The Effects of Exogenous Ascorbic Acid on the Mechanism of Physiological and Biochemical Responses to Nitrate Uptake in Two Rice Cultivars (Oryza sativa L.) Under Aluminum Stress

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• 作者：Xiaohua Zhou ; Zhaohu Gu ; Huini Xu ; Limei Chen…
• 关键词：Al ; Antioxidant enzyme ; AsA ; Plasma membrane H+ ; ATPase ; Rice ; 14 ; 3 ; 3 Protein
• 刊名：Journal of Plant Growth Regulation
• 出版年：2016
• 出版时间：December 2016
• 年：2016
• 卷：35
• 期：4
• 页码：1013-1024
• 全文大小：929 KB
• 刊物类别：Biomedical and Life Sciences
• 刊物主题：Life Sciences
  Plant Sciences
  Cell Biology
  Agriculture
  Forestry
  
• 出版者：Springer New York
• ISSN：1435-8107
• 卷排序：35

文摘

As a major antioxidant in plants, ascorbic acid (AsA) plays a very important role in the response to aluminum (Al) stress. However, the effect of AsA on the mitigation of Al toxicity and the mechanism of nitrate nitrogen (NO₃−–N) uptake by plants under Al stress are unclear. In this study, a hydroponic experiment was conducted using peak 1 A rice (sterile line, Indica) with weaker resistance to Al and peak 1 superior 5 rice (F1 hybrid, Indica) with stronger resistance to Al to study the effects of exogenous AsA on the physiological and biochemical responses to NO₃−–N uptake by rice roots exposed to 50 μmol L−1 Al. Al stress induced increases in the concentrations of H₂O₂ and malondialdehyde (MDA) and in the activities of antioxidant enzymes [such as superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX)]. Plasma membrane (PM) H+-ATPase and H+-pump activities, endogenous AsA content and NO₃−–N uptake in rice roots decreased under Al stress. After treatment with 2 mmol L−1 exogenous AsA combined with Al, concentrations of H₂O₂ and MDA in roots notably decreased, and endogenous AsA content and activities of SOD, POD, CAT, and APX in rice roots increased significantly; furthermore, the interaction of PM H+-ATPase and the 14-3-3 protein was also enhanced significantly compared with that in control plants without AsA treatment, which clearly increased NO₃−–N uptake. Based on all of these data, the application of AsA significantly reduced the accumulation of H₂O₂ and MDA and increased the activities of PM H+-ATPase and the H+-pump by increasing the endogenous AsA content, the antioxidant enzyme activities, and the interaction of PM H+-ATPase and the 14-3-3 protein in the roots of the two rice cultivars under Al stress, thereby improving the uptake of NO₃−–N in rice.