Abstract
Cytokinins play a crucial role in various aspects of plant growth and development. The spatial and temporal distribution of bioactive cytokinin levels is strictly controlled in plant development events. Recently, LONELY GUY (LOG) was identified from rice as a novel cytokinin-activating enzyme that works in the final step of bioactive cytokinin synthesis. In Arabidopsis genome, 9 genes (AtLOG1- AtLOG9) are predicted as homologs of rice LOG. To elucidate the functions of Arabidopsis LOG family genes, we characterized the activities of AtLOGs proteins and the expression patterns of AtLOGs genes. Several AtLOGs proteins have the activities in the final step of bioactive cytokinin synthesis as well as rice LOG. Analysis of GUS::AtLOGs fusion genes revealed that each AtLOGs genes show the different expression patterns. Possible role of the AtLOGs genes in plant growth and development will be discussed.