An Unconventional Fertilization and Weed Control System Based on Genetically Modified Plants able to Metabolize Phosphite

High crop yields depend on the continuous input of orthophosphate-based fertilizer and herbicide. Two major challenges for agriculture are that phosphorus is a nonrenewable resource and that weeds have developed broad herbicide resistance. One strategy to overcome both problems is to engineer plants to outcompete weeds and microorganisms for limiting resources, thereby reducing the requirement for both fertilizers and herbicides. Plants and most microorganisms are unable to metabolize phosphite, so we developed a dual fertilization and weed control system by generating transgenic plants that can use phosphite as a sole phosphorus source. Under greenhouse conditions, these transgenic plants require 30–50% less phosphorus input when fertilized with phosphite to achieve similar productivity to that obtained by the same plants using orthophosphate fertilizer and, when in competition with weeds, accumulate 2–10 times greater biomass than when fertilized with orthophosphate. The fertilization and weed control system based on plants able to metabolize phosphite not only has the potential to reduce the cost of producing food and feed, but it also has the potential of reducing the detrimental impact of traditional agriculture. This phoshite system is also useful as dominant selectable marker system to produce transgenic plants under in vitro conditions or to select for transgenic seed under greenhouse conditions.