A novel chloroplast-localized protein EMB1303 is required for chloroplast development in Arabidopsis.
To understand the molecular mechanisms underlying chloroplast development, we isolated and characterized the albino mutant emb1303-1 in Arabidopsis. The mutant displayed a severe dwarf phenotype with small albino rosette leaves and short roots on a synthetic medium containing sucrose. It is pigment-deficient and seedling lethal when grown in soil. Embryo development was delayed in the mutant, although seed germination was not significantly impaired. The plastids of emb1303-1 were arrested in early developmental stages without the classical stack of thylakoid membrane. Genetic and molecular analyses uncovered that the EMB1303 gene encodes a novel chloroplast-localized protein. Microarray and RT-PCR analyses revealed that a number of nuclear- and plastid-encoded genes involved in photosynthesis and chloroplast biogenesis were substantially downregulated in the mutant. Moreover, the accumulation of several major chloroplast proteins was severely compromised in emb1303-1. These results suggest that EMB1303 is essential for chloroplast development.
Huang
Xiaozhen
X
State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
Zhang
Xiaoyan
X
Yang
Shuhua
S
D017360:Arabidopsis / Q000254:growth & development*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D002736:Chloroplasts / Q000378:metabolism*; D015536:Down-Regulation; D018506:Gene Expression Regulation, Plant; D001678:Organelle Biogenesis; D010641:Phenotype; D010788:Photosynthesis; D030821:Plants, Genetically Modified / Q000254:growth & development
D029681:Arabidopsis Proteins; C546346:EMB1303 protein, Arabidopsis