Phosphorus is an essential nutrient for plants, which assimilate it in the form of orthophosphate, often delivered via fertilizers. However, plants compete with soil bacteria and weeds for the use of this compound, and, therefore, its uptake is inefficient. Phosphite is an alternative source of phosphorus but it cannot be used as fertilizer as plants do not metabolize it.

A solution to this problem comes from Damar Lizbeth López-Arredono and Luis Herrera-Esterella, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Mexico. The team introduced into plants a bacterial phosphate oxidoreductase, an enzyme which produces orthophosphate by oxidising phosphite. The plants carrying the bacterial gene, once fertilized with phosphite, assimilated phosphorus and grew as well as their non-transgenic counterparts treated with orthophosphate. Under these conditions, moreover, transgenic plants encountered less competition with weeds which, unable to metabolize phosphite, did not grow.

This system might be used to achieve fertilization and concomitantly control the growht of weeds without using herbicides.

• Engineering phosphorus metabolism in plants to produce a dual fertilization and weed control system,
  D.L. López-Arredondo, L. Herrera-Estrella,
  Nat Biotechnol. 2012, 30, 889–893.
  DOI: 10.1038/nbt.2346