Gong Xiaodi, Jiang Quan, Xu Jianlong, Zhang Jianhui, Teng Sheng, Lin Dongzhi, Dong Yanjun
Development Center of Plant Germplasm Resources, College of Life and Environmental Sciences, Shanghai Normal University, Shanghai 200234.
G3 (Bethesda). 2013 Oct 3;3(10):1769-77. doi: 10.1534/g3.113.007856.
Plastid ribosomal proteins (PRPs) are essential for ribosome biogenesis, plastid protein biosynthesis, chloroplast differentiation, and early chloroplast development. This study identifies the first rice PRP mutant, asl1 (albino seedling lethality1), which exhibits an albino lethal phenotype at the seedling stage. This albino phenotype was associated with altered chlorophyll (Chl) content and chloroplast development. Map-based cloning revealed that ASL1 encodes PRP S20 (PRPS20), which localizes to the chloroplast. ASL1 showed tissue-specific expression, as it was highly expressed in plumule and young seedlings but expressed at much lower levels in other tissues. In addition, ASL1 expression was regulated by light. The transcript levels of nuclear genes for Chl biosynthesis and chloroplast development were strongly affected in asl1 mutants; transcripts of some plastid genes for photosynthesis were undetectable. Our findings indicate that nuclear-encoded PRPS20 plays an important role in chloroplast development in rice.
质体核糖体蛋白（PRPs）对于核糖体生物合成、质体蛋白质生物合成、叶绿体分化以及早期叶绿体发育至关重要。本研究鉴定出首个水稻PRP突变体，即asl1（白化苗致死1），其在幼苗期表现出白化致死表型。这种白化表型与叶绿素（Chl）含量改变和叶绿体发育异常有关。图位克隆显示，ASL1编码定位于叶绿体的PRP S20（PRPS20）。ASL1呈现组织特异性表达，在胚芽和幼苗中高表达，而在其他组织中表达水平低得多。此外，ASL1的表达受光调控。asl1突变体中叶绿素生物合成和叶绿体发育的核基因转录水平受到强烈影响；一些参与光合作用的质体基因转录本检测不到。我们的研究结果表明，核编码的PRPS20在水稻叶绿体发育中起重要作用。
