• The Plant Pathology Journal
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• 제36권3호
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• pp.255-266
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• 2020

Plant immune responses can be triggered by chemicals, microbes, pathogens, insects, or abiotic stresses. In particular, induced systemic resistance (ISR) refers to the activation of the immune system due to a plant's interaction with beneficial microorganisms. The phenolic compound, 2,4-diacetylphloroglucinol (DAPG), which is produced by beneficial Pseudomonas spp., acts as an ISR elicitor, yet DAPG's mechanism in ISR remains unclear. In this study, transgenic Arabidopsis thaliana plants overexpressing the DAPG hydrolase gene (phlG) were generated to investigate the functioning of DAPG in ISR. DAPG was applied onto 3-week-old A. thaliana Col-0 and these primed plants showed resistance to the pathogens Botrytis cinerea and Pseudomonas syringae pv. tomato DC3000. However, in the phlG transgenic A. thaliana, the ISR was not triggered against these pathogens. The DAPG-mediated ISR phenotype was impaired in transgenic A. thaliana plants overexpressing phlG, thus showing similar disease severity when compared to untreated control plants. Furthermore, the DAPG-treated A. thaliana Col-0 showed an increase in their gene expression levels of PDF1.2 and WRKY70 but this failed to occur in the phlG transgenic lines. Collectively, these experimental results indicate that jasmonic acid/ethylene signal-based defense system is effectively disabled in phlG transgenic A. thaliana lines.

• Geomechanics and Engineering
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• 제21권5호
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• pp.447-459
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• 2020

This paper aims to investigate the effect of rotation on a micropolar thermoelastic medium with voids problem. The problem is assessed according to three-phase-lag model. The normal mode analysis used to obtain the analytical expressions of the considered variables. The non-dimensional displacement, temperature, Micro rotation, the change in the volume fraction field, and stress of the material are obtained and illustrated graphically. Comparisons are made with the results predicted by two theories; namely three- phase-lag model (3PHL) and Green-Naghdi theory of type III (G-N III). The considered variables were plotted for different values of the rotation parameter, the phase-lag of heat flux and the phase-lag of temperature. The numerical results reveal that the rotation and the phase-lag times significantly influence the distribution of the field quantities. Some particular cases of interest are deduced from the present investigation.

• 미생물학회지
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• 제34권3호
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• pp.115-119
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• 1998

Pseudomonas sp. DJ77로부터 전보에서 클로닝한 pHENX7의 하류방향으로 약 3kb 정도를 포함하는 pYCS500을 클로닝하였다. PYCS500의 제한효소지도를 작성하고 부분적으로 염기서열을 분석한 결과 465 bp의 HindIII-ClaI절편에서 282 bp로 이루어진 하나의 open reading frame(ORF)을 발견하였다. phnM으로 명명된 이 ORF는 93개의 아미노산으로 구성된 polypeptide를 암호화하고 있었으며 계산된 분자량은 10,008 Da이었다. PhnM은 NahT, XylT, DmpQ, AtdS, PhlG, PhhQ, TbuW 등 plant-type ferredoxin 형태의 단백질과 37.7%-53.9%의 상동성을 나타내었으며 이들이 공통적으로 가지고 있는 motif가 일치하였다.

• Geomechanics and Engineering
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• 제28권4호
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• pp.347-358
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• 2022

The main concern of this article is to discuss the problem of a two-temperature fiber-reinforced micropolar thermoelastic medium with voids under the effect rotation, mechanical force in the context four different theories with memory-dependent derivative (MDD) and variable thermal conductivity. The three-phase-lag model (3PHL), dual-phase-lag model (DPL), Green-Naghdi theory (G-N II, G-N III), coupled theory, and the Lord-Shulman theory (L-S) are employed to solve the present problem. Analytical expressions of the physical quantities are obtained by using Laplace-Fourier transforms technique. Numerical results are shown graphically and the results obtained are analyzed. The most significant points are highlighted.

