Poster: Emerging Technologies

Abs # 876: Production of marker-free transgenic soybean plants using Agrobacterium tumefaciens

Presenter:	Ye, Xudong , xudong.ye@monsanto.com
Authors	Ye, Xudong  (A)   Petersen, Michael W. (A)   Bouriakov, Venera D. (A)   Janssen, Karen A. (A)   Gilbertson, Gilbertson A. (A)
Affiliations:	(A): Monsanto Company
Web Site:	http://www.monsanto.com

The process of plant transformation generally requires the use of selectable maker genes to obtain primary transformants. Several strategies exist that provide the ability to derive marker-free plants from primary transformants. Among these, the use of Agrobacterium tumefaciens-mediated co-transformation using T-DNA binary vectors has several advantages over other methods. There are at least three ways in which T-DNA co-transformation can be done: mixing two Agrobacterium strains, each containing a single plasmid with a single T-DNA; using a single Agrobacterium strain containing two separate plasmids, each with a single T-DNA; using a single Agrobacterium strain containing a single plasmid with two T-DNAs. All of these methods have in common the use of two T-DNAs, one containing a selectable marker gene, and the other containing at least one gene of interest (trait gene). We have tested a variety of two T-DNA methods for the purpose of obtaining marker-free plants in Glycine max, including mixing two Agrobacterium strains, and using a single plasmid with two T-DNAs. Plants were assayed for co-transformation of the unselected T-DNA, expression of the gene of interest, transgene insert number, presence of vector backbone sequences, and presence of unlinked T-DNA insertions that allow the recovery of marker-free plants.