Functional Analysis Of WRKY12 Gene In Response Of Plants To Cadmium Stress In Arabidopsis

Soil cadmium pollution is becoming more and more serious.It has become an ecological problem in the world.The key to solve this problem is how to reuse the contaminated soil.Phytoremediation is the use of plant heavy metal over-accumulation characteristics that heavy metals can be absorbed from the soil and transport to the ground part for clear,and finally achieve the effect of soil purification.To study the response mechanism of plant to heavy metal signal and the absorption and transport of heavy metals can provide more theoretical basis for the application of phytoremediation technology.In this study,the response mechanism of Arabidopsis thaliana transcription factor WRKY12 to cadmium stress was studied.The function of WRKY12 gene and its mechanism were investigated by genetic engineering,molecular biology and genetics.After a series of experimental analysis,the following conclusions were obtained:1.The mutant wrky12-1 and wrky12-2 showed significant tolerance compared with WT under the condition of cadmium stress,which indicated that WRKY12 gene may be involved in the response mechanism of Arabidopsis thaliana stress,and its function loss could lead to the effect of Arabidopsis on cadmium of tolerance.Construction of WT seedlings with CdCl₂ showed that WRKY12 gene could be induced by Cd.2.The WRKY12 gene was cloned into the Arabidopsis thaliana WRKY12 gene and ligated into the pART27 vector containing the strong promoter to construct the WRKY12 overexpressing vector.The recombinant vector was transferred into Arabidopsis thaliana by transgenic technique to screen the WRKY12 overexpressing plants.3.WRKY12 overexpressing plants showed a sensitive phenotype compared to WT under cadmium stress,indicating that the function of WRKY12 gene in Arabidopsis thaliana response to cadmium stress may be a negative regulator.4.The accumulation of cadmium in roots and shoots of wrky12 mutants and overexpression plants showed that the accumulation of cadmium in the roots and shoots of Arabidopsis thaliana seedlings was significantly higher than that of WT after growing for about a period of time in CdCl₂-containing medium.The accumulation of cadmium in root and stem of plant was significantly lower than that in WT.It was suggested that the increase in cadmium accumulation in Arabidopsis thaliana may be due to loss of WRK12 gene function.5.The transcriptional level of related genes involved in GSH synthesis was analyzed by qRT-PCR.In the case of cadmium exposure,the expression levels of GSH1,PCS2,genes in wrky12 mutants were significantly increased.In WRKY12 overexpression plants,the expression of these genes showed a decreasing trend.Indicating that WRKY12 transcription factor may be involved in the transcriptional regulation of GSH synthesis related genes.6.The content of GSH in wrky12 mutants Cd was higher than that in WT,while the GSH content of WRKY12 overexpression plants showed a decreasing trend compared with WT.The PC content of wrky12 mutants Cd was significantly higher In WT,it was suggested that WRKY12 transcription factor may be involved in the response mechanism of cadmium stress by regulating the synthesis pathway of GSH and PC.In summary,WRKY12 is a negative regulatory factor involved in Arabidopsis response to cadmium stress and regulation of GHS,PC synthesis pathway-related genes can regulate the transcription of GSH,PC synthesis,and thus affect the Arabidopsis tolerance to cadmium.