茶小绿叶蝉转录组Bt潜在受体分析

Analysis on the potential Bt receptors in the transcriptome of Empoasca flavescens

Bt杀虫最重要的2个环节是原毒素在昆虫中肠的有效酶解和酶解后活性片段与中肠受体的特异性结合.在前期工作中已发现部分Bt毒素可被茶小绿叶蝉肠液有效酶解成相应活性片段.为进一步了解茶小绿叶蝉是否存在相应受体或受体是否能与毒素结合,从受体的角度展开研究.首先,分析前期获得的茶小绿叶蝉转录组数据,发现该虫存在大量ALP、APN和Cadherin潜在受体基因,筛选部分候选基因,通过RT-qPCR验证表达量差异,结果显示其与转录组数据一致;其次,通过表达分析数据中的FPKM值,筛选出这3类潜在受体基因中表达量高且在肠内外表达差异显著的基因,有8个ALP、7个APN、8个Cadherin;再次,通过构建NJ进化树对这23个候选基因种内同源性进行分析,为该虫的生物防治提供一定理论基础.

Bacillus thuringiensis(Bt)insecticidal mechanism consisted of 2 steps,which is the enzymolysis of protoxin in insect midgut and the specific binding of intestinal receptor.Based on our previous research,the enzymolysis of Cry protoxin has been detected in Empoasca flavescens.In order to explore whether potential receptors exist in E.flavescens or whether binding happens between Cry and potential receptors,Bt mechanism focusing on receptors was investigated.Firstly,potential receptor genes such as ALP,APN and Cadherin were detected based on the E.flavescens transcriptome data.The relatively expression level of some candidate genes were verified by RT-qPCR,which proved to be consistent with the transcriptome data.According to the FPKM value,8 ALP genes,7 APN genes and 8 Cadherin genes with high expression levels,whose expression varied significantly between intestine and other tissues were screened.At the same time,homology analysis of the 23 candidate genes was performed by constructing NJ evolutionary tree.These results will provide some meaning for E.flavescens biocontrol.