ABSTRACT
This chapter summarizes the present state of the art on the knowledge of brassinosteroids (BRs) in biosynthesis and metabolism, bioactivity, molecular and physiological effects, as well as their application in agriculture. Since then, successively new analogs of brassinolide were isolated and identified from many kinds of plants which indicate the ubiquitous occurrence in the plant kingdom, and constitute a new family of plant growth regulators called BRs. Subsequently, a more detailed explanation of the response of BRs in different bioassays, as well as its interactions with other plant growth regulators, is presented to better understand the BRs mode of action, which has been demonstrated to be different from other plant hormones. Plant growth regulators for yield enhancement, quality improvement, and the facilitation of harvesting, together with genetic engineering, represent supplemental technologies in agriculture for increasing crop production and optimizing the use of limited resources.
