Abstract
Cytokinins, adenine derivatives, play a crucial role in various aspects of plant growth and development. The initial product of de novo cytokinin biosynthesis is cytokinin nucleotide. To become biologically active, the nucleotide has to be converted to a nucleobase. There are two pathways for producing active cytokinin species from the nucleotide: the two-step pathway and the direct pathway. Recently, LONELY GUY (LOG) has been identified from rice as cytokinin-activating enzyme catalyzing a reaction of the direct pathway. To elucidate the functions of Arabidopsis LOG family genes in vivo, we produced and analyzed transgenic Arabidopsis lines overexpressing AtLOGs under the control of CaMV 35S or dexamethasone-inducible promoter. These transgenic plants showed change of cytokinin levels and cytokinin-related phenotypes. In addition, results through analyses of the gene expression, loss-of-function mutants, and subcellular localizations for AtLOGs genes will be presented and discussed.
