Virome Analysis Of Bemisia Tabaci And Laodelphax Striatellus

Virus is the most abundant and diversified life forms in nature that can parasitize all life forms,including animals,plants,bacteria,fungi,and even viruses.Currently,it is generally believed that the number of unknown viruses are far more than that of the known viruses.With the development of high-throughput sequencing(HGS)technology,the number of newly discovered viruses has increased sharply in the past10 years,from 2079 to 5561 during 2008-2018.To investigate the virus diversity in insects,an efficient insect virome analysis platform has been developed based on the HGS technology,which faci litates the virus identification in insects.RNA virome of two important plant virus,Bemisia tabaci and Laodelphax striatellus,were characterized using the established platform.For first time,whitefly viromes of different cryptic species were comprehensively investigated and characterized using transcriptomes derived from NCBI public SRA datasets and field collected sampled.Twenty novel insect-specific viruses(ISVs)were confidently identified,mostly associated with a particular cryptic species of B.tabaci while different cryptic species harbored one or more core ISVs.Furthermore,microinjection experiments showed that some ISVs might cross-infect between the two invasive whitefly cryptic species,Middle East Asia Minor 1(MEAM1)and Mediterranean(MED).In addition,a new isolate of a plant virus,Potato virus S(PVS),which is wellknown to be efficiently transmitted by aphid,was discovered in one of the whitefly dataset,implying that whitefly might be another potential vector for PVS.In addition,we also comprehensively analyzed the RNA virome of L.striatellu from ten transcriptomes of NCBI public SRA datasets,as well as one transcriptome generated in our lab.Four ISVs,including three known ISVs(Laodelphax striatellus iflavirus 1,Ls IV1;Himetobi P virus,Hi PV;Laodelphax striatellus honeydew virus 1,Ls HV1)and one novel Chuvirus(Laodelphax striatellus Mivirus 1,Ls MVs1)were identified in L.striatellus.Further analysis indicated that although the ISVs are widely distributed in L.striatellus datasets,the presents of some ISVs are different in various populations.For example,Ls MV1 was not identified in northern populations,suggesting that the ISVs may be related to the geographical distribution of L.striatellus population.Moreover,a conservative Motif(GQLGGIEGLNQDTW)was discovered in the group of Chuviruses,which might contribute to further research on the classification and function of the Chuvirus.In summary,an insect virome analysis platform has been constructed,and RNA viromes of B.tabaci and L.striatellus were successfully identified and characterized with the platform.The results of this study provide us with a new perspective to understand the co-evolutionary relationship between ISVs and insects.At the same time,it may help to develop new plant virus prevention and control strategies using these ISVs.