rhizosphere

thumb|upright=1.7| (A) Root system architecture is concerned with structural features of the root and responds to with environmental stimuli. (B) The rhizosphere produces photosynthetically fixed carbon that exudes into the soil and influences soil physicochemical gradients. (C) Free-living or [[parasitic nematodes interact with the rhizosphere via signaling interactions. (D) Mycorrhizal fungi create intimate relationships with the roots and engage in nutrient exchange. (E) Bacterial composition is distinct upon different parts, age, type of the roots.]]

The rhizosphere is the narrow region of soil or substrate that is directly influenced by root secretions and associated soil microorganisms known as the root microbiome. Soil pores in the rhizosphere can contain many bacteria and other microorganisms that feed on sloughed-off plant cells, termed rhizodeposition, and the proteins and sugars released by roots, termed root exudates. This symbiosis leads to more complex interactions, influencing plant growth and competition for resources. Much of the nutrient cycling and disease suppression by antibiotics required by plants occurs immediately adjacent to roots due to root exudates and metabolic products of symbiotic and pathogenic communities of microorganisms. The rhizosphere also provides space to produce allelochemicals to control neighbours and relatives.