Plant biotech & Risk Assessment
Hu, Qian , Nelson, Kimberly , Oliver, Melvin J. , Kausch, Albert , Joel, Chandlee , Hong, Luo .
Controlled total sterility for gene containment in genetically modified turfgrass.
Trait improvement of turfgrass through genetic engineering is important to the turfgrass industry and the environment. However, the possibility of gene escape from transgenics to wild and non-transformed species raises valid ecological concerns regarding commercialization of transgenic turfgrass. We have developed controlled total sterility in transgenic turfgrass using down regulation of a plant gene that determines reproductive transition, together with a site-specific DNA recombination system, for gene containment. An RNAi construction of the turfgrass FLO/LFY homolog introduced in transgenic Arabidopsis plants led to prolonged vegetative growth and defected, sterile flowers. Transgenic creeping bentgrass plants harboring a construct in which the rice ubiquitin promoter is separated from an RNAi construction of the turfgrass FLO/LFY homolog gene by the hyg gene flanked by directly oriented FRT sites were then generated and demonstrated to flower normally to produce seeds. These plants are being crossed with transgenics expressing the recombinase FLP. It is expected that in the hybrid, FLP should excise the blocking fragment thus bringing the RNAi construction proximal to the upstream ubiquitin promoter. The expression of RNAi construction should knock out the endogenous FLO/LFY homolog gene, leading to a total vegetative growth. The implementation of controllable total vegetative growth in genetically modified transgenic turfgrass will not only eliminate any potential risks of transgene flow, but also facilitate the propagation and management of primary transgenics. The similar strategy for transgene containment also can be applied to plant species able to be vegetatively propagated, or to those, such as vegetables, for which seeds are not the final targeted product.
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1 - Clemson University, Genetic and Biochemistry
2 - HybriGene, Inc
3 - USDA, ARS
4 - University of Rhode Island, Cell and Molecular Biology
5 - Clemson University, Genetics and Biochemistry, 110 Biosystems Research Complex, Clemson, SC, 29634, USA
Presentation Type: Plant Biology Abstract
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM