Abstract
Abiscisic acid (ABA) regulates many aspects of plant growth and development, including seed maturation, germination and adaptation to environmental stresses. To identify the components involved in the ABA signaling pathway, we had attempts to isolate novel ABA-related mutants. We screened for mutants that have an altered sensitivity to ABA analog, PBI-51 and isolated several candidates for ABA hypersensitive mutant. Here we will report the study of another ABA analog, #18. This analog more strongly inhibits the growth of stems or leaves than that of roots, whereas ABA usually inhibits the root elongation. We tested the response of known ABA mutants to this analog. All the tested ABA insensitive mutants showed insensitivity to this analog and ABA hypersensitive mutant, era1, showed an enhanced sensitivity, indicating that this analog affects ABA signaling pathway. We are now undertaking a genetic screen for mutants that are resistant to this analog.
