Cytokinins (CK) are important plant hormones with roles in regulating cell division, cell elongation and fate determination. CK signalling occurs via a multistep phosphorelay (MSP) cascade, and key components in this pathway have been identified, though the basis of the cellular plasticity of CK effects remains unclear. This project intends to examine CK-sensitive phosphorylation events in the early part of the root response to CK. It is expected to reveal novel aspects of the CK signalling pathway. The project utilises a combination of data mining of published microarray data, root growth assays with selected mutant lines and the isolation of ATP-binding proteins, such as Ser/Thr kinases.