Abstract
To dissect the signal transduction of ABA, we studied on the expression of ABA-responsive rd29B gene, and isolated Arabidopsis mutants altered in the responses to ABA. We compared the expression of the rd29B gene and those of genes encoding transcription factors such as AREB1 and ABI5. The results indicate that ABA-responsive gene expression during germination is different from that in mature plants. We introduced a chimeric gene construct consisting of the luciferase under the control of the rd29B promoter (rd29B-LUC) into Arabidospis plants. Activation tagged lines of Arabidospis containing rd29B-LUC were obtained by transformation; mediated by Agrobacterium carrying the vectors pPCVICEn4HPT or pSKI015. We also obtained mutant seeds using EMS treatment. We screened mutants altered in ABA-response of the rd29B-LUC gene during germination or under the stress conditions in mature plants. Some mutants altered in the regulation of the rd29B-LUC gene were identified. Analysis of the mutants is in progress.
