title: Molecular identification of zeaxanthin epoxidase of Nicotiana plumbaginifolia, a gene involved in abscisic acid biosynthesis and corresponding to the ABA locus of Arabidopsis thaliana.
abstract: Abscisic acid (ABA) is a plant hormone which plays an important role in seed development and dormancy and in plant response to environmental stresses. An ABA-deficient mutant of Nicotiana plumbaginifolia, aba2, was isolated by transposon tagging using the maize Activator transposon. The aba2 mutant exhibits precocious seed germination and a severe wilty phenotype. The mutant is impaired in the first step of the ABA biosynthesis pathway, the zeaxanthin epoxidation reaction. ABA2 cDNA is able to complement N.plumbaginifolia aba2 and Arabidopsis thaliana aba mutations indicating that these mutants are homologous. ABA2 cDNA encodes a chloroplast-imported protein of 72.5 kDa, sharing similarities with different mono-oxigenases and oxidases of bacterial origin and having an ADP-binding fold and an FAD-binding domain. ABA2 protein, produced in Escherichia coli, exhibits in vitro zeaxanthin epoxidase activity. This is the first report of the isolation of a gene of the ABA biosynthetic pathway. The molecular identification of ABA2 opens the possibility to study the regulation of ABA biosynthesis and its cellular location.
authors.affiliation: INRA, Laboratorie de Biologie Cellulaire, France.
authors.forename: E
authors.initials: E
authors.lastname: Marin
authors.forename: L
authors.initials: L
authors.lastname: Nussaume
authors.forename: A
authors.initials: A
authors.lastname: Quesada
authors.forename: M
authors.initials: M
authors.lastname: Gonneau
authors.forename: B
authors.initials: B
authors.lastname: Sotta
authors.forename: P
authors.initials: P
authors.lastname: Hugueney
authors.forename: A
authors.initials: A
authors.lastname: Frey
authors.forename: A
authors.initials: A
authors.lastname: Marion-Poll
mesh_terms: D000040:Abscisic Acid / Q000096:biosynthesis*; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics*; D001483:Base Sequence; D002338:Carotenoids / Q000031:analogs & derivatives / Q000378:metabolism; D002736:Chloroplasts / Q000201:enzymology; D003001:Cloning, Molecular; D016384:Consensus Sequence; D018076:DNA, Complementary / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics; D017343:Genes, Plant; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D010088:Oxidoreductases / Q000737:chemistry / Q000235:genetics*; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics*; D010947:Plants, Toxic; D011487:Protein Conformation; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014026:Nicotiana / Q000201:enzymology / Q000235:genetics*; D024341:Xanthophylls; D065146:Zeaxanthins; D019207:beta Carotene / Q000031:analogs & derivatives*
chemical_list: D018076:DNA, Complementary; D018744:DNA, Plant; D010940:Plant Proteins; D011993:Recombinant Fusion Proteins; D024341:Xanthophylls; D065146:Zeaxanthins; D019207:beta Carotene; D002338:Carotenoids; D000040:Abscisic Acid; D010088:Oxidoreductases; C097153:zeaxanthin epoxidase