Acta Entomologica Sinica ›› 2022, Vol. 65 ›› Issue (6): 675-683.doi: 10.16380/j.kcxb.2022.06.003

• RESEARCH PAPERS • Previous Articles     Next Articles

Function of vitellogenin receptor gene TaVgR in the regulation of reproductive development in Tuta absoluta (Lepidoptera: Gelechiidae)

YAN Xin1,2, YANG Hong1,4,*, SONG Jia-Hui2, LI Ren-Gui2, ZHANG Yi-Bo3, YANG Wen-Jia2,3,*   

  1. (1. Provincial Key Laboratory for Agricultural Pest Management of Mountainous Regions, Institute of Entomology, Guizhou University, Guiyang 550025, China; 2. Guizhou Provincial Key Laboratory for Rare Animal and Economic Insect of the Mountainous Region, College of Biology and Environmental Engineering, Guiyang University, Guiyang 550005, China; 3. State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China; 4. College of Tobacco Science, Guizhou University, Guiyang 550025, China)
  • Online:2022-06-20 Published:2022-07-08

Abstract: 【Aim】 This study aims to clarify the function of vitellogenin receptor (VgR) in the reproductive development of the tomato moth, Tuta absoluta, so as to provide a potential target for the green control of leaf miner pests. 【Methods】 Based on the transcriptomic data of T. absoluta, the full-length cDNA sequence of TaVgR was amplified by RT-PCR and analyzed by bioinformatics methods. The expression patterns of TaVgR in different developmental stages (1st-4th instar larvae, 1-7-day-old female pupae, and female adults) and female adult tissues (head, integument, foregut, midgut, hindgut, ovary, fat body, and Malpighian tubules) of T. absoluta were examined by RT-qPCR. RNAi was used to inhibit the expression of TaVgR in female pupae, and the changes in the ovarian development and fecundity of T. absoluta were observed after silencing of TaVgR. 【Results】 The cDNA sequence of TaVgR (GenBank accession no.: MZ682118) of T. absoluta was cloned. It contains an open reading frame of 5 496 bp in length, encoding 1 831 amino acids with the predicted molecular weight of 206 kD and isoelectric point of 5.17. The deduced protein of TaVgR has a signal peptide with 18 amino acid residues at the N-terminus and harbours the typical conserved functional domains of LDLR family proteins. The RT-qPCR results showed that the transcriptional level of TaVgR gradually rose with the increase of age of T. absoluta and reached the peak after female adult emergence. TaVgR exhibited the highest expression level in the ovaries of female adults of T. absoluta. RNAi of TaVgR inhibited the expression level of TaVgR in the early female pupae by 62.04%-72.55%, led to disruption of the deposition of yolk protein in the ovary, shortened the lengths of ovarioles and eggs, and reduced the total number of eggs laid per female adult in 10 d and the egg hatching rate of offspring, resulting in a decline in fertility. 【Conclusion】 TaVgR is ighly expressed in female adults and ovaries of T. absoluta. Silencing of TaVgR severely blocks the ovarian development of T. absoluta and impairs its fecundity. This study lays a theoretical foundation for the development of new control strategies of lepidopteran pests with VgR gene as the target.

Key words: Tuta absoluta, vitellogenin receptor, RNA interference, ovarian development; fecundity