Salinity-induced decrease in NADPH oxidase activity in the maize leaf blade elongation zone

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• 作者：André ; s A. Rodrí ; guez ; H. Ramiro Lascano ; Dolores Bustos ; Edith Taleisnik
• 关键词：Elongation ; Maize ; NADPH oxidase ; Reactive oxygen species ; Salt stress
• 刊名：Journal of Plant Physiology
• 出版年：2007
• 出版时间：7 March 2007
• 年：2007
• 卷：164
• 期：3
• 页码：223-230
• 全文大小：328 K

文摘

We reported previously that salinity-induced elongation constraints in the expansion zone of maize leaves are associated with reduced reactive oxygen species (ROS) production and could be alleviated by the addition of ROS. The NaCl effect was salt-specific and not osmotic. This paper explores the causes for such reduction. The decrease in ROS levels under salinity was not accompanied by increases in soluble apoplastic antioxidant activities such as superoxide dismutase, peroxidases and ascorbate. In experimental systems devoid of cell walls (protoplasts and membrane fractions) superoxide anion (O₂⁻) production was inhibited by 50 and 100 mM NaCl, 50 μM DPI, 10 mM EGTA, and 5 mM verapamil, a Ca²⁺ channel inhibitor. Inhibitory effects of NaCl and reduced Ca²⁺ supply were also observed in in gel assessment of O₂⁻-generating activity. The main activity band excised from the ND-PAGE was recognized by an antibody against the C-terminal portion of the tomato gp91^phox homolog. These results indicate the O₂⁻-generating activity negatively affected by NaCl was compatible with that of plasma membrane NADPH oxidase.