English

Abstract

Introduction This article surveys methodologies for gene stacking in plants and proposes a new strategy for precise transgene stacking by combining transcription activator-like effector nucleases and uni-directional site-specific recombination systems to precisely stack transgenes at a specific locus in the plant genome. Site-specific stacking would allow all inserted transgenes to co-segregate in progeny and also allow for their efficient removal as a unit, if necessary. Such a method could also target transgenes to a ‘safe spot’ in a plant genome that have decreased potential for transgene introgression and escape into wild relatives. Conclusion Site-specific recombination sitespecific recombination systems have been widely used in plant genetic transformation for the purpose of genome manipulation, including gene deletion, integration and stacking. The recent discovery of transcription activator-like effector nucleases (a type of engineered chimeric nucleases) provides a powerful molecular tool for gene targeting in a variety of cell types. The combined use of transcription activator-like effector nucleases and site-specific recombination can direct the site-specific recombination-mediated transgene stacking at a desirable genomic locus for more precise gene stacking.