Abstract:Cadmium (Cd) stress severely restricts plant growth, so it is particularly important to identify genes associated with plant cadmium stress tolerance. The UDP-glycosyltransferase gene (SlUDP) of tomato was screened by transcriptome data in response to cadmium stress in preliminary tests. In this research, the full-length sequence of the coding region of SlUDP gene was cloned, the expression of the gene were higher in leaves and fruits than other tissues, and the expression of the gene was up-regulated by cadmium stress. Cadmium tolerance analysis of yeast showed that the transfer of SlUDP gene improved the tolerance of cadmium stress in yeast. SlUDP-overexpressed Arabidopsis thaliana lines were obtained further, and the degree of cotyledonous greening of Arabidopsis overexpressing lines decreased under CdCl2 stress (40, 60, and 80 μM/L) compared with wild-type lines. The germination rate, root length and seed survival rate increased, while the malondialdehyde content decreased, meanwhile the soluble sugar content, superoxide dismutase activity and peroxidase activity increased, the expression levels of metal ion transporter genes ZIP1, IRT1, CSD1 and COPT2 were significantly higher than those of wild type. These results showed that the SlUDP overexpression line improved the cadmium tolerance of plants by regulating the antioxidant enzyme system, improving the ability of plants to scavenge reactive oxygen species, reducing the degree of membrane lipid peroxidation, and improving metal ion transport. This study provides a theoretical basis for the study of the role of glycosyltransferase genes in plant tolerance to cadmium stress, and provides candidate genes for molecular breeding of horticultural plant resistance.