外源亚精胺和精胺对NaHCO_3胁迫下南蛇藤抗氧化系统的影响

Effects of exogenous spermidine and spermine on Celastrus orbiculatus antioxidant system under soil NaHCO_3 stress

研究了叶面喷施亚精胺和精胺对NaHCO3胁迫下南蛇藤叶片抗氧化系统的影响.结果表明:外源亚精胺和精胺处理使NaHCO3胁迫下南蛇藤叶片O2·-产生速率、H2O2、丙二醛(MDA)含量和电解质外渗率显著降低(P<0.05).亚精胺处理明显提高了盐胁迫下超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)和抗坏血酸过氧化物酶(APX)等抗氧化酶的活性,以及还原型谷胱甘肽(GSH)、类胡萝卜素(CAR)和脯氨酸(Pro)等抗氧化剂的含量,但对还原型抗坏血酸(AsA)含量没有作用;精胺处理明显提高NaHCO3胁迫下POD和APX的活性以及GSH、CAR和Pro的含量,但对SOD和AsA含量影响不显著,甚至引起CAT活性明显降低.亚精胺和精胺处理明显改善了NaHCO3胁迫下南蛇藤的生长.外源亚精胺和精胺可以改善NaHCO3胁迫下南蛇藤叶片的膜保护功能,减少叶片中活性氧的积累,从而提高南蛇藤对NaHCO3胁迫的抗性.

This paper studied the effects of foliar spraying spermidine and spermine on the leaf anfioxidant system of Celastrus orbiculatus under soil NaHCO3 stress. The results showed that under the stress, spraying spermidine and spermine could significantly decrease the leaf O2^τ production rate, H2O2 and MDA contents, and electrolyte leakage of C. orbiculatus （P 〈 0. 05 ）. Spraying spermidine increased the leaf SOD, CAT, POD and APX activities and GSH, CAR and Pro contents obviously, but had no effect on leaf AsA content. Spraying spermine also increased leaf POD and APX activities and GSH, CAR and Pro contents obviously, but had lesser effect on leaf SOD activity and AsA content, and even, caused a significant decrease in leaf CAT activity. In the meantime, spermidine and spermine effectively improved the growth of C. orbiculatus seedlings. It was suggested that under soil NaHCO3 stress, exogenous spermidine and spermine could improve the functions of membrane protective system and decrease the O2^τ accumulation in C. orbiculatus leaves, and consequently, increase the C. orbiculatus tolerance to NaHCO3 exposure.