The Arabidopsis Prohibitin Gene PHB3 Functions in Nitric Oxide-Mediated Responses and in Hydrogen Peroxide-Induced Nitric Oxide Accumulation.
To discover genes involved in nitric oxide (NO) metabolism, a genetic screen was employed to identify mutants defective in NO accumulation after treatment with the physiological inducer hydrogen peroxide. In wild-type Arabidopsis thaliana plants, NO levels increase eightfold in roots after H(2)O(2) treatment for 30 min. A mutant defective in H(2)O(2)-induced NO accumulation was identified, and the corresponding mutation was mapped to the prohibitin gene PHB3, converting the highly conserved Gly-37 to an Asp in the protein's SPFH domain. This point mutant and a T-DNA insertion mutant were examined for other NO-related phenotypes. Both mutants were defective in abscisic acid-induced NO accumulation and stomatal closure and in auxin-induced lateral root formation. Both mutants were less sensitive to salt stress, showing no increase in NO accumulation and less inhibition of primary root growth in response to NaCl treatment. In addition, light-induced NO accumulation was dramatically reduced in cotyledons. We found no evidence for impaired H(2)O(2) metabolism or signaling in the mutants as H(2)O(2) levels and H(2)O(2)-induced gene expression were unaffected by the mutations. These findings identify a component of the NO homeostasis system in plants and expand the function of prohibitin genes to include regulation of NO accumulation and NO-mediated responses.
Wang
Yong
Y
Section of Cell and Developmental Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, California 92093.
Ries
Amber
A
Wu
Kati
K
Yang
Albert
A
Crawford
Nigel M
NM
D000040:Abscisic Acid / Q000378:metabolism; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D006861:Hydrogen Peroxide / Q000378:metabolism*; D007210:Indoleacetic Acids / Q000494:pharmacology; D016254:Mutagenesis, Insertional; D009154:Mutation; D009569:Nitric Oxide / Q000378:metabolism*; D018517:Plant Roots / Q000235:genetics / Q000254:growth & development; D054046:Plant Stomata / Q000378:metabolism; D000091402:Prohibitins; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D012965:Sodium Chloride / Q000494:pharmacology
D029681:Arabidopsis Proteins; C000717327:AtPHB3 protein, Arabidopsis; D004269:DNA, Bacterial; D007210:Indoleacetic Acids; D000091402:Prohibitins; D012097:Repressor Proteins; C036483:T-DNA; D009569:Nitric Oxide; D012965:Sodium Chloride; D000040:Abscisic Acid; D006861:Hydrogen Peroxide