title: Specific function of a plastid sigma factor for ndhF gene transcription.
abstract: The complexity of the plastid transcriptional apparatus (two or three different RNA polymerases and numerous regulatory proteins) makes it very difficult to attribute specific function(s) to its individual components. We have characterized an Arabidopsis T-DNA insertion line disrupting the nuclear gene coding for one of the six plastid sigma factors (SIG4) that regulate the activity of the plastid-encoded RNA polymerase PEP. This mutant shows a specific diminution of transcription of the plastid ndhF gene, coding for a subunit of the plastid NDH [NAD(P)H dehydrogenase] complex. The absence of another NDH subunit, i.e. NDHH, and the absence of a chlorophyll fluorescence transient previously attributed to the activity of the plastid NDH complex indicate a strong down-regulation of NDH activity in the mutant plants. Results suggest that plastid NDH activity is regulated on the transcriptional level by an ndhF-specific plastid sigma factor, SIG4.
authors.affiliation: Laboratoire Plastes et différenciation cellulaire, Université Joseph Fourier and Centre National de la Recherche Scientifique, B.P. 53, 38041 Grenoble, France.
authors.forename: Jean-Jacques
authors.initials: JJ
authors.lastname: Favory
authors.forename: Masanori
authors.initials: M
authors.lastname: Kobayshi
authors.forename: Kan
authors.initials: K
authors.lastname: Tanaka
authors.forename: Gilles
authors.initials: G
authors.lastname: Peltier
authors.forename: Martin
authors.initials: M
authors.lastname: Kreis
authors.forename: Jean-Gabriel
authors.initials: JG
authors.lastname: Valay
authors.forename: Silva
authors.initials: S
authors.lastname: Lerbs-Mache
mesh_terms: D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000502:physiology*; D001483:Base Sequence; D004269:DNA, Bacterial / Q000235:genetics; D017353:Gene Deletion; D018506:Gene Expression Regulation, Plant; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D009245:NADH Dehydrogenase / Q000096:biosynthesis / Q000235:genetics*; D010940:Plant Proteins / Q000096:biosynthesis / Q000235:genetics*; D018087:Plastids / Q000235:genetics* / Q000378:metabolism; D012322:RNA Precursors / Q000737:chemistry / Q000378:metabolism; D018749:RNA, Plant / Q000737:chemistry / Q000378:metabolism; D012808:Sigma Factor / Q000235:genetics / Q000502:physiology*; D014158:Transcription, Genetic
chemical_list: D029681:Arabidopsis Proteins; D004269:DNA, Bacterial; D010940:Plant Proteins; D012322:RNA Precursors; D018749:RNA, Plant; C505023:Sig4 protein, Arabidopsis; D012808:Sigma Factor; C036483:T-DNA; C489904:NdhF protein, plant; D009245:NADH Dehydrogenase