Use of Phosphite As a Fertilizer for Transgenic Cotton

Phosphites are alkali metal salts of phosphorous acid widely used in agricultural production as a fungicide. At high rates of Phi application, it may become phytotoxic and suppress plant growth. However, transgenic cotton plants expressing the bacterial phosphite dehydrogenase (ptxD) gene have the ability to convert phosphite (Phi) into orthophosphate (Pi) which is the metabolizable form of phosphorus (P). This genetic modification allows transgenic cotton plants to use Phi as a nutrient source of P while suppressing the growth of weeds unable to metabolize phosphite. A poster presentation will include highlights on research conducted to evaluate the potential benefits of using phosphite for cotton production in soils of the southeastern USA .