Engineering a Better Switchgrass


Perennial grasses such as switchgrass are considered prime candidates for bioenergy feedstocks because of their potential for substantial biomass yields on marginal lands. An approach that promises further improvement in this species is genetic transformation, the introduction and expression of desirable genes from other sources to increase yields and reduce recalcitrance. Current transformation technology, however, uses promoters (segments of DNA that control the expression of desired genes) from other plants making them inefficient for use in switchgrass. Researchers from the DOE BioEnergy Science Center (BESC) now report the identification of novel promoter regions from a specific switchgrass gene that is found in all eukaryotes and that can be used for efficient genetic transformation in switchgrass. A variety of transgenic plants constructed with these promoters exhibited significantly higher gene expression levels than observed using the non-switchgrass promoters, showing great potential for driving transgenic expression in switchgrass and other plants. This is the first characterization of native switchgrass promoter sequences for transgene expression. The results will facilitate improvement of switchgrass and other bioenergy feedstocks through engineering of key bioenergy-relevant traits.


Mann, D. G. J., Z. R. King, W. Liu, B. L. Joyce, R. J. Percifield, J. S. Hawkins, P. R. LaFayette, B. J. Artelt, J. N. Burris, M. Mazarei, J. L. Benentzen, W. A. Parrott, and C. N. Stewart. 2011. “Switchgrass (Panicum virgatum L.) Ubiquitin Gene (PvUbi1 and PvUbi2) Promoters for Use in Plant Transformation,” BMC Biotechnology 11, DOI: 10.1186/1472-6750-11-74.