title: Overexpression of the maize Corngrass1 microRNA prevents flowering, improves digestibility, and increases starch content of switchgrass.
abstract: Biofuels developed from biomass crops have the potential to supply a significant portion of our transportation fuel needs. To achieve this potential, however, it will be necessary to develop improved plant germplasm specifically tailored to serve as energy crops. Liquid transportation fuel can be created from the sugars locked inside plant cell walls. Unfortunately, these sugars are inherently resistant to hydrolytic release because they are contained in polysaccharides embedded in lignin. Overcoming this obstacle is a major objective toward developing sustainable bioenergy crop plants. The maize Corngrass1 (Cg1) gene encodes a microRNA that promotes juvenile cell wall identities and morphology. To test the hypothesis that juvenile biomass has superior qualities as a potential biofuel feedstock, the Cg1 gene was transferred into several other plants, including the bioenergy crop Panicum virgatum (switchgrass). Such plants were found to have up to 250% more starch, resulting in higher glucose release from saccharification assays with or without biomass pretreatment. In addition, a complete inhibition of flowering was observed in both greenhouse and field grown plants. These results point to the potential utility of this approach, both for the domestication of new biofuel crops, and for the limitation of transgene flow into native plant species.
authors: Plant Gene Expression Center/ US Department of Agriculture (USDA) and University of California (UC) Berkeley, Albany, CA 94710, USA. georgechuck@berkeley.edu
authors: George S
authors: GS
authors: Chuck
authors: Christian
authors: C
authors: Tobias
authors: Lan
authors: L
authors: Sun
authors: Florian
authors: F
authors: Kraemer
authors: Chenlin
authors: C
authors: Li
authors: Dean
authors: D
authors: Dibble
authors: Rohit
authors: R
authors: Arora
authors: Jennifer N
authors: JN
authors: Bragg
authors: John P
authors: JP
authors: Vogel
authors: Seema
authors: S
authors: Singh
authors: Blake A
authors: BA
authors: Simmons
authors: Markus
authors: M
authors: Pauly
authors: Sarah
authors: S
authors: Hake
mesh_terms: D001483:Base Sequence; D056804:Biofuels; D015415:Biomarkers; D035264:Flowers / Q000254:growth & development; D015870:Gene Expression; D017343:Genes, Plant; D035683:MicroRNAs / Q000235:genetics*; D008897:Panicum / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D030821:Plants, Genetically Modified; D018749:RNA, Plant / Q000235:genetics*; D013213:Starch / Q000378:metabolism; D003313:Zea mays / Q000235:genetics*
chemical_list: D056804:Biofuels; D015415:Biomarkers; D035683:MicroRNAs; D018749:RNA, Plant; D013213:Starch