Mutation of an RNase E/G-type en-doribonuclease, OsRNE, produces defective chloroplast and causes early seedling lethality in rice

Endoribonuclease E (RNase E) has been reported to play a vital role in chloroplast RNA metabo-lism. We characterized the function of the OsRNE (Oryza sativa RNase E) in rice. Analysis of mutant plants generated by CRISPR-Cas9 system revealed that RNase E is essential for survival of rice. The osrne mutant displayed a white phenotype at the seedling stage and did not survive past the three-leaf stage. Transcriptome analysis showed that most of the genes associated with photosynthesis and carbohydrate metabolism pathways were significantly down-regulated. Chlorophyll- and other pigment-related genes were also differentially expressed in the osrne mutant. Our findings demonstrated that OsRNE plays an important role in chlorophyll biosynthesis and chloroplast development in rice.