Analysis Of Gene Expression Pattern After Interaction Between Populus Simonii ×p.nigra And Alternaria Alternata

Poplar leaf blight is a leaf disease caused by Alternaria alternata.In this study,the pathogen and its molecular characteristics of poplar and the pathogen of leaf blight were identified,the transcriptional level of the pathogen in response to H2O2 stress was analyzed,and the transcriptional level of the poplar in response to the stress of leaf blight was also analyzed,hoping to lay a foundation for the identification of disease resistance genes and the improvement of poplar disease resistance in the future The results are as follows:First,isolate and purify the leaf blight pathogen to obtain a pure strain,and then determine the conditions and temperature suitable for colony growth.According to the principle that plant cells are stressed to produce a large number of reactive oxygen species,H2O2 solution was used to simulate the conditions of reactive oxygen species to treat pathogenic bacteria,and the experimental group and the control group samples were subjected to transcriptome sequencing.The results showed that under the condition of active oxygen stress,the gene expression of pathogenic bacteria changed significantly.The differentially expressed genes were compared with the GO,COG,KOG,and KEGG databases,and the functions of differentially expressed genes were involved in multiple processes.There are a large number of genes enriched in structure and other aspects.The leaf blight pathogen was used to subject the poplar leaves to stress for 48 hours,and the differential expression of genes was detected using RNA-seq technology.The results showed that the gene expression of poplar leaves under stress changed significantly,mainly involving metabolic processes,redox enzymes,Membrane structure and pathogenesis-related proteins are involved in 14 metabolic pathways such as photosynthesis.A total of 27 transcription factors were found,involving WRKY,MYB,bZIP and other families.Microscopy was performed at 0,4,8,12,24,48 and 72 hours of stress,and gene expression was detected by RNA-seq.The non-stress T0 group was used as a control to analyze the differential expression of genes and the expression pattern of WRKY gene at different time points.The results showed that 436,448,411,374,459,and 241 genes were differentially expressed at 6.stress time points,and the spatiotemporal expression pattern of 184 WRKY genes also changed.The RT-qPCR technology was used to detect the spatiotemporal expression of 18 WRKY genes and the expression patterns of three tissues.The results showed that poplars had a tendency of "induction-recovery" in response to the stress of leaf blight,and found that the leaves were the most significant,followed by the stems.The root does not respond to stress and is tissue-specific.