Nontransgenic Genome Modification in Plant Cells (Plant Phisiology,September 2010).
Ira Marton, Amir Zuker, Elena Shklarman, Vardit Zeevi, Andrey Tovkach,Suzy Roffe, Marianna Ovadis, Tzvi Tzfira* and Alexander Vainstein
Zinc finger nucleases (ZFNs) are a powerful tool for genome editing in eukaryotic cells. ZFNs have been used for targeted mutagenesis in model and crop species. In animal and human cells, transient ZFN expression is often achieved by direct gene transfer into the target cells. Stable transformation, however, is the preferred method for gene expression in plant species, and ZFN-expressing transgenic plants have been used for recovery of mutants that are likely to be classified as transgenic due to the use of direct gene-transfer methods into the target cells. Here we present an alternative, nontransgenic approach for ZFN delivery and production of mutant plants using a novel Tobaccorattle virus (TRV)-based expression system for indirect transient delivery of ZFNs into a variety of tissues and cells of intact plants.To full text
Permanent genome modifications in plant cells by transient viral vectors.
( Trends in Biotechnology, May 2, 2011)
Alexander Vainstein, Ira Marton, Amir Zuker, MichaDanziger and TzviTzfira
Endonuclease-mediated induction of genomic double-strand breaks has enabled genome editing in living cells. However, deploying this technology for the induction of gene disruption in plant cells often relies on direct gene transfer of endonuclease (i.e. zinc finger nuclease or homing endonuclease) expression constructs into the targeted cell, followed by regeneration of a mutated plant. Such mutants, even when they have no detectable traces of foreign DNA, might still be classified as transgenic because of the transgenic nature of the endonuclease delivery method. Indirect delivery of endonucleases into target cells by viral vectors provides a unique non-transgenic approach to the production of mutated plants. Furthermore, viral vectors can spread into the growing and developing tissues of infected plants, which could provide a unique opportunity to bypass the regeneration step that is often required in direct gene-transfer methods.
Genome modifications in plant cells by custom-made restriction enzymes
(Plant Biotechnology Journal, January 3rd 2012 )
Tzvi Tzfira, Dan Weinthal, Ira Marton, Vardit Zeevi, Amir Zuker, Alexander Vainstein
Genome editing, i.e. the ability to mutagenize, insert, delete and replace sequences, in living cells is a powerful and highly desirable method that could potentially revolutionize plant basic research and applied biotechnology. Indeed, various research groups from academia and industry are in a race to devise methods and develop tools that will enable not only site-specific mutagenesis but also controlled foreign DNA integration and replacement of native and transgene sequences by foreign DNA, in living plant cells. In recent years, much of the progress seen in gene targeting in plant cells has been attributed to the development of zinc finger nucleases and other novel restriction enzymes for use as molecular DNA scissors. Full text
New Technology for More Efficient Breeding
By Joli A. Hohenstein , GPN - November 2011.
As plant breeding continues to evolve and become more precise, Danziger Innovations Ltd. is taking it to even higher levels with technology that gives them unprecedented ability to improve and select for specific traits and characteristics. MemoGene, a viral-based tissue culture independent technology for precise plant genomic modification, can be applied to all plants without using common genetic engineering. Full Text