NO-3胁迫下K+、Ca2+对黄瓜幼苗膜质过氧化及活性氧清除酶系统的影响

通过水培试验探讨了NO3-胁迫下K 、C a2 对黄瓜幼苗膜质过氧化及活性氧清除酶系统的影响。结果表明,在相同NO3-浓度胁迫7d后,C a2 浓度越大,膜脂过氧化产物丙二醛(M DA)含量越高,而K 浓度越大,电解质相对渗透率越高,由此说明K 、C a2 对细胞膜造成伤害的机理不同。黄瓜幼苗活性氧清除酶系统对K 、C a2 的响应亦不同,在一定程度上,K 和C a2 可提高SOD、POD和CAT活性,保护植物免受自由基伤害,继而可增强植物对逆境的适应能力。

Effects of K+ and Ca2+ on membrane lipid peroxidation and endogenous oxygen radicals scavenging enzymes systems under NO-3 stress in cucumber seedling

The effects of K~ and Ca~(2 ) on membrane lipid peroxidation and endogenous oxygen radicals scavenging enzymes systems under high NO~-_3 stress in cucumber seedling were studied.The results showed that cucumber seedlings stressed under same high NO~-_3 concentration for 7 d,membrane lipid peroxidation produce(MDA)(increased) with the increase of Ca~(2 ) concentration and relative electrolytic leakage was rising when K~ concentration rised.So injury mechanism brought by K~ and Ca~(2 ) on cell membrane was different. And the response of(endogenous) oxygen radicals scavenging enzymes system in cucumber seedlings on K~ and Ca~(2 ) concentration was also different.To a certain extent,K~ and Ca~(2 ) could improve the activities of SOD,POD and CAT,and protect plants against damage from free radical to strength adaptability of plants to adversity.