关键词: 烟粉虱, 味觉受体, 基因克隆, 序列分析, 表达谱

Abstract: 【Objective】Bemisia tabaci is an important agricultural and invasive pest worldwide. Although B. tabaci has many host plants, there are differences in the tropism of B. tabaci to these different hosts. The gustatory receptor genes (GRs) play an important role in its feeding selection and other behaviors. In this study, We cloned the two gustatory receptor genes (GR1 and GR2) of Bemisia tabaci, and clarified their expression profiles at different developmental stages and adult tissues, so as to provide a theoretical basis for further functional study of the two gustatory receptor genes.【Method】The gustatory receptor genes were screened from the adult head transcriptome of B. tabaci. The open reading frame (ORF) of two gustatory receptor genes was cloned by nest PCR, and the two genes were named BtabGR1 and BtabGR2, respectively. Encoded amino acid sequence features and structure characteristics of the two genes were analyzed by multiple bioinformatics methods. Phylogenetic tree between BtabGR1, BtabGR2 and other Hemiptera insects GRs was constructed using neighbor-joining. The expression levels of the two genes at different developmental stages (egg, 1-4 instar larva, female and male adults), different adult tissues (head, thorax, abdomen, leg) were detected by qRT-PCR.【Result】 The cDNA sequences of BtabGR1 and BtabGR2 (GenBank accession number: OL845904 and OL845905) were obtained. The complete ORFs of these two genes are 1 287 and 1 344 bp in length, encoding 428 and 434 amino acids with the predicted molecular weight of 48.54 and 51.50 kD, the isoelectric point of 8.85 and 8.74, 4 and 6 transmembrane domains. Amino acid sequence alignment and phylogenetic analysis showed that BtabGR1 and BtabGR2 were closely related to the GR28b and GR43a-like of other Hemiptera insects. Developmental stages expression results showed that BtabGR1 and BtabGR2 were expressed in various developmental stages of B. tabaci. The expression levels of BtabGR1 in female and male adults were higher than those in other developmental stages, while BtabGR2 was highly expressed in the egg. Tissue expression results showed that BtabGR1 and BtabGR2 were expressed in different tissues of adult B. tabaci, and two genes were both highly expressed in the head of adults. 【Conclusion】The cloning of the full-length ORF gustatory receptor genes BtabGR1 and BtabGR2 from B. tabaci MED, having the typical characteristics of insect gustatory receptor genes, and their expression profiles provide a basis for future functional study.

Key words: Bemisia tabaci,  , gustatory receptor, gene cloning, sequence analysis, expression profile