title: Isolation and characterization of the cytoplasmic male sterility-associated orf456 gene of chili pepper (Capsicum annuum L.).
abstract: Cytoplasmic male sterility (CMS) in plants is known to be associated with novel open reading frames (ORFs) that result from recombination events in the mitochondrial genome. In this study Southern and Northern blot analyses using several mitochondrial DNA probes were conducted to detect the presence of differing band patterns between male fertile and CMS lines of chili pepper (Capsicum annuum L.). In the CMS pepper, a novel ORF, termed orf456, was found at the 3'-end of the coxll gene. Western blot analysis revealed the expression of an approximately 17-kDa product in the CMS line, and the intensity of expression of this protein was severely reduced in the restorer pepper line. To investigate the functional role of the ORF456 protein in plant mitochondria, we carried out two independent experiments to transform Arabidopsis with a mitochondrion-targeted orf456 gene construct by Agrobacterium-mediated transformation. About 45 % of the T1 transgenic population showed the male-sterile phenotype and no seed set. Pollen grains from semi-sterile T1 plants were observed to have defects on the exine layer and vacuolated pollen phenotypes. It is concluded that this newly discovered orf456 may represent a strong candidate gene--from among the many CMS-associated mitochondrial genes--for determining the male-sterile phenotype of CMS in chili pepper.
authors.affiliation: Department of Plant Science, College of Agriculture and Life Sciences, and Center for Plant Molecular Genetics and Breeding Research, Seoul National University, Seoul 151-921, Korea.
authors.forename: Dong Hwan
authors.initials: DH
authors.lastname: Kim
authors.forename: Jeong Gu
authors.initials: JG
authors.lastname: Kang
authors.forename: Byung-Dong
authors.initials: BD
authors.lastname: Kim
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D015139:Blotting, Southern; D002212:Capsicum / Q000235:genetics / Q000502:physiology*; D003001:Cloning, Molecular; D003593:Cytoplasm; D004926:Escherichia coli; D005298:Fertility; D007246:Infertility / Q000235:genetics*; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D010940:Plant Proteins / Q000235:genetics; D011058:Pollen / Q000235:genetics; D015183:Restriction Mapping
chemical_list: D010940:Plant Proteins