Translocation is the process within plants that functions to deliver nutrients and other molecules over long distances throughout the organism. Translocation occurs within a series of cells known as the phloem pathway, or phloem transport system, with phloem being the principal food-conducting tissue in vascular plants. Nutrients are translocated in the phloem as solutes in a solution called phloem sap.

The predominant nutrients translocated are sugars, amino acids, and minerals, with sugar being the most concentrated solute in the phloem sap. Various cell types utilize these nutrients to support their requirements for life or store them for future use. Because translocation is responsible for the delivery of nutrients to developing seeds and fruits, this process is critical to the achievement of optimal crop yield. It also accounts for the ultimate nutritional composition of plant foods important to humans.

Various plant hormones, proteins, and nucleic acids are also moved...