• 생태와환경
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• 제40권1호
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• pp.149-154
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• 2007

남조류의 독성 잠재력을 확인하기 위해 microcystins 합성 유전자인 mcyB에 특이적으로 작용하는 TOX2P/TOX2M primer쌍을 이용한 whole-cell PCR을 실시하였다. 환경시료를 대상으로 한 실험 결과에서 TOX2P/TOX2M primer쌍은 약 1,000 $cells{\cdot}mL^{-1}$의 낮은 밀도에서 효과적으로 mcyB 유전자의 증폭에 성공하였으며, mcyB유전자를 지닌 종들은 모두 ELISA분석에 의해 microcystins의 생성이 확인되었다. 따라서, TOX2P/TOX2M primer쌍은 국내의 수체에서 독성 남조류의 신속하고 효과적인 검출을 위한 유용한 probe로 판단되었다.

• The Plant Pathology Journal
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• 제34권2호
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• pp.139-142
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• 2018

Pyrenophoratritici-repentis is the causal agent of tan spot. According to their ability to produce necrosis and/or chlorosis on a set of four differential bread wheats, the isolates of this fungus are currently grouped into eight races. When durum wheat genotypes were added to the differential set, a new virulence type was identified in Algeria. The isolates showing this virulence pattern are unable to attack bread wheat while they cause necrosis in durum genotypes. In this work, characterization of those isolates was based on pathological and molecular aspects. This included inoculation of bread and durum wheat, and virulence gene analysis using PCR and sequencing. The results showed that all isolates caused a resistance on all bread wheats of the differential set, while they produced necrosis in durum. ToxA and ToxB genes were amplified in all isolates, whereas toxb was absent. Sequence analysis for both genes showed no differences with those found in the two functional genes. The presence of two genes, ToxA and ToxB, despite the absence of symptoms usually caused by their products, suggests the existence of a new homologous for these two genes yet unknown. The presence of ToxA in the isolate unable to produce necrosis in Glenlea is reported for the first time.

• The Plant Pathology Journal
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• 제33권3호
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• pp.229-237
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• 2017

Rye (Secale cereale L.) serves as an alternative host of Pyrenophora tritici-repentis (PTR) the cause of tan spot on wheat. Rye is cultivated as a forage or cover crop and overlaps with a significant portion of wheat acreage in the U.S. northern Great Plains; however, it is not known whether the rye crop influences the evolution of PTR races. We evaluated a global collection of 211 rye accessions against tan spot and assessed the diversity in PTR population on rye in South Dakota. All the rye genotypes were inoculated with PTR races 1 and 5, and infiltrated with Ptr ToxA and Ptr ToxB, at seedling stage. We observed 21% of the genotypes exhibited susceptibility to race 1, whereas, 39% were susceptible to race 5. All 211 accessions were insensitive to both the Ptr toxins. It indicates that though rye exhibits diversity in reaction to tan spot, it lacks Ptr ToxA and ToxB sensitivity genes. This suggests that unknown toxins or other factors can lead to PTR establishment in rye. We characterized the race structure of 103 PTR isolates recovered from rye in South Dakota. Only 22% of the isolates amplified Ptr ToxA gene and were identified as race 1 based on their phenotypic reaction on the differential set. The remaining 80 isolates were noted to be race 4. Our results show that races 1 and 4 are prevalent on rye in South Dakota with a higher frequency of race 4, suggesting a minimal role of rye in the disease epidemiology.

• The Plant Pathology Journal
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• 제37권2호
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• pp.99-114
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• 2021

Tan spot of wheat, caused by Pyrenophora tritici-repentis (Ptr), results in a yield loss through chlorosis and necrosis of healthy leaf tissue. The major objective of this study was to compare gene expression in resistant and susceptible wheat cultivars after infection with Ptr ToxA-producing race 2 and direct infiltration with Ptr ToxA proteins. Greenhouse experiments included exposure of the wheat cultivars to pathogen inoculum or direct infiltration of leaf tissue with Ptr-ToxA protein isolate. Samples from the experiments were subjected to RNA sequencing. Results showed that ToxA RNA sequences were first detected in samples collected eight hours after treatments indicating that upon Ptr contact with wheat tissue, Ptr started expressing ToxA. The resistant wheat cultivar, in response to Ptr inoculum, expressed genes associated with plant resistance responses that were not expressed in the susceptible cultivar; genes of interest included five chitinases, eight transporters, five pathogen-detecting receptors, and multiple classes of signaling factors. Resistant and susceptible wheat cultivars therefore differed in their response in the expression of genes that encode chitinases, transporters, wall-associated kinases, permeases, and wound-induced proteins, among others. Plants exposed to Ptr inoculum expressed transcription factors, kinases, receptors, and peroxidases, which are not expressed as highly in the control samples or samples infiltrated with ToxA. Several of the differentially expressed genes between cultivars were found in the Ptr resistance QTLs on chromosomes 1A, 2D, 3B, and 5A. Future studies should elucidate the specific roles these genes play in the wheat response to Ptr.

