PLOS Pathog: 浙大王晓伟教授团队揭示昆虫传播植物病毒新机制

2018-07-17 来源：中国病毒学论坛标签：掌上医生喝茶减肥一天瘦一斤安全减肥 cps联盟美容护肤

摘要：许多植物病毒通过昆虫的传播在自然界持续的循环，在昆虫体内循环的过程中，病毒从肠腔输送到血淋巴是一个非常重要的步骤。鉴定参与病毒传输过程中的重要组分可能为对抗病毒传播提供新策略。

国际知名病原学期刊PLoSPathogens在线发表了浙江大学农业与生物技术学院王晓伟教授课题组题为“Intracellulartraffickingofbegomovirusesinthemidgutcellsoftheirinsectvector”的最新成果。该研究发现双生病毒在烟粉虱中肠上皮细胞内，利用管状网络结构直接由早期内体被分泌至上皮细胞的基底面，完成跨细胞运输。

许多植物病毒通过昆虫的传播在自然界持续的循环，在昆虫体内循环的过程中，病毒从肠腔输送到血淋巴是一个非常重要的步骤。鉴定参与病毒传输过程中的重要组分可能为对抗病毒传播提供新策略。课题组研究发现，植物双生病毒在穿过其昆虫媒介烟粉虱的肠道的过程中，可以利用上皮细胞的胞吞胞吐以及囊泡结构进行跨细胞运输，从而越过肠道上皮细胞对病毒的阻碍。研究首次报道了双生病毒在昆虫肠道上皮细胞细胞中的运输机制。这一发现进一步阐明了烟粉虱传播双生病毒的机理，为阻断烟粉虱在田间传播双生病毒提供了新的防控思路。

Abstract

Begomovirusesareexclusivelytransmittedbywhitefliesinapersistentcirculativemannerandcauseconsiderableeconomiclossestocropproductionworldwide.Previousstudieshaveshownthatbegomovirusesaccumulateinvesicle-likestructuresinwhiteflymidgutcellsandthatclathrin-mediatedendocytosisisresponsiblefortheirinternalization.However,theprocessbywhichbegomovirusesaretraffickedwithinwhiteflymidgutcellsremainslargelyunknown.Inthisstudy,weinvestigatedtherolesofvesicletraffickinginthetransportofTomatoyellowleafcurlvirus(TYLCV),abegomovirusthathasspreadtoover50countriesandcausedextensivedamagetoarangeofimportantcrops,withinmidgutcellsofwhitefly(Bemisiatabaci).BydisruptingvesicletraffickingusingRNAsilencingandinhibitors,wedemonstratedthattheearlystepsofendosomaltraffickingareimportantfortheintracellulartransportofTYLCVinthewhiteflymidgut.Inaddition,ourdatashowthat,unlikemanyanimalviruses,TYCLVistraffickedwithincellsinamannerindependentofrecyclingendosomes,lateendosomes,lysosomes,theGolgiapparatusandtheendoplasmicreticulum.Instead,ourresultssuggestthatTYLCVmightbetransporteddirectlyfromearlyendosomestothebasalplasmamembraneandreleasedintothehemolymph.SilencingofthesortingnexinSnx12,whichmaybeinvolvedinmembranetubulation,resultedinfewerviralparticlesinhemolymph;thissuggeststhatthetubularendosomalnetworkmaybeinvolvedinthetransportofTYLCV.Ourresultsalsosupportarolefortheendo-lysosomalsysteminviraldegradation.WefurthershowedthatthefunctionsofvectorearlyendosomesandsortingnexinSnx12areconservedinthetransmissionofseveralotherbegomoviruses.Overall,ourdataindicatetheimportanceofearlyendosomesandthetubularendosomalnetworkinbegomovirustransmission.

Authorsummary

Manyplantvirusesarevectoredbyinsectsinapersistentcirculativemanner.Inthisprocess,thetransportofvirusfromthegutlumenintothehemolymphofthevectorisanimportantstep.Identificationofvectorcomponentsinvolvedinthistransportprocesscouldleadtonewstrategiestocombatvirusspread.Here,wedemonstratethattheearlystepsofendosomaltraffickingareimportantforthetransportofbegomovirusesacrossepithelialcellsinthewhiteflymidgut.Afterinternalizationbymidgutepithelialcells,begomovirusesaretransporteddirectlyfromearlyendosomestothebasalplasmamembraneinafastrecyclingroute.Wealsoidentifiedseveralhostprocessesthatareinvolvedinbegomovirustransmission,includingvesicletransportandmembranefusioneventsthatpromotevirustrafficking.Toourknowledge,thisisthefirstreportonmechanismsgoverningtheintracellulartransportofbegomovirusesintheirinsectvector.Ourstudyprovidesnewinsightsintothetransmissionmechanismsofcirculativeplantvirusesandgivesdirectiontofutureresearchintobegomovirustransmissionblockingstrategies.