Cytokinin signaling pathway.

Cytokinins are key regulators of a large number of processes in plant development, which is highly plastic and adaptive, and remarkably resilient and self-perpetuating. Cytokinin signaling involves a multistep two-component system, also called a phosphorelay signaling system. Genes encoding the central components to build the cytokinin phosphorelay system are found in diverse plant species, resulting in the establishment of a canonical model of cytokinin signaling that is likely representative and conserved in plants. The cytokinin signaling pathway can be modulated by nutrients, stress, and other hormones, and is integrated into a signaling network in both shoots and roots.