• 한국환경성돌연변이발암원학회:학술대회논문집
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• 한국환경성돌연변이발암원학회 2003년도 추계학술대회
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• pp.150-150
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• 2003

• 한국독성학회:학술대회논문집
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• 한국독성학회 2003년도 추계학술대회
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• pp.150-150
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• 2003

Botulinum toxin type A was intramuscularly administered to Sprague-Dawley rats in both single and 28-day repeated dose toxicity studies. In the single dose toxicity study performed at 25, 50, 100, and 200 ng/kg, LD50 was estimated to be 70.71 ng/kg for males and 97.63 ng/kg for females.(omitted)

• Mycobiology
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• 제50권1호
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• pp.96-98
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• 2022

The Aspergilli of the section Nidulantes series Versicolores are among the most recurrent molds in indoor environments. These species cause damage to the quality of air. Indeed, they are responsible for allergies, aggravation of asthma and can even cause infections in immunocompromised patients. Molds belonging to the Versicolores series also produce sterigmatocystin, a mycotoxin classified as potential human carcinogen by the International Agency for Research on Cancer (group 2B). Here, we provide for the first time the genome of three species of the series Versicolores: Aspergillus creber, Aspergillus jensenii and Aspergillus protuberus which are the most abundant species of this series in bioaerosols. The genomes of these three species could be assembled with a percentage of completeness of 97.02%, 96.21% and 95.35% for Aspergillus creber, A. jensenii and A. protuberus respectively. These data will allow to study the genes and gene clusters responsible for the expression of virulence factors, the biosynthesis of mycotoxins and the proliferation of these ubiquitous and recurrent molds.

• Journal of Microbiology
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• 제41권2호
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• pp.161-164
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• 2003

Recombinant light chain of Clostridium botulinum neurotoxin type B stimulated transglutaminase activity in a dose dependent manner, Compared to native toxin, recombinant light chain showed av greater stimulatory effect on transglutaminase activity. Zn-chelating agents, inhibiting the proteolytic activity of the clostridial toxins, did not interfere with this stimulation. These results suggest that the light chain plays a major stimulatory role, which is not due to its metallopeptidase activity, but is possibly due to specific interaction with transglutaminase. More importantly, this report provides a new insight into the intracellular action of C. botulinum neurotoxins.

• Journal of Microbiology and Biotechnology
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• 제33권6호
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• pp.736-744
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• 2023

The introduction of the toxT-139F allele triggers the expression of TCP (toxin co-regulated pilus) and CT (cholera toxin) under simple laboratory culture conditions in most Vibrio cholerae strains. Such V. cholerae strains, especially strains that have been used in OCVs (oral cholera vaccines), can induce antibody responses against TCP in animal models. However, CT produced in these V. cholerae strains is secreted into the culture medium. In this study, V. cholerae strains that can express intracellular CTB under the control of the toxT-139F allele have been constructed for potential application in OCVs. First, we constructed a recombinant plasmid directly linking the ctxAB promoter to ctxB without ctxA and confirmed CTB expression from the plasmid in V. cholerae containing the toxT-139F allele. We constructed another recombinant plasmid to express NtrCTB, from which 14 internal amino acids-from the 7^th to the 20^th amino acid-of the leader peptide of CTB have been omitted, and we found that NtrCTB remained in the cells. Based on those results, we constructed V. cholerae strains in which chromosomal ctxAB is replaced by ntrctxB or ntrctxB-dimer. Both NtrCTB and NtrCTB-dimer remained in the bacterial cells, and 60% of the NtrCTB-dimer in the bacterial cells was maintained in a soluble form. To develop improved OCVs, these strains could be tested to see whether they induce immune responses against CTB in animal models.

• 한국인터넷방송통신학회논문지
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• 제10권2호
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• pp.61-67
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• 2010

현재 운영 중인 주요하천과 강의 수질오염 측정시스템은 대부분이 단순한 원격 모니터링 시스템이거나 독립적인 모니터링 시스템으로서, 다양한 수집정보의 동시 분석능력이나 통합적인 관리 관제시스템이 극히 미흡하다. 정보를 발생시키는 각종 센서들도 정확하지를 않아 개선의 여지를 남겨놓고 있다. 또한 정 취수장 및 하 폐수처리장의 관련 정화시설이 있으나, 이를 통합하여 측정 관리 관제할 수 있는 체계가 부족한 상태에 있다. 본 논문의 결과로서 전국적인 수질오염 및 수변환경을 모니터링 할 수 있다. 또한 USN과 지그비 또는 RFID 등 다양한 센서들, 그리고 서비스들을 통합 수용할 수 있는 미들웨어와 서비스 플랫폼 구축으로 확장성이 뛰어 난 서비스플랫폼의 표준화 방안을 제시하고자 한다.