Development of A New Herbicide Tolerance Trait to Improve Weed Control in Glyphosate Tolerant Soybean.

A synthetic gene (AAD12) has been developed by Dow AgroSciences from Delftia acidovorans.   In planta this gene produces an enzyme that deactivates several herbicides having an aryloxyalkanoate moiety, including Phenoxy auxins (e.g., 2,4-D, MCPA) and Pyridyloxy auxins (e.g., fluroxypyr, triclopyr).  The gene was introduced into soybean (Glycine max L.). In this presentation, we describe transformed soybean plant event characterization at the molecular level from generation to generation, and plant performance in the greenhouse and field.  We have selected several high quality, simple events that are expressing the target protein at the levels that effectively protect the soybean events from 2,4-D applications. Protection or tolerance is observed from the early seedling stage to the reproductive stage at application rates exceeding 4 times typical herbicide use rates.  Agronomic performance of individual events is comparable to iso-lines.  Based on our data, it is clear that this technology enables broadcasting of mixtures of 2,4-D and glyphosate from pre-emergence to the end of the glyphosate application window,  improves and enhances the performance of glyphosate & glufosinate cropping systems, improves the control of “hard to kill” broadleaf weeds, reduces selection pressure for glyphosate resistance and sustains the glyphosate cropping system.