title: Mutation of the rice ASL2 gene encoding plastid ribosomal protein L21 causes chloroplast developmental defects and seedling death.
abstract: The plastid ribosome proteins (PRPs) play important roles in plastid protein biosynthesis, chloroplast differentiation and early chloroplast development. However, the specialised functions of individual protein components of the chloroplast ribosome in rice (Oryza sativa) remain unresolved. In this paper, we identified a novel rice PRP mutant named asl2 (Albino seedling lethality 2) exhibiting an albino, seedling death phenotype. In asl2 mutants, the alteration of leaf colour was associated with chlorophyll (Chl) content and abnormal chloroplast development. Through map-based cloning and complementation, the mutated ASL2 gene was isolated and found to encode the chloroplast 50S ribosome protein L21 (RPL21c), a component of the chloroplast ribosome large subunit, which was localised in chloroplasts. ASL2 was expressed at a higher level in the plumule and leaves, implying its tissue-specific expression. Additionally, the expression of ASL2 was regulated by light. The transcript levels of the majority of genes for Chl biosynthesis, photosynthesis and chloroplast development were strongly affected in asl2 mutants. Collectively, the absence of functional ASL2 caused chloroplast developmental defects and seedling death. This report establishes the important role of RPL21c in chloroplast development in rice.
authors.affiliation: Development Center of Plant Germplasm Resources, College of Life and Environment Sciences, Shanghai Normal University, Shanghai, China.
authors.forename: D
authors.initials: D
authors.lastname: Lin
authors.forename: Q
authors.initials: Q
authors.lastname: Jiang
authors.forename: K
authors.initials: K
authors.lastname: Zheng
authors.forename: S
authors.initials: S
authors.lastname: Chen
authors.forename: H
authors.initials: H
authors.lastname: Zhou
authors.forename: X
authors.initials: X
authors.lastname: Gong
authors.forename: J
authors.initials: J
authors.lastname: Xu
authors.forename: S
authors.initials: S
authors.lastname: Teng
authors.forename: Y
authors.initials: Y
authors.lastname: Dong
mesh_terms: D000595:Amino Acid Sequence; D002734:Chlorophyll / Q000235:genetics / Q000378:metabolism; D060365:Chloroplast Proteins / Q000235:genetics* / Q000378:metabolism; D002736:Chloroplasts / Q000378:metabolism*; D003001:Cloning, Molecular; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D008027:Light; D008969:Molecular Sequence Data; D009154:Mutation; D012275:Oryza / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D010641:Phenotype; D010788:Photosynthesis / Q000235:genetics; D018515:Plant Leaves / Q000378:metabolism; D012269:Ribosomal Proteins / Q000235:genetics* / Q000378:metabolism; D054657:Ribosome Subunits; D036226:Seedlings / Q000254:growth & development / Q000378:metabolism
chemical_list: D060365:Chloroplast Proteins; D012269:Ribosomal Proteins; C060232:ribosomal protein L21; D002734:Chlorophyll
keywords: Chloroplast development; chloroplast ribosomal protein; gene mutation; map-based cloning; rice (Oryza sativa L.)