The Expression Analysis Of WRKY Genes And Interaction With MAPK In Brachypodium Distachyon

WRKY proteins are transcription factor in eukaryotic cells that can directly combinewith the promoter of the related genes, which can regulate gene expression. WRKYtranscription factors have been reported to participate in seed development, bio-andabiotic stress response, and play important roles in abscisic acid, methyl jasmonate andsalicylic acid signaling pathways.MAPK cascade pathway is highly conserved in the evolution of the plant，it transducesexternal signal to the nucleus by stepwise amplification process, so that the cells couldrespond to changes in the external environment. MAPK cascade plays an important role inplant responses to various bio-and abiotic stresses.It has been reported that MAPKs can interact with WRKY by means ofphosphorylation, thus regulate WRKY activity and mediate various bio-and abioticstress in the plants.Brachypodium distachyon is a new type of model plant species and its genome’ssequecing has been completed, but there is still no report on WRKYs in response to abioticstress and the interaction with MAPKs. In this study, cDNA of five WRKY genes from B.distachyon were cloned, their expression changes under stress condition were analyzed byRT-PCR, and the interactions between BdWRKYs and BdMAPKs were exzamined byyeast two-hybrid technology. The results are as follows:(1) Based on BdWRKYs sequences in NCBI database, full-length cDNAs sequencesWRKY of five WRKYs were successfully clond using sequence-specific primers, anddesigned BdWRKY3、BdWRKY4、BdWRKY4-1、BdWRKY20and BdWRKY26.(2) Biological informatic analyses of the five BdWRKY gene sequences suggest thatthose BdWRKYs belong to the WRKY family members.(3) RT-PCR analysis results of five BdWRKY gene expression under abiotic stresses,such as osmosis, low temperature and high salt as well as signaling molecules such asABA, ethylene and hydrogen peroxide treatments indicated that BdWRKY3geneexpression was downregulated under high-salt treatment, BdWRKY4gene expression was upregulated under low temperature and high-salt treatment, BdWRKY4-1gene expressionwas upregulated under osmosis and high-salt treatment, BdWRKY20gene expression wasupregulated under osmosis、low temperature and high-salt treatment, BdWRKY26geneexpression was downregulated under osmosis and high-salt, while upregulated under lowtemperature, in addition, ABA, ethylene and hydrogen peroxide signaling maybe involvedin BdWRKYs expression regulation(4) The BdWRKYs overexpression vector were constructed by inserting them intopGBKT7, and were transformed into yeast with pGADT7-BdMAPK plasmid, and it wasfound that BdWRKY26could interact with BdMAPK7-1.There results of present study provided useful information for functional analyses ofBdWRKY and BdMAPK in the response to abiotic stresses.