茉莉酸甲酯对烟草抵御棉铃虫的诱导作用

为进一步阐明茉莉酸甲酯（MeJA）诱导植物抗虫的机理，研究了外源MeJA对烟草多酚氧化酶（PPO）、过氧化物酶（POD）、脂氧合酶（LOX）活性及编码氢过氧化物裂解酶（HPL）和蛋白酶抑制剂（PI-I和PI-II）基因表达的诱导作用，并对棉铃虫取食烟草叶片面积及其体重进行了生物学测定。结果表明，用100 μmol/L MeJA处理后，烟草体内PPO、POD和LOX活性显著升高，HPL、PI-I和PI-II表达明显增强，叶片被取食面积减少，棉铃虫体重增加变慢。说明MeJA对诱导烟草抵御棉铃虫有重要作用。

Inducement of Methyl Jasmonate on Resistance of Tobacco to Cotton Bollworms

To further clarify the mechanism of plant resistance to insects induced by methyl jasmonate （MeJA）, the inducement of exogenous MeJA on activities of polyphenol oxidase （PPO）, peroxidase （POD）, lipoxygenase （LOX）, and expression of genes encoding hydroperoxide lyase （HPL） and proteinase inhibitor （PI-I and PI-II） in tobacco leaves were studied. And the damaged area of leaves and weight of cotton bollworms were bioassayed. The results showed that after exogenous application of MeJA at a concentration of 100 μmol/L, the activities of PPO, POD and LOX increased significantly. Also, expression ofHPL ,PI-I andPI-II enhanced evidently. The damaged area of tobacco leaves treated with MeJA decreased apparently compared with that of control. The larvae after 72 h feeding on control plants were larger than that on plants treated with MeJA. Together, our findings indicated that MeJA plays critical roles in induced resistance to cotton bollworms in tobacco.