Jung-Dae Lim

Intraspecific relationship analysis by DNA markers and in vitro cytotoxic and antioxidant activity in Eleutherococcus senticosus

To analyse genetic relationships and intraspecific variation within Eleutherococcus senticosus, the polymerase chain reaction (PCR) was performed on total genomic DNAs of 10 Eleutherococcus collections. Ten primers were used for amplification, yielding 106 bands, of which 87 were polymorphic. The genetic diversity and genetic distance among 10 collections of Eleutherococcus species were used to describe the dendrogram showing the phylogenic relationship. The 10 collections were classified into two groups (groups I and II) at a similarity coefficient of 0.50. Group I included E. senticosus from Bukhaedo (Japan), E. sessliliflorus from Youngwal (Korea), E. seoulense and E. chiisanesis, while group II included several internal and Russian collections. The range of polymorphism was from 66.7 to 90.9% in the 87 amplified polymorphic DNA fragments. The similarity value of all collections ranged from 0.41 to 0.92, and the average genetic distance was 0.61. Thus, RAPD analysis was useful in determining genetic relatedness among collections and in identifying different genotypes of E. senticosus and other Eleutherococcus species. Also, the biological activity on DPPH radical scavenging, antilipid peroxidation in rat liver microsomes and cytotoxic sulforhodamine B (SRB) assay was evaluated using root extracts of E. senticosus, Odaesan, Korea. Ethyl acetate and n-butanol fractionation revealed strong antioxidant against scavenging on DPPH free radical and also ethyl acetate fractionation exhibited high antilipid peroxidative activities. In the cytotoxic effects were evaluated on seven human cancer cell lines, the values of 50% growth inhibition (GI(50)) were mostly below 30 microg/ml for crude extracts to be considered as significantly active.

Overexpression of the γ-TMT gene in Codonopsis lanceolata.

A cDNA-encoding γ-tocopherol methyltransferase (γ-TMT) from Arabidopsis thaliana was overexpressed in deoduck (Codonopsis lanceolata L.) to improve the tocopherol composition. Deoduck (T2) containing the γ-TMT transgene was produced by Agrobacterium-mediated transformation. Transgene expression was confirmed by polymerase chain reaction and RNA gel blot analysis. The transgenic plants produced more leaves than control plants. In addition, the transgenic plants showed higher levels of the CSOD, CTRX, CAPX, CNADP+-IDCH, and CSO transcripts and higher SOD-like activity compared with the control plants.

RETRACTED: Immunotoxicity activity from various organic solvents extract of Allium genus from South Korea against Aedes aegypti L.

RETRACTED

Antifungal Gene (Rs-AFP) Introduction into Rehmannia glutinosa and Gene Expression Mediated by Agrobacterium tumefaciens

Rehmannia glutinosa is one of the most important medicinal crops in Korea. However, various plant pathogens, including Fusatium spp., cause great damage on R. glutinosa and result in enormous economic losses. This study was conducted to breed Fusarium-resistant plants by using Agrobacterium tumefaciences and AFP (anti-fungal protein) gene. The plant material used was a native accession of R. glutinosa. The PCR analysis was conducted to verify transgenicity. Based on the PCR analysis, nptII band was observed in transgenic plant genome. Southern blot and AFP protein analyses also showed the expression of this gene in transgenic plants. Expression of AFP in transgenic plants offers the possibility of developing resistance to fungal infection.

Molecular characterization and stress signaling of the Miscanthus sinensis MsCOMT gene by transient assay

The full-length 1089-bp cDNA of caffeic acid 3-O-methyltransferase (COMT) was isolated from a Miscanthus sinensis cDNA library and was found to encode a 362-amino-acid-long protein. The analysis of the deduced tomato MsCOMT amino acid sequence revealed that it shares 98, 95, 92, and 80% sequence homologies with the respective proteins in Saccharum, Sorghum, maize, and Festuca arundinacea. The transcript level of the MsCOMT gene responded only to ABA signaling as compared to other environmental stressors such as mannitol, NaCl, and methyl viologen (MV) related to drought, salt, and ROS. However, MsCOMT expression decreased following the treatments with NaCl and MV. We analyzed NbPAL (Nicotiana benthamiana phenylalanine ammonia-lyase) gene expression in the leaves of Nicotiana benthamiana plants in response to the antisense MsCOMT-AS at the period ranging from 0 to 48 h. The PAL transcript level decreased when the antisense MsCOMT gene was transiently overexpressed. PR (Pathogenesis-Related) group genes led to a decrease in MsCOMT-AS gene expression in leaves. The NbAPX (Nicotiana benthamiana ascorbate peroxidase) expression level decreased following a decrease in NbPAL and PR group gene expression.