Toward the development of Ac/Ds transposon-mediated gene tagging system for functional genomics in oat (Avena sativa L.).

Cultivated oat (Avena sativa L.) is an important cereal grown worldwide due to its multifunctional uses for animal feed and human food. Oat has lagged behind other cereals in the genetic and genomic studies attributed to its large and complex genomes. Transposon-based genome characterization has been utilized successfully for identifying and determining gene function in large genome cereals. To develop gene tagging and gene-editing resources for oat, maize Activator (Ac) and Dissociation (Ds) transposons were introduced into the oat genome using the biolistic delivery system. A total of 2035 oat calli were bombarded and twenty-four independent, stable transgenic events were obtained. Transformation frequencies were up to 19.0%, and 1.9% for bialaphos and hygromycin selection, respectively. Re-mobilization of the non-autonomous Ds element, by introducing Ac transposase source, led to a transposition frequency up to 16.8%. The properties of ten unique flanking sequences have been characterized to reveal the Ds-tagged sites in the oat genome. Genes at Ds insertion sites showed homology to gibberellin 20-oxidase 3, (1,3;1,4)-beta-D-glucan synthase, and aspartate kinase. This Ac/Ds transposon-based gene tagging system could facilitate and expedite functional genomic studies in oat.