Control of shoot and root meristem function by cytokinin.

Plant hormones regulate a variety of processes fundamental for growth and development. Recent studies have clearly shown that establishing adequate spatial and temporal distribution of hormones is central in the control of development. The activity of cytokinins (CKs) is essential to maintain undifferentiated cells in shoot apical meristem (SAM) and to promote cell differentiation in the root meristem (RAM). Detailed mechanisms how the gradient of CK activities is established in the meristem has begun to be elucidated.