A Rice Yellow-Green-Leaf 219 Mutant Lacking the Divinyl Reductase Affects Chlorophyll Biosynthesis and Chloroplast Development

Leaf-color mutants are ideal genetic materials for studying the mechanism of chlorophyll (Chl) biosynthesis and chloroplast development. Here we isolated and identified a novel rice yellow-green-leaf mutant from a Co-60-irradiated mutant pool, named ygl219. In the ygl219 mutant, the pigments contents were decreased and the development of chloroplast was arrested. Map-based cloning and subsequent DNA sequencing analysis revealed a single nucleotide substitution happened in divinyl reductase (DVR) gene in the ygl219 mutant. Genetic complementation of the ygl219 mutant restored normal green leaf by expressing full length coding sequence of DVR. Subcellular localization indicated the DVR protein was located in the chloroplast. qRT-PCR analysis revealed that most of the genes associated with chlorophyll biosynthesis were significantly upregulated, while most of the genes associated with chloroplast development and photosynthesis were significantly downregulated in the ygl219 mutant. These data indicated that DVR plays an important role in chlorophyll biosynthesis and chloroplast development in rice.