High-frequency transformation of oat via microprojectile bombardment of seed-derived highly regenerative cultures

A highly efficient and reproducible transformation system for oat (AL ena s ativa L. cv. GAF/Park-1) was developed using microprojectile bombardment of highly regenerative tissues derived from mature seeds. Callus was induced under dim light conditions on medium containing 2,4-dichlorophenoxyacetic a cid (2,4-D), 6-benzylaminopurine (BAP) and high cupric sulfate. Highly rege nerative tissues, generated from embryogenic callus, were used as a transfo rmation target. From 327 individual explants bombarded with the beta-glucur onidase gene (uidA; gus) and a hygromycin phosphotransferase gene (hpt), 84 independent transgenic events were obtained after an 8-12-week selection p eriod on hygromycin. All events were regenerable, giving an effective trans formation frequency of 26%; co-expression of GUS activity occurred in 70% o f the independent events. Presence of the foreign genes in DNA from leaf sa mples of T-0 and T-1 plants was confirmed by polymerase chain reaction (PCR ) amplification and:or DNA blot hybridization. Fertility of the plants from the transgenic lines was 63% (24/38) and the transgene(s) was stably trans mitted to T-1 and T-2 progeny. (C) 1999 Elsevier Science Ireland Ltd. All r ights reserved.