Transformed cassava plants were successfully produced from friable embryogenic calli derived from leaf lobes byAgrobacterium tumefaciens-mediated transformation. We used A. twnefaciens strain LBA4404 containing pCAMmPHY whichcontained a binary vector with

Recent results reveal that high frequencies of cytogenetic abnormalities occur in transgenic barley, oat and orchardgrass plants generated from either immature embryos or highly regenerative, green tissues via microprojectile bombardment, compared with no

To demonstrate the importance of transformation efficiency in independent event, molecular and cytogenetic analysis were conducted with genomic DNA and chromosome of transgenic plants produced by Agrobacterium tumefeciens LBA4404 (pSBM-PPGN: gusA and bar). Selection ratios of putative transgenic calli were similar in independent experiments, however, transformation efficiencies were critically influenced by the type of regeneration media. MSRK5SS-Pr regeneration mediun, which contains 5 mgL-1 kinetin, 2% (w/v) sucrose in combination with 3% (w/v) sorbitol, and 500 mgL-1 proline, was efficient to produce transgenic plant of rice from putative transgenic callus in the presence of L-phosphinotricin (PPT). With MSRK5SS-Pr medium, transformation efficincies of Nagdongbyeo were significantly enhanced from 3.7% to 6.3% in independent callus lines arid from 7.3% to 19.7% in plants produced, respectively. Stable integration and expression of bar gene were confirmed by basta herbicide assay, PCR amplification and Southern blotting of bar gene, and fluorescence in situ hybridization (FISH) analysis using pSBM-PPGN as a probe. In Southern blot analysis, diverse band patterns were observed in total 44 transgenic plants regenerated from 20 independent PPT resistant calli showing from one to five copies of T-DNA segments, however, the transformants obtained from one callus line showed the same copy numbers with the same fractionized band patterns.

Transgenic rice plants expressing a Bacillus subtilis protoporphyrinogen oxidase (Protox), the last shared enzyme of the porphyrin pathway in the expressed cytoplasm or the plastids, were compared with non-trangenic rice plants in their growth characteristics such as tiller number, plant height, biomass, and yield. Transgenic rice plants of ~textrmT3 generation had 8 to 15 % and 25 to 43% increases in tiller number compared to non-transgenic rice plants at 4 and 8 weeks after transplanting(WAT); similar values were observed for ~textrmT4 generation at 4 and 8 WAT. However, the plant height in both ~textrmT3 and ~textrmT4 generations was similar between transgenic rice plants and non-transgenic rice plants at 4 and 8 WAT. Transgenic rice plants had 13 to 32% increase in above-ground biomass and 9 to 28% increase in grain yield compared to non-transgenic rice plants, demonstrating that biomass and yield correlate with each other. The increased grain yield of the transgenic rice plants was closely associated with the increased panicle number per plant. The percent of filled grain, thousand grains and spikelet number per panicle were similar between transgenic and non-transgenic rice plants. Generally, the growth and yield of transgenic generations (~textrmT2 , ~textrmT3 , and ~textrmT4 ) and gene expressing sites (cytoplasm-expressed and plastid-targeted transgenic rice plants) were similar, although they slightly varied with generations as well as with gene expressing sites. The transgenic rice plants had promotive effects, indicating that regulation of the porphyrin pathway by expression of B. subtilis Protox in rice influences plant growth and yield.

This study was carried out to obtain basic information for possibility of oral vaccine in carrot using Agrobacteruim -mediated transformation system. The epitope region of porcine epidemic diarrhea virus (PEDV) spike gene which is classified as a member of the Coronaviridae and causes an acute enteritis in pigs was successfully expressed in carrot (Daucus carota) using the Agrobacterium-mediated transformation system. Hypocotyl segments of in vitro germinated plantlets were infected with Agrobacteriun tumefaciens LBA 4404 harboring PEDV spike gene. Embryogenic callus (EC) was induced on MS selection medium with 1 mg/L 2,4-D, 50 mg/L kanamycin and 300 mg/L cefotaxime after 45 days of culture. Subcultured ECs on MS selection medium without 2,4-D were converted to somatic embryos (SE) of various stage; globular, heart and torpedo stage. Putative transgenic embryos were selected on MS medium with 50 mg/L kanamycin and 300 mg/L cefotaxime. Regenerated plantlets from transformed SE were induced on MS medium containing 50 mg/L kanamycin after 30 days of culture. Genomic PCR confirmed the integration of PEDV spike gene into nuclear genome of carrot and northern blot analysis demonstrated the expression of PEDV spike gene in transgenic carrot.