• KSBB Journal
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• v.5 no.3
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• pp.263-268
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• 1990

New methods have been developed to transform Panax ginseng with Ri plasmids of Agrobacterium rhizogenes 15834 and A. rhizogenes A4. Modified leaf disc method was made feasible to establish hairy root culture even when an axonic plantlet was not available as in the case of P. ginseng. The contents of ginsenosides (Rgl, Rf, Rc, Rbl, and Rb2) in hairy roots. were determined by HPLC. Hairy root cultures, established as liquid culture in MS medium, was produced 0.34~1.19% ginsenosides on dry weight basis, and this result is significantly higher level than that of normal P. ginseng.

• KSBB Journal
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• v.5 no.3
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• pp.207-214
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• 1990

Growth properties of carrot hairy roots transformed by Agrobacterium rhizogenes were compared in flask and bioreactor. Oxygen transfer coefficient KLa was measured during the cultivation in bioreactor. In flask cultures, initially sucrose 30g/l was nearly exhausted after 20days. pH was dropped from initially 5.8 to 4.79 after 4 days, but it is stable after that time. Finally, after 28 days, hairy roots were grown about twelve times. In view of the results studied optimum conditions, hairy roots were maintained high growth rates in sucrose 50g/l, pH 5.8, total nitrogen 60mM. Also in bioreactor cultures, fixed stainless sieve in bottom and aerated 0.31 vvm, the results of cultivation by the use of sucrose 50g/l had grown about twenty-eight times and pH variations were liked in flask. As a results, growth rate of 1.756g fresh weight/day/g inoculum in bioreactor were higher about three times than 0.57g fresh weight/day/g inoculum in flask culture. KLa values were showed a tendency to decrease from 0.209 min-1 to 0.068 min-1.

• Journal of Plant Biotechnology
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• v.36 no.4
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• pp.336-343
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• 2009

Tall fescue is an open-pollinated, perennial, cool season grass species widely used for forage and turf. Tremendous progress has been made in genetic transformation of tall fescue in the past decade. Methods for generating transgenic tall fescue plants have been developed based on biolistic transformation and Agrobacterium-mediated transformation. Potentially useful agronomic genes have been tested to environmental stress tolerance, herbicide tolerance and improve forage quality in tall fescue plants. We review progress in biotechnological improvement of tall fescue and discuss future molecular breeding of this species.

• Journal of Plant Biotechnology
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• v.36 no.4
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• pp.344-351
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• 2009

Current status of soybean transformation method in Korera was reviewed with recent publications. Most frequently used method for genetic transformation was Agrobacterium-mediated transformation on cotyledonary node which is most popular method used in foreign country. In addition to this, various methods such as sonicationmediated transformation, in planta transformation, and transformation on meristem tissue of germinating seed, have been tried in Korea, even though their efficiencies on repeatability and stability were relatively low. Based on the promising results developed recently by reviewer, several important considerations for successful soybean transformations were suggested. They are 1) proper genotype screening, 2) targeting transformation on exact point, 3) multiple shoot formation, 4) efficient selection pressure, 5) successful shoot elongation, 6) efficient root formation. These are the basic requirements for stable and highly efficient soybean transformation of Korean soybean.

• Journal of Plant Biotechnology
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• v.33 no.2
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• pp.75-84
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• 2006

Heteroplasmic rice plastid transformant was generated using suspension cells as bombardment materials. PCR analyses confirmed incorporation of aadA and cp4-epsps genes into the rice plastid genome by homologous recombination events via the flanking sequences of the trnI and trnA. Transplastomic calli were actively proliferated when cultured on AAM2 medium supplemented with various concentrations (500-3000 mg/L) of streptomycin in dark condition, and transplastomic suspension cells showed resistance to nonselective herbicide, glyphosate. Through 'agarose pie selection' method, heteroplastomic calli, containing considerably high level of transplastome and expressing the CP4 EPSPS protein, were obtained. They were further regenerated to green shoots with healthy roots.

• KSBB Journal
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• v.6 no.4
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• pp.385-388
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• 1991

Embryogenic cell suspension cultures of B. striata were established as transferred selected embryogenic callus into liquid medium. Protoplasts isolated from embryogenic cell suspensions were electroporated in buffered solutions containing plasmid DNA of pBI121. Transient GUS (beta-glucuronidase) activity measurement and selection for kanamycin resistent showed that expression of foreign genes and stable transformation were achieved. GUS transient gene expression was increased by increasing DNA concentration of pBI121 plasmid and affected by the level of the applied voltage. An optimal level of GUS activity was obtained after electroporation with a pulse of 200-300 voltage/1180 uF. Protoplast viability was up to the 80% at the optimal voltage.

• Journal of Plant Biology
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• v.36 no.1
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• pp.75-81
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• 1993

Ginseng (Panax ginseng C.A. Meyer) hairy root transformed with Agrobacterium rhizogenes (strain A4) was examined cytogenetically and histologically to assess its characteristics. The optimum growth of hairy root obtained in hormone-free MS medium (sucrose 30 g/L, pH5-6) for long period cultures. All hairy root strains (HB1, HB2, HB3) had the 2n diploid number (2n=48) of chromosomes in root tip cells. There were no alteration in chromosome structure except in one cell of HB3 strain. Results of SDS-PAGE showed a few difference in pattern and number of bands between normal and hairy root of ginseng. The root anatomy of normal root and hairy root differed each other. The hairy root had a clearly defined vascular strand, and the morphology of cortical cells were disorganised with large intercellular spaces.

• Proceedings of the Korean Society of Grassland Science Conference
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• 2005.06a
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• pp.188-189
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• 2005

• Proceedings of the Korean Society of Grassland Science Conference
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• 2005.06a
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• pp.152-153
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• 2005

• Proceedings of the Korean Society of Grassland Science Conference
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• 2005.06a
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• pp.150-151
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• 2005