Plant Cell 1998 Jun;10(6):1043-54
Department of Molecular, Cellular, and Developmental Biology,
University of California, Santa Barbara, California 93106, USA.
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.
PMID: 9634591, UI: 98299844