外源SA对李花抗坏血酸-谷胱甘肽循环的影响

Effect of Exogenous SA Hormones on AsA-GSH Cycle of Plum Flower

为研究外源水杨酸(SA)对李花抗坏血酸-谷胱甘肽循环以及对李花抗寒性的影响,以‘大石早生李’‘安哥诺李’2个品种为试材,以喷水处理为对照,研究了喷施适宜浓度的外源水杨酸(SA)对-2℃低温处理4h后2个品种的李花H_2O_2质量摩尔浓度以及对抗坏血酸-谷胱甘肽循环中酶及抗氧化物质的影响。结果表明:0.20、0.15 mmol·L^(-1)SA可以分别降低‘大石早生李’‘安哥诺李’的H_2O_2质量摩尔浓度,显著增强谷胱甘肽过氧化物酶(GPX)、抗坏血酸过氧化物酶(APX)、谷胱甘肽还原酶(GR)、脱氢抗坏血酸还原酶(DHAR)活性,提高抗坏血酸(AsA)、谷胱甘肽(GSH)、氧化型谷胱甘肽(GSSG)、总抗坏血酸、总谷胱甘肽质量摩尔浓度和AsA/DHA、GSH/GSSG。低温胁迫下,AsA-GSH循环受到破坏,但喷施适宜浓度的外源SA可以显著增强李花的抗氧化酶活性,提高抗氧化物质质量摩尔浓度,降低李花的膜质过氧化作用,降低低温对细胞膜的破坏,维持AsA-GSH循环系统的稳定性,从而一定程度上提高李花的抗寒性。

To investigate the effects of exogenous SA hormones on AsA-GSH cycle and the cold resistance of plum flower, with water as control, we studied the effects of exogenous SA in the proper concentration on the peroxide content and ascorbate-glu- tathione cycle of Prunus salicina ＇ Oishiwas＇ and ＇ Angeleno＇ flowers under -2℃ chilling stress. The 0.2 mmol·L^-1 SA for P. salicina ＇ Oishiwas＇ , 0.15 mmol·L^-1 SA for ＇ Angeleno＇ could reduce the H202 content and significantly enhance the activities of APX, DHAR, GR and GPX. The contents of AsA, GSH, GSSG, AsA＋DHA, GSH＋GSSG and the rations of AsA/DHA, GSH/GSSG were higher than those of the control. Therefore, low temperature stress could block AsA-GSH cycle. Compared with the control, the application of suitable content of exogenous SA could significantly enhance activities of antioxidant enzymes, enhance contents of antioxidants, reduce the membrane lipid peroxidation as well as the destruc- tion of cell membrane, and maintain the stability of AsA-GSH cycle system to improve the cold resistance of plum flowers.