Agrobacterium-mediated transformation and plant regeneration from hypocotyl segments of Japanese persimmon (Diospyros kaki Thunb).

Hypocotyl segments from the seeds of Japanese persimmon (Diospyros kaki Thunb) were cultured on a modified Murashige and Skoog medium supplemented with N-(2-chloro-4-pyridyl)-N'-phenylurea, zeatin or 6-benzylaminopurine. The highest frequency of shoot regeneration was observed when the segments were cultured on medium containing 2 mg/l of zeatin. This culture system was adapted to Agrobacterium-mediated transformation. The hypocotyl segments were inoculated with Agrobacterium tumefaciens strains harboring binary vectors, which contained the neomycin phosphotransferase II gene and the β-glucuronidase gene. Regenerated shoots were selected on a medium containing kanamycin. Histochemical GUS assay showed that the shoots regenerated from the segments inoculated with EHA101/pSMAK251 expressed the gus gene. The presence and integration of the gus gene was confirmed by polymerase chain reaction (PCR) and Southern blot analysis. The regeneration frequency of transformed shoot was 11.1%. The transgenic shoots were rooted and developed into whole plants within 4-5 months.