Alfalfa and sorghum are two major forage crops in the U.S. each offering advantageous traits for the agricultural value chain. Alfalfa, a perennial dicot, generally offers high protein content. Sorghum, an annual monocot, offers more cellulose and other nutritious carbohydrates. As forage crops, traits such as rapid growth rates, increased harvest yields, and high quality (digestibility) are desirable. Improvement of such traits has been the goal of numerous biotechnology efforts. However, alternative biotechnology techniques are typically constitutive and when applied to commercial crops have resulted in net negative consequences. For example, efforts to improve quality by lowering lignin biosynthesis have resulted in plants with poor structural integrity and diminished mass at maturity. In this USDA SBIR Phase I project, AFINGEN will transfer a simple tissue-targeting technology from our previously demonstrated switchgrass project to two forage crops, alfalfa and sorghum. These two commercial crops will be enabled to offer three beneficial agricultural traits - faster growth, more harvested biomass, and improved digestibility. We will generate a total of eight constructs with unique gene assemblies for alfalfa and sorghum. We intend to characterize the viability, gene integration and transgene expression of the constructs and will perform further growth, morphological and quality analyses of the selected lines. This proposed project with first generation engineered plants will narrow down the two best strategies to increase biomass yield by at least 30%, reduce lignin content by 20% for better forage digestibility, and demonstrate robust, healthy plants with shorter life cycle. Given the positive outcomes in earlier projects we are confident to state the above targets - and if the project demonstrates these goals in both alfalfa and sorghum, this new biotechnology platform would be able to be applied to many other varieties of forage and energy crop.
