OsDXR interacts with OsMORF1 to regulate chloroplast development and the RNA editing of chloroplast genes in rice

Abstract

Plant chlorophyll biosynthesis and chloroplast development are two complex processes regulated by exogenous and endogenous factors. In this study, we identified OsDXR , a gene expressing a reductoisomerase that positively regulates chlorophyll biosynthesis and chloroplast development in rice. OsDXR knock-out lines displayed the albino phenotype and could not complete the whole life cycle process. OsDXR was highly expressed in rice leaves, and subcellular localization indicated that OsDXR was a chloroplast protein. Many genes involved in chlorophyll biosynthesis and chloroplast development were differentially expressed in the OsDXR knock-out lines compared to the wild type. Moreover, we found that the RNA editing efficiency of ndhA -1019 and rpl2 -1 were significantly reduced in the OsDXR knock-out lines. Furthermore, OsDXR interacted with the RNA editing factor OsMORF1 in a yeast two-hybrid screen and bimolecular fluorescence complementation assay. We demonstrate that disruption of the plastidial 2-C-methyl-derythritol-4-phosphate pathway results in defects in chloroplast development and RNA editing of chloroplast genes.