Abscisic acid represses the transcription of chloroplast genes

0422266 - ÚEB 2014 RIV GB eng J - Journal Article
Yamburenko, M.V. - Zubo, Y.O. - Vaňková, Radomíra - Kusnetsov, V. - Kulaeva, O.N. - Borner, T.
Abscisic acid represses the transcription of chloroplast genes.
Journal of Experimental Botany. Roč. 64, č. 14 (2013), s. 4491-4502. ISSN 0022-0957. E-ISSN 1460-2431
R&D Projects: GA ČR GA522/09/2058
Institutional research plan: CEZ:AV0Z50380511
Keywords : Abscisic acid (ABA) * chloroplast * cytokinin
Subject RIV: ED - Physiology
Impact factor: 5.794, year: 2013

Numerous studies have shown effects of abscisic acid (ABA) on nuclear genes encoding chloroplast-localized proteins. ABA effects on the transcription of chloroplast genes, however, have not been investigated yet thoroughly. This work, therefore, studied the effects of ABA (75 M) on transcription and steady-state levels of transcripts in chloroplasts of basal and apical segments of primary leaves of barley (Hordeum vulgare L.). Basal segments consist of young cells with developing chloroplasts, while apical segments contain the oldest cells with mature chloroplasts. Exogenous ABA reduced the chlorophyll content and caused changes of the endogenous concentrations not only of ABA but also of cytokinins to different extents in the basal and apical segments. It repressed transcription by the chloroplast phage-type and bacteria-type RNA polymerases and lowered transcript levels of most investigated chloroplast genes drastically. ABA did not repress the transcription of psbD and a few other genes and even increased psbD mRNA levels under certain conditions. The ABA effects on chloroplast transcription were more pronounced in basal vs. apical leaf segments and enhanced by light. Simultaneous application of cytokinin (22 M 6-benzyladenine) minimized the ABA effects on chloroplast gene expression. These data demonstrate that ABA affects the expression of chloroplast genes differentially and points to a role of ABA in the regulation and coordination of the activities of nuclear and chloroplast genes coding for proteins with functions in photosynthesis.
Permanent Link: http://hdl.handle.net/11104/0228562