CAJ | 학술논문

采用营养液栽培,研究了外源一氧化氮(NO)供体硝普钠(SNP)对150 mmol/L NaCl胁迫下黑麦草幼苗叶片抗坏血酸-谷胱甘肽(ASA-GSH)循环中抗氧化酶活性和抗氧化物质及丙二醛(MDA)和H_2O_2含量的影响.结果表明,正常条件下100 μmol/L SNP略微降低了黑麦草幼苗叶片的MDA和H_2O_2含量,NO信号转导途径关键酶鸟苷酸环化酶(GC)抑制剂亚甲基蓝(MB)促进了MDA和H_2O_2水平的提高.NaCl胁迫下,SNP显著缓解了MDA和H_2O_2的积累,提高了抗坏血酸过氧化物酶(APX)、谷胱甘肽还原酶(GR)和脱氢抗坏血酸还原酶(DHAR)活性及还原型抗坏血酸(ASA)、谷胱甘肽(GSH)含量,降低脱氢抗坏血酸(DHA)和氧化型谷胱甘肽(GSSG)含量,使ASA/DHA和GSH/GSSG提高,却对单脱氢抗坏血酸还原酶(MDAR)活性无显著影响;MB逆转了SNP对NaCl胁迫下MDA、H_2O_2、ASA、GSH、DHA、GSSG含量和APX、GR活性及ASA/DHA和GSH/GSSG的调节作用,对MDAR和DHAR活性无显著影响.由此表明,NO可能通过GC介导参与盐胁迫下黑麦草叶片ASA-GSH循环中APX、GR活性和ASA、GSH含量及ASA/DHA、GSH/GSSH的调节,缓解盐胁迫诱导的氧化伤害,提高植株的耐盐性.
채용영양액재배,연구료외원일양화담(NO)공체초보납(SNP)대150 mmol/L NaCl협박하흑맥초유묘협편항배혈산-곡광감태(ASA-GSH)순배중항양화매활성화항양화물질급병이철(MDA)화H_2O_2함량적영향.결과표명,정상조건하100 μmol/L SNP략미강저료흑맥초유묘협편적MDA화H_2O_2함량,NO신호전도도경관건매조감산배화매(GC)억제제아갑기람(MB)촉진료MDA화H_2O_2수평적제고.NaCl협박하,SNP현저완해료MDA화H_2O_2적적루,제고료항배혈산과양화물매(APX)、곡광감태환원매(GR)화탈경항배혈산환원매(DHAR)활성급환원형항배혈산(ASA)、곡광감태(GSH)함량,강저탈경항배혈산(DHA)화양화형곡광감태(GSSG)함량,사ASA/DHA화GSH/GSSG제고,각대단탈경항배혈산환원매(MDAR)활성무현저영향;MB역전료SNP대NaCl협박하MDA、H_2O_2、ASA、GSH、DHA、GSSG함량화APX、GR활성급ASA/DHA화GSH/GSSG적조절작용,대MDAR화DHAR활성무현저영향.유차표명,NO가능통과GC개도삼여염협박하흑맥초협편ASA-GSH순배중APX、GR활성화ASA、GSH함량급ASA/DHA、GSH/GSSH적조절,완해염협박유도적양화상해,제고식주적내염성.
Effects of the exogenous NO donor sodium nitroprusside (SNP) on the ascorbate-glutathione cycle dependent antioxidant enzyme activities, contents of antioxidant substance, H_2O_2 and malondialdehyde (MDA) in leaves of hydroponically-grown perennial ryegrass (Lolium perenne) seedlings under 150 mmol/L NaCl stress were investigated. The results showed that 100 μmol/L SNP slightly reduced the MDA and H_2O_2 contents of ryegrass seedling leaves under normal growth conditions, but exogenous methylene blue (MB), the inhibitor of the key enzyme guanylate cyclase (GC) during signal transfer of NO, increased the MDA and H_2O_2 contents. Exogenous SNP significantly alleviated MDA and H_2O_2 accumulations in ryegrass seedling leaves under NaCl stress, while the activities of APX, GR and DHAR, the contents of ASA and GSH, and the ratios of ASA/DHA and GSH/GSSG were increased. Under NaCl stress, the DHA and GSSG contents were reduced while the activity of MDAR was not affected. MB reversed some effects of SNP under NaCl stress, such as increasing the levels of MDA and H_2O_2, but reducing the activities of APX and GR, the contents of ASA and GSH, and the ratios of ASA/DHA and GSH/GSSG. The DHA and GSSG contents were increased but the activities of MDAR and DHAR were not significantly affected under NaCl stress. These findings suggested that NO might be involved in regulation of ascorbate-glutathione cycle metabolism dependent on the activities of APX and GR, the contents of ASA and GSH, and the ratios of ASA/DHA and GSH/GSSG through the GC pathway thus alleviating the oxidative damage to ryegrass seedling leaves from salt stress and improving salt resistance of the perennial ryegrass plants.