One important source of renewable clean energy is lignocellulosic biomass from non-food perennial grasses such as switchgrass, which is a dedicated bioenergy feedstock in the U.S. Increasing the biomass yield and sugar release efficiency of switchgrass have been a major focus by genetic improvement research to meet the demands for a sustainable lignocellulosic fuel production from biomass.
Consequently, Dr. Million Tadege, Associate Professor from OSU’s Plant and Soil Sciences Department, collaborated with Drs. Hui Wang, Yingying Meng, Pengcheng Yin, Jinxia Wu, and Tiegang Lu (Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, China), Drs. Lifang Niu, Hao Lin, and Dajun Sang (Institute of Agricultural Biosciences, OSU), Drs. ChunXiang Fu and Zeng-Yu Wang (Forage Improvement Division, Samuel Roberts Noble Foundation), and Dr. Yuhong Tang (Plant Biology Division, Samuel Roberts Noble Foundation) to find a way to increase biomass yield in switchgrass by producing wider leaf blades and thicker stems. The research team genetically manipulated the switchgrass leaf using a master leaf blade outgrowth regulator, STENOFOLIA (STF), which is a WOX family transcription factor from Medicago truncatula. “Enzymatic hydrolysis of the dry biomass without pretreatment was also performed to determine sugar release efficiency,” Tadege said.
The team found that overexpression of the STF gene in the switchgrass lines showed significantly wider leaf blades and thicker stems than the control resulting in an approximately two-fold increase in total dry biomass yield with significantly improved sugar release. This is hitting two key targets in one shot. The team has previously patented STF (U.S. Patent No. 9,074,216) for biomass feedstock improvement. “The current results demonstrate the potential of the STF gene for switchgrass genetic improvement in order to maximize the efficiency of conversion of switchgrass into biofuels, to reduce processing costs, and to meet the demand of biofuel production,” Tadege said. This study was published in the respected journal PLoS Genetics.
Funding of this study was provided by the U.S. Department of Agriculture-National Institute of Food and Agriculture, National Science Foundation, Samuel Roberts Noble Foundation, and China’s Ministry of Science and Technology, National Natural Science Foundation and the Chinese Academy of Agricultural Sciences.