Modern Molecular Genetics: Improving the Biomass Yield of Switchgrass

Oklahoma EPSCoR researcher Million Tadege and his co-researchers are manipulating the flowering genes of native switchgrass to develop engineered plants that will produce more biofuels per acre than their wild counterparts. This increased productivity will mean more money for farmers, lowered bioenergy prices for consumers and less dependence on foreign oil.

When switchgrass plants flower, the plants’ energies are redirected from increasing foliage growth to reproductive growth. Additionally, lignin, a component of the cell wall that is resistant to enzymatic digestion during bio conversion, increases during flowering. Million Tadege and Yanqi Wu, OK EPSCoR researchers and OSU plant and soil sciences professors, are studying and manipulating the flowering time genes of switchgrass to address these issues.

Tadege, in collaboration with Kiran Mysore, OK EPSCoR researcher and Samuel Roberts Noble Foundation associate professor, recently generated late-flowering mutants in a model plant species (Medicago truncatula) that produced double the plant height and canopy of wild-type plants, thereby increasing above-ground biomass. Additionally, cell walls of the modified plants contained fifty percent less lignin than non-modified plants, which will decrease recalcitrance to saccharification.

According to Tadege, reduced lignin content in switchgrass will decrease the amount of chemicals needed during the conversion process. Less chemical usage benefits the environment and helps consumers’ pocketbooks by lowering the cost of Biofuels production.

By working to bridge the gap between classical breeding techniques and modern molecular genetics, the EPSCoR research team is optimistic that they may ultimately achieve unprecedented success in biomass feedstock improvement that will significantly enhance Biofuels productivity and lower overall energy costs.