Gene Editing Cuts Cadmium in Rice Grains Without Yield Penalty

Researchers from the Chinese Academy of Sciences and partners have identified a gene that could help develop rice varieties with lower cadmium (Cd) levels while maintaining crop yields. The findings of the study could support efforts to improve food safety in areas where paddy soils are contaminated with Cd, a toxic heavy metal that can enter the food chain through crops.

The researchers found that Cd exposure increased OsGONST3 activity in rice roots and shoots. The gene encodes a protein located in the cell membrane that appears to help Cd enter plant tissues. When OsGONST3 was disrupted using CRISPR-Cas9, mutant rice plants had 22-25% less Cd in their roots, about 13% less in shoots, and 16-21% less in xylem sap compared with normal plants under controlled conditions. In contrast, plants that overexpressed the gene accumulated substantially more Cd in these tissues.

Field trials showed that disrupting OsGONST3 reduced Cd levels in rice grains by about 25-26% without significantly affecting yield. The researchers also observed changes in other genes involved in Cd regulation. The findings identify OsGONST3 as a promising genetic target for breeding low-Cd rice and limiting the entry of Cd into the food supply.

For more information, read the study in the Journal of Hazardous Materials.