisher, year, edition, pages
Biochemistry and Molecular Biology
IdentifiersURN: urn:nbn:se:umu:diva-81460OAI: oai:DiVA.org:umu-81460DiVA: diva2:655905
Tuominen, Hannele, Lektor