摘要
Although the multiple organellar RNA editing factors （MORFs） in the plastids of Arabidopsis thaliana have been extensively studied, molecular details underlying how MORFs affect plant development in other species, particularly in rice, remain largely unknown. Here we describe the characterization of wspl, a rice mutant with white-stripe leaves and panicles. Notably, wspl exhibited nearly white immature panicles at the heading stage. Transmission electron microscopy analysis and chlorophyll content measurement re- veale i a chloroplast developmental defect and reduced chlorophyll accumulation in wspl. Positional cloning of WSP1 found a point mutation in OsO4g51280, whose putative product shares high sequence similarity with MORF proteins. Complementation experiments demonstrated that WSP1 was responsible for the variegated phenotypes of wspl. WSP1 is localized to chloroplasts and the point mutation in wspl affected the editing of multiple organellar RNA sites. Owing to the defect in plastid RNA editing, chloroplast ribosome biogenesis and ndhA splicing were also impaired in wspl, which may affect normal chloroplast development in the leaves and panicles at the heading stage. Together, our results demonstrate the importance of rice WSP1 protein in chloroplast development and broaden our knowledge about MORF family members in rice.
Although the multiple organellar RNA editing factors （MORFs） in the plastids of Arabidopsis thaliana have been extensively studied, molecular details underlying how MORFs affect plant development in other species, particularly in rice, remain largely unknown. Here we describe the characterization of wspl, a rice mutant with white-stripe leaves and panicles. Notably, wspl exhibited nearly white immature panicles at the heading stage. Transmission electron microscopy analysis and chlorophyll content measurement re- veale i a chloroplast developmental defect and reduced chlorophyll accumulation in wspl. Positional cloning of WSP1 found a point mutation in OsO4g51280, whose putative product shares high sequence similarity with MORF proteins. Complementation experiments demonstrated that WSP1 was responsible for the variegated phenotypes of wspl. WSP1 is localized to chloroplasts and the point mutation in wspl affected the editing of multiple organellar RNA sites. Owing to the defect in plastid RNA editing, chloroplast ribosome biogenesis and ndhA splicing were also impaired in wspl, which may affect normal chloroplast development in the leaves and panicles at the heading stage. Together, our results demonstrate the importance of rice WSP1 protein in chloroplast development and broaden our knowledge about MORF family members in rice.
