Mucilage secretion and its interaction with soil, and contact reduction

Contact reduction is a mechanism by which plant roots are able to mobilise Mn from insoluble oxides in the rhizosphere. Contact between the root surface is established and develops when the mucilage produced by root cells forms a gel upon its interaction with the soil. The mucigel may not only mould to the surface of soil particles, but also may diffuse into aggregates such that the soil and root surfaces overlap. In such a zone, the apparent free space and the soil solution become one and the "right set of circumstances" to facilitate reduction and subsequent uptake of Mn and perhaps Fe are established.