研究报告
李蕊,仪慧兰.NR途径参与调节SO2胁迫下拟南芥含硫抗氧化物水平[J].环境科学学报,2016,36(10):3864-3869
NR途径参与调节SO2胁迫下拟南芥含硫抗氧化物水平
- Role of nitrate reductase in the regulation of sulfur-containing antioxidants in Arabidopsis response to sulfur dioxide stress
- 基金项目：国家自然科学基金（No.30870454，30470318，31371868）；高等学校博士学科点专项科研基金（No.20070108007，20121401110007）
- 作者
- 单位
- 李蕊
- 山西大学生命科学学院, 太原 030006
- 仪慧兰
- 山西大学生命科学学院, 太原 030006
- 摘要：以拟南芥为材料，研究了硝酸还原酶（NR）途径在植株响应SO2过程中对含硫抗氧化物水平的影响.结果发现，野生型拟南芥植株中谷胱甘肽过氧化物酶（GPX）和谷胱甘肽硫转移酶（GST）活性高于NR缺失突变体（nia1nia2）；SO2暴露后，野生型和突变体nia1nia2植株中半胱氨酸（Cys）和谷胱甘肽（GSH）含量显著增加，GPX和GST的活性诱导性增高，且野生型植株中上述4项指标的增幅高于突变体；拟南芥逆境响应基因GSTU24和GPX7在野生型和突变体nia1nia2中差异表达，且对SO2的响应程度不同.研究表明，植株体内NR途径与拟南芥细胞中含硫抗氧化物水平有关，NR缺失影响逆境应答中含硫抗氧化物水平的提高及抗逆基因转录，说明NR途径参与调节了植株逆境响应中含硫抗氧化物的合成及相关氧化还原反应与解毒过程.
- Abstract：Impacts of nitrate reductase (NR) pathway on sulfur-containing antioxidants were investigated in Arabidopsis in plant response to sulfur dioxide (SO2).An Arabidopsis mutant nia1nia2 (for nitrate reductase [NR]-defective double mutant) and wildtype plants were selected as the materials.The results showed that the activities of glutathione S-transferase(GST) and glutathione peroxidase(GPX) in wildtype plants were higher than those in nia1nia2 mutant.Exposure to higher concentrations of SO2 significantly increased both the contents of sulfur-containing compounds such as cysteine(Cys) and glutathione,and the activities of sulfur-containing enzymes such as GST and GPX.The increments of these four indicators in Arabidopsis wildtype plants were higher than those in nia1nia2 mutant.Furthermore,some defense-related genes such as GSTU24 and GPX7 were differentially expressed at the mRNA level between wildtype and nia1nia2 mutant after plants were exposed to SO2.These results indicated that nitrate reductase was involved in the regulation of sulfur-containing antioxidant levels and defense-related gene transcription.NR deficiency could affect the sulfur assimilation pathway resulting in changes of Cys synthesis and then sulfur-containing antioxidant synthesis,especially during plant response to SO2 stress.In conclusion,NR-dependent pathway can mediate the response of plants to environmental stress through regulating the levels of sulfur-containing antioxidants,indicating its involvement in the reduction-oxidation reaction and cellular detoxification.
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