Brassinosteroid actions in plants

Recent studies on dwarf mutants of Arabidopsis, tomato and pea have provided convincing evidence that brassinosteroids are a unique class of plant hormones that are essential for normal plant growth. Detailed metabolic analyses of these mutants, coupled with thorough molecular and biochemical studies of their corresponding genes and gene products, are essential for a better understanding of brassinosteroid biosynthesis and its regulation. Molecular and genetic approaches have been undertaken to dissect the brassinosteroid signalling pathway, leading to the identification of a putative brassinosteroid receptor and a few brassinosteroid-response genes. Further studies should expand our knowledge on how brassinosteroids are perceived and transduced to regulate plant development.