The occurrence of exotic weeds and their influx into farmlands due to climate change poses many problems. Therefore, it is necessary to generate a prediction model for the occurrence pattern of these exotic weeds based on scientific evidence and devise prevention measures. The photosynthetic apparatus is known as the most temperaturesensitive component of a plant cell and its initial response to temperature stress is to inhibit the activation of photosystem II. This study investigated the potential of OJIP transients in assessing temperature stress in exotic weeds. The four exotic weeds currently flowing into Korean farmlands include Amaranthus spinosus, Conyza bonariensis, Crassocephalum crepidioides, and Amaranthus viridis. These weeds were treated at 5°C, 10°C, 15°C, 20°C, 25°C, 30°C, 35°C, and 40°C and the OJIP curves and JIP parameters were measured and analyzed. The results showed that heat and chilling stress affected the photosystem II (PSII) electron transport of A. spinosus, whereas C. crepidioides and A. viridis were more affected by high-temperature stress than by low-temperature stress. Lastly, C. bonariensis showed resistance to both high and low-temperature stress. The results of this study suggest that OJIP transients and JIP parameters can be used to analyze damage to the photosynthetic apparatus by temperature stress and that they can serve as sensitive indicators for the occurrence pattern of exotic weeds.

The present study aimed to analyze the metaproteome of the microbial community comprising harmful algal bloom (HAB) in the Daechung reservoir, Korea. HAB samples located at GPS coordinates of 36°29’N latitude and 127°28’E longitude were harvested in October 2013. Microscopic observation of the HAB samples revealed red signals that were presumably caused by the autofluorescence of chlorophyll and phycocyanin in viable cyanobacteria. Metaproteomic analysis was performed by a gelbased shotgun proteomic method. Protein identification was conducted through a two-step analysis including a forward search strategy (FSS) (random search with the National Center for Biotechnology Information (NCBI), Cyanobase, and Phytozome), and a subsequent reverse search strategy (RSS) (additional Cyanobase search with a decoy database). The total number of proteins identified by the two-step analysis (FSS and RSS) was 1.8-fold higher than that by one-step analysis (FSS only). A total of 194 proteins were assigned to 12 cyanobacterial species (99 mol%) and one green algae species (1 mol%). Among the species identified, the toxic microcystin-producing Microcystis aeruginosa NIES-843 (62.3%) species was the most dominant. The largest functional category was proteins belonging to the energy category (39%), followed by metabolism (15%), and translation (12%). This study will be a good reference for monitoring ecological variations at the meta-protein level of aquatic microalgae for understanding HAB.

본 연구는 몇가지 전처리제 및 보존용액 처리가 국내 육성 절화 프리지아 ‘Gold Rich’의 수확후 절화수명과 개화 품질에 미치는 영향을 구명하고자 수행하였다. 10% sucrose, 200mg･L-1 Al2(SO4)3, 200mg･L-1 GA3, 150mg･L-1 citric acid가 혼용된 전처리 용액에서 절화 관상 기간 동안 수분 흡수량과 생체중은 유의적으로 증가한 것으로 조사되었지만 절화수명에는 큰 영향을 미치지 않았다. 보존용액으로 5% sucrose와 살균제인 300mg･L-1 8-HQ를 혼용 처리하였을 때 절화수명 연장(1일 이상), 높은 개화율(82.3~89.1%) 및 만개율(71.5~84.2%) 등의 개화 품질이 향상되었다. 이러한 결과들을 통해 10% sucrose, 200mg･L-1 Al2(SO4)3, 200mg･L-1 GA3, 150mg･L-1 citric acid를 혼합한 전처리제와 5% sucrose, 300mg･L-1 8-HQ를 혼합한 보존용액 처리는 절화수명 연장, 개화율 및 만개율 증가에 효과적일 것이라고 판단된다. 특히, sucrose가 포함된 보존용액은 절화 프리지아 ‘Gold Rich’ 의 상품성 향상에 있어 매우 유용할 것이다.

Canine parvovirus (CPV) remains a leading infectious cause of death in canines, especially in young puppies. Though vaccination is being carried out regularly, immunization failures occur, and puppies may be exposed to infection. Virus-like particles (VLPs) act like a subunit vaccine, mimicking the structure of authentic viruses. Therefore, VLPs have the potential to be used as vaccine candidates. Since Viral Protein 2 (VP2), a major structural protein of CPV, is the crucial antigen for CPV, the purpose of this study was to produce a recombinant VP2 of new canine parvovirus-2a using the baculovirus expression system in SF9 insect cells. The results revealed that recombinant VP2 assembles to form VLPs with antigenic properties similar to those of natural CPV, the recombinant VLP can produce a hemagglutination assay (HA) titer (1:210) in SF9 cells. Expression of the recombinant 6-His-tagged VP2 in SF9 cells was confirmed by western blotting. These findings suggest that the recombinant VP2 expressed in this study could be used as an efficient subunit vaccine against CPV infection.

Porcine parvovirus 2 (PPV2) was recently detected in the Republic of Korea. This paper reports two near-complete genome sequences of PPV2 identified for the first time in the lung tissue of aborted pig fetuses.

Widespread consumption of fresh-cut vegetables without cooking results in ingestion of major foodborne pathogens including Bacillus cereus. In this study, we aimed to develop a method to rapidly detect B. cereus in fresh-cut vegetables by combining commercial PCR analysis with enrichment of the pathogenic levels. A mixture of B. cereus strains (KCTC1013, KCTC1014, KCTC1092, KCTC1094, and KCTC3624) was inoculated on the surface of fresh-cut cabbage lettuce (20 g) and baby leafy vegetables (10 g) to concentration 1, 2, 3, 4, and 5 log CFU/g. Eighty milliliters of TSB with 0.15% polymyxin B was used for cabbage lettuce, and 90 mL of medium was used for baby leafy vegetables and incubated at 42oC for 0, 2, 3, 4, 5, 6, and 7 h. One milliliter of the enriched media was plated on mannitol-egg yolk-polymyxin agar for quantification, and another 1 mL was used for DNA extraction for PCR analysis. Additionally, the minimum number of sub-samples to be tested from a pack of fresh-cut vegetable samples was determined using 5 sub-samples. The results from this study showed that for detecting B. cereus in fresh-cut cabbage lettuce, 3, 4, 5, 6, and 7 h enrichment were required to at least detect 5, 4, 3, 2, and 1 log CFU/g of B. cereus, respectively. B. cereus in fresh-cut baby leafy vegetables could be detected after 2, 3, 4, 5, and 6 h of enrichment at 5, 4, 3, 2, and 1 log CFU/g, respectively, using a combination of enrichment and PCR analysis. To determine if a pack of fresh-cut vegetable is positive, the minimum number of sub-samples should be 3. These results can be used to develop a rapid detection method to semi-quantify B. cereus in fresh-cut vegetable samples combining enrichment and PCR.