title: The Arabidopsis abscisic acid response locus ABI4 encodes an APETALA 2 domain protein.
abstract: Arabidopsis abscisic acid (ABA)-insensitive abi4 mutants have pleiotropic defects in seed development, including decreased sensitivity to ABA inhibition of germination and altered seed-specific gene expression. This phenotype is consistent with a role for ABI4 in regulating seed responses to ABA and/or seed-specific signals. We isolated the ABI4 gene by positional cloning and confirmed its identity by complementation analysis. The predicted protein product shows homology to a plant-specific family of transcriptional regulators characterized by a conserved DNA binding domain, the APETALA 2 domain. The single mutant allele identified has a single base pair deletion, resulting in a frameshift that should disrupt the C-terminal half of the protein but leave the presumed DNA binding domain intact. Expression analyses showed that despite the seed-specific nature of the mutant phenotype, ABI4 expression is not seed specific.
authors.affiliation: Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, California 93106, USA. finkelst@lifesci.lscf.ucsb.edu
authors.forename: R R
authors.initials: RR
authors.lastname: Finkelstein
authors.forename: M L
authors.initials: ML
authors.lastname: Wang
authors.forename: T J
authors.initials: TJ
authors.lastname: Lynch
authors.forename: S
authors.initials: S
authors.lastname: Rao
authors.forename: H M
authors.initials: HM
authors.lastname: Goodman
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology*; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins; D001483:Base Sequence; D002874:Chromosome Mapping; D005720:Gamma Rays; D018506:Gene Expression Regulation, Plant / Q000187:drug effects / Q000502:physiology*; D017343:Genes, Plant; D005816:Genetic Complementation Test; D018398:Homeodomain Proteins / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009687:Nuclear Proteins / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics; D010940:Plant Proteins / Q000096:biosynthesis; D030821:Plants, Genetically Modified; D012150:Polymorphism, Restriction Fragment Length; D011995:Recombination, Genetic; D012639:Seeds / Q000502:physiology; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
chemical_list: C499534:APETALA2 protein, Arabidopsis; D029681:Arabidopsis Proteins; D018398:Homeodomain Proteins; D009687:Nuclear Proteins; D010940:Plant Proteins; D000040:Abscisic Acid