Cloning And Expresson Analysis Of The Potato Transcription Factor StWRKY8-Like Gene Induced By Ralstonia Solanacearum

Potato is one of the most important food crops in the world, and it has significant economic and edible value for human beings. In view of the diseases caused by bacterial wilt, there is no chemical agent can effectively prevent and control up to now. It is possible to do research of plant disease resistance aspects discover more defense-related genes and understand their functioning mechanisms and features provide some theoretical basis for the prevention of plant diseases.In this thesis, in potato the inoculation and cloning of gene sequences were carried out by using the method of injury root inoculation and 5 '-RACE(5 '-End Amplification of cDNA).The cDNA sequence of the StWRKY8-like gene was obtained from a cultivated Solanum tuberosum Zhongshu 3 after inoculation with Ralstonia solanacearum, whose length was 563 bp, and it contained a 258 bp open reading frame coding a peptide with 85 amino acids. The StWRKY8-like protein has a classical conserved WRKY domain with a zinc finger motif of C2H2 and belongs to the subgroup II of WRKY family. Solanaceae and its amino acid sequence was found(the Solanaceae) having high homology toother members via the phylogenetic tree which was constructed by neighbor joining method. It is similar to the potato transcription factor StWRKY8 and even as high as 98%. The corresponding bioinformatics software was used to analyze and predict the gene.The StWRKY8-like protein was predicted as a hydrosoluble protein with an isoelectric point of 9.1 and half-life period of 5.5 h.Three-dimensional structure of a non-spherical, containing three phosphorylation sites was found, and the others were Ser phosphorylation sites and Tyr phosphorylation sites. It belongs to intracellular proteins. Quantitative analysis by RT-PCR and q RT-PCR showed that the StWRKY8-like gene was upregulated after R.solanacearum infection, and differentially expressed in susceptible and resistant S.tubosum. The expression of StWRKY8-like in resistant S. tubosum was significantly higher than in susceptible S.tubosum at 6 h post infection. By means of DIG in situ hybridization,the expression of target gene was located. The results showed that StWRKY8-like gene was mainly expressed in the vascular system of the stem and leaves.StWRKY8-like was a putative transcription factor gene,upregulated at R. solanacearum infection and differentially expressed in susceptible and resistant S. tubosum. It may be involved in the S. tubosum defense against R. solanacearum.