History of Plant virology

Detail introduction about plant virology

1. LANDMARKS IN THE
DEVELOPMENT OF VIROLOGY
N. H. SHANKAR REDDY
PH.D., PLANTPATHOLOGY
ANNAMALAIUNIVERSITY

2. 16
th
century–
Tulipomania–TulipbulbsintroducedformNetherlandproduced
‘brokencolourflowerwithvariegations’havegreatdemandand
expandmarketvaluewithgreatextentinshortperiod,leadingto
increaseoftulipprizesunimaginably.
Laterdaysitwasdiscoveredthatitwascausedbypotyvirus
groupandaretransmittedbyaphids.

3. 1886 –Adolf Mayer (Germany)-
•Coinedtheterm‘Mosaic’
•Firsttoprovethetransmissibleplantvirusi.e.TMV
•Hecalledsaptransmissionoftobaccodiseaseis
‘Mosaikkrankheit’
•LaterheperformedexperimentswithChamberlandfilterpaper,
eventhoughthevirusretainsinfectivity.
•Hethoughtthatthecausalagentofmosaicdiseaseoftobaccowas
duetothebacteria.

4. 1892–D.Ivanovsky(Russia)–
•Provedthatthecausalagentoftobaccomosaicdiseasecould
passthroughbacteriaprooffilters.
•Concludedthatthecausalagentoftobaccomosaic(virus)is
smallerthanbacteria.
•1
st
manwhodiscovered‘inclusionbodies’
•Describedthehorizontaltransmissionofplantviruses

5. 1898 –Beijerinck–
•Dutchmicrobiologistandbotanist.
•FounderandFatherofVirology/FatherofEnvironmental
Ecology
•Performedagardiffusionexperimentsandcoinedtheterm‘Virus’
•Hecalledtheliquidmaterialofvirusis“Contagiumvivum
fluidum”whichcausetherepeatedinfectioninTobaccomosaic
virus
•Thefirstknownsulfate-reducingbacterium,wasisolatedand
describedbyBeijerinck(Spirillumdesulfuricans,nowcalled
asDesulfovibriodesulfuricans)
•Clostridiumbeijerinckiiisagrampositive,rod
shaped;motilebacteriumwasnamedafterBeijerinck.

6. 1915 –Twort, 1917 -F. D. Herelle–Individually discovered bacteriophages
1929–Holmes–DevelopedlocallesionassayinNicotianaglutinosa
•(Locallesionassay-Atoolbywhichviruscouldbemeasuredbyshowingthatthe
amountofviruspresentintheplantsappreparationisproportionaltothenumberof
lesionsproducedonappropriatehostplantleavesrubbedwiththesap)
•Observedthatsingledominantgenecontrollingthehypersensitivereaction(HR)and
proposedthe“viralhypersensitivity”.Singledominantgenesubsequentlytransferred
fromN.glutinosatoN.tabacuminwhichtheTMVresistantcultivarsareproduced

7. 1929 –Mckinney–
•Developed cross protection/ pre-immunization technique for control of citrus tristeza
virus (CTV)
•Cross protection was 1
st
used against TMV
1931-1933 -Knoll and Ruska-
•Thefirstprototypeofelectronmicroscopewas
developedbyErnstRuska(1931)andKnollwhichis
capableof400magnificationpower
•Then,Ruska(1933)builtthefirstelectronmicroscope
thatattainshighresolutionwithanoptical(light)
microscope.
•HewontheNobelPrizeinPhysicsin1986forhis
fundamentalworkinelectronoptics,includingthe
designofthefirstelectronmicroscope.

8. 1931-K.M.Smith–
Usedindicatorplantinviralstudieswastaughtbyhim
SeparationofPotatovirusesandnamedasXandY.
Authoredatextbook“PlantVirusDiseases”in1937
Henamedandgroupedvirusesaccordingtothegenericnameofthehost.
1933-MartinSchlesinger–
Hungarianchemist
Separatedandpurifiedbacteriophagesbythetechniqueofultracentrifugationand
concludedthatitcontainsequalamountofproteinsandDNA

9. 1935-W. M. Stanley –
•Americanbiochemist,virologist
•Done Purification/ Crystallisation of virus (by using
ammonium sulphate)
(Preparation of enzymes and virus proteins in a pure form)
•HereceivedNobelPrizein1946(forcrystallisationofvirus)
•Hebelievedthatviruswasanautocatalyticproteinthatcould
multiplywithinthelivingcell
•MolecularplantpathologyworkcanbeinitiatedwithW.M.
Stanleywork
•(Note-X-raydiffractionstudiesbyJ.D.BernalandI.
Fankuchenshowedthattheyaretruethreedimensionalcrystals,
theywereparacrystallineandthattherodlikevirusparticles.

