Generation and characterization of herbicide-resistant soybean plants expressing novel phosphinothricin N-acetyltransferase genes

Abstract

Herbicide resistance genes have been widely used in plant biotechnology both for commercial applications and as selectable markers. Phosphinothricin N-acetyltransferase (PAT) detoxifies the nonselective herbicide phosphinothricin (PPT, the ammonium salt of which is known as glufosinate), which is the active ingredient in bialaphos. Two novel PAT genes, hpat and mat, have been isolated from PPT-resistant soil bacteria, and we have now introduced these genes under the control of the 35S promoter of cauliflower mosaic virus into soybean [Glycine max (L.) Merrill] by particle bombardment and subsequent hygromycin selection. The expression of each enzyme was confirmed in leaves of the transgenic soybean plants by immunoblot analysis with specific antibodies and by measurement of PAT activity. The transgenic plants showed complete resistance to a commercial formulation of PPT at the recommended concentration. Our results suggest that these PAT genes may prove useful as markers for soybean transformation as well as in the production of herbicide-resistant transgenic plants.