The common bed bug, Cimex lectularius, possesses a cholinesterase expressed exclusively in the salivary gland (ClSChE). In this paper, we investigated the molecular structure, tissue distribution patterns, and biochemical properties of ClSChE and showed that ClSChE exists as a soluble monomeric form or a soluble dimeric form connected by a disulfide bridge. Immunohistochemical analysis confirmed that ClSChE was expressed in the epithelial cells of both the salivary gland and the duct. In addition, the secretion of monomeric ClSChE through the proboscis during feeding was detected by western blotting using a ClSChE-specific antibody. To predict the role of ClSChE injected into the tissue of an animal host, we analyzed the extent of sequestration and hydrolysis of acetylcholine (ACh)/choline (Ch) by ClSChE by ultra-performance liquid chromatography-tandem mass spectrometry. Kinetic analysis revealed that ClSChE possesses extremely low Km (high affinity to ACh) and Vmax values. These findings suggest that ClSChE functions as a sequestering enzyme specific to ACh (not to Ch) by having a very strong affinity to ACh but an extremely long turnover time.

A colony of Solenopsis invicta was first intercepted on Gamman pier, Pusan port in Korea at September, 2017 by Animal and Plant Quarantine Agency. The mitochondrial DNA (mt-DNA) of workers was analyzed and compared with vary libraries of mt-DNA haplotypes to elucidate the origin of the introduced colony with the trade pattern of the Gamman pier. The mt-DNA fragment of 768 bp, which is part of the Cytochrome oxidae I gene, was amplified and sequenced. The results showed that the mt-DNA was in the clade of haplotype 5, which is endemic in southern USA, China, Taiwan, and Australia. More than 60% of containers are imported from China into Gamman pier, it may be possible to assume that the colony was inadvertently invaded through containers from China.

The sugar beet cyst nematode (SBCN), Heterodera schachtii is a well known pathogen on Chinese cabbage in thehighland fields of Korea. However, recent reports have shown a coexistence of SBCN with the clover cyst nematode,H. trifolii in Korea. This study aimed at detailing and reviewing morphological and molecular characteristics conceivablyessential in differentiating the two nematode species. A comparison of morphometric measurements of both infective juvenilesand vulval cones of cysts showed significant differences between the two cyst nematodes. Indeed, using assorted cystsfrom field populations for molecular analysis resulted into a mixture of bands after gel electrophoresis, indicating a combinationof the two species. Thus, this study confirms the coexistence of the two species on Chinese cabbage fields in Korea.

Biological activities of bombolitins from Bombus ardens, B. consobrinus, B. terrestris and B. ussurensis (bombolitinsA, C, T and U, respectively) were examined using hemolytic, anti-microbial, anti-fungal and anti-tumor activity assays.Among the four bombolitins tested, bombolitin T showed the highest hemolytic and anti-tumor activities. All bombolitinsexhibited strong anti-microbial and anti-fungal activities, and bombolitin A specifically possessed the highest anti-microbialactivity against the Gram-negative bacteria Escherichia coli. Circular dichroism spectrometry analysis revealed that allfour bombolitins had over 61.7% and 45.5% of α-helicity in 30 mM sodium dodecyl sulfate and 50% trifluoroethanolbuffers, respectively, which form lipid-membrane-mimicking environments. Bombolitin T showed the lowest IC50 valuesof 8.5 μM and 8.8 μM against SK-OV-3 and NIH-OVCAR-3 cell lines, respectively, after 72 h of treatment, but itsrelative hemolytic activity at a concentration of 200 μM was 2.3-fold higher than that of 0.1% Triton X-100. Thisstudy provides new information on the biological and molecular properties of venom peptides of bumblebees. However,further studies on reducing cytotoxicity of bombolitins are needed for designing selective anti-tumor peptides.

