Effects of calcium and calmodulin antagonist W7 on antioxidant systems of roots of alfalfa roots under PEG stress | Ca2＋和钙调素拮抗剂W7对PEG胁迫下不同耐旱型紫花苜蓿抗氧化系统的影响

Chinese. 陇东苜蓿(抗旱型)、BL-02-329(干旱敏感型)2种抗旱性强弱差异较大的紫花苜蓿(Medicago sativa L.)为试材, 采用水培法研究Ca2＋和钙调素拮抗剂W7[N-(6-aminohexyl)-5-chloro-1-naphthalene sulfonamide]预处理对干旱胁迫下紫花苜蓿根系抗氧化系统的影响。结果表明：钙调素拮抗剂W7浸种处理显著提高了不同耐旱型紫花苜蓿丙二醛(MDA)、H2O2含量和O2.-产生速率, 抑制了超氧化物歧化酶(SOD)和过氧化物酶(POD)活性, 加剧了抗坏血酸(AsA)和还原型谷胱甘肽(GSH)的破坏;而Ca2＋处理显著降低了PEG胁迫下紫花苜蓿MDA、H2O2含量和O2.-产生速率, 提高了SOD和POD活性, 减轻了干旱胁迫对AsA和GSH的破坏。相同处理条件下, 抗旱型品种陇东较干旱敏感型品种BL-02-329伤害程度轻, Ca2＋-CaM信号系统可缓解干旱胁迫对紫花苜蓿的伤害。

English. The effect of Ca2＋ and calmodulin antagonist W7 on antioxidant systems of alfalfa under drought stress induced by 10% polyethylene glycol(PEG6000) was studied using hydroponics culture. Results showed that alfalfa seedlings pretreated with calmodulin antagonist W7 under PEG stress had lower SOD and POD activities, and higher production rate of O2-, MDA and H2O2, and the aggravated damage of AsA and GSH. On the contrary, Ca2＋ treatment enabled alfalfa to keep relatively higher activities of SOD and POD, lower production rate of O2-and MDA content, at the same time, alleviated the accumulation of AsA and GSH. These results indicated that Ca2＋-CaM signal transduction might regulate the resistance of alfalfa to PEG stress by affecting the activity of some antioxidant enzymes and the content of antioxidant substance. The experiment showed that Ca2＋-CaM signal system played an important regulating role in alleviating PEG stress.