Sunday, May 3, 2009
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Development of a Gateway-Compatible Vector Set for Overexpression of Transgenes and RNAi-Mediated Knockdown of Native Genes in Switchgrass (Panicum virgatum. L)

David Mann1, Laura Abercrombie1, C. Neal Stewart, Jr.1, Peter LaFayette2, and Wayne Parrott2. (1) Dept. of Plant Sciences, University of Tennessee, Knoxville, TN 37996, (2) University of Georgia, Center for Applied Genetic Technologies, Athens, GA 30602-6810

The current demand for energy and the limited supply of fossil fuels worldwide has led to an increased interest in renewable sources of bioenergy in the recent years.  Switchgrass (Panicum virgatum L.) is a promising feedstock for the production of lignocellulosic ethanol, and switchgrass biotechnology is now playing a pivotal role in the development of improved energy crops.  A crucial component of creating transgenic switchgrass is having the capability of transforming the explants with DNA sequences of interest using vector constructs.  However, there are very limited monocot plant vectors currently available.  With this in mind, we have designed and constructed a versatile set of 24 Gateway-compatible destination vectors (termed “pANIC”) to be used in monocot plants for transgenic crop improvement.  Gateway compatibility allows for convenient insertion of any open reading frame (ORF) or other target sequence of interest with speed and efficiency.  These vectors can be used for 1) transgene overexpression or 2) targeted gene silencing using double stranded RNA interference.  Two main transformation methods exist for monocots:  biolistic-mediated and Agrobacterium-mediated transformation.  The pANIC vector set includes vectors which can be utilized for both applications, with all vectors containing three basic elements:  1) a Gateway cassette for overexpression or silencing of the target sequence, 2) a plant selection cassette and 3) a visual reporter cassette.  The pANIC vector set allows for high throughput screening of sequences of interest in switchgrass, as well as other monocot plant species.