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。结果表明，在相同NO^-₃浓度胁迫7d后， Ca²⁺浓度越大，膜脂过氧化产物丙二醛(MDA)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⁺、Ca²⁺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⁺、Ca²⁺的响应亦不同，在一定程度上，K⁺和Ca²⁺ 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 Ca²⁺ 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 Ca²⁺ concentration and relative electrolytic leakage was rising when K⁺ concentration rised. So injury mechanism brought by K⁺ and Ca²⁺ on cell membrane was different. And the response of endogenous oxygen radicals scavenging enzymes system in cucumber seedlings on K⁺ and Ca²⁺ concentration was also different. To a certain extent, K⁺ and Ca²⁺ could improve the activities of SOD, POD and CAT, and protect plants against damage from free radical to strength adaptability of plants to adversity.