Dimethyl sulfoxide synergistically mitigates cadmium-induced oxidative damage in pak choi by activating antioxidant and autophagy mechanisms

Cadmium (Cd) is one of the highly toxic heavy metals that restricts plant growth, affects crop yields, and triggers food crises. Dimethyl sulfoxide (DMSO) is frequently used solvent in biological studies, and its potential application in resistance to Cd toxicity in plants and animals has not been reported. Here, low concentrations of DMSO alone were demonstrated to increase the biomass of pak choi seedlings; more importantly, under Cd stress conditions, DMSO was shown to reduce Cd accumulation, and thereby alleviate Cd-induced damages. Specifically, DMSO could enhance plant defense mechanisms against Cd stress by strengthening the activities of endogenous reactive oxygen species (ROS) -scavenging enzymatic or non-enzymatic antioxidants, regulating the expression of key stress-responsive genes, as well as activating autophagy and apoptosis protection in root cells, thereby scavenging excessive ROS, restoring integration of cell membranes, and conferring tolerance to Cd-induced phytotoxicity. Our results showed that DMSO could play a vital role in mitigating Cd-induced oxidative damage by activating the protective mechanisms generated by the synergistic effects of both autophagy and antioxidants. These findings will help to formulate strategies to mitigate Cd contamination and to ensure the safety of cabbage production, an important vegetable source.