Expression Profile Of NPR1 And Gene (NPR1,AOS) Transformation In Rice

NPR1,functionally conserved in diverse plant species including rice Oryza sativaL.(Poeceae),plays a key role in induced plant resistance and mediates the cross talkbetween different defense pathways.Allene oxide synthase(AOS) is a focal point incontrolling biosynthesis of JAs,which are important signals in mediating plant resistanceagainst herbivores.However,the roles of NPR1 and AOS in induced resistance in ricecrop against herbivores remained unclear.To elucidate the biological functions of NPR1and AOS in herbivore-induced rice defenses,we observed the expression profile of NPR1following application of signaling molecules and herbivore feeding,and develop ricelines with silencing ofNPR1 orAOS gene.Our study layout and main results are:1) According to the published sequences,fragments of rice genes NPR1 and AOS were PCRamplified and cloned.Expression profiles of NPR1 in different tissues of healthy riceplants,following treatment with signaling molecules(salicylic acid,SA;jasmonicacid,JA;H₂O₂;ethylene,ET) and herbivores feeding [stripped stem borer SSB,Chilosuppressalis Walker(Lepidoptera:Pyralidae);leaf folder LF,Cnaphalocrocismedinalis Guenee(Lepidoptera:Pyralidae);brown plant hopper BPH,Nilaparvatalugens Stal(Hemiptera:Delphacidae)] was observed using realtime RT-PCR,one ofthe enabling techniques of the genomic era.The expression of NPR1 was highest inroots followed by inflorescence,leaves and stem.Following treatment with JA,SA,and H₂O₂,an early NPR1 induction was observed,however,drastic changes in genelevels were observed by 24 h after ET treatment.Among herbivores,the maximumgene induction was observed after BPH feeding.An early gene induction by SSB instem tissues was also observed but LF decreased the gene levels.The results showthat NPR1 may participates in defense responses in rice.2) To analyze the role of NPR1 and AOS in rice defense,rice lines silencing NPR1 and AOSexpression were obtained with an Agrobacterium-based transformation system.Theseeds of T₁ generation of these lines were collected,which lays the foundation forelucidating the functions of genes NPR1 and AOS in herbivore-induced rice defenseresponses. Modifying plant responses through manipulating expression of genes involved indefense pathways can greatly help to control pests in an environmental friendly way.NPR1 and AOS are no doubt an important such candidates to work on.Knowing their rolein rice plant resistance may open new opportunities and possibilities for improving cropresistance against herbivores.