Mechanism By Which WRKY47 Gene Regulating The Cadmium Stress Response In Arabidopsis Thaliana

The phytoremediation technology is one of the most effective ways to treat cadmium pollution in soil.In order to find cadmium-related genes,WRKY47 significantly induced by cadmium which in the WRKY transcriptional family IIb group.(1)Phenotype analysis of wrky47-1 and wrky47-2 showed that it was resistant to cadmium.The cadmium resistance phenotype of the mutant disappeared and restored by BSO,suggesting that WRKY47 mediated cadmium tolerance dependent GSH pathway.(2)Phenotype analysis of WRKY47OE3 and WRKY47OE6 showed that WRKY47 overexpressed plants were highly tolerant to cadmium.(3)wrky47-1 and WRKY47OE3 plants were tolerant to BSO,indicating that the WRKY47 is involved in the glutathione synthesis degradation cycle.The determination of cadmium and GSH in roots and stems of mutant and overexpressing plants,showed that cadmium was less than WT and GSH content was higher than WT in mutant and overexpressed plants.Suggesting that WRKY47 reduced the absorption of cadmium by storing high content of GSH in roots to tolerance cadmium.(4)The expression of glutathione regulated genes in wrky47 mutant and WRKY47 overexpressing plants was detected.It was found that the gene CLT1 was positively correlated with WRKY47,and the gene GGCT2;1 was negatively correlated with WRKY47.(5)Cloning of the promoter region of the gene CLT1 and the gene GGCT2;1revealed that there are three W-BOX sites in the promoter region of both genes.Tansient expression results showed that transcription factor WRKY47 fine-tuned CLT1 expression level and inhibited GGCT2.1 expression level.(6)Cadmium induction of ProWRKY47-GUS and ProGGCT2;1-GUS was found to be strongly expressed in Arabidopsis root tip,wrky47 plant ProGGCT2;1-GUS expression level was higher than WT,WRKY47 gene deletion increased ProGGCT2;1-GUS root tip The expression level.(7)The wrky47 mutant and the WRKY47 overexpressing plant were tolerant to arsenic.In conclusion,this study found that WRKY47 negatively regulates degradation of GSH glutamine transferase GGCT2;1 gene expression,increases apical GSH content and reduces cadmium uptake to cadmium,and confirms WRKY47 is a GSH balance factor that regulates glutathione cycle.