茉莉酸信号转导途径介导番茄对棉铃虫的抗性

摘要

以过表达前系统素转基因番茄(35S∷prosys)、茉莉酸合成突变体番茄( spr2)和野生型番茄( WT)为试验材料，研究了其被棉铃虫取食后叶片保护酶活性和防御反应基因表达情况，以及对棉铃虫抗性的影响.结果表明：棉铃虫取食不同基因型番茄叶片后，多酚氧化酶、过氧化物酶、超氧化物歧化酶和脂氧合酶活性在35S∷prosys植株中最高，在WT植株中次之，在spr2植株中最低.荧光定量PCR检测表明，棉铃虫取食不同基因型番茄叶片后，脂氧合酶基因、丙二烯氧化物环化酶基因和蛋白酶抑制剂基因的转录水平在35S∷prosys植株中最高，在WT植株中次之，而在spr2植株中这些抗性基因的表达未受到虫害的诱导.生物测定表明，取食spr2的棉铃虫体重是取食WT和35S∷prosys棉铃虫体重的2.17和2.96倍.可见，茉莉酸信号途径介导了番茄对棉铃虫的抗性.%Jasmonic acid (JA)-overexpression transgenic plants (35S::prosys), JA biosynthetic mutant (spr2) as well as corre-sponding wild type ( WT) of tomato ( Lycopersicon esculentum Miller) were planted, which was followed by being fed to Helicoverpa armigera. Results showed that 35S::prosys plants demonstrated the highest induction of putative defensive enzymes, which include polyphenol oxidase, peroxidase, superoxide dismutase and lipoxygenase than the other gene types, and transcription of defense-relat-ed genes of lipoxygenase D, allene oxide cyclase and protease inhibitorsⅡin 35S::prosys plants, which was higher than those of the WT plants, but no induction JA biosynthetic defective mutant spr2 plants. Bioassay showed that 35S::prosys plants were the most re-sistant and spr2 plants were more susceptible to the caterpillars. These results suggest that JA signaling pathway mediates tomato re-sistance against H.armigera.