• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.143-143
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• 2022

Plant defense systems against pathogens have been studied extensively and are currently a hot topic in plant science. Using a reverse genetics technique, this study looked into the involvement of the NO-downregulated NAD(P)-binding Rossmann-fold superfamily gene in plant growth and defense in Arabidopsis thaliana. For this purpose, the knockout and overexpressing plant of the candidate gene along with the relevant controls were exposed to control, oxidative and nitro-oxidative stresses. The results showed that candidate gene negatively regulates plants' root and shoot lengths. To investigate the role of the candidate gene in plant basal defense, R-gene-mediated resistance and systemic acquired resistance (SAR) plants were challenged with virulent or avirulent strains of Pseudomonas syringae pathovar tomato (Psf) DC3000. The results showed that the candidate gene negatively regulates plants' basal defense, R-gene-mediated resistance and SAR. Further characterization via GO analysis associated the candidate gene with metabolic and cellular processes and response to light stimulus, nucleotide binding and cellular location in the cytosol and nucleus. Protein structure analysis indicated the presence of a canonical Oxidoreductase family NAD (P)-binding Rossmann fold domain of 120 amino acids with a total of 121 plant homologs across 35 different plant species in the clad streptophyta. Arabidopsis eFP browser showed its expression in almost all the above-ground parts. Protein analysis indicated C225 and C359 as potential targets for S-Nitrosylation by NO. SMART analysis indicated possible interactions with mevalonate/galactokinase, galacturonic acid kinase, arabinose kinase, putative xylulose kinase, GroES-like zinc-binding alcohol dehydrogenase and various glyceraldehyde-3-phosphate dehydrogenases.

• Journal of Plant Biotechnology
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• 제43권3호
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• pp.281-292
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• 2016

Plants can recognize and respond in various ways to diverse environmental stresses, including pathogenic microorganisms, salt, drought, and low temperature. Salicylic acid (SA) is one phytohormone that plays important roles in the regulation of plant growth and development. Nonexpressor of pathogenesis-related genes 1 (NPR1) was originally identified as a core protein that could function as a transcriptional co-regulator and SA receptor during systemic acquired resistance (SAR), a plant immune response that could activate PR genes after pre-exposure of a pathogen. Although the function of NPR1 in plant defense response and the role of SA hormone in the regulation of plant physiological processes have been well characterized, the biological role of NPR1 in plant abiotic stress responses is largely unknown. In this review, we will summarize and discuss the current understanding of NPR1 function in response to plant environmental stresses.

• Mycobiology
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• 제43권3호
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• pp.311-318
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• 2015

Culture filtrates of six different edible mushroom species were screened for antimicrobial activity against tomato wilt bacteria Ralstonia solanacearum B3. Hericium erinaceus, Lentinula edodes (Sanjo 701), Grifola frondosa, and Hypsizygus marmoreus showed antibacterial activity against the bacteria. Water, n-butanol, and ethyl acetate extracts of spent mushroom substrate (SMS) of H. erinaceus exhibited high antibacterial activity against different phytopathogenic bacteria: Pectobacterium carotovorum subsp. carotovorum, Agrobacterium tumefaciens, R. solanacearum, Xanthomonas oryzae pv. oryzae, X. campestris pv. campestris, X. axonopodis pv. vesicatoria, X. axonopodis pv. citiri, and X. axonopodis pv. glycine. Quantitative real-time PCR revealed that water extracts of SMS (WESMS) of H. erinaceus induced expressions of plant defense genes encoding ${\beta}$-1,3-glucanase (GluA) and pathogenesis-related protein-1a (PR-1a), associated with systemic acquired resistance. Furthermore, WESMS also suppressed tomato wilt disease caused by R. solanacearum by 85% in seedlings and promoted growth (height, leaf number, and fresh weight of the root and shoot) of tomato plants. These findings suggest the WESMS of H. erinaceus has the potential to suppress bacterial wilt disease of tomato through multiple effects including antibacterial activity, plant growth promotion, and defense gene induction.

