Mg deficiency changes the isoenzyme pattern of reactive oxygen species-relatedenzymes and regulates NADPH-oxidase-mediated ROS signaling in cotton

Authors : RENGİN ÖZGÜR UZİLDAY, BARIŞ UZİLDAY, TOLGA YALÇINKAYA, İSMAİL TÜRKAN

Pages : 868-880

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Publication Date : 2017-12-01

Article Type : Research Paper

Abstract :The aim of this work was to investigate changes in isoenzyme patterns of enzymes related to reactive oxygen species insert ignore into journalissuearticles values(ROS); detoxification such as superoxide dismutase insert ignore into journalissuearticles values(SOD);, catalase insert ignore into journalissuearticles values(CAT);, peroxidase insert ignore into journalissuearticles values(POX);, ascorbate peroxidase insert ignore into journalissuearticles values(APX);, glutathione reductase insert ignore into journalissuearticles values(GR);, and glutathione-S-transferase insert ignore into journalissuearticles values(GST); in cotton under Mg deficiency. Moreover, we aimed to elucidate how a ROS producer, NADPH oxidase insert ignore into journalissuearticles values(NOX);, responds to changing Mg levels. Cotton plants were grown with different concentrations of MgSO4 in hydroponic medium to create nutrient deficiency insert ignore into journalissuearticles values(0, 75, 150, 1000 μM Mg);. Gradual decreases in growth and photosynthetic rates were observed with declining Mg concentrations and 0, 75, and 150 μM Mg increased oxidative stress as evidenced by H2O2 and lipid peroxidation. Total activities of SOD, CAT, POX, APX, GR, and GST were increased while NOX activity was decreased with Mg deficiency. The activities of GR and GST were highest in plants treated with 0 μM Mg, indicating excess use of glutathione for redox regulation. The most striking results were the changes in isoenzyme patterns of SOD, NOX, POX, and GST. For example, a new Cu/ZnSOD isoenzyme was induced in plants treated with 0 μM Mg. Cotton plants adapt to Mg deficiency by changing the intensity of existing isoenzymes or inducing new ones.
Keywords : Antioxidant enzymes, cotton, Gossypium hirsutum, magnesium deficiency, magnesium starvation, NADPH oxidase, redox regulation