A mutation in BrPRPL1 causes leaf yellowing by influencing chloroplast protein translation in Chinese cabbage

Leaf color directly affects the appearance quality and nutritional quality of leafy vegetables, thereby determining their economic value. Here, we identified a golden leaf mutant, Mut298, from an ethyl methanesulfonate (EMS)-induced mutant library of Chinese cabbage. Through the approach of forward genetics, it has been demonstrated that the phenotype of Mut298 is due to a single nucleotide substitution from C to T that changes glycine to arginine in the conserved domain of BrPRPL1, which encodes the large subunit ribosomal protein L1 of the chloroplast. Because the PRPL1 mutation causes embryonic lethality in Arabidopsis, the function of PRPL1 in leaf development remains elusive. In this study, the mutation of BrPRPL1 causes a substantial reduction in the expression of key chloroplast-encoded proteins (RbcL, PsaA, and PsaB) and disrupts chloroplast development. Moreover, the chlorophyll content and photosynthetic parameters are significantly lower in Mut298 plants than in wild-type plants, resulting in golden yellow leaves in Chinese cabbage. This study reveals the impact of PRPL1 mutation on ribosome translation within chloroplasts and provides a theoretical a foundation for future research into the regulatory roles of PRPL1 in plant growth and development.