title: Plastid RNA polymerases, promoters, and transcription regulators in higher plants.
abstract: Plastids are semiautonomous plant organelles exhibiting their own transcription-translation systems that originated from a cyanobacteria-related endosymbiotic prokaryote. As a consequence of massive gene transfer to nuclei and gene disappearance during evolution, the extant plastid genome is a small circular DNA encoding only ca. 120 genes (less than 5% of cyanobacterial genes). Therefore, it was assumed that plastids have a simple transcription-regulatory system. Later, however, it was revealed that plastid transcription is a multistep gene regulation system and plays a crucial role in developmental and environmental regulation of plastid gene expression. Recent molecular and genetic approaches have identified several new players involved in transcriptional regulation in plastids, such as multiple RNA polymerases, plastid sigma factors, transcription regulators, nucleoid proteins, and various signaling factors. They have provided novel insights into the molecular basis of plastid transcription in higher plants. This review summarizes state-of-the-art knowledge of molecular mechanisms that regulate plastid transcription in higher plants.
authors.affiliation: Faculty of Human Environment, Kyoto Prefectural University, Kyoto 606-8522, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Shiina
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Tsunoyama
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Nakahira
authors.forename: Muhammad S
authors.initials: MS
authors.lastname: Khan
mesh_terms: D012321:DNA-Directed RNA Polymerases / Q000235:genetics* / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D010802:Phylogeny; D018514:Plant Structures / Q000235:genetics / Q000378:metabolism; D018087:Plastids / Q000235:genetics* / Q000378:metabolism; D011401:Promoter Regions, Genetic; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D014157:Transcription Factors; D012321:DNA-Directed RNA Polymerases