Brassinosteroids (BRs) participate in the regulation of important physiological processes, such as germination, photomorphogenesis, elongation, and the development of reproductive organs. Unlike other phytohormones, BRs are not subject to active transport within the plant, therefore, their levels are determined by the balance between local biosynthetic and inactivation reactions. BR accumulation shows good correlation with the induction of biosynthetic genes, which are stringently regulated, primarily at the transcriptional level. These genes function under developmental, organ-specific and diurnal control, and respond to homeostatic feedback adjustment. Excess amounts of bioactive BRs are removed by reversible or irreversible inactivation mechanisms. The regulation of BR-inactivating genes is also fairly complex and often opposite to those of the biosynthetic functions. Though many details are yet to be clarified, the known regulatory mechanisms of BR metabolism reveal a finely orchestrated system capable of ensuring optimal BR supply from germination to seed production.
|Title of host publication||Brassinosteroids|
|Subtitle of host publication||A Class of Plant Hormone|
|Number of pages||25|
|Publication status||Published - Jan 1 2011|
- Gene expression
ASJC Scopus subject areas
- Agricultural and Biological Sciences(all)