Transcriptome Analysis Of Eutrema Salsugineum In Response To Salt Stress And Identification Of WRKY Gene Family

Salt stress affects the growth,development,yield and quality of crops.Eutrema salsugineum is a model plant for studying the mechanism of plant stress tolerance.It is important to find out the stress-resistance related genes from E.salsugineum in order to improve the adaptability of plants in adversity.WRKY transcription factors play an important role in plant growth and development,environmental adaptation and other biological aspects.In this paper,the WRKY transcription factors family of E.salsugineum were identified and phylogenetic analysis was performed by bioinformatics analysis based on the sequence results of salt-stressed E.salsugineum transcriptome,the induced expression pattern of 20 differentially expressed WRKY genes under salt stress was validated,and 16 of them were cloned for preliminary verification of salt tolerance in Saccharomyces cerevisiae.The main results were as follows:(1)Sequence and analysis of the transcriptome of E.salsugineum treated with NaClThe transcriptome of E.salsugineum treated with NaCl for 12 h and 48 h was analyzed.A total of 80490 transcripts were obtained,of which 76839 were annotated.5324 and 756 differentially expressed genes were detected in the transcripts of E.salsugineum seedlings 12 and 48 hours after NaCl treatment.There were 2649 genes up-regulated and 2675 genes down-regulated at 12 h,298 genes up-regulated and 458 genes down-regulated at 48 h.A total of 2357 differentially expressed genes were inserted into 124 KEGG standard metabolic pathways in 12 h NaCl-treated E.salsugineum,and 272 differentially expressed genes were inserted into 83 KEGG standard metabolic pathways in 48 h NaCl-treated E.salsugineum.KEGG pathway enrichment analysis showed that the concentration level of "Plant-pathogen interaction"pathway was the most significant in E.salsugineum samples treated with NaCl for 12h The most significant pathways for enrichment levels in 48h samples were "Anthocyanin biosynthesis" and"Biosynthesis of flavonoids and flavonols".(2)Identification and characterization of WRKY transcription factors in E.salsugineumIn this study,45 members of the WRKY gene family were selected and renamed Es WRKY1-45 according to their chromosome distribution.The WRKYGQK conserved sequences were found in 42 WRKY proteins,and the WRKYGKK domain was found in the other 3 WRKY proteins.The zinc finger structures of all WRKY transcription factors were C2H2 or C2HC type.According to the number of WRKY domains and the type of zinc finger structure,the WRKY family is divided into groups ?,? and ? with 11,27 and 7 members respectively,of which Group II can be further divided into 5 subgroups ?a,?b,?c,?d and ?e.The exon content of WRKY family members in E.salsugineum is 2-6.The results of collinearity analysis showed that segment repeat was the main mode of gene amplification of E.salsugineum WRKY family,and there were 7 pairs of segment repeat in 45 genes of E.salsugineum WRKY family.(3)Preliminary identification of the salt tolerance function of WRKY gene in response to salt stressThe results showed that 15 genes up-regulated and 5 down-regulated after 12 h NaCl treatment,3 genes up-regulated and 17 genes down-regulated after 48 h NaCl treatment.The results showed the same trend as the sequencing results,which proved the reliability of the transcriptome data.EsWRKYs gene was constructed into yeast expression vector PYES2 and transferred into yeast INVScl receptor state.The survival of recombinant and non-recombinant yeast under NaCl stress was compared with that of yeast without PYES2.The results showed that the Es WRKY gene significantly improved the tolerance of yeast to NaCl.