Agrobacterium tumefaciens mediated transformation of Orychophragmus violaceus cotyledon and regeneration of transgenic plants.
Excised cotyledons of Orychophragmus violaceus were used as explants for tissue culture. They were cultured on the MS medium supplemented with BA (3 mg/L) and NAA (0.2 mg/L). When the regenerated buds were 2 cm long, they were excised and transferred onto 1/2 MS medium with IBA (0.03 mg/L), then the whole plants were regenerated. The frequency of plant regeneration was 100%. Subsequently, the genetic transformation of O. violaceus was studied. After 2-3 days of cocultivation with Agrobacterium tumefaciens strain A208se (pTiT37, pROA93), the cotyledons were transferred onto the selection medium containing 25 mg/L Km and 250 mg/L Ap. After shoots emerged, they were excised and transferred onto the rooting medium containing 25 mg/L Km and 100 mg/L Cef. The roots were formed within 4-5 weeks. The whole plants were transplanted into pots and grew well. The frequency of plant regeneration was about 51%. The regenerated plants showed high enzymatic activities of beta-glucuronidase and neomycine phosphotransferase II. Southern blot analysis confirmed that NPTII gene had been stably integrated into the chromosomal genome of O. violaceus. The transformation frequency was 5.6%. The first transgenic plant of O. violaceus is being reported.