Glucose-6-phosphate dehydrogenase plays a pivotal role in tolerance to drought stress in soybean roots
Glucose-6-phosphate dehydrogenase plays a pivotal role in tolerance to drought stress in soybean roots
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6-磷酸葡萄糖脱氢酶在大豆根系耐旱胁迫中发挥着关键作用
DOI：
10.1007/s00299-012-1374-1
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发表时间：
2013-03-01
影响因子：
6.2
通讯作者：
Bi, Yurong
中科院分区：
文献类型：
--
作者：
Liu, Jie;Wang, Xiaomin;Bi, Yurong
两个大豆品种表现出明显的抗旱性差异。G6PDH在H(2)O(2)调节GR、DHAR和MDHAR活性以维持GSH和ASC水平的过程中起核心作用，葡萄糖-6-磷酸脱氢酶(G6PDH)在植物对环境胁迫的抗性中起关键作用。本研究以两个大豆品种JINDOU21(JD-21)和WDD00172(WDD-172)为材料，研究了G6PDH在聚乙二醇6000(PEG6000)诱导的干旱胁迫下氧化还原动态平衡的调控作用。在PEG6000处理过程中，JD-21和WDD-172的G6PDH活性分别在96h和72h达到峰值。在PEG6000处理下，氨基葡萄糖(一种G6PDH抑制剂)明显抑制两种大豆的G6PDH活性。经PEG6000处理后，JD-21表现出比WDD-172更高的耐受性，不仅表现在超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)、谷胱甘肽还原酶(GR)、脱氢抗坏血酸还原酶(DHAR)和单脱氢抗坏血酸还原酶(MDHAR)的活性更高，而且谷胱甘肽(GSH)和抗坏血酸(ASC)的含量也更高。我们还发现过氧化氢(H_2O_2)对根伸长区的细胞长度有调节作用。质膜NADPH氧化酶抑制剂DPI能拮抗PEG6000诱导的H_2O_2积累，降低GR、DHAR、MDHAR活性以及GSH和ASC含量。此外，外源H_2O_2提高了干旱胁迫下被葡萄糖降低的GR、DHAR和MDHAR活性。Western印迹分析表明，PEG6000和丁硫亚胺(BSO，谷胱甘肽生物合成抑制剂)均能促进G6PDH的表达，而谷氨酰胺、DPI和N-乙酰-L-半胱氨酸(NAC，谷胱甘肽前体)则抑制G6PDH的表达。综上所述，我们的证据表明，G6PDH在过氧化氢调节GR、DHAR和MDHAR活性以维持GSH和ASC水平的过程中发挥核心作用。
Two soybean cultivars showed markedly different drought tolerance. G6PDH plays a central role in the process of H (2) O (2) regulated GR, DHAR, and MDHAR activities to maintain GSH and Asc levels.Glucose-6-phosphate dehydrogenase (G6PDH) plays a pivotal role in plant resistance to environmental stresses. In this study, we investigated the role of G6PDH in modulating redox homeostasis under drought stress induced by polyethylene glycol 6000 (PEG6000) in two soybean cultivars JINDOU21 (JD-21) and WDD00172 (WDD-172). The G6PDH activity markedly increased and reached a maximum at 96 h in JD-21 and 72 h in WDD-172 during PEG6000 treatments, respectively. Glucosamine (Glucm, a G6PDH inhibitor) obviously inhibited G6PDH activity in both soybeans under PEG6000 treatments. After PEG6000 treatment, JD-21 showed higher tolerance than WDD-172 not only in higher activities of superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), glutathione reductase (GR), dehydroascorbate reductase (DHAR), and monodehydroascorbate reductase (MDHAR), but also in higher content of glutathione (GSH) and ascorbate (Asc). And we found that hydrogen peroxide (H2O2) regulated the cell length in root elongation zone. Diphenylene iodonium (DPI, a plasma membrane NADPH oxidase inhibitor) counteracted the PEG6000-induced H2O2 accumulation and decreased the activities of GR, DHAR, and MDHAR as well as GSH and Asc content. Furthermore, exogenous application of H2O2 increased the GR, DHAR, and MDHAR activities that were decreased by Glucm under drought stress. Western blot analysis showed that the G6PDH expression was stimulated by PEG6000 and buthionine sulfoximine (BSO, glutathione biosynthesis inhibitor), and blocked by Glucm, DPI and N-acetyl-l-cysteine (NAC, GSH precursor) in both cultivars. Taken together, our evidence indicates that G6PDH plays a central role in the process of H2O2 regulated GR, DHAR, and MDHAR activities to maintain GSH and Asc levels.