Hydrogen peroxide is involved in the regulation of rice (Oryza sativa L.) tolerance to salt stress
Hydrogen peroxide is involved in the regulation of rice (Oryza sativa L.) tolerance to salt stress
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DOI：
10.1007/s11738-012-1132-6
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发表时间：
2013-03
影响因子：
2.6
通讯作者：
Xiaomin Wang;C. Hou;Jie Liu;Wenliang He;W. Nan;H. Gong;Y. Bi
中科院分区：
文献类型：
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作者：
Xiaomin Wang;C. Hou;Jie Liu;Wenliang He;W. Nan;H. Gong;Y. Bi
本研究以抗旱性和抗病能力不同的两个水稻品种郑旱2号和豫粳6号为材料，研究了它们的耐盐机制。与郑旱2号根相比，盐胁迫诱导豫粳6号根的膜脂过氧化程度和离子渗漏程度更高。盐胁迫下郑旱2号根的过氧化氢积累量低于豫粳6号根。对照和盐胁迫条件下，盐胁迫条件下，盐胁迫下两种水稻根系中O2-−含量均没有增加，但豫京6号根系中O2-−含量高于郑旱2号。抗坏血酸过氧化物酶(APX)活性在郑旱2号根中的增加幅度明显高于豫京6号。盐胁迫下，两种水稻根系的过氧化氢酶(CAT)、过氧化物酶(POD)、超氧化物歧化酶(SOD)和葡萄糖-6-磷酸脱氢酶(G6PDH)活性均有不同程度的提高，但郑旱2号高于豫京6号。外源H_2O_2对两种水稻根部的APX、CAT、POD、SOD和G6PDH活性均有促进作用，且呈浓度依赖关系。质膜NADPH氧化酶抑制剂二苯基碘(DPI)能显著抑制盐诱导的过氧化氢积累，降低上述酶的活性。此外，在NaCl+DPI处理下，郑旱2号根的离子渗漏率显著增加，达到与豫粳6号根相近的水平。综上所述，主要由质膜NADPH氧化酶产生的过氧化氢通过提高细胞内抗氧化剂水平参与了水稻郑旱2号对盐胁迫的耐性。
In the present study, we investigated the salt tolerance mechanism of two rice cultivars (Zhenghan-2 and Yujing-6), which show different tolerance to drought and disease. NaCl induced higher extent of lipid peroxide and ion leakage in Yujing-6 roots than those in Zhenghan-2 roots. H2O2accumulation in Zhenghan-2 roots was lower than that in Yujing-6 roots under salt stress. Comparatively, NaCl treatment did not increase O2−contents in both rice roots, however, O2−level in Yujing-6 roots was higher than that in Zhenghan-2 roots under both control and salt stress conditions. Ascorbate peroxidases (APX) activity increased more significantly in Zhenghan-2 roots than that in Yujing-6 roots. The activity of catalase (CAT), peroxidase (POD), superoxide dismutase (SOD), and glucose-6-phosphate dehydrogenase (G6PDH) was similarly enhanced in both rice roots under salt stress; however, they showed higher levels in Zhenghan-2 roots than in Yujing-6 roots. Exogenous H2O2could enhance APX, CAT, POD, SOD and G6PDH activities in a concentration-dependent manner in both rice roots. Diphenylene iodonium (DPI), a plasma membrane (PM) NADPH oxidase inhibitor, which counteracted the NaCl-induced H2O2accumulation, markedly decreased the activity of above enzymes. Moreover, ion leakage increased dramatically in Zhenghan-2 roots and reached to the similar level of Yujing-6 roots under NaCl+DPI treatment. Taken together, H2O2, which is mainly generated from PM NADPH oxidase, is involved in Zhenghan-2 rice tolerance to salt stress by enhancing the cellular antioxidant level.