Heterologous Expression of Bacterial Dehydrin Promotes Arabidopsis Tolerance to Cadmium and Arsenic Stress

Background: Abiotic stresses, such as drought, salinity, temperature fluctuations, waterlogging, and heavy metal contamination, have a detrimental impact on plants, leading to reduced global agricultural productivity. The accumulation of cadmium (Cd) and arsenic (As) in agricultural soil, resulting from both natural and anthropogenic activities, poses significant threats to crop production and food safety. Dehydrins, also known as Group II Late Embryogenesis Abundant (LEA) proteins, are intrinsically disordered proteins that play crucial roles in protecting cellular structures during abiotic stress conditions. These proteins are considered promising candidates for enhancing plant tolerance to environmental stresses through their membrane-stabilizing and protective functions. Methods: This study evaluated the tolerance of Arabidopsis transgenic lines expressing a bacterial dehydrin gene (BG757) to Cd and As stresses using various physiological and biochemical parameters. Results: Compared with the wild-type (WT) control, the transgenic line (35S::BG757-1/Col-0) displayed significant increases in root and shoot growth upon exposure to Cd and As. Furthermore, transgenic plants exposed to heavy metal stress exhibited higher concentrations of chlorophyll, total protein, free proline, total flavonoid, and total phenolic content compared to WT plants. Likewise, transgenic plants showed higher 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and retained higher relative water content under stress conditions. Conclusions: Taken together, these findings suggest that bacterial dehydrins confer enhanced tolerance to heavy metal stress in transgenic Arabidopsis plants, highlighting their potential application in developing stress-resilient crops for contaminated environments.