茉莉酸浸种对云烟87斜纹夜蛾抗性的影响

为明确茉莉酸（Jasmonic acid，JA）浸种对烟草抗虫性的影响，测定了JA浸种的云烟87对斜纹夜蛾（Spodoptera litura）的抗性及植株中JA和茉莉酸-异亮氨酸（JA-Ile）的含量。结果表明，以JA浸种的云烟87为食物的斜纹夜蛾幼虫重量比未浸种的降低了15%。在模拟斜纹夜蛾取食后，JA浸种的云烟87幼苗诱导出的JA含量比未浸种的增加41%，JA-Ile含量增加42%。斜纹夜蛾取食的JA浸种的云烟87幼苗，其抗虫次生代谢物如咖啡酰丁二胺、二咖啡酰亚精胺、尼古丁和二萜糖苷的含量分别增加60%，79%，19%和29%，胰蛋白酶抑制剂活性增强80%。同时，JA浸种后6周，云烟87植株干质量与对照植株差异不显著。JA浸种可以提高云烟87对斜纹夜蛾的抗性，同时不影响其产量。

Effects of Jasmonic acid Seed Treatment on Yunyan 87 Resistance to Spodoptera litura

To test whether application of jasmonic acid (JA) to seeds influence the resistance of tobacco (Var.Yunyan87) to insects, the herbivore performance of Spodoptera litura, as well as the contents of JA and JA-Ile of the Yunyan87 plants were measured.The caterpillars feeding on the Yunyan 87 plants from JA-treated seeds gained 15% less weight than those grown on the control plants.After simulated S.litura larval feeding, JA and JA-Ile (a bioactive signal which can induce defenses to arthropod herbivores) accumulation was 41% and 42% higher in tobacco plants from JA-treated seeds, respectively.Meanwhile, several JA-Ile-dependent defensive metabolites including caffeoylputrescine, dicaffeoylspermidine, nicotine, diterpene glycosides, and the activities of trypsin proteinase inhibitors increased 60%, 79%, 19%, 29%, and 80%, respectively, in tobacco grown from JA-treated seeds.Importantly, the JA treatment to seeds did not influence the growth of plants:the dry weight of 6-week-old plants grown from the JA-treated seeds was not reduced.We conclude that application of JA to seeds increases tobacco resistance to S.litura, without reducing the yield.