PLOS Pathog: 浙大王曉偉教授團隊揭示昆蟲傳播植物病毒新機制

2018-07-17 來源：中國病毒學論壇標簽：掌上醫(yī)生喝茶減肥一天瘦一斤安全減肥 cps聯(lián)盟美容護膚

摘要：許多植物病毒通過昆蟲的傳播在自然界持續(xù)的循環(huán)，在昆蟲體內(nèi)循環(huán)的過程中，病毒從腸腔輸送到血淋巴是一個非常重要的步驟。鑒定參與病毒傳輸過程中的重要組分可能為對抗病毒傳播提供新策略。

國際知名病原學期刊PLoSPathogens在線發(fā)表了浙江大學農(nóng)業(yè)與生物技術(shù)學院王曉偉教授課題組題為“Intracellulartraffickingofbegomovirusesinthemidgutcellsoftheirinsectvector”的最新成果。該研究發(fā)現(xiàn)雙生病毒在煙粉虱中腸上皮細胞內(nèi)，利用管狀網(wǎng)絡(luò)結(jié)構(gòu)直接由早期內(nèi)體被分泌至上皮細胞的基底面，完成跨細胞運輸。

許多植物病毒通過昆蟲的傳播在自然界持續(xù)的循環(huán)，在昆蟲體內(nèi)循環(huán)的過程中，病毒從腸腔輸送到血淋巴是一個非常重要的步驟。鑒定參與病毒傳輸過程中的重要組分可能為對抗病毒傳播提供新策略。課題組研究發(fā)現(xiàn)，植物雙生病毒在穿過其昆蟲媒介煙粉虱的腸道的過程中，可以利用上皮細胞的胞吞胞吐以及囊泡結(jié)構(gòu)進行跨細胞運輸，從而越過腸道上皮細胞對病毒的阻礙。研究首次報道了雙生病毒在昆蟲腸道上皮細胞細胞中的運輸機制。這一發(fā)現(xiàn)進一步闡明了煙粉虱傳播雙生病毒的機理，為阻斷煙粉虱在田間傳播雙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.