Streptococcus mutans and Streptococcus sobrinus play important roles in dental caries. Coptis chinensis is a natural product with antimicrobial activity against enterobacteria; however, its effects on oral streptococci are still unknown. Therefore, the effects of C. chinensis on the growth and biofilm formation of the representative cariogenic bacteria S. mutans and S. sobrinus were investigated for the possible use of C. chinensis as an anticaries agent. The C. chinensis extract was diluted with sterile distilled water, and 0.1–2.5% of the extract was used in the experiment. The effects of the C. chinensis extract on the growth and glucan formation of S. mutans and S. sobrinus were measured by viable cell counting and spectrophotometry at 650 nm absorbance, respectively. Crystal violet staining was also carried out to confirm the C. chinensis extract’s inhibitory effect on biofilm formation. The C. chinensis extract significantly inhibited the growth of S. mutans and S. sobrinus at concentrations of ≥ 0.3% as compared with the control group. The viable cell count of colonies decreased by 1.7-fold and 1.2-fold at 2.5% and 1.25%, respectively, compared with the control group. The biofilm formation of S. mutans and S. sobrinus was inhibited by > 20-fold at C. chinensis extract concentrations of ≥ 1.25% as compared with the control group. In summary, the C. chinensis extract inhibited the growth and biofilm and glucan formation of S. mutans and S. sobrinus . Therefore, C. chinensis might be a potential candidate for controlling dental caries.

Monochamus alternatus and M. saltuarius were reported as the vectors of Bursaphelenchus xylophilus, pine wood nematode in Korea. According to Kwon et al. (2006), each of 2 species has occupied their own regional distribution : M. saltuarius in southern part including Jeju island and M. alternatus in mid-northern part of Korean peninsula. We measured the supercooling point (SCP) of 2 species (laboratory-reared populations) by each of developmental stages. The SCPs of 2nd, 3rd and 5th instar larvae of M. saltuarius were -7.68±0.19℃, -7.02±0.69℃, -4.93±1.34℃ each of stages. On the other hand, the SCPs of 3rd, 4th, 5th instar larvae and pupae of M. alternatus. were -4.46±1.12℃, -5.94±1.33℃, -7.83±1.44℃, -9.53±1.78℃ each of stages. The SCPs of M. saltuarius larvae generally was lower than that of M. alternatus. The pupae of M. alternatus and 2nd instar larvae of M. saltuarius had the lowest SCP among measured samples. On the other hand, the highest SCP were recorded in 2nd and 5th instar larvae, each. This result shows that regional distribution of 2 beetles may be associated with the adaptation capacity to low temperature represented by the SCP as well as the developmental temperature. However, beetles experimented were not collected from pine forest fields. In further study, we are planning experiments with field populations and all developmental stages.

Sclerodermus harmandi populations were collected from 6 Korean regions (Seoul, Gangwon, Chungcheong, Jeolla, Gyeonasang and Jeju provinces), 1 Chinese region (Nanjing) and 1 Japanese region (Tokyo). Above all was identified as the same species based on morphological characteristics. In present study, we compared the intra-specific characteristics of regional isolated populations of S. harmandi based on nucleotide and amino acid sequences of variant genomic and mitochondrial loci: the full length of internal transcribed spacer 1 and 2 (ITS1 & ITS2), the complete cytochrome oxidase subunit I and II (COI & COII) and tRNA genes for aspartate and lysine and 5'end of ATPase 8 genes. There were no significant differences among the analysed 9 populations regardless of regional segregation. The nucleotide and translated amino acid sequences similarities were significantly high, despite some sequence differences were found in same loci. This result support the report based on the morphological characteristics. However, we are conducting further study to identify whether sequence differences in specific loci are the characteristics of individual level in population or population level and to analyse the full sequences of mitochondrial DNA by regional segregation.

UGT72E3/2 gene encodes UDP-glycosyltransferase shown to glucosylate several phenylpropanoids such as syringin and coniferin. Syringin has effect of anti-stress and anti-fatigue. Korean soybean variety Kwangan was transformed with UGT72E3/2 gene. This gene was transformed into Kwangan using highly efficient soybean transformation system. This study used two promoters, beta-conglycinin promoter for seed-specific expression and 35s promoter for total expression. Transgenic plants were confirmed for gene introduction and their expression using PCR and RT-PCR. The analysis of syringin in transgenic plants was performed using HPLC. Currently, the confirmation of stable gene introduction with UGT72E3/2 gene is also performing by Southern blot analysis.

Soybean mosaic virus (SMV), a member of Potyviridae family, is one of the most typical viral diseases and results in yield and quality loss of cultivated soybean. Due to the depletion of genetic resources for resistance breeding, a trial of genetic transformation to improve disease resistance has been performed by introducing SMV-CP and HC-Pro gene by RNA interference (RNAi) method via Agrobacterium-mediated transformation. Transgenic plants were infected with SMV strain G5 and investigated the viral response. As a result, two lines (3 and 4) of SMV-CP(RNAi) transgenic plants and three lines (2, 5 and 6) of HC-Pro(RNAi) transgenic plants showed viral resistance. In genomic Southern blot analysis, most of lines contained at least one T-DNA insertion in both SMV-CP(RNAi) and HC-Pro(RNAi) transgenic plants. Subsequent investigation confirmed that no viral CP and HC-Pro gene expression was detected in two SMV-resistant lines of SMV-CP(RNAi) and three lines of HC-Pro(RNAi) transgenic plants, respectively. On the other hand, non-transgenic plants and other lines showed viral RNA expression. Viral symptoms affected seed morphology, and clean seeds were harvested from SMV-resistant line of SMV-CP(RNAi) and HC-Pro(RNAi) transgenic plants. In addition, strong viral gene expression was detected from seeds of SMV-susceptible non-transgenic plants and SMV-susceptible transgenic lines. When compared the viral resistance between SMV-CP(RNAi) and HC-Pro(RNAi) transgenic plants, soybean transgenic plants with the HC-Pro gene using RNAi strategy showed much stronger and higher frequency of viral resistance.

Bacillus thuringiensis(Bt) crystal protein (Cry1Ac) genes encode insecticidal δ-endotoxins that are widely used for the development of insect-resistant crops. Common soybean is a crop of economic and nutritious importance in many parts of the world. Korea soybean variety Kwangan was transformed with Bacillus thuringiensis(Bt) crystal protein genes. We transformed three difference Cry1Ac (Cry1Ac and two modified Cry1Ac) genes into Kwangan using highly efficient soybean transformation system. Transgenic plants with Bt crystal protein genes were confirmed for gene introduction and their expression using PCR, real-time PCR, and RT-PCR. We generated 30 independent lines of transgenic soybean plants. Analysis of the flanking sequences isolated by Inverse PCR revealed complex T-DNA insertion patterns and preferential integration of T-DNA into the intergenic spacer region of the soybean genome. We found 5 different intergenic transgenic soybean lines of soybean genome. Currently, the confirmation of stable gene introduction with Bt genes is also performing by southern blot analysis, physiology test, and agronomic characters are investigating.