• Journal of Animal Science and Technology
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• 제49권5호
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• pp.639-646
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• 2007

본 연구는 섬유소공급원 7종, alfalfa hay cube (AHC), corn cob(CC), corn silage(CS), cotton seed hull(CSH), peanut hull(PHL), rice straw (RS), sugar cane bagasse(SCB)이 면양에서의 저작행동에 미치는 영향을 알아보기 위하여 실시하였다. 평균체중 37.1 kg인 Corridale종 수컷 면양 5두를 공시하여 실험기간동안 각각의 섬유소공급원 45%와 corn-based 사료 55%의 비율로 하여 1일 2회(09:00, 21:00) 총 800g(dry matter basis)을 급여하였다. 저작횟수는 CC구에서 유의적으로 높은 값을 나타내었으며 CSH구에서 가장 낮은 값을 나타내었고(p<0.001), 그 외의 구에서는 중간정도였다. 반추소비시간은 RS구와 CC구가 각각 352분과 367분으로 높게 나타났다. kg NDF 섭취당 저작횟수는 CC구에서 가장 높았으나 kg NDF 섭취당 반추소비시간은 CSH구(p<0.001)를 제외하고 다른 구에서는 차이가 나타나지 않았다. 입자도의 분포는 RS구에서 더 길었으며 PHL구에서는 더 짧게 나타났다.이상의 결과로부터 섬유소 공급원에 따라 저작행동이 크게 영향을 받는 것을 확인할 수 있었으며, 섬유소 공급원에 따른 저작행동을 반추가축의 사료설계에 지표로 활용할 수 있을 것으로 판단되었다.

• 한국초지조사료학회지
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• 제25권3호
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• pp.177-184
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• 2005

본 연구는 섬유소공급원 7종, alfalfa hay cube (AHC), corn cob (CC), corn silage (CS), cotton seed hull (CSH), peanut hull (PHL), rice straw(RS), sugar cane bagasse(SCB)의 반추위에서의 반추활동, pH, 완충능력과 전소화기관 내 소화율을 알아보고자 실시하였다. 공시 동물은 평균체중 37.1kg인 Corridale종 수 면양 5두 (3두는 반추위 fistula 부착)를 사용하였으며, 실험기간동안 공시동물에게 급여한 사료는 각각의 조사료원 $45\%$와 corn-based 사료 $55\%$의 비율로 하여 1일 2회 (09:00, 21:00) 총 800g(dry matter basis)을 급여하였다. Ruminal pH는 급여 후 4시간까지는 처리구 간에 차이가 없었지만 8시간 후 타 조사료원$(6.24\~6.61)$과 RS(5.78)간에는 차이가 있었다(p<0.05). 반추위 내 완충능력은 SCB구, CC구와 비교하여 CS구에서 사료급여 후 0시간(p<0.05), 2시간(p<0.05)에 유의한 차이를 나타내었고, 사료급여 후 12시간 경과 시 AHC구를 제외한 CC구, CS구, SCB구와 RS구 보다 PHL구(p<0.01)에서 높게 나타났다. DM 소화율은 CS구에서 $78.19\%$로 타처리보다 유의하게 높았으며(p<0.05), DNF 소화율은 CC구, CS구, CSH구와 RS구가 다른 조사료원 급여구보다 높게 나타났다. (p<0.001).

• Steel and Composite Structures
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• 재36권6호
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• pp.617-629
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• 2020

The purpose of this paper is to depict the effect of rotation and initial stress on a magneto-thermoelastic medium with diffusion. The problem discussed within memory-dependent derivative in the context of the three-phase-lag model (3PHL), Green-Naghdi theory of type III (G-N III) and Lord and Shulman theory (L-S). Analytical expressions of the considered variables are obtained by using Laplace-Fourier transforms technique. Numerical results for the field quantities given in the physical domain and illustrated graphically in the absence and presence of a magnetic field, initial stress as well as the rotation. The differences in variable thermal conductivity are also presented at different parameter of thermal conductivity. The numerical results of the field variables are presented graphically to discuss the effect of various parameters of interest. Some special cases are also deduced from the present investigation.

