Figure 1. Functional organization of plant root apex.

The root apex actively releases carbon via several different pathways. Root cap cells secrete mucilage which facilitates root growth within soil. Peripheral root cap cells are released in large amounts; these cells often continue to live in, and actively manipulate, the rhizosphere. For example, root apices of Gossypium hirsutum shed up 10,000 cells in 24 h. Root apices also compound for manipulating the biotic and biotic rhizosphere environment as well as carbon‐based volatiles and info‐chemicals. Finally, root apices also provide large amounts of sucrose and lipids to feed their symbiotic fungal partners. The sheer abundance of root apices in the soil biosphere makes the plant root apex one of the most important plant organs.