A screen for genes that function in abscisic acid signaling in Arabidopsis thaliana.
The plant hormone abscisic acid (ABA) controls many aspects of plant growth and development under a diverse range of environmental conditions. To identify genes functioning in ABA signaling, we have carried out a screen for mutants that takes advantage of the ability of wild-type Arabidopsis seeds to respond to (-)-(R)-ABA, an enantiomer of the natural (+)-(S)-ABA. The premise of the screen was to identify mutations that preferentially alter their germination response in the presence of one stereoisomer vs. the other. Twenty-six mutants were identified and genetic analysis on 23 lines defines two new loci, designated CHOTTO1 and CHOTTO2, and a collection of new mutant alleles of the ABA-insensitive genes, ABI3, ABI4, and ABI5. The abi5 alleles are less sensitive to (+)-ABA than to (-)-ABA. In contrast, the abi3 alleles exhibit a variety of differences in response to the ABA isomers. Genetic and molecular analysis of these alleles suggests that the ABI3 transcription factor may perceive multiple ABA signals.
Department of Botany, University of Toronto, 25 Willcocks Street, Toronto, Ontario M5S 3B2, Canada.
Eiji
E
Nambara
Masaharu
M
Suzuki
Suzanne
S
Abrams
Donald R
DR
McCarty
Yuji
Y
Kamiya
Peter
P
McCourt
D000040:Abscisic Acid / Q000737:chemistry / Q000494:pharmacology / Q000502:physiology*; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics* / Q000502:physiology; D017343:Genes, Plant / Q000187:drug effects; D015398:Signal Transduction / Q000235:genetics*; D013237:Stereoisomerism; D014157:Transcription Factors / Q000378:metabolism
D014157:Transcription Factors; D000040:Abscisic Acid