Functional Analysis Of Psammotettix Alienus Proteins And Gut Bacteria Communities Involved In WDV Transmission

As an important insect vector,Psammotettix alienus transmits various viruses including wheat dwarf virus(WDV).Here,we used the combination of leafhopper and WDV as model to survey the influence of ARF1,ADF and gut microbiota on virus transmission characteristic of insect vector.The results as follows: 1 ADP ribosylation factor 1 facilitates spread of wheat dwarf virus in its vector insectIn this study,ADP ribosylation factor 1(ARF1)was found to interact with the coat protein(CP)of WDV in a yeast two-hybrid,Pull-down assay and to colocalize with virions in the gut and salivary glands of P.alienus.When transcription of ARF1 was suppressed by RNA interference,the WDV titer decreased in the hemolymph and salivary glands,and transmission efficiency decreased,but titer in the gut did not differ from that of the control.These data suggest that ARF1 of P.alienus binds to the WDV virion and helps virus spread from gut to hemolymph.2 Characterization and functional analysis of Psammotettix alienus actin depolymerizing factor involved in wheat dwarf virus transmissionIn this study,actin depolymerizing factor(ADF/cofilin)was found to interact with the CP of WDV in a yeast two-hybrid,Pull-down assay and to colocalize with virions in Sf9 cells.When transcription of ADF was suppressed by RNAi,the WDV titer decreased in the leafhopper,and transmission efficiency decreased.These data suggest that ADF of P.alienus is essential for WDV transmission.Interestingly,the interaction between CP and ADF inhibit the function of ADF.We infer that on the one hand,ADF may regulate the actin filaments on the plasma membrane and promote the virus spread in the leafhopper,on the other hand,WDV hijack ADF and disturb actin organization function,thus achieving the coevolution for the virus,insect vector and host plant.3 Characterization and functional analysis of Psammotettix alienus gut bacteria communities involved in wheat dwarf virus transmissionWe have characterized 22 phyla and 249 genera of all gut bacterial communities in the leafhopper populations collected from six geographic regions in China.Community composition and diversity varied across different geographic populations.However,WDV transmission efficiencies of these six field populations were all greater than 80% with no significant difference.Interestingly,the transmission efficiency of WDV by laboratory reared insects with decreased gut bacterial diversity was similar to that of field populations.Furthermore,we found that the composition of the leafhopper gut bacteria was dynamic and could reversibly respond to WDV acquisition.Higher bacterial diversity and abundance of gut microbiota in different leafhopper populations did not influence their WDV transmission efficiency,while the acquisition of WDV changes gut microbiota by a dynamic and reversible manner.This report provides insight into the complex relationship between the gut microbiota,insect vector and virus.4 Identify the novel virus in the P.alienusTwo novel viruses were identified in the Psammotettix alienus,one is tentatively named Psammotettix alienus iflavirus 1(PaIV1),a new member of genus Iflavirus,family Iflaviridae,the other one is Tàiyuán leafhopper virus(TYLeV),a new species of chuviridae.In conclusion,we clarified the function of P.alienus ARF1,ADF and gut bacteria communities involved in the WDV transmission.This will help us better understand the interaction between plant viruses and their transmitting vectors and may open new avenues for therapeutic intervention for plant virus-induced diseases.