Chapter7 Signal transduction in plant cell

growthanddevelopmentPhysiologicalfunctionMetabolicreactionEnzymesynthesisGeneexpressionGeneticmessageEnvironmentalmessageChapter7SignaltransductioninplantcellMessageflow:theorderlydevelopmentofplantisaprogammedsequencecontroledbygeneticmessageandenvironmentalmessage.Signaltransduction:suchinternal(external)signalingagentstypicallybringabouttheireffectsbymeansofsequencesofbiochemicalreactions.Thatgreatlyamplifytheoriginalsignalandultimatelyresultintheactivationorrepressionofgenes.1.1SignalPhysicalsignal:Light、eletricityChemicalsignal(ligand):Hormone、PathogenyfactorExternalsignalInternalsignalSection1Signalandsignalperception1.2Receptor:•proteinsassociatedwiththeplasmamembrane•Speciality,highappetency(亲和力),reversibility•transferingandamplifingsignalsintracellularreceptorcellsurfacereceptorcellsuefacereceptorG-protein-linkedreceptor(G蛋白连接受体)enzyme-linkedreceptor(酶连受体)•Ionchannel-linkedreceptorSection2transmenbranetransductiontransmenbranetransduction:receptorscombinewithsignalstransmenbranetransductionofGproteintwo-componentsystemortwo-componentsignaling（二元组分系统)Section3networkintracellularsignaltransductionPrimarysignal:ExternalsignalSecondarymessenger:intracellularsignal,transferandamplifytheexternalsignalCa2+、cAMP、IP3、、DAG3.1Ca2＋/CaM3.1.1homeostasis（钙稳态）Ca2＋channelCa2＋pumpCa2＋/nH+antiporterRegulationofcalciumhomeostasis（钙稳态）:红光刺激后大麦叶肉原生质体的钙离子浓度变化3.1.2calmodulin（CaM钙调素）ahighlyconserved,ubiquitousproteinFunction:bindswithCa2+Ca2+CaMcomplextorecognizeandactivatetargetproteinstargetproteins:Ca2+-ATPases,NADkinase,proteinkinasesSporegerminationoffernkaryokinesis(有丝分裂)bioplasmflowhormonesactivitytropism(向性)3.2IP3&DAGPIP2（磷脂酰肌醇-4、5-二磷酸）PIkinasePIPkinaseDAG—activingproteinPIPIPPIP2IP3—releasingCa2+kinaseCDoublesignalssystemproteinkinasenNTPnNDPproteinprotein-nPinPiH2OproteinphorsphataseSection4reversibleproteinphosphorylationSignaltransductionSignalReceptorG-protein-linkedreceptorenzyme-linkedreceptorIonchannel-linkedreceptorSecondarymessengernetworkintracellularsignaltransductionreversibleproteinphosphorylation