Molecular Cloning,expression Pattern And Function Analysis Of Vitellogenin And Target Of Rapamycin Gene In Sogatella Furcifera

Sogatella furcifera is an important agricultural pest on rice.It damages rice by sucking rice phloem sap,spreading rice virus,and using female ovipositor to pierce leaves and easily attacked by bacteria.At present,the control of white-backed planthoppers is mainly through chemical control,and long-term irrational use of pesticides has exacerbated the development of resistance in the white-backed planthopper.The Vitellogenin(VG)and Target of rapamycin(TOR)are important genes involved in the regulation of insect reproduction,and are directly related to the reproduction of insect offspring.The research and investigation of these two genes will help us to find new and effective control of pest control targets.In the present study,the two genes;SfVG and Sf TOR,were cloned.Temporal and spatial expressions of VG and TOR in white-backed planthoppers were analyzed by qRT-PCR.The functions of these two genes were studied by RNAi technology.The results of the study are as following:Cloning,Expression Pattern and Function of Vitellogenin Gene in White-backed Planthoppers1.The full-length cDNA of SfVG gene is 6247 bp,encoding 2037 amino acid residues,This protein has typical conserved domains Vitellogenin-N,DUF1943 and von Willebrand factor type D domain.The amino acid sequence alignment analysis showed that the amino acid sequence of SfVG was similar to those of other Hemiptera species,and the similarities with Laodelphax striatellus and Nilaparvata lugens were 89% and 81%,respectively.2.The results of SfVG gene expression pattern analysis showed that,It was mainly synthesized in the fat body of white-backed planthopper females.3.The dsRNA was injected into the white-backed planthopper females using a microinjection apparatus.The development of the ovary after the injection of white-backed planthoppers was inhibited and no eggs could be produced.Cloning,expression patterns and functions of the target of rapamycin gene in white-backed planthoppers1.The full-length TOR gene sequence cDNA of the white-backed planthopper was 7881 bp,encoding 2447 amino acid residues.It has a typical poly A tail.The protein has conserved domains FAT,FRB,PI3K/PI4 K and FATC.The amino acid sequence alignment analysis showed that the SfTOR amino acid sequence had the highest similarity with Nilaparvata lugens,which was 93%.2.SfTOR was expressed in all stages of S.furcifera,and the expression of adult stage was significantly higher than that of nymphal stage.At the same time,It was highly expressed in Malpighian tubes of white-backed planthopper.After silencing Sf TOR,the mRNA transcriptional level decreased,and the expression levels of SfVG and SfFoXO genes related to ovarian development decreased too.Anatomy of the ovary system of the female white-backed planthoppers revealed that the development of the ovaries was inhibited and no eggs could be laid.