The I1NF-YC6 transcription factor of Iris lactea var. chinensis (Fisch.) activates the llCDT1 gene and enhances tolerance to cadmium stress in Arabidopsis thaliana

Heavy metal pollution of soil has become a serious global concern in recent years. In particular, cadmium (Cd) contamination is a ubiquitous environmental problem among heavy metals. Iris lactea var. chinensis is a perennial herb with significant ecological and industrial value. It is known for its good cadmium tolerance and cadmium enrichment capabilities; thus, it is considered an important plant for the restoration of cadmium-contaminated soil. Previous studies have shown that the cysteine-rich gene, IlCDT1 isolated from I. lactea conferred tolerance to Cd stress in yeast and Arabidopsis thaliana. However, the molecular mechanism of its regulation is poorly understood to date. In the current study, we screened and identified the transcription factor IlNF-YC6 that regulates IlCDT1 using yeast one-hybrid assay (Y1H). Overexpression of IlNF-YC6 conferred a significant tolerance to Cd stress in A. thaliana. Furthermore, the detection of physiological markers and transcriptome analysis revealed that IlNF-YC6 might increase plant tolerance to Cd stress primarily by improving plant detoxification ability and antioxidant capacity. Overall, our study would provide a genetic resource for candidate gene selection that might enhance plant tolerance to Cd contamination in soil or groundwater and subsequently lowering Cd absorption in the future.