title: The virescent-2 mutation inhibits translation of plastid transcripts for the plastid genetic system at an early stage of chloroplast differentiation.
abstract: The rice virescent-2 mutant (v(2)) is temperature conditional and develops chlorotic, chloroplast-deficient leaves at the restrictive temperature. In the v(2) mutant, plastid-encoded proteins involved in photosynthesis and plastid transcriptional regulation were not detectable at any time during chloroplast differentiation. However, the plastid transcripts for these two classes of proteins behaved differently in the mutant, with those for the plastid transcription/translation apparatus accumulating to wild-type levels and those for photosynthetic apparatus being suppressed. Polysome analysis showed that translation of the plastid transcripts encoding the plastid transcription/translation apparatus was blocked at an early stage of chloroplast differentiation. Accumulation of transcripts of nuclear-encoded photosynthetic genes, such as cab and rbcS, was strongly suppressed in the mutant at later stages of chloroplast differentiation, whereas transcripts of genes for the plastid transcription apparatus, such as OsRpoTp and OsSIG2A, accumulated to abnormally high levels at these stages. These results suggest that activation of the plastid translation machinery at an early stage of chloroplast differentiation is important for triggering the transmission of information about plastid developmental state to the nucleus, which in turn is required for the induction of nuclear-encoded chloroplast proteins at later stages of chloroplast differentiation.
authors.affiliation: Department of Biology, Faculty of Science, Kyushu University, Fukuoka, 812-8581 Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Sugimoto
authors.forename: Kensuke
authors.initials: K
authors.lastname: Kusumi
authors.forename: Yuzuru
authors.initials: Y
authors.lastname: Tozawa
authors.forename: Junshi
authors.initials: J
authors.lastname: Yazaki
authors.forename: Naoki
authors.initials: N
authors.lastname: Kishimoto
authors.forename: Shoshi
authors.initials: S
authors.lastname: Kikuchi
authors.forename: Koh
authors.initials: K
authors.lastname: Iba
mesh_terms: D002454:Cell Differentiation / Q000235:genetics; D002467:Cell Nucleus / Q000235:genetics; D012321:DNA-Directed RNA Polymerases / Q000235:genetics; D015536:Down-Regulation / Q000235:genetics; D018506:Gene Expression Regulation, Plant / Q000235:genetics; D005809:Genes, Regulator / Q000235:genetics; D045342:Light-Harvesting Protein Complexes / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics*; D012275:Oryza / Q000166:cytology / Q000235:genetics* / Q000254:growth & development; D010788:Photosynthesis / Q000235:genetics; D010940:Plant Proteins / Q000096:biosynthesis* / Q000235:genetics; D018087:Plastids / Q000235:genetics* / Q000378:metabolism; D014176:Protein Biosynthesis / Q000235:genetics*; D012273:Ribulose-Bisphosphate Carboxylase / Q000235:genetics / Q000378:metabolism; D037941:Silencer Elements, Transcriptional / Q000235:genetics
chemical_list: D045342:Light-Harvesting Protein Complexes; D010940:Plant Proteins; D012321:DNA-Directed RNA Polymerases; C486921:RpoTp protein, Hordeum vulgare; D012273:Ribulose-Bisphosphate Carboxylase