Fermented food consists of a variety of lactic acid bacteria (LAB) that are also used in the industry as starter cultures. This genus comprises of different species that find importance as a preservatives in food like meat and sausages. Likewise, Lactobacillus brevis has been recognized as GRAS and is a potential probiotic strain extensively being used on an industrial scale. Since such bacteria are directly related to human health, there has been a need to identify and characterize them on the molecular level. In this study, LAB was identified and characterized from various fermented food samples available in South Korea. Two types to PCR-based molecular typing methods were used to analyze the 13 Lactobacillus brevis isolates, of which one was based on difference in the banding patterns originated on agarose gel and the other was related to the sequence analyses of various housekeeping genes in the particular strain. The former rep-PCR technique used three primers namely, REP, ERIC and (GTG)5 that amplified repetitive sequences in the genome and provided characteristic fingerprint profile for each isolate. This clustered the strains in 3 groups with the help of UPGMA method of clustering distinguishing between closely related strains. However, the latter multilocus sequencing typing (MLST) technique provided definite identification of the strains. A set of 7 housekeeping genes were determined as groEL, gyrB, rpoA, rpoB, pheS, recA and dnaK. These genes were amplified and sequenced and were subjected to comparative analysis. Discrete allelic profiles and 13 sequence types (STs) were resolved and minimum spanning tree (MST) was constructed, revealing the genetic relatedness among the isolates. On comparing the results from both the techniques, MLST proved to generate accurate and precise fingerprints owing to the sequence analysis of conserved genes thus providing a scope for research in the monitoring related species.

In the present study, a severe outbreak of Sclerotium rot on Korean melon(Cucumis melo L. var. makuwa Makino) observed in Jinju, Korea in August of 2014 and 2015 is reported. The fruit rot disease on the surface of Korean melon fruit appeared as water soaked lesion followed by the development of large rotten areas with abundant white mycelial growth. Abundant white mycelial mats with globoid and white to brown sclerotia(1-3 mm) were also developed on stems near the soil line, and infected plants withered. The fungal pathogen was isolated on potato dextrose agar(PDA) and formed white colonies with numerous sclerotia on PDA. The sclerotia were globoid in shape, 1-3 mm in size, and white to brown in color. The mycelium formed typical clamp connection. These measurements and taxonomic characteristics were most similar to those of Sclerotium. DNA sequencing and phylogenetic analysis of the complete internal transcribed spacer rRNA gene region confirmed that the fungal isolates were Sclerotium rolfsii Saccardo. Koch’s postulates were supported by pathogenicity tests conducted on fruit. Based on mycological characteristics, pathogenicity tests, and molecular identification, the fungus was identified as Sclerotium rolfsii. To the best of our knowledge, this is the first report of a Sclerotium rot caused by S. rolfsii on Korean melon in Korea.

염생식물 퉁퉁마디의 종자 발아에 영향을 미치는 환경 요인을 조사하고 환경 스트레스에 의해 유도되는 2CysPrx 유전자를 클로닝한 후 스트레스 조건에 따른 2CysPrx 유전자의 발현 양상에 대하여 조사하였다. 염생식물에 대한 가장 대표적인 스트레스는 염분 스트레스로서 퉁퉁마디 발아에 중요한 요인으로 작용하고 있다. 퉁퉁마디의 발아에 대한 NaCl의 한계 농도는 7%로 나타났고, 최적의 발아 조건은 NaCl이 없는 상태로 확인되었다. 퉁퉁마디 발아에서 최적 온도는 20°C로 98%의 발아율을 보였다. 스트레스에 유도되는 유전자 후보군 중 2CysPrx 유전자의 cDNA를 클론하여 분석한 결과 275개의 아미노산으로 이루어져 있고 두 개의 시스테인 잔기를 가지고 있으며 분자량은 30.1kDa 으로 나타났다. 2CysPrx 유전자는 서던 블롯에 의해 유전체에 한 카피 존재하는 것으로 나타났고, 6개의 인트론과 7개의 엑손으로 구성되어 있다. qPCR에 의한 2CysPrx 유전자의 전사율을 분석한 결과, 3.5% NaCl과 40mM H2O2 처리 조건에서 전사율이 가장 높게 나타났고, 고온(40°C)과 75μM ABA 처리 조건에서는 처리 후 8시간에 최고의 전사율을 보였으며, 저온(4°C)에서는 유전자 발현이 일어나지 않는 것으로 나타났다. 우리는 여러 환경 스트레스에 의해 유도되는 다른 유전자의 클로닝을 시도하고 있다.