Molecular mechanisms of steroid hormone signaling in plants.
Brassinosteroids (BRs), the polyhydroxylated steroid hormones of plants, regulate the growth and differentiation of plants throughout their life cycle. Over the past several years, genetic and biochemical approaches have yielded great progress in understanding BR signaling. Unlike their animal counterparts, BRs are perceived at the plasma membrane by direct binding to the extracellular domain of the BRI1 receptor S/T kinase. BR perception initiates a signaling cascade, acting through a GSK3 kinase, BIN2, and the BSU1 phosphatase, which in turn modulates the phosphorylation state and stability of the nuclear transcription factors BES1 and BZR1. Microarray technology has been used extensively to provide a global view of BR genomic effects, as well as a specific set of target genes for BES1 and BZR1. These gene products thus provide a framework for how BRs regulate the growth of plants.
Vert
Grégory
G
Plant Biology Laboratory and Howard Hughes Medical Institute, The Salk Institute for Biological Studies, La Jolla California 92037, USA. vert@salk.edu
Nemhauser
Jennifer L
JL
Geldner
Niko
N
Hong
Fangxin
F
Chory
Joanne
J
D017360:Arabidopsis / Q000235:genetics / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D008954:Models, Biological; D010840:Phytosterols / Q000378:metabolism*; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology*
D029681:Arabidopsis Proteins; D010840:Phytosterols