• The Plant Pathology Journal
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• 제17권2호
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• pp.77-82
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• 2001

Erwinia amylovora causes a devastating disease called fire blight in rosaceous trees and shrubs such as apple, pear, and raspberry. To successfully infect its hosts, the pathogen requires a set of clustered genes termed hrp. Studies on the hrp system of E. amylovora indicated that it consists of three functional classes of genes. Regulation genes including hrpS, hrpS, hrpXY, and hrpL produce proteins that control the expression of other genes in the cluster. Secretion genes, many of which named hrc, encode proteins that may form a transmembrane complex, which is devoted to type III protein secretion. Finally, several genes encode the proteins that are delivered by the protein secretion apparatus. They include harpins, DspE, and other potential effector proteins that may contribute to proliferation of E. amylovora inside the hosts. Harpins are glycine-rich heat-stable elicitors of the hypersensitive response, and induce systemic acquired resistance. The pathogenicity protein DseE is homologous and functionally similar to an avirulence protein of Pseudomonas syringae. The region encompassing the hrpldsp gene cluster of E. amylovora shows features characteristic of a genomic island : a cryptic recombinase/integrase gene and a tRNA gene are present at one end and genes corresponding to those of the Escherichia coli K-12 chromosome are found beyond the region. This island, designated the Hrp pathogenicity island, is more than 60 kilobases in size and carries as many as 60 genes.

• The Plant Pathology Journal
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• 제26권1호
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• pp.63-69
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• 2010

The effect of Acibenzolar-S-methyl (ASM) and Rahnella aquatilis Ra39 against apple fire blight disease caused by Erwinia amylovora were tested as a possible alternative to streptomycin. In vitro studies, no inhibition effect against the pathogen was found when ASM was tested. Under greenhouse conditions, application of R. aquatilis Ra39 with the highly susceptible M26 rootstock resulted in a marked disease suppression. Application of ASM and strain Ra39 caused a high decrease of the disease, 82% and 58% respectively; this was correlated with a reduction of the growth of the pathogen within host plants up to 64% and 49.5% respectively. Further studies in the field under artificial infection condition during full bloom revealed that application of ASM and R. aquatilis Ra39 with Gala variety resulted in a control effect up to 21 and 29% respectively. In physiological studies, enhanced activities of PR-proteins (chitinase and $\beta$-1, 3-glucanase) were detected, which are well known as biochemical markers for systemic acquired resistance. Application of ASM to apple shoots caused the highest chitinase activity followed by strain Ra39. The enzyme activity was increased after 2, 4 and 6 days from application. In addition, ASM-treatment caused the higher $\beta$-1, 3-glucanase activity than strain Ra39. Maximum enzyme activity was recorded after 6 days from application and then decreased after 8 and 10 days from application.

• The Plant Pathology Journal
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• 제19권2호
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• pp.85-91
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• 2003

Pre-treatment with DL-3-aminobutyric acid (BABA) in the cucumber plants caused the decrease of disease severity after inoculation with anthracnose pathogen Colletotrichum orbiculare. In this study, ultrastructures of the vascular bundle and the infection structures in the leaves of BABA-treated as well as untreated cucumber plants were observed after inoculation with the anthracnose pathogen by electron microscopy. The ultrastructures of vascular bundle in the leaves of BABA-treated plants were similar to those of the untreated plants except plasmodesmata. In the BABA-treated plants, the plasmodesmata were more numerous than in the untreated plants, suggesting that the BABA treatment may cause the active transfer of metabolites through the vascular bundle. In the leaves of untreated plants, the fungal hyphae were spread widely in the plant tissues at 5 days after pathogen inoculation. Most cellular organelles in the hyphae were intact, indicating a compatible interaction between the plant and the parasite. In contrast, in the leaves of BABA pre-treated plants the growth of most hyphae was restricted to the epidermal cell layer at 5 days after inoculation. Most hyphae cytoplasm and nucleoplasm was electron dense or the intracellular organelles were degenerated. The cell walls of some plant cells became thick at the site adjacent to the intercellular hyphae, indicating a mechanical defense reaction of the plant cells against the fungal attack. Furthermore, hypersensitive reaction (HR) of the epidermal cells was often observed, in which the intracellular hyphae were degenerated. Based on these results it is suggested that BABA causes the enhancement of defense mechanisms in the cucumber plants such as cell wall apposition or HR against the invasion of C. orbiculare.

• 식물병연구
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• 제28권2호
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• pp.82-91
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• 2022

