西花蓟马P450基因在继代适应菜豆植株中的应答反应

菜豆是西花蓟马的重要寄主,但西花蓟马对豆荚的嗜食性高于叶片。为探讨西花蓟马在适应菜豆植株过程中P450基因的应答反应,利用实时荧光定量PCR技术检测了西花蓟马从菜豆豆荚转换到菜豆植株后F 1、F 2和F 3三个世代2龄若虫和成虫体内9个P450基因相对表达量的变化。结果表明,西花蓟马2龄若虫体内CYP4-1、CYP4-2、CYP4-3和CYP6-4的表达量在转换到菜豆植株后F 1代显著升高,然后下降;而CYP4-4和CYP6-2的表达量到F 3代才显著上升;CYP6-1的表达量只有在F 2代显著下降,仅为对照的42.21%,其余世代下和对照均无显著差异;CYP4-5和CYP6-3的表达量在不同世代均显著低于对照。对于成虫而言,CYP4-4、CYP4-5和CYP6-4的表达量在转换到菜豆植株F 1后显著上升,分别是对照的2.28倍、1.40倍和1.31倍;CYP6-1、CYP6-2、CYP6-3的表达量在F 1代开始下降,而CYP4-1、CYP4-2、CYP4-3的表达量在F 2代才开始下降。在同一个世代下,西花蓟马2龄若虫与成虫体内P450基因表达量不完全相同,除CYP4-2的表达量在F 1和F 3代,以及CYP4-4、CYP4-5和CYP6-3的表达量在F 1代两个虫态间差异不显著外,其余情况下均是2龄若虫的表达量高于成虫的。结果说明西花蓟马通过调节P450基因适应菜豆植株,其表达量与其取食的世代和虫态相关。

The response of P450 genes in Frankliniella occidentalis in the succession adaptation to kidney bean plant

Kidney bean is the host plant of Frankliniella occidentalis,and F.occidentalis prefers bean pod to leave.Real-time quantitative PCR was used to detect the relative expression level of P450 genes(CYP4-1、CYP4-2、CYP4-3、CYP4-4、CYP4-5、CYP6-1、CYP6-2、CYP6-3 and CYP6-4)in 2 nd instar nymph and adult of F.occidentalis at F 1,F 2 and F 3 respectively after thrips were transferred from kidney bean pod to bean plant.The results showed that the expression levels of CYP4-1,CYP4-2,CYP4-3 and CYP6-4 in 2 nd instar nymphs significantly increased in F 1 generation after F.occidentalis were transferred to kidney bean plants,then decreased.The expression levels of CYP4-4 and CYP6-2 didn t rose until F 3 generation.The expression level of CYP6-1 dramatically decreased at F 2,which was only 42.21%of that of control.There weren t significant different with control in other generations.The expression levels of CYP4-5 and CYP6-4 fluctuated below the control.As to adult,the expression levels of CYP4-4,CYP4-5 and CYP6-4 significant rose in F 1 generation,which were 2.28,1.40 and 1.31 times as high as that of control,respectively.The expression levels of CYP6-1、CYP6-2 and CYP6-3 decreased from F 1 generation,while the expression levels of CYP4-1、CYP 4-2 and CYP 4-3 decreased from F 2 generation.The expression levels of genes between 2 nd instar nymph and adult in the same generation were different.The expressions in 2 nd instar nymphs were higher than that in adults except that CYP4-2 in F 1 generation and F 3 generation,and CYP4-4、CYP4-5 and CYP6-3 in F 1 generation.The results indicated that F.occidentalis could regulate P450 genes to adapt kidney bean plant,and its expressions were related to the generations and stages of F.occidentalis.