Effect Of Trehalase On Transmission Of Tomato Chlorotic Virus By Bemisia Tabaci

Bemisia tabaci(Gennadius)is a highly invasive alien invasive pest.In China,Q whitefly gradually replaced B whitefly and became the dominant population.B.tabaci can transmit a variety of plant viruses,such as Tomato chlorosis virus(ToCV),and cause the outbreak and spread of plant virus diseases,resulting in a large-scale reduction in the yield of tomato crops,which causes serious economic losses to vegetable crops and horticultural ornamental plants.There is a strict interaction between ToCV and B.tabaci and plants.The key step in the comprehensive prevention and control of crop viral diseases is to strengthen the control of vector insects.Trehalose is the "blood sugar" of insects,and trehalase plays a very important role in the normal physiological function of B.tabaci.In our study,B.tabaci was used as the object,and the trehalase inhibitor-Validamycin was selected to explore the mechanism of trehalase in the transmission of ToCV by B.tabaci.Our results can provide an important theoretical basis for the prevention and control of ToCV transmission.The main results are as follows:1.After being fed by ToCV-infected tomato plants for different AAPs,the trehalose content in the Q whitefly did not accumulate significantly compared with the control group fed on the uninfected tomato,and significantly decreased in each time period;The activity of trehalase decreased first and then increased.And with the extension of feeding time,the trehalase in Q whitefly showed higher activity compared with the control.2.When Q whiteflies were transferred to ToCV-infected tomatoes treated with 20 mg/mL Validamycin,the trehalose content of Q whiteflies had a significant accumulation since 12 h compared with the water-treated control group.At each time period the trehalose content was significantly higher than that of the control.The trehalase activity of Q whitefly also decreased significantly at 12 h.With the extension of feeding time,the trehalase in Q whitefly has lower activity compared with the control.3.After Validamycin treatment,the ability Q whitefly to acquire virus was significantly reduced.The amount of ToCV obtained by whitefly increased significantly with the extension of feeding time.The amount of virus obtained by whitefly feeding on Validamycin-treated tomatoes was significantly lower than that of the water-treated control at each time point.4.After Validamycin treatment,the ability Q whitefly to transmit virus was also significantly decreased.The accumulation of virus in tomato was detected by reverse transcription-real time polymerase chain reaction about 3 weeks after inoculated with ToCV.The results show that Validamycin significantly reduced the transmission efficiency of Q whitefly to ToCV.5.After Validamycin treatment,the number of viruliferous Q whiteflies tended to feed tomato plants at the four-true-leaf stage was lower than that of the water-treated control group.