干旱胁迫下Ca^(2+)·CaM信使系统对稻苗保护酶活性的影响

Effects of Ca^(2+)·CaM on activities of antioxidant enzymes in rice seedlings under drought stress

以氯丙嗪 CPZ 和LaCl3对水稻幼苗根际预处理,阻断其Ca2+·CaM信使系统传导后,研究了干旱胁迫下稻苗膜脂过氧化和保护酶活性的变化.结果表明:干旱胁迫下,LaCl3和CPZ根际预处理显著加剧稻苗膜脂过氧化,加剧过氧化氢酶 CAT 活性和抗坏血酸过氧化物酶 APX 活性下降,对胁迫前期超氧化物岐化酶 SOD 和过氧化物酶 POD 活性无显著影响,且CPZ和LaCl3预处理加剧CAT和APX活性下降与加剧稻苗MDA含量积累分别呈极显著和显著正相关.这些结果暗示Ca2+·CaM信使系统可能主要通过调节或影响CAT和APX活性而调节稻苗的抗旱性.

After being blocked (Ca^(2+)·CaM )messenger transduction by pretreating with CPZ (chlorpromazine) or LaCl_3, membrane lipid peroxidation and activities of antioxidant enzymes in rice seedling under drought stress were investigated. The results showed that,under drought stress, pretreating led to more high MDA content and more serious decrease of activities of catalase(CAT)and ascorbate peroxidase(APX),and led to little changes of activities of superoxide dismutase(SOD) and peroxidase(POD). The enhanced increase value of MDA content was significantly positively correlated with the enhanced decrease value of CAT and APX activities due to pretreatment under drought stress. These results suggested that effects of CPZ and LaCl_3 on drought resistance of rice seedlings were mainly related to CAT and APX under drought stress. The results also suggested that Ca^(2+)·CaM messenger system might control drought resistance of rice seedling by affecting activities of some antioxidant enzymes.