Identification Of Pathogen Causing Bacterial Pustule Spot Of Soybean And Prediction Of Small RNA In Bacterial Blight Of Soybean

Bacterial pustule of Soybean,is one kind of bacterial diseases which caused by Xanthomonas axonopodis pv.glycines.In recent years,this disease occurs in some soybean growing areas in Jiangsu is more serious.Most of the infected plants with small brown spots on leaves of both yellow halo on the incidence of severe confluent lesions contiguous blade,leaf brown withered.It has caused a significant impact on soybean yield.In this study,we collect diseased leaves from the experimental field of Nanjing Agricultural University,Jiangsu Province.We isolated the pathogens of A224,B523,C12 and C5.B523 and C5 were screened which have strong in theregion,for the next step of new soybean varieties were bred and evaluation of resistance tothis disease.The results show that these four strains,which were isolated from different soybean leaf samples could result in the same symptom,were identified as the pathogen.Then,we make more phology,biochemical and physiological identifications.Though 16S rDNA and gyrB cluster analysis,these four strains were further classed as the Xanthomonas axonopodis pv.glycines.In this study,two strains were screened which have strong pathogenicity strains provide a good source of strain for the next step of the experiment that new soybean germplasm evaluation of resistance,in order to select the germplasm of soybean resistance to bacterial diseases,to provide the reference for the effective prevention and treatment of disease.Bacterial blight of Soybean is one kind bacterial diseases of soybean,which caused by Pseudomonas syringae pv.glycinea.sRNA,which also knows as small non-coding RNA,refers to the size in the range of 50-500 nt normally,don,t encode proteins,can perform certain functions independently but different from rRNA and tRNA.In our lab,we have been isolated 7 strains of Bacterial blight of Soybean from the northeast China,including A1.And we also have finished the research of type III effector molecules and hrpZ gene.At present,domestic and foreign research on Bacterial blight of Soybean still remains in common pathogenic gene or resistant breeding aspects,the research of sRNAs has not been reported in Pseudomonas syringae pv.glycinea.Therefore,at the beginning of this study,we look for the sRNAs according to the sRNAs have been reported in the Pseudomonas,such as DC3000s?1448A and B728a,whose complete genome sequence have been reported on the NCBI.We got six sRNAs at last.Then we use RT-PCR to identified these sRNAs.The results indicate that the sRNAs of rsmX2,rsmX5 and rsmZ have transcripts in total RNA.In accordance with the identification characteristics of sRNAs.Followed we pridected the secondary structure and the target genes of the 3 sRNAs,we found that the stem loop structure of these 3 sRNAs are extremely stable,and the pridected target genes are also in different vrieties.At the end of the whole genome sequencing of A1,we get 20 candidate sRNAs molecules,and then we get a preliminary analysis on these sRNAs.This study lays a foundation for further study on the type of sRNAs and the mechanism of Pseudomonas syringae pv.glycinea.