Role Of Chemosensory Proteins Of Bemisia Tabaci In The Transmission Of Tomato Yellow Leaf Curl Virus

Tomato yellow leaf curl virus(TYLCV)is one of the main viruses that threaten agricultural production.It is transmitted by the insect vector Bemisia tabaci under natural conditions.Studies have shown that females have a stronger ability to acquire and transmit viruses than males.The purpose of this study was to investigate the difference in chemosensory proteins(CSPs)expression between male and female in B.tabaci,and to find a new way to control the occurrence of the virus.Infected tomato plants were obtained with the TYLCV infectious clone,and uninfected B.tabaci were collected in micro-cages and fixed on the leaves of the virus strains for 48 hours.The expression of CSPs in females and males B.tabaci with TYLCV-infected and uninfected were determined by quantitative PCR(q PCR)technology,and CSP with significantly high expression in virulent female B.tabaci was selected.The differentially expressed of CSP in female B.tabaci was down-regulated by RNAi,after that the acquisition rate,accumulation and transmission rates of B.tabaci after feeding double-stranded were recorded.The main results are as follows:1.The results of infectious clone showed that the infection rate of 30 tomatoes was 90%(3 tomatoes were uninfected).According to the absolute quantitative standard curve of TYLCV,the virus load range of infected tomato was 0.05×10~7～0.31×10~7 copies/μL,which could be utilized for subsequent experiments.2.The expression of BtabCSP6 was found to be significantly different between female and male B.tabaci at 48 hours before and after infection,and it was highly expressed in TYLCV-infected females.Results from expression level measurements in the head,thorax,and abdomen showed that it was highly expressed in the abdomen of both healthy and TYLCV-infected female B.tabaci.3.The expression level of BtabCSP6 in female B.tabaci decreased gradually after Btab CSP6 interference by RNAi.Compared with the control,the expression of Btab CSP6 in female B.tabaci fed with 400 ng/u L ds CSP6 for 48 h decreased by 73%.In addition,the efficiency of virus acquisition and transmission of B.tabaci were also significantly reduced.The results of the study indicated that BtabCSP6 played an important role in the acquisition and transmission of TYLCV by B.tabaci.The transmission of TYLCV by B.tabaci can be affected by inhibiting the expression of target genes by synthesizing the corresponding ds RNA.The results provide a new target for disease control in agricultural production.