Cytosolic NADP-isocitrate dehydrogenase of pea plants: genomic clone characterization and functional analysis under abiotic stress conditions.
NADPH is an essential electron donor in numerous biosynthetic and detoxification reactions. In animal, yeast and bacteria, the NADP-dependent isocitrate dehydrogenase (NADP-ICDH), which catalyzes the production of NADPH, is being recognized as an essential component of the antioxidative defence mechanisms. In plant cells, there is little information on the antioxidant properties of NADP-ICDH. Using a pea cDNA lambdagt11 library, the full-length cDNA of a NADP-ICDH was obtained. In pea leaves, the analyses of activity, protein and transcript expression of NADP-ICDH under six different abiotic stress conditions (CL, continuous light, HLI, high light intensity, D, continuous dark, LT, low-temperature HT, high-temperature and W, mechanical wounding) revealed a differential regulation at transcriptional and post-translational level depending on the abiotic stress. The activity and protein expression of NADP-ICDH and catalase increased only under HLI but the NADP-ICDH transcripts were up-regulated by cold stress (70%) and W (40%). Under the same conditions, the transcript analysis of glutathione reductase (GR), monodehydroascorbate reductase (MDAR) and ascorbate peroxidase (APX), key components of the antioxidative ascorbate-glutathione cycle, showed similar inductions. These data indicate that in pea plants the cytosolic NADP-ICDH shows a differential response, at mRNA and activity level, depending on the type of abiotic stress and suggests that this dehydrogenase could have a protective antioxidant role against certain environmental stresses in plants.
Leterrier
Marina
M
Departamento de Bioquímica, Biología Celular y Molecular de Plantas, Instituto de Biología Vegetal y Medio Ambiente, Estación Experimental del Zaidín, CSIC, Apartado 419, Granada, E-18080, Spain.
Del Río
Luis A
LA
Corpas
Francisco J
FJ
D060387:Ascorbate Peroxidases; D002374:Catalase / Q000032:analysis; D003080:Cold Temperature; D003600:Cytosol / Q000201:enzymology*; D018076:DNA, Complementary / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics; D004307:Dose-Response Relationship, Radiation; D004790:Enzyme Induction / Q000528:radiation effects; D018506:Gene Expression Regulation, Plant / Q000528:radiation effects; D005980:Glutathione Reductase / Q000096:biosynthesis / Q000235:genetics; D006358:Hot Temperature; D007521:Isocitrate Dehydrogenase / Q000737:chemistry / Q000235:genetics* / Q000502:physiology; D008027:Light; D008969:Molecular Sequence Data; D009247:NADH, NADPH Oxidoreductases / Q000096:biosynthesis / Q000235:genetics; D018532:Pisum sativum / Q000201:enzymology* / Q000235:genetics / Q000528:radiation effects; D010544:Peroxidases / Q000096:biosynthesis / Q000235:genetics; D018515:Plant Leaves / Q000201:enzymology / Q000528:radiation effects; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics* / Q000502:physiology; D012333:RNA, Messenger / Q000096:biosynthesis; D018749:RNA, Plant / Q000096:biosynthesis; D013314:Stress, Mechanical
D018076:DNA, Complementary; D018744:DNA, Plant; D010940:Plant Proteins; D012333:RNA, Messenger; D018749:RNA, Plant; D007521:Isocitrate Dehydrogenase; C039355:isocitrate dehydrogenase (NADP+); D010544:Peroxidases; D060387:Ascorbate Peroxidases; D002374:Catalase; D009247:NADH, NADPH Oxidoreductases; C023927:monodehydroascorbate reductase (NADH); D005980:Glutathione Reductase