chapter  14
18 Pages

IN SITU IMMUNOCYTOCHEMICAL LOCALIZATION OF PLANT PROTEINS

Plantproteinsarekeycomponentsinanumberofbiologicalfunctionssuchascellgrowth anddevelopment,metabolicregulation,transport,self-incompatibility,andresistanceto stress.Inconsideringthebroadspectrumofresearchdevotedtoplantproteins,ithasbecome apparentthatvisualizingthespatialdistributionofthesemoleculescouldcomplementour understandingoftheirfunctions.Ithasbeenmorethantwodecadessinceimmunocytochemicalstudiesofextracellularantigenswerefirstappliedtoplanttissues. 1Sincethen,theyhave provedextremelyusefulforidentifyinganddeterminingthepreciselocationofawiderange ofmoleculesinplantcells.2-3Therearenowseveralareasinwhichimmunocytochemistry isbeingexploredasanessentialcomplementtochemical,biochemical,andmolecular investigations.Agrowingbodyofevidenceindicatesthatresearchonparticulartopicssuch asmembranestructure,cellwallelongation,photosynthesis,hormonalregulation,storage processes,andresistancetostresshasgreatlybenefitedfromtheinformationprovidedby theinsitulocalizationofplantantigens.4-7

Althoughplantsexhibitsomeofthefeaturesofimmunityinthattheyarecapableof discriminatingselffromnonself,theydonotpossessanimmunesystemsimilartothatfound invertebrates.Thus,antigen-antibodyinteractionsarerestrictedtodefensereactionsin vertebrates,andtheanalogyinplantsmaybesomewhatrelatedtotheproductionofinhibitory phenolsandphytoalexinsaswellastothesynthesisoflectinswithagglutinatingproperties. Thediscoverythatmanyplantproteinsandglycoproteinsarepowerfulantigenshasledto theconceptthatantibodies,raisedinexperimentalanimalsagainstpurifiedplantmolecules, couldbevaluabletoolsforserological.immunological,andimmunocytochemicalpurposes.8

Theconsiderableimprovementofmethodsforplantproteinpurification.togetherwiththe productionofmoreandmoreantiserawithspecificbindingproperties,explainsthecurrent interestinplantimmunocytochemistry.n