Study On The Function Of A Disease Resistance Gene In Plant

At present,crops around the world are generally subjected to various biotic and abiotic stresses,resulting in reduced food production and increased living pressures.China is a big agricultural country,the problem of food has not been completely solved..The infection of pathogenic bacteria is one of the stresses that lead to severe crop yield reduction.It is of great significance to improve the quality and yield of crops by improving their resistance to pathogens.f In the previous study of this subject,we found that the WRKY1 gene can respond to the infection of Pseudomonas syringae pv tomato DC3000(Pst.DC3000)in Arabidopsis,but the signal transduction pathway involved in the WRKY1 gene in this process is not clear.Therefore,this study further explored the involvement mechanism of the WRKY1 gene in the regulation of Pst.DC3000.The main findings are as follows:1.WRKY1 loss-of-function mutants are more tolerant to Pst.DC3000 and inhibit the propagation of the pathogen in vivo.WRKY1 overexpression transgenic plants were constructed in Arabidopsis thaliana,and WRKY1 overexpressing plants reduce tolerance and increase the number of Pst.DC3000.2.The data showed by qRT-PCR that the expressions of pathogen-induced SA-regulated genes PR1,PR2 and PR5 were higher in wrky1 mutants compared with WT,whereas the results in WRKY1-overexpressing plants were reversed.This indicates that the WRKY1 gene negatively regulates the response of Arabidopsis thaliana to Pst.DC3000 via the SA signaling pathway.3.The experiment of transient expression shows that WRKY1 inhibits the expression level of PR1,PR2 and PR5.In addition,it was found that WRKY1 protein can directly bind to W-BOX regions of PR1 and PR5 promoters by using chromatin immunoprecipitation,and negatively regulates the transcriptional activities of PR1 and PR5.Though the expression of PR2 gene in WRKY1-overexpressing plant was inhibited,the WRKY1 did not directly bind to PR2.It was possibly because that WRKY1 gene regulates the transcription level of the gene through other influencing factors.To sum up,it was proved that WRKY1 gene negatively regulates the tolerance of Arabidopsis thaliana to Pst.DC3000 through SA signaling pathway.However,whether the WRKY1 gene also regulates the response of plants to pathogens through other disease-resistant defense pathways needs further exploration.