Entry URI http://metadb.riken.jp/db/SciNetS_ria224i/cria224u4ria224u16856986i
Entry name Chai Mao-Feng et al. 2006 Sep. Plant J. 47(5):665-74.
Title NADK3, a novel cytoplasmic source of NADPH, is required under conditions of oxidative stress and modulates abscisic acid responses in Arabidopsis.
Authors An Rui|Chai Mao-Feng|Chen Jia|Chen Qi-Jun|Wang Xue-Chen|Wei Peng-Cheng|Yang Shuhua
Abstract In plants, excess reactive oxygen species are toxic molecules induced under environmental stresses, including pathogen invasions and abiotic stresses. Many anti-oxidant defense systems have been reported to require NADPH as an important reducing energy equivalent. However, the sources of NADPH and the molecular mechanisms of maintaining cytoplasmic redox balance are unclear. Here, we report the biological function of a putative cytoplasmic NADH kinase (NADK3) in several abiotic stress responses in Arabidopsis. We found that cytoplasmic NADPH is provided mostly by the product of the NADK3 gene in Arabidopsis. Expression of he NADK3 gene is responsive to abscisic acid (ABA) and abiotic stress conditions, including methyl violgen (MV), high salinity and osmotic shock. An NADK3 null mutant showed hypersensitivity to oxidative stress in both seed germination and seedling growth. Seed germination of the mutant plants also showed increased sensitivity to ABA, salt and mannitol. Furthermore, stress-related target genes were identified as upregulated in the mutant by mannitol and MV. Our study indicates that this cytoplasmic NADH kinase, a key source of the cellular reductant NADPH, is required for various abiotic stress responses.
Pubmed ID 16856986
Journal The Plant journal
Volume 47
Issue 5
Pages 665-74
Publication date 2006 Sep
Num of phenotype gene 0