Translocation of Organic Solutes

Leaves manufacture food through photosynthesis and, in the short term, store the surplus as starch grains inside the chloroplast; when that food is actually needed elsewhere in the plant, the starch is converted back into simple sugars that can be transported. Because the site where food is made (the leaves) and the sites where it is actually used or stored (roots, developing fruits, growing tissue, and so on) are typically far apart, this dissolved organic food - generically referred to as 'solute' - must be moved across the plant, and the phenomenon of …