An ancient event of Horizontal Gene Transfer (HGT) from Agrobacterium into sweetpotato and its wild relatives.
D. QUISPE-HUAMANQUISPE (1), J. Kreuze (2), G. Gheysen (3), T. Kyndt (3), R. Jarret (4), M. Ghislain (2) (1) Ghent University, Belgium; (2) International Potato Center (CIP), Peru; (3) Ghent University, Belgium; (4) USDA, U.S.A.

Horizontal Gene Transfer (HGT) is a potential creative force both in eukaryotic and prokaryotic genome evolution. In plants, HGT has been relatively well documented, and in most cases involve the transfer of genetic material from a plant-parasite to its host plant. Some examples of HGT from bacteria to plants include Agrobacterium rhizogenes and representatives of the genera Nicotiana and Linaria. Nevertheless, such findings have never been associated with domesticated edible crops until our discovery of IbT-DNA1 and IbT-DNA2 sequences originating from Agrobacterium spp. inserted in the cultivated sweetpotato and its wild relatives. Here, we report that IbT-DNA1 was found to contain at least four functional open reading frames (ORFs) homologous to iaaM, iaaH, C-prot, and Acs genes of Agrobacterium spp. It was detected in cultivated sweetpotatoes and in the wild relatives [Ipomoea batatas (L.) Lam (4x), Ipomea triloba, Ipomea cordatriloba and Ipomoea tenuissima]. IbT-DNA2 contained at least five functional ORFs with significant homology to ORF14, ORF17n, RolB/RolC, ORF13, and ORF18/ORF17n genes of A. rhizogenes. It also occurs in cultivated sweetpotatoes and the wild relatives [Ipomoea batatas (L.) Lam (4x) and Ipomoea trifida]. The acquisition of these genes may have played a role in the domestication/evolution of this crop and could shed light on the evolutionary relationship between the cultivated sweetpotato and its wild ancestors.

Abstract Number: P12-399
Session Type: Poster