Overexpression of OsABCG48 Lowers Cadmium in Rice (Oryza sativa L.)

Cadmium pollution threatens food safety and security by causing health issues and reducing farmland availability. Engineering genetic changes in crop plants to lower Cd accumulation can be a cost-effective approach to address this problem. Previously, we reported that a rice line, 2B, which expresses a truncated version of OsO3L2 had reduced Cd accumulation throughout the plant, including in seed. However, downstream events caused by expression of this gene were not known. In this study, RNA-seq was used to identify differentially expressed genes between the wild type and 2B rice with or without Cd treatment, leading to the study of an ABC transporter gene, OsABCG48 (ATP-Binding Cassette transporter G family member 48). Heterologous expression of OsABCG48 conferred tolerance to Cd in Schizosaccharomyces pombe, Arabidopsis and rice. Moreover, overexpressing OsABCG48 in rice lowered root Cd accumulation that was associated with more extensive lateral root development. These data suggest that OsABCG48 might have applications for engineering low-Cd rice.

Automated summary

This study identified the ABC transporter gene OsABCG48 as having a role in regulating cadmium accumulation in rice roots. Overexpression of OsABCG48 increased cadmium tolerance in plants, reduced root cadmium accumulation, and promoted lateral root development. These findings suggest that OsABCG48 has potential applications for engineering low-cadmium rice varieties.