title: Modification of plasma membrane NADPH oxidase activity in cucumber seedling roots in response to cadmium stress.
abstract: The aim of this study was to investigate the effect of cadmium on plasma membrane (PM) NADPH oxidase activity in cucumber roots. Plants were treated with cadmium for 1, 3 or 6 days. Some of the plants after 3-day exposure to cadmium were transferred to a medium without the heavy metal for the next 3 days. Treatment of plants with cadmium for 6 days stimulated the activity of NADPH oxidase. The highest stimulation of O2(•-) production by NADPH oxidase was observed in post-stressed plants, which was correlated with the stimulation of activity of PM H(+)-ATPase in the same conditions. In order to examine the effects of cadmium stresses on the expression level of genes encoding NADPH oxidase, putative cucumber homologs encoding RBOH proteins were selected and a real-time PCR assay was performed. NADPH is a substrate for oxidase; thus alterations in the activity of glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, NADP-isocitrate dehydrogenase and NADP-malic enzyme under cadmium stress were studied. The activity of NADPH dehydrogenases was increased under cadmium stress. The results indicate that PM NADPH oxidase could be involved in plants' response to cadmium stress by affecting the activity of PM H(+)-ATPase, and NADPH-generating enzymes could play important roles in this process.
authors: Department of Plant Molecular Physiology, Institute of Experimental Biology, University of Wrocław, Kanonia Street 6/8, 50-328 Wrocław, Poland. Electronic address: dagmara.jakubowska@uni.wroc.pl.
authors: Dagmara
authors: D
authors: Jakubowska
authors: Department of Plant Molecular Physiology, Institute of Experimental Biology, University of Wrocław, Kanonia Street 6/8, 50-328 Wrocław, Poland. Electronic address: malgorzata.janicka@uni.wroc.pl.
authors: Małgorzata
authors: M
authors: Janicka-Russak
authors: Department of Plant Molecular Physiology, Institute of Experimental Biology, University of Wrocław, Kanonia Street 6/8, 50-328 Wrocław, Poland. Electronic address: katarzyna.kabala@uni.wroc.pl.
authors: Katarzyna
authors: K
authors: Kabała
authors: Department of Plant Molecular Physiology, Institute of Experimental Biology, University of Wrocław, Kanonia Street 6/8, 50-328 Wrocław, Poland. Electronic address: mmigocka@biol.uni.wroc.pl.
authors: Magdalena
authors: M
authors: Migocka
authors: Department of Plant Molecular Physiology, Institute of Experimental Biology, University of Wrocław, Kanonia Street 6/8, 50-328 Wrocław, Poland. Electronic address: redam@biol.uni.wroc.pl.
authors: Małgorzata
authors: M
authors: Reda
mesh_terms: D001483:Base Sequence; D002104:Cadmium / Q000633:toxicity*; D002462:Cell Membrane / Q000201:enzymology; D018553:Cucumis sativus / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D008291:Malate Dehydrogenase / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D019255:NADPH Oxidases / Q000235:genetics / Q000378:metabolism*; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000201:enzymology / Q000235:genetics; D006180:Proton-Translocating ATPases / Q000235:genetics / Q000378:metabolism; D036226:Seedlings / Q000187:drug effects / Q000201:enzymology / Q000235:genetics; D017422:Sequence Analysis, DNA
chemical_list: D010940:Plant Proteins; D002104:Cadmium; D008291:Malate Dehydrogenase; C031917:malate dehydrogenase (oxaloacetate-decarboxylating) (NADP+); D019255:NADPH Oxidases; D006180:Proton-Translocating ATPases
keywords: Cadmium; NADPH oxidase; NADPH-generating enzymes; Plasma membrane