title: Expression and developmental function of the 3-ketoacyl-ACP synthase2 gene in Arabidopsis thaliana.
abstract: The 3-ketoacyl-ACP synthase (KAS) II is a fatty-acid-related enzyme which catalyzes the elongation of 16:0-acyl carrier protein (ACP) to 18:0-ACP in plastids. The fatty acid biosynthesis 1-1 (fab1-1) mutant of Arabidopsis thaliana is partially deficient in its activity of Arabidopsis thaliana 3-ketoacyl-ACP synthase 2 (AtKAS2), and its phenotype has been intensively studied in connection with the chilling resistance and fatty acid composition. In this study, we used the T-DNA insertion mutant of AtKAS2 to examine its possible role in plant development. Reverse transcription (RT)-PCR showed that the AtKAS2 gene was expressed in various plant organs, except for roots, and was highly expressed in siliques. The fusion of beta-glucuronidase (GUS) to the AtKAS2 promoter demonstrated that the promoter was active in various tissues such as embryos, stomatal guard cells, inflorescences and pollen grains. We were not able to identify atkas2 homozygous mutant adult plants in heterozygous mutant progeny. Phenotypic and genetic analyses showed that disruption of the AtKAS2 by T-DNA insertion caused embryo lethality, and the development of the embryos was arrested at the globular stage. Taken together, our results suggest that AtKAS2 is required for embryo development in Arabidopsis during the transition from the globular to the heart stage.
authors.affiliation: Laboratory of Plant Reproductive Genetics, Graduate School of Life Sciences, Tohoku University, Sendai, Japan.
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Hakozaki
authors.forename: Jong-In
authors.initials: JI
authors.lastname: Park
authors.forename: Makoto
authors.initials: M
authors.lastname: Endo
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Takada
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Kazama
authors.forename: Yoshimitsu
authors.initials: Y
authors.lastname: Takeda
authors.forename: Go
authors.initials: G
authors.lastname: Suzuki
authors.forename: Makiko
authors.initials: M
authors.lastname: Kawagishi-Kobayashi
authors.forename: Masao
authors.initials: M
authors.lastname: Watanabe
mesh_terms: D015099:3-Oxoacyl-(Acyl-Carrier-Protein) Synthase / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000196:embryology* / Q000201:enzymology* / Q000235:genetics; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D015870:Gene Expression; D008969:Molecular Sequence Data; D009154:Mutation; D010641:Phenotype; D017386:Sequence Homology, Amino Acid
chemical_list: D029681:Arabidopsis Proteins; D015099:3-Oxoacyl-(Acyl-Carrier-Protein) Synthase