최근에는 작물의 유도 저항성을 이용한 항바이러스제 개발에 관한 많은 연구가 수행되고 있으나 실제 농업현장에 널리 보급되지 못하고 있는 실정이다. 본 실험은 시설토마토 재배현장에 외생 살리실산, 키토산, 유제놀 처리에 따른 토마토황화잎말림바이러스(Tomato yellow leaf curl virus, TYLCV) 감염억제효과를 검증하고자 수행되었다. 실내검정에서 TYLCV에 감수성 품종인 '슈퍼도태랑'은 항바이러스제 처리 후 TYLCV에 감염된지 12일 후 VP (virus infected control plants)에서 바이러스 증상이 나타나기 시작했다. 접종 32일 후 TYLCV 발병도는 VP에서 98.8%였고, SAT (2 mM salicylic acid)+VP, EGT (200 ㎍/ml eugenol)+VP에서는 각각 98.8%, 98.7%로 발병도가 높았으나, CHT (0.1% chitosan)+VP는 85.7%로 다른 처리들과 통계적으로 유의한 차이를 보였다. 그러나 TYLCV 농도는 CHT+VP에서 OD값이 0.3으로 오히려 가장 높게 나타났으며, 토마토의 초장, 지상부 및 지하부 생체중에서도 뚜렷한 효과를 보이지 않았다. 여름작형 시설재배지에서 도태랑 계열의 토마토품종 '도태랑솔라'를 사용하여 항바이러스 3종의 효과를 조사한 결과, 수확기에 모든 처리구에서 100.0%에 가까운 TYLCV 감염률은 나타냈으며, 수확량에도 처리간의 통계적 유의차가 인정되지는 않았다. 이와 대조적으로 Ty-1과 Ty-3a 유전자를 보유한 TYLCV에 내병성 품종인 'TY자이언츠'는 저항성 유묘검정의 전 조사기간 동안 바이러스 증상이 전혀 관찰되지 않았고, 식물체내 바이러스 농도도 무접종 수준이었다. 본 실험 결과 'TY자이언츠' 품종은 TYLCV 발생이 만연한 지역 및 재배시기에 감수성 품종을 대체할 수 있을 것으로 생각된다. 반면, 저항성 유도물질인 살리실산, 유제놀, 키토산의 항바이러스 효과는 입증되지 않았기 때문에, 아직 시설토마토 재배현장에 적용하기는 어려울 것으로 판단된다.

• 분석과학
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• 제25권6호
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• pp.364-369
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• 2012

Isotianil은 쌀 도열병을 방제하기 위한 새로이 개발된 식물활성 살균제로 다른 식물활성제에 비해 소량으로도 장시간의 효과를 나타내는 특징을 가지고 있다. 신규 농약 Isotianil에 대한 기준은 국내의 경우 2010년 쌀에 대하여 0.1 mg/kg으로 최초 설정되었으며, 이에 따른 식품 중 안전관리를 위해 Isotianil을 분석하기위한 검사법을 개발하였다. 검체 일정량에 acetonitrile을 가하고 균질화하여 대상농약을 추출하였으며, 액-액분배하고 florisil 카트리지를 이용한 고체상 추출 후 GC-NPD 및 GC-MSD로 분석하였다. 분석결과 농산물에 의한 간섭물질은 없었으며, 대표 농산물 현미 등 6 종에 대한 Isotianil의 분석 시험법의 정량한계와 직선성은 각각 0.05 mg/kg과 0.999($r^2$)이었다. 회수율은 대표 농산물에서 70.0~103.9%이었으며, 분석오차는 10% 미만으로 CODEX 잔류분석 기준에 적합하였다.

• Journal of Plant Biotechnology
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• 제35권3호
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• pp.169-176
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• 2008

SA는 천연 페놀 화합물로써 식물체가 생성하는 호르몬 중의 하나이다. SA는 특히 병저항성, 생물학적, 비생물학적 스트레스로 인해 합성이 촉진되며 식물 방어 기작을 일으킨다고 알려져 있다. 식물의 방어 기작은 바로 식물에서 얻어지는 생산량에 영향을 미치기 때문에 SA에 대한 연구가 많이 되어져 왔다. 하지만 SA를 이해하기에는 아직까지 많은 연구가 필요 되어 지고 있다. 따라서 본 연구는 애기장대에서 SA 생합성하는데 중요한 효소인 SID2가 병저항성이 강한 siz1-2 돌연변이체와 야생형에서 어떠한 조절의 차이를 보이는 지를 SID2 promoter에 의해서 조절되는 GUS와 LUC를 가진 각각의 형질전환 식물체를 통하여 관찰하였다. GUS의 발현을 GUS histochemical assay, GUS enzyme assay 그리고 LUC의 발현을 CCD 카메라를 이용한 이미지 촬영과 Luciferase enzyme assay 수행한 결과, siz1-2를 사용한 형질전환 식물체에서 야생형에 비해 발현이 높게 일어났다. 이것을 바탕으로 SA에 반응하는 유전자들의 발현이 siz1-2 돌연변이체에서는 높은 이유가 SID2의 발현이 높게 조절 받기 때문이라는 것을 SID2 promoter:GUS::LUC/siz1-2 형질전환 식물체를 통해 알 수 있었다.