NaCl胁迫对菜用大豆种子抗坏血酸-谷胱甘肽循环的影响

Effects of NaCl stress on ascorbate-glutathione cycle in vegetable soybean seeds

采用蛭石栽培,在100 mmol/L NaCl胁迫下,对耐盐性不同的两个菜用大豆[Glycine max(L.)Merr.]品种种子的过氧化氢(H2O2)含量及抗坏血酸-谷胱甘肽(AsA-GSH)循环进行了研究。结果显示,NaCl胁迫显著增加了菜用大豆种子的H2O2含量,但耐盐品种"绿领特早"的增幅低于盐敏感品种"理想高产95-1"。NaCl胁迫期间,"绿领特早"种子中抗坏血酸过氧化物酶(APX)、脱氢抗坏血酸还原酶(DHAR)、谷胱甘肽还原酶(GR)活性,AsA、GSH含量以及AsA/DHA值和GSH/GSSG值的增幅高于同期的"理想高产95-1",或降幅低于同期的"理想高产95-1";脱氢抗坏血酸(DHA)、氧化型谷胱甘肽(GSSG)含量的增幅低于同期的"理想高产95-1"。表明"绿领特早"种子在胁迫期间能够保持较高的AsA-GSH循环效率,可有效地抑制H2O2的积累,这可能是其耐盐性较强的重要原因之一。

The peroxide（H2O2）content and ascorbate（AsA）-glutathione（GSH）cycle in seeds of two vegetable soybean cultivars[Glycine max（L.）Merr.]with different salt tolerances were studied using the vermiculite culture under 100 mmol/L NaCl stress.The results show that H2O2 contents in seeds of two vegetable soybean cultivars are significantly increased under the NaCl stress,and the increased amount of ＂Lülingtezao＂ resistant to the NaCl stress is lower than that of ＂Lixianggaochan 95-1＂susceptible to the NaCl stress.During the NaCl stress period,the activities of ascorbate peroxidase（APX）,dehydroascorbate reductase（DHAR）and glutathione reductase（GR）,contents of AsA and GSH,and ratios of AsA/DHA and GSH/GSSG of ＂Lülingtezao＂are higher than those of ＂Lixianggaochan 95-1＂,and/or their decrease were lower than those of ＂Lixianggaochan 95-1＂.While contents of dehydroascorbic acid（DHA）and oxidized glutathione（GSSG）of ＂Lülingtezao＂are lower than those of ＂Lixianggaochan 95-1＂.These results indicate that ＂Lülingtezao＂could maintain efficient metabolism of AsA-GSH cycle during the stress period,and further maintain lower H2O2 accumilation.This might be one of important reasons for higher salt tolerance of ＂Lülingtezao＂.