The essential roles of OsFtsH2 in developing the chloroplast of rice

Abstract

Background Filamentation temperature-sensitive H (FtsH) is an ATP-dependent zinc metalloprotease with ATPase activity, proteolysis activity and molecular chaperone-like activity. For now, a total of nine FtsH proteins have been encoded in rice, but their functions have not revealed in detail. In order to investigate the molecular mechanism of OsFtsH2 here, several osftsh2 knockout mutants were successfully generated by the CRISPR/Cas9 gene editing technology. Results All the mutants exhibited a phenotype of striking albino leaf and could not survive through the stage of three leaves. OsFtsH2 was located in the chloroplast and preferentially expressed in green tissues. In addition, osftsh2 mutants could not form normal chloroplasts and had lost photosynthetic autotrophic capacity. RNA sequencing analysis indicated that many biological processes such as photosynthesis-related pathways and plant hormone signal transduction were significantly affected in osftsh2 mutants. Conclusions Overall, the results suggested OsFtsH2 to be essential for chloroplast development in rice.