DEVELOPMENT OF A HERBICIDE RESISTANCE TRAIT INCAPABLE OF POLLEN TRANSMISSION TO WEED PLANTS

The goal of this project is to produce crop plants with stable and long-lived herbicide resistance traits. Weeds can gain herbicide resistance by receiving pollen from crop plants and acquiring resistance genes directly. Such weeds are tremendous problems, especially for rice farmers in the southern US states as well as in Asia, Latin America and Europe. This weedy rice problem is eroding the efficacy of herbicides resulting in significant gain yield losses. Consequently, it is highly desirable to produce crop plants that cannot transmit herbicide resistance through pollen. Such crop plants are not available currently; however, the new technology we develop at NAPIGEN will provide a means for their development. Specific objectives of this Phase I project are the following: (1) Achieve a level of engineered mitochondrial DNA in plant tissue culture cells to allow for stable inheritance of an herbicide resistance gene. We have previously made a breakthrough by developing the first selectable marker genes for plant mitochondrial transformation. We will pursue various strategies to enrich for the proportion of transformed mitochondrial DNA. (2) Confirm herbicide resistance in T0 plants, i.e., plants regenerated from transformed tissue culture cells. The resulting plants contain an herbicide-resistance gene derived from rice itself. They will not have any exogenous genes from other species, accommodating public preference regarding gene edited products.