10. 1936 –F. E. Bawdenand N. W. Pirie –
•Demonstratedthatvirusisanucleoproteinwhichconsistsbothnucleicacidandprotein
•Theyalsopurified/crystallisedTMVin1936(afterW.M.Stanleyexperiment),further
purificationofproteininneutralaqueoussolutioncanbeobtainedinliquidcrystalline
states.
•Firstsuggestedthatvirusreplicationmightbeanalogoustothesynthesisofcellular
components(1936)
•DetectthatphosphateisinherentpartinRNAmolecule.
•Theirstudiesrevealsthat1-2gmofproteincanbeisolatedfromalitreofsap,itdepends
basedontheageoftheplantanddurationofinfection

11. LuriaandDelbruck–
Discovered‘bacterialmutation’
Consideredasfoundingfathersofphagegenetics
ReceivedNobelprizeinPhysiologyandmedicinein
1969
Alsoworkedonreplicationmechanismandgenetic
structureofviruses
Delbruckalonediscovered‘mutationinvirus’in
1939

12. 1952-1953 –Watson and Crick –
•DiscoveredthedoublehelicalstructureofDNA,inwhichtheir
discoveryrevolutionizedtheentirebiology.
•Theycontendedthatallvirusesmustbebuiltupsymmetrically
fromidenticalproteinsubunitsthatsurroundthenucleicacid
in1956
•Generaltheoryofstructureofcapsidofvirus;thecoatprotein
madeupofnumerousidenticalsubunitsasheliclerodsor
sphericalshell.
•Gotnobleprizeinphysiologyandmedicinein1962

13. 1952–HarsheyandChase–
DemonstratedtheinfectionbehaviourofbacteriophageandshowedthatonlyDNA
entersintothehostcellandproteinremainoutside.
Nucleicacidportionthatwasresponsiblefortheinfectivityandcarriedthegenetic
material.

14. 1956 –Gierrerand Schramm –
•Showedthatnucleicacidistheinfectiousagent
•(ShowedthatonlynucleicacidofTMVisinfectiveandproteincoatdoesnothaveany
roleininfection,NucleicacidscarryhereditaryinformationandthatNucleicacidalone
issufficientforviralinfectivity)
•AlsoinvestigatedaboutdoublestandardRNAviruses(dsRNA)

15. 1958 –Hewitt et al–Reported grape fan leaf virus is transmitted by nematode Xiphinema
index, and nematode implicated the transmissions.
1962 –Teakle–1
st
transported fungal transmission (Olpidiumbrassicae) of soil borne
Tobacco necrosis virus
1968 -Shepherd et al-Reported 1
st
DNA plant viruses, double-stranded DNA (ds DNA) in
cauliflower mosaic virus
1968–I.TakebeandY.Ostsuki
Describedatechniqueforpropagatingandinfectingprotoplastswithviruses
Theprocedureallowedmanydetailedstudiesofviralreplicationandeventualthe
regressionofplantsfromasinglecelltoprotoplasts,whichwasanimportantstepin
producingtransgenicplants.

16. 1975–KohlerandMilstein-Developed“Hybridomatechnology”inmonoclonalantibodies
production–Nobelprizein1984.
1976–Volleretal,1977–ClarkandAdams–DevelopedELISAtechniqueandused
ELISAinPlantvirusdetection.

17. 1982–AaronKlug-Forhisdevelopmentofcrystallographicelectronmicroscopyandhis
structuralelucidationofbiologicallyimportantnucleicacid-proteincomplexes
1986–Powel-abelandBeachy–
Initiatedmolecularplantpathologyworkbyimprovingthediseaseresistancegene.
Developed1
st
transgenicresistancemediatedbytheCPgeneobtainedfromtobacco
plantsagainstTMV.
Beachydeveloped“coatproteinmediatedgeneresistance”.

18. 1984-Prusiner-
•DiscoveredofPrionsinanimals:
•ReceivedNobelPrizein1997inphysiologyof
Medicinesforthediscoveryof‘Prions’andbiological
principlesofinfection

19. 1998 -Andrew Fire & Craig Mello –
•First described their work on RNA interference Gene silencing by dsRNA, in the
nematode Caenorhabdatiselegans.
•RNA interference is traditionally/ otherwise called as Post transcriptional gene
silencing (PTGS)
•shared Nobel prize in 2006.

20. 2001-Lietal–Reportedtheroleofproteinspresentintheheadtissueofaphidvectorinthe
transmissionofthevirus-theyfoundtwoproteinsasreceptorofBYDV;theyactassensors
andifabsentinanyaphidnotransmissionoccurs
2003–P.LavaKumaratICRISAT,madeamajorbreakthroughbyidentifyingand
characterizingthevirusassociatedwithpigeonpeasterilitymosaicandreportedthat,itis
transmittedbyEriophyidmite.Hewashonouredwiththeyoungscientistawardofthe
ConsultativeGrouponInternationalAgriculturalResearch(CGIAR)forthisachievement

21. THE MAN WHO STUDIES HISTORY, CAN MAKES HISTORY

22. Video available at you tube
Channel –Geeky Researcher