Direct Regeneration of Transgenic Buckwheat from Hypocotyl Segment by Agrobacterium-mediated Transformation

Transgenic plants from hypocotyl segments of buckwheat were produced with the Agrobacterium strain LBA4404 harboring the binary vector pBI121 containing chimeric genes of neomycin phosphotransferase II (npt II) and $\beta$-glucuronidase (gus). Two weeks after co-cultivation with Agrobacterium, most of the hypocotyl segments gradually became brown and died on the selection medium containing 100mg/$\ell$ of kanamycin. Plants regenerated from the hypocotyl explants grown on selection medium were GUS-positive in the leaf, stem and vascular tissues by histochemical assay, and varied in gus activity (440-2568 pmol, 4-MU/mg protein) by fluorimetry. The plants showing GUS activity were confirmed of containing GUS and NPT-II genes by polymerase chain reaction (PCR). Within 3 months, transgenic buckwheat plants were able to obtained from the hypocotyl segments.