Silencing of V-ATPase-E gene causes midgut apoptosis of Diaphorina citri and affects its acquisition of Huanglongbing pathogen

摘要

The Asian citrus psyllid,Diaphorina citri Kuwayama,is among the most im-portant pests of citrus.It is the main vector of the Huanglongbing(HLB)pathogen Can-didatus Liberibacter asiaticus(CLas),which causes severe losses in citrus crops.Control of D.citri is therefore of paramount importance to reduce the spread of HLB.In this re-gard,using RNA interference(RNAi)to silence target genes is a useful strategy to control psyllids.In this study,using RNAi,we examined the biological functions of the V-ATPase subunit E(V-ATP-E)gene of D.citri,including its effect on acquisition of CLas.The amino acid sequence of V-ATP-E from D.citri had high homology with proteins from other insects.V-ATP-E was expressed at all D.citri life stages analyzed,and the expres-sion level in mature adults was higher than that of teneral adults.Silencing of V-ATP-E resulted in a significant increase in mortality,reduced body weight,and induced cell apop-tosis of the D.citri midgut.The reduced expression of V-ATP-E was indicated to inhibit CLas passing through the midgut and into the hemolymph,leading to a majority of CLas being confined to the midgut.In addition,double-stranded RNA of D.citri V-ATP-E was safe to non-target parasitic wasps.These results suggest that V-ATP-E is an effective RNAi target that can be used in D.citri control to block CLas infection.