Light and brassinosteroid signals are integrated via a dark-induced small G protein in etiolated seedling growth

Citation
Jg. Kang et al., Light and brassinosteroid signals are integrated via a dark-induced small G protein in etiolated seedling growth, CELL, 105(5), 2001, pp. 625-636
Citations number
36
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Cell & Developmental Biology
Journal title
CELL
ISSN journal
0092-8674 → ACNP
Volume
105
Issue
5
Year of publication
2001
Pages
625 - 636
Database
ISI
SICI code
0092-8674(20010601)105:5<625:LABSAI>2.0.ZU;2-0
Abstract
Plant growth and development are regulated through coordinated interactions between light and phytohormones. Here, we demonstrate that a dark-induced small G protein, pea Pra2, regulates a variant cytochrome P450 that catalyz es C-2 hydroxylation in brassinosteroid biosynthesis. The cytochrome P450 i s dark-induced and predominantly expressed in the rapidly elongating zone o f etiolated pea epicotyls, where Pra2 is also most abundant. Transgenic pla nts with reduced Pra2 exhibit a dark-specific dwarfism, which is completely rescued by exogenous brassinolide. Overexpression of the cytochrome P450 r esults in enhanced hypocotyl growth even in the light, which phenocopies th e etiolated hypocotyls. We therefore propose that Pra2 and its orthologs ar e molecular mediators for the cross-talk between light and brassinosteroids in the etiolation process in plants.