Transgene autoexcision in switchgrass pollen mediated by the Bxb1 recombinase

BMC Biotechnology

Maria N Somleva¹  Chang Ai Xu¹  Kieran P Ryan¹  Roger Thilmony²  Oliver Peoples¹  Kristi D Snell¹  James Thomson² 

[1] Metabolix, Inc., 21 Erie St., Cambridge, MA 02139, USA

[2] USDA-ARS-CIU, 800 Buchanan St., Albany, CA 94710, USA

关键词: Switchgrass;    Panicum virgatum L.;    Pollen-mediated gene flow;    Developmentally programmed transgene excision;    Bxb1 site-specific recombinase;    Autoexcision;   

Others  :  1084651
DOI  :  10.1186/1472-6750-14-79

 received in 2014-06-12, accepted in 2014-08-18,  发布年份 2014

【 摘 要 】

Background

Switchgrass (Panicum virgatum L.) has a great potential as a platform for the production of biobased plastics, chemicals and energy mainly because of its high biomass yield on marginal land and low agricultural inputs. During the last decade, there has been increased interest in the genetic improvement of this crop through transgenic approaches. Since switchgrass, like most perennial grasses, is exclusively cross pollinating and poorly domesticated, preventing the dispersal of transgenic pollen into the environment is a critical requisite for the commercial deployment of this important biomass crop. In this study, the feasibility of controlling pollen-mediated gene flow in transgenic switchgrass using the large serine site-specific recombinase Bxb1 has been investigated.

Results

A novel approach utilizing co-transformation of two separate vectors was used to test the functionality of the Bxb1/att recombination system in switchgrass. In addition, two promoters with high pollen-specific activity were identified and thoroughly characterized prior to their introduction into a test vector explicitly designed for both autoexcision and quantitative analyses of recombination events. Our strategy for developmentally programmed precise excision of the recombinase and marker genes in switchgrass pollen resulted in the generation of transgene-excised progeny. The autoexcision efficiencies were in the range of 22-42% depending on the transformation event and assay used.

Conclusion

The results presented here mark an important milestone towards the establishment of a reliable biocontainment system for switchgrass which will facilitate the development of this crop as a biorefinery feedstock through advanced biotechnological approaches.

【 授权许可】

   
2014 Somleva et al.; licensee BioMed Central Ltd.

【 图 表 】

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