BRASSINOSTEROIDS: Essential Regulators of Plant Growth and Development.
Brassinosteroids (BRs) are growth-promoting natural products found at low levels in pollen, seeds, and young vegetative tissues throughout the plant kingdom. Detailed studies of BR biosynthesis and metabolism, coupled with the recent identification of BR-insensitive and BR-deficient mutants, has greatly expanded our view of steroids as signals controlling plant growth and development. This review examines the microchemical and molecular genetic analyses that have provided convincing evidence for an essential role of BRs in diverse developmental programs, including cell expansion, vascular differentiation, etiolation, and reproductive development. Recent advances relevant to the molecular mechanisms of BR-regulated gene expression and BR signal transduction are also discussed.
Clouse
Steven D.
SD
Department of Horticultural Science, North Carolina State University, Raleigh, North Carolina 27695, School of Forestry and Resource Conservation, University of Melbourne, Parkville, Victoria 3052, Australia.
Sasse
Jenneth M.
JM