AUXIN-CYTOKININ INTERACTIONS IN HIGHER-PLANTS - OLD PROBLEMS AND NEW TOOLS

The plant hormones auxin and cytokinin interact in a complex manner to control many aspects of growth and differentiation. Recent advances i n understanding their metabolism and the cell cycle are now helping to clarify the mechanisms by which these hormones act together to contro l various physiological and developmental responses, Molecular and gen etic tools are being used to reveal interactions between auxin and cyt okinin at multiple levels, including mutual regulation of active hormo ne availability, input into multiple signal transduction pathways, alt eration of gene expression, post-translational modifications and direc t modulation of enzyme activity.