Plant molecular farming has attracted a lot of attention lately in the field of mass production of industrially valuable materials by extending application of the plant as a kind of factory concept. Among them, protein expression system using rice(Oryza sativa L.) callus is a technology capable of mass culture and industrialization because of a high expression rate of a target protein. This study was carried out to develop an Agrobacterium-mediated transformation system to increase the utilization of rice callus. The transformation efficiency was improved by using the hand when seeds were de-husked for callus induction. Furthermore, we were possible induction of callus from 6 years old seed smoothly. Selection of the callus contained the target gene was required a cultivation period of at least 3 weeks, and the most efficient selection period was after 6 weeks of culture including one passage. This selection was confirmed that the gene was stably inserted into the genomic DNA of the plant cell by the southern blot analysis and progeny test. Such an efficient selection system of rice callus that can be cultured in the long term will be contribute to the industrialization of useful recombinant proteins using rice.

This study was carried out to establish the optimal conditions for callus induction and plant regeneration using immature inflorescence of M. sacchariflorus cv. ‘Wooram’, a bioenergy crop selected in Korea. Callus induction rate was the highest (93.3%) in MS medium containing 3 mg L^-1 2,4-D, and 86.7% in MS medium containing 3 mg L^-1 2,4-D combined with 0.1 mg L^-1 BA. Plant regeneration rate was high when the calli derived from the medium containing BA was used, as compared with those derived from the BA-minus medium. The results showed that the medium conditions containing 5 mg L^-1 BA combined with 0.1 mg L^-1 NAA was the most effective in plant regeneration of which the rate reached 86.7%. The regenerated shoots were separated from the calli and roots over 3 cm were developed from the shoots after 4 week culture on basal MS medium without supplementation. The plantlets were then transferred to soil and cultured in greenhouse. After 5 weeks, the plants with the height of at least 20 cm were successfully acclimatized.

We tried to develop the protocol for embryogenesis and plant regeneration from anther culture of carrot (Daucus carota L.) genotype ‘S&P2342’. Anthers were cultured on MS medium with B5 vitamins containing different combinations of 2,4-D and NAA for 18 weeks in the dark. The best induction of callus and embryo was obtained in the medium containing 0.1 mg/L 2,4-D and 0.1 mg/L NAA, on which 22.0% callus and 2.0% embryo were induced. When primary embryos induced directly from anther culture were transferred to the regeneration medium, secondary embryos were initiated from primary embryos after 4 weeks of culture and 62.5% converted into plantlets after 8 weeks of culture. The plantlets with true leaves were obtained after 12 weeks of culture. When the calli derived from anther culture were transferred to the regeneration medium, 38.8% of the calli produced primary embryos and plantlets after 8 weeks of culture. The plantlets with 2 or more leaves cultured on the regeneration under the different light intensity for the growth of in vitro plantlets. The plantlets cultured at 100 μmol·m^-2·s^-1 showed the highest growth rate. For the acclimatization, the in vitro plantlets with 4 or more leaves cultivated under the different light intensity and temperature, respectively. The survival rate and growth of plantlets was best at 15℃ and 100 μmol·m^-2·s^-1, respectively. The plants were successfully acclimatized and had a normal phenotype. The anther culture system could be used to prepare the doubled haploid lines as an appropriate breeding material for F₁ hybrid breeding program.