Premium
Brassinosteroid‐Promoted Growth
Author(s) -
Müssig C.
Publication year - 2005
Publication title -
plant biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.871
H-Index - 87
eISSN - 1438-8677
pISSN - 1435-8603
DOI - 10.1055/s-2005-837493
Subject(s) - biology , brassinosteroid , dwarfism , cell growth , microbiology and biotechnology , mutant , cell division , gene , cell , biochemistry , genetics , arabidopsis
Brassinosteroids (BRs) are highly potent growth‐promoting sterol derivatives. BR‐deficient or BR‐insensitive mutants display dwarfism. Whole plants and excised tissues have been used to analyse the mechanisms involved in BR‐promoted growth. BR stimulates cell elongation and cell division, and BR has specific effects on differentiation. Underlying physiological pathways include modification of cell wall properties, effects on carbohydrate assimilation and allocation, and control of aquaporin activities. BR apparently coordinates and integrates diverse processes required for growth, partly via interactions with other phytohormones setting the frame for BR responses. Ultimately, BR‐promoted growth is mediated through genomic pathways. Positive regulators of the BR response (such as BZR1 and BES1) and putative downstream components (such as EXO) are involved in the regulation of BR‐responsive genes and growth promotion. BR‐responsive genes have been identified in several plant species. However, causal links between physiological effects and changes of transcript patterns, for the most part, are still unresolved. This review focuses on physiology and molecular mechanisms underlying BR‐promoted growth in the different plant organs. Interactions with other phytohormones are discussed.