title: hcf5, a nuclear photosynthetic electron transport mutant of Arabidopsis thaliana with a pleiotropic effect on chloroplast gene expression.
abstract: A photosynthetic mutant of Arabidopsis thaliana, hcf5, was isolated by screening M2 seedlings for high chlorophyll fluorescence. Thylakoid morphology was strikingly abnormal, with large grana stacks and almost no stroma lamellae. Fluorescence induction kinetics, activity assays, and immunoblotting showed that photosystem II was absent. Polypeptides of the photosystem I complex, the Cyt b6/f complex, coupling factor, and the large subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase were also severely depleted. However, the nuclear-encoded chlorophyll a/b light-harvesting complex polypeptides were unaffected. The rbcL transcript was present at very low levels, the pattern of transcripts from the polycistronic psbB-psbH-petB-petD operon was abnormal, and the mature psbH message was almost completely lacking. This suggests that the hcf5 locus may encode a product required for the correct expression of several chloroplast genes.
authors.affiliation: Department of Botany, University of British Columbia, Vancouver, Canada.
authors.forename: R D
authors.initials: RD
authors.lastname: Dinkins
authors.forename: H
authors.initials: H
authors.lastname: Bandaranayake
authors.forename: L
authors.initials: L
authors.lastname: Baeza
authors.forename: A J
authors.initials: AJ
authors.lastname: Griffiths
authors.forename: B R
authors.initials: BR
authors.lastname: Green
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism; D002736:Chloroplasts / Q000378:metabolism*; D003573:Cytochrome b Group / Q000235:genetics / Q000378:metabolism; D045346:Cytochrome b6f Complex; D004579:Electron Transport; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D045342:Light-Harvesting Protein Complexes; D009154:Mutation; D009876:Operon; D010788:Photosynthesis / Q000235:genetics*; D045322:Photosynthetic Reaction Center Complex Proteins / Q000235:genetics / Q000378:metabolism; D045331:Photosystem I Protein Complex; D045332:Photosystem II Protein Complex; D018749:RNA, Plant / Q000378:metabolism; D012273:Ribulose-Bisphosphate Carboxylase / Q000096:biosynthesis / Q000235:genetics; D014158:Transcription, Genetic
chemical_list: D003573:Cytochrome b Group; D045342:Light-Harvesting Protein Complexes; D045322:Photosynthetic Reaction Center Complex Proteins; D045331:Photosystem I Protein Complex; D045332:Photosystem II Protein Complex; D018749:RNA, Plant; D045346:Cytochrome b6f Complex; D012273:Ribulose-Bisphosphate Carboxylase