Fig. 1

Overview of the rapid transformation protocol. Two reference Bd transformation protocols [6, 32] are represented on top for comparison to the method described in this study, developed for the accession Bd21-3. Boxes in blue, in vitro culture steps on Callus Induction Medium (CIM); in green, on Shoot Induction Medium (SIM); in brown, on rooting medium. Arrows, steps involving explant transfer between plates. Tr., transformation via coculture of plant tissues with Agrobacterium tumefaciens strains. a Immature zygotic embryo (izEmb) explants after one week on CIM. b Explants co-cultivated for three days on paper filter with Agrobacteirum. Inset shows where elongated coleoptiles are chopped off (red dotted line) prior transfer onto selective CIM. c GUS-stained izEmb after agroinfiltration showing that embryogenic proliferating tissues protruding from the scutellum transiently express the reporter gene. d Transformed izEmb explants at the start of the 3-week hygromycin selection. e Resulting calli at the end of the selection. f Regenerated plantlets at the end of in vitro rooting