野生甘蓝表皮毛对菜青虫的抗性机理

为明确一种全身覆盖表皮毛的野生甘蓝Brassica incana（编号C01）是否具有抗虫性，通过测定菜青虫Pieris rapae对野生甘蓝C01和无毛甘蓝B. alboglabra（编号C41）的拒食、取食和产卵行为进行抗虫性分析，同时通过测定两者的内源激素含量、表皮毛发育相关基因表达量和防御酶活性探讨野生甘蓝C01对菜青虫的抗性机理。结果显示，生长至8～10叶期，无毛甘蓝C41叶片被菜青虫啃食严重，但野生甘蓝C01叶片未被啃食；菜青虫对无毛甘蓝C41和剪除表皮毛的野生甘蓝C01叶片取食面积差异不显著，但均显著大于对野生甘蓝C01叶片的取食面积；着卵的无毛甘蓝C41植株显著多于野生甘蓝C01。野生甘蓝C01叶片中茉莉酸和茉莉酸甲酯含量都显著高于无毛甘蓝C41叶片，而两者中水杨酸和水杨酸甲酯的含量差异不显著。BolJAZ1基因在无毛甘蓝C41叶片中高表达，而BolGL3和BolGL2基因在野生甘蓝C01叶片中高表达；且野生甘蓝C01叶片中多酚氧化酶、过氧化物酶和苯丙氨酸解氨酶3种防御酶的活性均显著高于无毛甘蓝C41。表明野生甘蓝C01叶片的表皮毛会影响菜粉蝶产卵，对菜青虫表现出显著抗...

The mechanism of trichome resistance in wild Brassica oleracea to cabbage white butterfly Pieris rapae

To determine whether a wild type of Brassica incana (coded as C01) covered with trichomes was insect-resistant, the insect resistance analysis of C01 and hairless B. alboglabra (coded as C41) was performed by measuring the antifeeding effect, feeding effect and the spawning behavior of cabbage white butterfly Pieris rapae. Meanwhile, to explore the mechanism of C01 resistance to P. rapae, the endogenous hormone content, gene expression patterns related to trichome development and the activity of defense enzymes in C01 and C41 were further determined. The results showed that the leaves of C41 were more seriously eaten than C01 by P. rapae during the 8- to 10-leaf stage. There was no significant difference in the areas eaten by P. rapae between the leaves of C41 and C01 with trichomes cut off, but the leaf area of C41 eaten by P. rapae was significantly larger than that of wild C01. The number of eggs in C41 was significantly greater than that in C01. In addition, the average contents of jasmonic ac id (JA) and methyl jasmonate (MeJA) in C01 leaves were significantly higher than those in C41 leaves, while the average contents of salicylic acid and methyl salicylate had no significant difference between the two types of leaves. Gene expression analysis indicated that BolJAZ1 was highly expressed in C41 leaves, while BolGL3 and BolGL2 were highly expressed in C01 leaves. The activities of polyphenol oxidase, peroxidase and phenylalanine ammonia-lyase in C01 leaves were significantly higher than those in C41 leaves. In brief, the trichome of C01 affected the spawning of the butterfly, and thus showed significant resistance to P. rapae. Meanwhile, the increase of endogenous JA and MeJA in C01 leaves and the high expression of BolGL3/BolGL2 genes suggested that the JA pathway might be involved in the differentiation of trichome in B. oleracea.