• The Plant Pathology Journal
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• 제28권1호
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• pp.93-100
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• 2012

The rhizobacterium NJ134, showing strong $in$ $vitro$ antifungal activity against $Fusarium$ $oxysporum$, was isolated from field grown tomato plants and identified as $Pseudomonas$ sp. based on 16S ribosomal DNA sequence and biochemical analyses. The antifungal compound purified by gas chromatography-mass spectrometry, infrared, and nuclear magnetic resonance analyses from NJ134 cultures was polyketide 2,4-diacetylphloroglucinol (DAPG). Analysis of the sequence of part of one of the genes associated with DAPG synthesis, $phlD$, indicated that the DAPG producer NJ134 was a novel genotype or variant of existing genotype termed O that have been categorized based on isolates from Europe and North America. A greenhouse study indicated that about $10^8$ CFU/g of soil NJ134 culture application was required for effective biocontrol of Fusarium wilt in tomato. These results suggest that a new variant genotype of a DAPG-producing strain of $Pseudomonas$ has the potential to control Fusarium wilt under the low disease pressure conditions.

• 한국식품영양과학회지
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• 제36권7호
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• pp.938-943
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• 2007

향후 소비가 더욱 증가할 것으로 예상되는 즉석섭취식품 중 샌드위치를 대상으로 제조공정의 특성상 생물학적 위해 중 높은 빈도로 검출될 것으로 예상되는 황색포도상구균에 대해서 정성적${\cdot}$정량적 검출실험을 실시하였다. 분석시료는 편의점, 대형할인마트, 샌드위치 전문점, 개인운영제과점, 패스트푸드점, 급식소에서 판매되는 샌드위치를 대상으로 하였다. 분석결과 전체 174개의 시료 중 18개, 전체 10.3%에서 황색포도상구균이 검출되었으며 검출량은 평균 1.74 log CFU/g으로 0.30 log CFU/g에서 최대 4.08 log CFU/g까지 검출되었다. 황색포도상구균의 계절에 따른 검출량은 여름철(3.24 log CFU/g)이 겨울철(1.10 log CFU/g)에 비해서 3배 정도 많아 통계적으로 유의적인 차이가 있었다(p<0.001). 영국 PHLS의 즉석섭취식품의 황색포도상구균에 대한 미생물 가이드라인을 기준으로 평가했을 때 본 실험의 전체 분석 대상 시료 중 95.4%가 허용할 수 있는 수준이었다. 또한 햄 치즈샌드위치에 대한 독소형성 확인 실험 결과 4.95 log CFU/g 이상으로 황색포도상구균이 증식되지 않으면 독소가 생성되지 않는다는 것을 알 수 있었다. 샌드위치의 황색포도상구균에 대한 정량적 오염도 분석에 대한 본 실험 결과는 샌드위치를 포함한 즉석섭취식품의 정량적 위해평가를 위한 기초자료로써 활용될 수 있을 것으로 사료된다.

• The Plant Pathology Journal
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• 제29권2호
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• pp.125-135
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• 2013

In agro-ecosystems worldwide, some of the most important and devastating diseases are caused by soil-borne necrotrophic fungal pathogens, against which crop plants generally lack genetic resistance. However, plants have evolved approaches to protect themselves against pathogens by stimulating and supporting specific groups of beneficial microorganisms that have the ability to protect either by direct inhibition of the pathogen or by inducing resistance mechanisms in the plant. One of the best examples of protection of plant roots by antagonistic microbes occurs in soils that are suppressive to take-all disease of wheat. Take-all, caused by Gaeumannomyces graminis var. tritici, is the most economically important root disease of wheat worldwide. Take-all decline (TAD) is the spontaneous decline in incidence and severity of disease after a severe outbreak of take-all during continuous wheat or barley monoculture. TAD occurs worldwide, and in the United States and The Netherlands it results from a build-up of populations of 2,4-diacetylphloroglucinol (2,4-DAPG)-producing fluorescent Pseudomonas spp. during wheat monoculture. The antibiotic 2,4-DAPG has a broad spectrum of activity and is especially active against the take-all pathogen. Based on genotype analysis by repetitive sequence-based-PCR analysis and restriction fragment length polymorphism of phlD, a key 2,4-DAPG biosynthesis gene, at least 22 genotypes of 2,4-DAPG producing fluorescent Pseudomonas spp. have been described worldwide. In this review, we provide an overview of G. graminis var. tritici, the take-all disease, Pseudomonas biocontrol agents, and mechanism of disease suppression.