Patterns of incorporation of (3H)galactose by cells of Zea mays root tips.

['H]galactose shows a selective pattern of uptake distribution in the apical portion of the root tip of Zea mays. In cells entering division it is incorporated into the Golgi apparatus within 10 min and is transferred from that organelle to the forming cell plate. The pattern of uptake suggests a specific biochemical activity on the part of the Golgi apparatus at the time of division so far as the incorporation of galactose is concerned. Apparently little galactose is converted to glucose in the most apical portion of the root. In normal secretory cells, the heaviest uptake is found in the sieve tube elements, epidermal cells and the outer cells of the root cap.