Selection And Functional Analysis Of Arabidopsis WRKY Transcription Factor Gene In Response To Abiotic Stress

WRKY transcription factor originally thought to be a plant-specific transcription factors, but the latest studies show that protists, algae, slime mold have been found exist WRKY transcription factors, a huge number of WRKY gene family plays an important role in the regulation of plant growth and development, substance metabolism and response to various adversity stress. In this study, gene screening, mainly through the analysis of abiotic stress in Arabidopsis WRKY family gene expression patterns, and build WRKY28 and WRKY38 genes of plant expression vector,and integrated into the Arabidopsis genome using genetic transformation,and analyze its function. The main research included:1. The 72 Arabidopsis transcription factors, their structure characteristics were analyzed by bioinformatics methods, the results showed that AtWRKY family was further divided into three groups:GroupⅠ, GroupⅡ and GroupⅢ. In addition, the gene members in GroupII can be further divided into five sub-groups:Ⅱa, Ⅱb, Ⅱe, Ⅱd, Ⅱe. The differential expression of WRKY genes were determined by real-time RT-PCR. Results showed that there are 30 genes response to salt stress, in which 23 were up-regulated genes, and 7 were down-regulated genes.2. Appling enzyme digestion technology, the Arabidopsis WRKY28 and WRKY38 plant expression vector was constructed and transformed into Arabidopsis by floral dip method via agrobacterium tumefaciens-mediated,using PCR prove the WRKY28 and WRKY38 has been successfully imported into Arabidopsis from the DNA level, and the expression of genes in different strains were identified by RT-PCR from the RNA level.3. The seed kernels per, seed protein content, germination rate, root length and leaf water loss rate were analysed between transgenic plants and wild type plants under NaCl ABA and PEG treatment, the results show that:abiotic stress may cause WRKY38 gene a histone methylation is reduced so that its seed kernels per, seed protein content, germination rate and leaf water loss rate is higher than that of wild-type plants.4. The determination of physiological index of transgenic and wild-type Arabidopsis plants under NaCl, ABA and PEG stress treatments, found that the activity of SOD and POD in transgenic plants were higher than wild-type plants when treat 3days and 5 days,and the content of MDA is lower than the wild-type plant while the Pro content was significantly higher than the wild-type plants.The results showed that the transgenic plants have stronger resistance to abiotic stress.