Efficient breeding of low glutelin content rice germplasm by simultaneous editing multiple glutelin genes via CRISPR/Cas9.

Chronic kidney disease (CKD) and phenylketonuria (PKU) patients need to eat rice with low glutelin content. Therefore, breeding low glutelin content rice varieties with high yield and delicious taste is one of the major goals of rice breeders due to the high demand for the product. In this study, we designed three sgRNAs targeting nine glutelin genes and generated nine T-DNA-free homozygous editing lines with reduced glutelin content compared with the wild-type due to simultaneous mutation(s) in 5-7 glutelin genes. The glutelin content of two lines is even significantly lower than that of the low glutelin content cultivar, LGC-1. Compared to the wild-type, these low glutelin lines showed similar agronomic traits, including yield components and viscosity properties, and can be used as new varieties or parental materials for further breeding.