Identification Of Disease-resistance Cancer-critical Genes And Functional Research Of NPR-like Family In Poplar

Poplar due to high growth,strong adaptability,high yield etc widely cultivated for the world,at the same time it is also a model plant in the garden plant.However,due to the various Yang Shuzhong virus must break the traditional determines its disease-resistant mechanism,vigorously develop molecular genetic breeding.The system acquired resistance(SAR)is a kind of plant immune responses.Is usually caused by local infection to protect plants from bacteria,fungi and virus infection,it is recognized as efficient broad-spectrum disease resistance.NPR1 gene is an important SAR signal pathways regulating factor,salicylic acid can be induced to stimulate the pathogen or PR genes.NPR1 gene expression of excessive can effectively improve the plant's own resistance.In this study,using genetic engineering will import to Yang Shuzhong PtNPR3 genes,can improve the disease resistance of poplar,which reduces the resulting from the excessive use of chemical and environmental pollution problems.The main results are summarized as follow:1.The poplar genome and protein sequences as research materials,using a variety of bioinformatics software to search the whole genome,comparison and selection,combination Pfam online tools,received 15 NPR gene types.According to the result of the genes in the chromosome location for NPR gene named,will predict the NPR gene named Pt NPR1-9.2.For the poplar NPR gene and conservative domain structure of multiple sequence alignment,and build PtNPR genes and the evolutionary tree structure of the domain system,both received similar evolutionary relationships.Protein sequences and phylogentic analysis of PtNPR3 showed high homology with NPR1 in Arabidopsis3.MEME online program was employed as a method to analyse motif distribution and check the results of domain prediction.4.To analysis of the NPR protein sequences,we observed that numerous PtNPR genes contained an intron in their NPR domains.5.With PopGeneIE databases,we analysed expression characteristics of PtNPR genes,and 9 genes have microarray data support.The expression pattern demonstrated that PtNPR genes have different expression levels in various tissues.To explore the stress responses of the PtNPR genes,we analyzed their expression profiles under various abiotic stress conditions SA treatment using Real-time PCR and Affymetrix.The results indicate that almost all genes exhibited significant differences in their expression level in response to one or more stress treatment.PtNPR3 gene was remarkable responsive to SA.6.One homologous poplar genes,PtNPR3 were cloned.Promoters of PtNPR3 was cloned and cis-element analysis revealed that the PtNPR3 promoters contain RAV1 AAT and W-boxes motifs,both of which are known to related to SA signal pathway.The over-expression vector pRI201-AN-GUS+PtNPR3 was constructed and transformed into “Nanlin 95”.5 transformed plants were obtained after screening.