Abstract: 【Aim】 Tomato yellow leaf curl virus (TYLCV) is one of the main viruses that threaten agricultural production and transmitted by the insect vector Bemisia tabaci under natural conditions. Studies have shown that female adults of B. tabaci have stronger ability to acquire and transmit virus than male adults. The objective of this study is to investigate the influence of the expression of the chemosensory protein (CSP) gene BtabCSP6 in B. tabaci on virus transmission, and to find a new way to control the occurrence of virus. 【Methods】 Infected tomato plants were obtained by the TYLCV infectious clone, and uninfected B. tabaci MED adults were collected in micro-cages and fixed on leaves of the TYLCV-infected tomato plants for 48 h. RT-qPCR technology was used to measure the changes in the expression levels of BtabCSP1-8 in female and male adults of B. tabaci MED fed with TYLCV-infected and uninfected tomato plants, respectively. The BtabCSP6 gene in female adults of B. tabaci MED was suppressed by RNAi for 48 h through feeding method followed by feeding with TYLCV-infected tomato plants, and the virus acquisition and transmission rates of female adults of B. tabaci MED were determined. 【Results】The RT-qPCR results showed that the expression levels of BtabCSP3 and BtabCSP6 in TYLCV-infected female adults of B. tabaci MED changed most significantly as compared to those in the uninfected female adults. Similarly, the expression levels of BtabCSP4 and BtabCSP6 in TYLCV-infected male adults of B. tabaci MED changed most significantly as compared to those in the uninfected male adults. After being fed with dsBtabCSP6 for 48 h, the expression level of BtabCSP6 in female adults of B. tabaci MED decreased. The virus acquisition rates of female adults of B. tabaci MED after feeding with TYLCV-infected tomato plants for different time and the virus transmission rates of female adults of B. tabaci MED in different numbers to uninfected tomato plants were significantly decreased as compared to those of the control. 【Conclusion】 Down-regulating the expression of BtabCSP6 in female adults of B. tabaci MED can significantly reduce their virus acquisition and virus transmission rates, suggesting that BtabCSP6 may affect the transmission of TYLCV.

Key words: Bemisia tabaci; Tomato yellow leaf curl virus, chemosensory proteins, RNA interference, gene expression