| As an important food crop and industrial raw material,maize has formed a complex regulatory network for the response to various environmental stresses during the process of evolution.One of them,transcription factor binding to the target gene to regulate the expression of various stress related genes is able to achieve the effect of anti reverse.Many studies showed that the MYB transcription factor family can respond to plant stress actively.Among them,the R2R3 is the most conserved and extensive subfamily,that participate in plant stress.But the research of R1R2R3 subfamily in plant stress is less,just some members to be reported as known as related to salt and drought tolerance from Arabidopsis thaliana and rice and wheat.In this study,we analyzed the 3R subfamily gene in maize,identified and cloned the Zm MYB3 R gene.Through a series of studies on subcellular localization,fluorescence quantitative PCR,and overexpression transgene the function of this gene was identified.Then,the mechanism of this gene in response to stress was analyzed preliminary.Specific results are as follows:1.By sequence analysis,the total length of 1692 bp was found to Zm MYB3 R encoding 563 amino acids.The molecular weight is 61.66 k D,and the isoelectric point is 8.33.At the amino end,there are three MYB domains with three Amino acid residue in each MYB domain.In addition,the Zm MYB3 R gene is closely related to the 3R gene,which is closely related to the stress of the near edge species.2.Fluorescence quantitative PCR results showed that the expression of Zm MYB3 R gene expression induced by exogenous ABA,drought and high salt stress.At the same time,tissue expression pattern analysis showed that Zm MYB3 R had different levels of expression in various tissues,with high expression in stems and leaves.3.The Zm MYB3 R transcription factor is a nuclear localization protein,which is found by the subcellular localization analysis.Transcriptional activity analysis showed that the gene had transcriptional activity,and the minimal active region is 217-563 bp.4.The PCR method was used to construct the expression vector,transgenic Arabidopsis thaliana plants were obtained by agrobacterium mediated transformation.Na Cl and mannitol were added to MS medium to simulate the high salt and drought environment.In addition,plants were treated with high salt and drought in the real environment,and the damage degree was measured.Stress treatment showed that: compared to the wild type,the salt tolerance and drought resistance of transgenic plants were significantly increased.5.ABA sensitivity test showed that the germination rate of transgenic plants wassignificantly higher than that of wild type,and the stomatal aperture of leaves was significantly decreased.Using exogenous ABA to deal with transgenic and wild type Arabidopsis thaliana,the germination rate of transgenic Arabidopsis was significantly higher than that of wild type.The stomatal aperture of transgenic Arabidopsis was relatively narrow after ABA treatment.Suggesting Zm MYB3 R could affect the growth and development of plants in the presence of exogenous ABA.6.Fluorescence quantitative PCR analysis showed that the expression of ABA synthesis and downstream related gene in transgenic plants was significantly higher than that of wild type,which suggested that Zm MYB3 R can enhanced the stress resistance of plants by regulating ABA signaling pathway.The results indicate that Zm MYB3 R can induced downstream stress related gene expression depend on ABA,thereby improving abiotic stress tolerance of plants. |
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