NaCl胁迫对菜用大豆种子膨大过程中抗氧化系统及渗透调节物质的影响

采用蛭石栽培试验,在100mmol.L-1 NaCl胁迫下,对耐盐性不同的两个菜用大豆品种种子膨大、抗氧化系统及渗透调节物质进行了研究。结果显示:(1)耐盐品种‘绿领特早’种子干质量及大小的增加在NaCl胁迫15d时未受显著影响,而盐敏感品种‘理想高产95-1’种子的膨大受到了显著抑制。(2)NaCl胁迫导致菜用大豆种子超氧阴离子(O2.-)、过氧化氢(H2O2)及丙二醛(MDA)的过量积累,但‘绿领特早’种子的相对积累量均低于‘理想高产95-1’。(3)与‘理想高产95-1’相比,‘绿领特早’在NaCl胁迫期间维持了相对较高的超氧化物歧化酶(SOD)、抗坏血酸过氧化物酶(APX)及谷胱甘肽还原酶(GR)活性,以及较高的抗坏血酸(AsA)、可溶性蛋白和可溶性糖含量;胁迫中期维持了相对较高的过氧化物酶(POD)活性,胁迫后期维持了相对较高的过氧化氢酶(CAT)活性;胁迫前中期维持了相对较高的谷胱甘肽(GSH)含量。研究发现,‘绿领特早’种子在NaCl胁迫期间能够保持较高且协调平衡的保护酶SOD、POD、CAT活性和较高的AsA-GSH循环效率,同时维持了较强的渗透调节能力,有效抑制了O2.-和H2O2的过量积累,进而有效降低了细胞膜质过氧化程度,这可能是其耐盐性较强的重要原因之一。

Effects of NaCl Stress on Antioxidant System and Osmotic Regulation Substances during Seed Filling Period of Two Vegetable Soybean Cultivars

With vermiculite culture,seed filling,and their antioxidant system and osmotic regulation substances of two vegetable soybean cultivars with different salt tolerance were studied under 100 mmol/L NaCl stress.The results showed that:(1)Seed enlargement was normal for salt resistant cultivar ’Lülingtezao’,but seed enlargement was inhibited for salt susceptible cultivar ’Lixianggaochan 95-1’ under NaCl stress for 15 h.(2)O-·2 producting rate,H2O2 and malondialdehyde(MDA) contents in seeds of two cultivars were significantly increased under NaCl stress,while the increasing amount of salt resistant cultivar ’Lülingtezao’ was lower than those of salt susceptible cultivar ’Lixianggaochan 95-1’.(3)During the period of NaCl stress,the activities of superoxide dismutase(SOD),ascorbate peroxidase(APX) and glutathione reductase(GR),the contents of ascorbic acid(AsA),soluble protein and soluble sugar of ’Lülingtezao’ were relatively higher compared with those of ’Lixianggaochan 95-1’,and its activities of peroxidase(POD) and catalase(CAT),content of reduced glutathione(GSH) maintained relatively higher values in the intermediate,later,early and intermediate periods,respectively,under NaCl stress compared with those of ’Lixianggaochan 95-1’.These results indicated that ’Lülingtezao’ could maintain higher and mutually concordant activities of SOD,POD and CAT,maintain efficient metabolism of AsA-GSH cycle and stronger osmotic regulation ability.These resulted in the effective inhibition of lipid peroxidation,which might be one of the important reasons for stronger salt tolerance of ’Lülingtezao’.