Identification and characterization of the yls mutation in rice (Oryza sativa L.) with lower photosynthetic pigment content

Abstract

Normal chloroplast development in rice is essential for photosynthesis and yield potential. To explore the physiological and molecular mechanism of chloroplast development, we isolated the rice mutant yls, which has yellow-green leaves at the rice seedling stage. In comparison with wild type (WT) plants, mutant plants had lower chlorophyll and carotenoid contents at the seedling stage. Transmission electron micrographs of the leaves of mutant plants showed abnormal grana stacking. We finally mapped the YLS gene within the BAC clone OSJNBa0032M21 of chromosome 11. Sequence analysis revealed the existence of a 33-bp deletion within the 3'-untranslated region (UTR) of the cpSRP54 gene, which encodes the 54-kDa subunit of the chloroplast signal recognition particle (SRP). A knockdown of cpSRP54 using RNAi technology produced the yls phenotypes, indicating that cpSRP54 is responsible for the phenotypic changes found in the yls mutant. The study suggests the existence of a functional association between cpSRP54 and chloroplast development in rice.

Keywords

• chloroplast development
• map-based cloning
• srp54 protein
• yellow-green leaf mutant