作　　者： (杨小环）; (赵维峰）; (孙娜娜）; (孙亮亮）; (马金虎）;

机构地区： 山西农业大学农学院,山西太谷030801

出　　处： 《核农学报》 2017年第9期1811-1817,共7页

摘　　要： 为探讨低温胁迫下外源水杨酸(SA)对植物种子萌发和早期幼苗生长影响的生理机制,本研究以先玉335玉米品种为试验材料,用0.05 mmol·L^(-1)的SA水溶液和去离子水(对照,记作CK)对种子进行浸种处理,研究外源SA对低温胁迫下种子发芽、种胚淀粉酶、氧化损伤水平、抗氧化酶、抗氧化物质和渗透调节物质等的影响。结果表明,与CK相比,SA处理玉米种子的发芽率、发芽指数、活力指数、幼苗干重和鲜重分别显著提高了5.57%、7.20%、23.76%、15.49%和28.52%。SA处理的玉米种胚淀粉酶活性显著提高,在种子萌发第2、第6、第8、第10天比CK提高了28.6%、15.1%、9.6%和16.9%;而超氧阴离子(O_2~)和丙二醛(MDA)含量经SA处理后显著下降。SA处理提高了种胚抗氧化酶的活性,在种子萌发第2、第4、第6和第8天时,超氧化物歧化酶(SOD)活性比CK分别提高了36.6%、25.9%、43.6%和46.3%;过氧化物酶(POD)活性在种子萌发12 d时比CK提高了9.0%;和过氧化氢酶(CAT)活性在第4、第6、第8天时比CK分别提高了13.0%、5.7%和17.0%。此外,SA处理还提高了种胚抗氧化物质还原型谷胱甘肽(GSH)和渗透调节物质脯氨酸、可溶性蛋白和可溶性糖的含量。综上所述,SA可以通过改善渗透调节能力和加速淀粉转化来缓解低温胁迫诱导的氧化损伤。本研究结果为探究SA调控低温胁迫下种子萌发和早期幼苗生长的机制开拓了新视野。 In this study, the maize cuhivar Xianyu 335 hybrid was used to investigate the physiological mechanism of SA on seed germination and early seedlings growth under low temperature condition. The maize seed soaking treatments were performed with 0. 05 mmol L-1 SA and deionized water （control, CK） , and then we studied the effects of SA on maize seed germination, amylase activity, oxidative damage, protective enzyme activities and osmotic adjustment substances content under low temperature stress. The results showed that, compared with the control, seed germination rate, activity index, vigor index, fresh weight and dry weight of seedlings in SA-treated maize were significantly increased by 5.57% , 7.20% , 23.76% , 15.49% and 28.52% , respectively. In SA-treated maize seed embryo, the amylase activity was significantly increased by 28.6% ,15.1% ,9.6% and 16.9% , respectively, at 2, 6, 8 and 10 d after seed germination. However, the levels of superoxide anion free radical （ 02 ） and malondialdehyde （MDA） were significantly decreased. Further research suggested that SA-treated improved antioxidant enzyme activity, superoxide dismutase （SOD） activity was increased by 36.6% ,25.9% ,43.6% and 46.3% , respectively, at 2, 4, 6 and 8 d after seed germination. Peroxidase （POD） activity was increased by 9.0% at 8 d after seed germination. Catalase （CAT） was increased activity by 13.0%, 5.7% and 17.0%, respectively, at 4, 6, 8d after seed germination. Moreover, the contents of glutathione （GSH） and osmotic adjustment substances （including proline, soluble protein, and soluble sugar） were improved by SA treatment. Taken together, SA could alleviate low temperature stress-induced oxidative damage by improving the osmotic adjustment ability and accelerating starch conversion. This findings provide an insight into the mechanism how SA regulates seed germination and early seedling growth under low temperature stress.

关 键 词： 水杨酸 低温胁迫 玉米 种子萌发 氧化伤害