title: The Pea DELLA proteins LA and CRY are important regulators of gibberellin synthesis and root growth.
abstract: The theory that bioactive gibberellins (GAs) act as inhibitors of inhibitors of plant growth was based originally on the slender pea (Pisum sativum) mutant (genotype la cry-s), but the molecular nature of this mutant has remained obscure. Here we show that the genes LA and CRY encode DELLA proteins, previously characterized in other species (Arabidopsis [Arabidopsis thaliana] and several grasses) as repressors of growth, which are destabilized by GAs. Mutations la and cry-s encode nonfunctional proteins, accounting for the fact that la cry-s plants are extremely elongated, or slender. We use the la and cry-s mutations to show that in roots, DELLA proteins effectively promote the expression of GA synthesis genes, as well as inhibit elongation. We show also that one of the DELLA-regulated genes is a second member of the pea GA 3-oxidase family, and that this gene appears to play a major role in pea roots.
authors: School of Plant Science, University of Tasmania, Hobart, Tasmania 7001, Australia.
authors: Diana E
authors: DE
authors: Weston
authors: Robert C
authors: RC
authors: Elliott
authors: Diane R
authors: DR
authors: Lester
authors: Catherine
authors: C
authors: Rameau
authors: James B
authors: JB
authors: Reid
authors: Ian C
authors: IC
authors: Murfet
authors: John J
authors: JJ
authors: Ross
mesh_terms: D018506:Gene Expression Regulation, Plant; D005875:Gibberellins / Q000096:biosynthesis*; D006899:Mixed Function Oxygenases / Q000235:genetics; D009154:Mutation; D018532:Pisum sativum / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics*; D018517:Plant Roots / Q000254:growth & development / Q000378:metabolism*
chemical_list: D005875:Gibberellins; D010940:Plant Proteins; C007842:gibberellic acid; D006899:Mixed Function Oxygenases; C108186:gibberellin 3beta-hydroxylase