Isolation And Characterization Of Maize Transcription Factor ZmWRKY114 Gene

Abiotic stress is the main factor affecting plant growth and crop yield loss,which seriously restricts the development of agricultural economy.Maize is the main food crop in China,so mining the genes related to stress resistance and analyzing their functions and breeding maize varieties with strong stress resistance can provide a new and effective way for improving maize stress resistance breeding.Recent studies have shown that transcription factors play an extremely important role in regulating the expression of functional genes for stress resistance and improving crop adaptation to stress.In this study,the salt stress response gene WRKY114,which encodes a WRKY transcription factor,was cloned from maize,and its biological function and molecular mechanism of action were investigated.The main results are as follows:1.Quantitative real-time PCR analyses showed that ZmWRKY114 gene was expressed at different levels in different tissues of maize,with the highest expression levels in stems and leaves.ZmWRKY114 gene expression was up-regulated during ABA treatment and downregulated during salt treatment.2.Sequence analysis of ZmWRKY114 gene showed that ZmWRKY114(Gen Bank Accession number: NM＿001158417)c DNA is 936 bp and encodes 311 amino acids.The molecular weight is 31.889 k Da and the isoelectric point is 9.54.The N-terminal region contains a highly conserved WRKY domain,a C2H2-type zinc finger motif,a HARF motif and a putative basic nuclear localization signal which indicates that ZmWRKY114 is a member of the subgroup IId.3.Sub-cellular localization analysis of the ZmWRKY114-GFP fusion expression vector by PEG-mediated protoplast method showed that the ZmWRKY114 protein was localized in the nucleus.4.Transcriptional activity analysis showed that ZmWRKY114 had no transcriptional activity in yeast cells.A yeast one-hybrid analysis showed that ZmWRKY114 can specifically bind to the W-box.5.ZmWRKY114 transgenic rice lines were obtained by Agrobacterium-mediated method.The seeds of WT and OE6 and OE8 overexpression lines were germinated and treated with different concentrations of Na Cl,and the results showed that the plant height and root length of WT were higher than those of OE6 and OE8 overexpression lines.At the four-leaf stage of maize,WT and OE6 and OE8 overexpression lines were treated with high salt stress(250m M Na Cl),and the results showed that malondialdehyde content and relative electrolyte leakage were higher in OE6 and OE8 rice lines compared with WT,while proline content was lower than WT.Thus,the overexpression of ZmWRKY114 in rice enhances plant sensitivity to salt stress.6.ABA sensitivity assay showed that the ZmWRKY114 transgenic lines reduced the sensitivity of rice to ABA.In addition,transcriptome and quantitative real-time PCR analyses showed that the overexpression of ZmWRKY114 affected the expression levels of some ABA response functions and stress-related genes,indicating that ZmWRKY114 may negatively regulate the response to salt stress in rice through ABA-mediated signaling pathway.