The effect of epibrassinolide on senescence in wheat leaves

Abstract

Brassinosteroids (BRs) are new groups of plant hormones with significant growth-promoting activity. Brassinolide (BL) is the most biologically active BR. BRs are considered as hormones, as they influence varied developmental processes like growth, germination of seeds, rhizogenesis, flowering and senescence. Senescence is regulated by phytohormones. This research shows that epibrassinolide (eBL) accelerates or delays senescence in wheat leaf segments. For this aim, epibrassinolide was applied exogenously into the excised wheat leaf segments. An increase in peroxidase activity and decrease in protease activity, chlorophyll content (at 10 and 0.1 μM. eBL) were detected. However, protein content decreased only at 10 μM. eBL. Finally, it was observed that eBR accelerated senescence specially at high concentration. © 2007 Taylor and Francis Group, LLC.