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.
Publication types
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, Non-P.H.S.
MeSH terms
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Abscisic Acid / pharmacology*
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Amino Acid Sequence
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Arabidopsis / drug effects
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Arabidopsis / genetics*
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Arabidopsis / metabolism
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Arabidopsis Proteins
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Base Sequence
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Chromosome Mapping*
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Gamma Rays
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Gene Expression Regulation, Plant / drug effects
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Gene Expression Regulation, Plant / physiology*
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Genes, Plant
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Genetic Complementation Test
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Homeodomain Proteins / biosynthesis*
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Homeodomain Proteins / chemistry
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Homeodomain Proteins / genetics
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Molecular Sequence Data
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Mutagenesis
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Nuclear Proteins / biosynthesis*
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Nuclear Proteins / chemistry
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Nuclear Proteins / genetics
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Plant Proteins / biosynthesis
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Plants, Genetically Modified
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Polymorphism, Restriction Fragment Length
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Recombination, Genetic
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Seeds / physiology
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Sequence Alignment
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Sequence Homology, Amino Acid
Substances
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APETALA2 protein, Arabidopsis
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Arabidopsis Proteins
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Homeodomain Proteins
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Nuclear Proteins
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Plant Proteins
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Abscisic Acid