The structure, biosynthesis and function of brassinosteroids

The hormonal status of brassinosteroids has been established by coupling molecular genetics with studies of the pathway of biosynthesis. This approach led to the identification of mutants of Arabidopsis and pea with defects in brassinosteroid biosynthesis or sensitivity - these mutants are all dwarfs, and the phenotype can be rescued by the application of exogenous brassinosteroids, It appears that brassinosteroids promote cell elongation, thereby influencing the growth of plants, and that the control of brassinosteroid levels is an essential requirement for normal plant growth.