Abstract
Abiscisic acid (ABA) regulates many aspects of plant growth and development, including seed maturation, germination and adaptation to environmental stresses. Despite of its important function, ABA signal-transduction-pathway still remains to be elucidated. To identify the components involved in the ABA signaling pathway, we tried to isolate new ABA related mutants using a HSP90 inhibitor. HSP90 has been reported to buffer genetic variation in morphogenetic pathways in Drosophila melanogaster (Rutherford & Lindquist, 1998). We conducted a genetic screen for ABA-resistant mutants in the presence of geldanamycin, a HSP90 inhibiter. Although we could not isolate mutants depend on HSP90 inhibiter, we isolated a novel ABA insensitive mutant, named abi101. Genetic analysis revealed that abi101 has a novel relationship called synergistic heterozygosity with abi5, suggesting the functional interaction between them. We are going to report about this mutant.