Abstract
The initial event of cytokinin response in Arabidopsis cells is composed of the His-to-Asp phosphorelay from receptor histidine kinases to transcription-factor-type (type-B) response regulators including ARR1. We reported in the last annual meeting that all the type-A response regulator genes in Arabidopsis are primarily responsive to cytokinins and can be directly activated by ARR1. Although artificial activation of ARR1 induces various cytokinin-related phenomena including ectopic shoot formation, pathways from the regulation by ARR1 to the phenomena are still difficult to be supposed mainly because an overall view of the genes regulated by ARR1 remains unclear. To identified ARR1 target genes other than those for type-A proteins, we compared two batches of transcripts prepared from plants in which ARR1 is artificially activated or not by the High Coverage Expression Profiling (HiCEP) analysis. We will report on the novel ARR1 target genes and discuss how they are related with cytokinin-induced phenomena.
