Understanding Winter Hardiness in Switchgrass
The nation’s dependence on imported fossil fuels could be alleviated, at least in part, by the domestication of dedicated bioenergy crops such as native perennial switchgrass for lignocellulosic ethanol production. Switchgrass is a promising feedstock candidate because it produces high yields of biomass on marginal lands unsuitable for production of food crops. In addition, perenniality (the ability of a plant to survive over winter and resume growth in the spring) is important for sustainability, since the unharvested below-ground tissues help maintain the integrity and nutrient status of the soil. Perennial biomass cultivars will need to tolerate fluctuations in temperature and rainfall, traits influenced by the overall health of below-ground tissues. Research¬ers at the USDA-ARS in Lincoln, Nebraska, with funding from the joint USDA-DOE Plant Feedstocks Genomics for Bioenergy Program, analyzed changes in gene expression patterns in below-ground tissues (crowns and rhizomes) of the switchgrass cultivar ‘Summer’ to gain insight into the genetic mechanisms regulating these processes. The results revealed that these tissues are metabolically active, including pathways involved in basal cell metabolism and stress response. In addition, several novel gene sequences of unknown function were identified, which may represent genes specific to these tissues and with unique functions. These analyses should yield further insights into perenniality that will improve switchgrass as a sustainable bioenergy feedstock.
Palmer, N. A., A. J. Saathoff, J. Kim, A. Benson, C. M. Tobias, P. Twigg, K. P. Vogel, S. Madhavan, and G. Sarath. 2011. “Next-Generation Sequencing of Crown and Rhizome Transcriptome from Upland, Tetraploid Switchgrass,” BioEnergy Research, DOI: 10.1007/s12155-011-9171-1.