茉莉酸甲酯浸种对水稻幼苗白叶枯病抗性及抗氧化酶活性的影响

Effects of Seed Soaking with Methyl Jasmonate on Resistance to Bacterial Leaf Blight and Antioxidant Enzyme Activities of Rice Seedlings

以温229(感白叶枯病)和嘉早312(抗白叶枯病)为材料,研究外源茉莉酸甲酯(methyl jasmonate,MeJA)浸种对水稻幼苗接种白叶枯病菌后抗氧化酶活性及膜脂过氧化的影响。结果表明,MeJA浸种显著降低了水稻幼苗白叶枯病病情指数,对抗病品种的诱导效果优于感病品种;幼苗叶片超氧化物歧化酶(superoxide dismutase,SOD)、过氧化物酶(peroridase,POD)、过氧化氢酶(catalase,CAT)和抗坏血酸过氧化物酶(ascorbate peroxidase,APX)等酶活性随MeJA浓度的升高先增强后减弱,丙二醛(Malondialdehyde,MDA)含量先降低后升高,MeJA浓度为0.5mmol/L时表现为毒害作用。不同抗性品种幼苗抗氧化酶活性和MDA含量对MeJA浸种响应不同,表明MeJA浸种可有效减轻水稻幼苗白叶枯病的发生,其中,抗氧化物酶活性的提高和MDA的下降与水稻对白叶枯病的抗性反应有关。

This experiment was carried out to study the effects of seed soaking with exogenous methyl jasmonate（MeJA）on resistance to bacterial leaf blight and antioxidant enzyme activities of rice seedlings with Wen 229（susceptible to rice bacterial leaf blight）and Jiazao 312（resistant）as experimental materials.The results showed that MeJA soaking significantly decreased the disease indexes of bacterial leaf blight in rice seedlings,especially for the resistant cultivar.With rising MeJA solution concentration,the activities of superoxide dismutase,peroridase,catalase and ascorbate peroxidase in leaves of rice seedlings increased firstly and then decreased,while the malondialdehyde（MDA）content raised at first and dropped afterwards.At a concentration of 0.5 mmol/L,MeJA soaking caused damage to rice seedings.The responses of antioxidant enzyme activities and lipid peroxidation content to MeJA soaking varied with variety.The above results indicated that MeJA soaking could effectively relieve the bacterial leaf blight of rice seedlings.The increase of the antioxidant enzyme activities and the decrease of the MDA content are related to its resistant reactions to bacterial leaf blight.