Consequences of induced brassinosteroid deficiency in Arabidopsis leaves

BMC Plant Biology

Research Article

Alexander Erban¹  Lothar Willmitzer¹  Eugenia Maximova¹  Joachim Kopka¹  Toshihiro Obata¹  Alisdair R Fernie¹  Patrick Giavalisco¹  Carsten Müssig²  Janina Lisso²  Florian Schröder² 

[1] Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany;University of Potsdam, c/o Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany;

关键词: Brassinosteroids;    Arabidopsis;    Tricarboxylic acid cycle;    Biomass;    Cell expansion;    Growth;   

DOI  :  10.1186/s12870-014-0309-0

 received in 2014-06-23, accepted in 2014-10-27,  发布年份 2014

来源: Springer

【 摘 要 】

BackgroundThe identification of brassinosteroid (BR) deficient and BR insensitive mutants provided conclusive evidence that BR is a potent growth-promoting phytohormone. Arabidopsis mutants are characterized by a compact rosette structure, decreased plant height and reduced root system, delayed development, and reduced fertility. Cell expansion, cell division, and multiple developmental processes depend on BR. The molecular and physiological basis of BR action is diverse. The BR signalling pathway controls the activity of transcription factors, and numerous BR responsive genes have been identified. The analysis of dwarf mutants, however, may to some extent reveal phenotypic changes that are an effect of the altered morphology and physiology. This restriction holds particularly true for the analysis of established organs such as rosette leaves.ResultsIn this study, the mode of BR action was analysed in established leaves by means of two approaches. First, an inhibitor of BR biosynthesis (brassinazole) was applied to 21-day-old wild-type plants. Secondly, BR complementation of BR deficient plants, namely CPD (constitutive photomorphogenic dwarf)-antisense and cbb1 (cabbage1) mutant plants was stopped after 21 days. BR action in established leaves is associated with stimulated cell expansion, an increase in leaf index, starch accumulation, enhanced CO2 release by the tricarboxylic acid cycle, and increased biomass production. Cell number and protein content were barely affected.ConclusionPrevious analysis of BR promoted growth focused on genomic effects. However, the link between growth and changes in gene expression patterns barely provided clues to the physiological and metabolic basis of growth. Our study analysed comprehensive metabolic data sets of leaves with altered BR levels. The data suggest that BR promoted growth may depend on the increased provision and use of carbohydrates and energy. BR may stimulate both anabolic and catabolic pathways.

【 授权许可】

CC BY   
© Schröder et al.; licensee BioMed Central Ltd. 2014