OsGSTU5 and OsGSTU37 encoding glutathione reductases are required for cadmium tolerance in rice

Cadmium damages rice cells and affects rice yield and quality. Glutathione S-transferase (GST) plays a diverse role in plant responses to cadmium stress by binding exogenous toxic molecules to glutathione (GSH). Here, we identified two new GST genes, OsGSTU5 and OsGSTU37, and found that their transcripts were induced by cadmium. Yeast cells containing OsGSTU5 or OsGSTU37 displayed high tolerance to cadmium. The seed germination rate, seedling growth and the survival rate under cadmium stress were improved in OsGSTU5- or OsGSTU37-overexpressing lines. In contrast, CRISPR/Cas9-mediated OsGSTU5 or OsGSTU37 knockout lines showed cadmium-hypersensitive phenotypes. Physiological analysis showed that the activities of antioxidant enzymes and glutathione reductase were increased in OsGSTU5-OE and OsGSTU37-OE, which enhanced their tolerance to cadmium. In conclusion, OsGSTU5 and OsGSTU37 are involved in the regulatory mechanism of cadmium tolerance in rice.

Automated summary

Two newly identified GST genes, OsGSTU5 and OsGSTU37, play a role in the regulatory mechanism of cadmium tolerance in rice by enhancing the activity of antioxidant enzymes and glutathione reductase.