• Plant Biotechnology Reports
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• 제5권4호
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• pp.301-308
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• 2011

This study tested the relative and combined efficacy of ShPx2 and ShPAL transgenes by comparing Nicotiana tabacum hybrids with enhanced levels of $_L$-phenylalanine ammonia lyase (PAL) activity and cationic peroxidase (Prx) activity with transgenic parental lines that overexpress either transgene. The PAL/Prx hybrids expressed both transgenes driven by the 35S CaMV promoter, and leaf PAL and Prx enzyme activities were similar to those of the relevant transgenic parent and seven- to tenfold higher than nontransgenic controls. Lignin levels in the PAL/Prx hybrids were higher than the PAL parent and nontransgenic controls, but not significantly higher than the Prx parent. All transgenic plants showed increased resistance to the necrotrophs Phytophthora parasitica pv. nicotianae and Cercospora nicotianae compared to nontransgenic controls, with a preponderance of smaller lesion categories produced in Prx-expressing lines. However, the PAL/Prx hybrids showed no significant increase in resistance to either pathogen relative to the Prx parental line. These data indicate that, in tobacco, the PAL and Prx transgenes do not act additively in disease resistance. Stacking with Prx did not prevent a visible growth inhibition from PAL overexpression. Practical use of ShPAL will likely require more sophisticated developmental control, and we conclude that ShPx2 is a preferred candidate for development as a resistance transgene.

• 한국작물학회지
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• 제22권1호
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• pp.11-15
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• 1977

대두 품질에 영향을 미치는 자반병에 대하여 우리나라의 각 지역으로부터 수집한 재래종대두 467계통을 관행법으로 재배수확한후에 조사한 종실의 자반병 자연감염율로서 저항성 정도를 판별하고 숙기에 따른 감염율의 차이와 재배 환경과의 관계를 조사한 결과는 다음과 같다. 1. 자반병에 감염된 종자를 파종하여 포장발아율(출토율)을 조사한 결과 계통간에 차이는 있으나 건전종자의 발아율에 비하여 평균 45%의 발아율 감소를 보였다. 2. 공시계통의 자반병 자연감염율은 전체의 28.9%가 0.1% 미만의 감염율을 나타냈고 1% 이상의 감염율을 보인 계통은 약 30%였으며 최고 감염율은 12.7%였다. 3. 자반병 자연감염율은 일반적으로 조숙계통이 만숙계통에 비하여 높았으며 개화기와는 부의 상관을 그리고 개화기에서 성숙기 까지의 기간과의 정의 상관을 보였다. 4. 대두 품종의 개화기와 유협형성시기의 온도와 강우일수는 자반병 자연감염율과 밀접한 상관관계가 있었다. 5. 조숙품종 육성시에는 자반병저항성 문제가 고려되어야 할 것이다.

• The Plant Pathology Journal
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• 제39권5호
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• pp.513-521
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• 2023

Seed-borne diseases reduce not only the seed germination and seedling growth but also seed quality, resulting in the significant yield loss in crop production. Plant seed harbors diverse microbes termed endophytes other than pathogens inside it. However, their roles and application to agricultures were rarely understood and explored to date. Recently, we had isolated from soybean seeds culturable endophytes exhibiting in-vitro antagonistic activities against common bacterial and fungal seed-borne pathogens. In this study, we evaluated effects of seed treatment with endophytes on plant growth and protection against the common seed-borne pathogens: four fungal pathogens (Cercospora sojina, C. kikuchii, Septoria glycines, Diaporthe eres) and two bacterial pathogens (Xanthomonas axonopodis pv. glycines, Pseudomonas syringae pv. tabaci). Our experiments showed that treatment of soybean seeds with seed endophytes clearly offer protection against seed-borne pathogens. We also found that some of the endophytes promote plant growth in addition to the disease suppression. Taken together, our results demonstrate agricultural potential of seed endophytes in crop protection.

• The Plant Pathology Journal
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• 제22권4호
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• pp.323-328
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• 2006

Serratia marcescens W1, isolated from cucumber-cultivated soil in Suwon, Korea, evidenced profound antifungal activity and produced the extracellular hydrolytic enzymes, chitinase and protease. In order to isolate the antifungal genes from S. marcescens W1, a cosmid genomic library was constructed and expressed in Escherichia coli. Transformants exhibiting chitinase and protease expression were selected, as well as those transformants evidencing antifungal effects against the rice blast fungus, Magnaporthe grisea, and the cucumber leaf spot fungus, Cercospora citrullina. Cosmid clones expressing chitinase or protease exerted no inhibitory effects against the growth of fungal pathogens. However, two cosmid clones evidencing profound antifungal activities were selected for further characterization. An 8.2 kb HindIII fragment from these clones conditioned the expression of antagonistic activity, and harbored seven predicted complete open reading frames(ORFs) and two incomplete ORFs. The deduced amino acid sequences indicated that six ORFs were highly homologous with genes from S. marcescens generating pyrroloquinoline quinone(PQQ). Only subclones harboring the full set of pqq genes were shown to solubilize insoluble phosphate and inhibit fungal pathogen growth. The results of this study indicate that the functional expression of the pqq genes of S. marcescens W1 in E. coli may be involved in antifungal activity, via as-yet unknown mechanisms.

• 농약과학회지
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• 제20권4호
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• pp.369-374
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• 2016

Bacillus velezensis YP2 균주는 쌈채소에서 분리한 Cercospora sp. 1~3, Septoria sp., Colletotrichum sp., Sclerotinia sclerotiorum, Phoma sp., Botrytis cinerea에 대하여 균사생육을 억제하였다. B. velezensis YP2 균주의 LB배양액을 10배 희석액은 적겨자와 청겨자에 발생하는 Erysiphe cruciferarm에 의한 흰가루병을 91.8%와 80.9% 방제효과을 보였다. B. velezensis YP2 균주의 배양액을 10배 희석하여 5일 간격 4회 처리구가 적겨자 흰가루병을 70.6%, 7일 간격 3회 처리구는 65.0%, 10일 간격 2회 처리구는 49.5% 방제하였다. 또한 B. velezensis YP2 균주는 적겨자 종자 발아를 증가시켜고 생육을 촉진하였다. 이상의 결과에서 YP2 균주는 겨자채 흰가루병 방제에 매우 효과적이었다.

• 한국식물병리학회지
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• 제14권3호
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• pp.191-202
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• 1998

About 300 actinomycetes were isolated from two forest and one sea-shore soil and tested for inhibitory effects on mycelial growth of six plant pathogenic fungi Magnaporthe grisea, Alternaria mali, Colletotrichum gloeosporioides, Phytophthora capsici, Fusarium oxysporum f. sp. cucumerinum, and Rhizoctonia solani. Among 300 actinomycetes tested, only 16 actinomycetes showed the antifungal activity against the test fungi. Isolate NH 50 was selected for production and purification of antifungal antibiotic substances. Actinomycete isolate NH 50 displayed the broad antifungal spectra against 11 plant pathogenic fungi. To identify actinomycete isolate NH 50, cultural characteristics on various agar media, diaminopimelic acid type, and morphological characteristics by scanning electron microscopy were examined. As a result, actinomycete isolate NH 50 was classified as a rare actinomycete that had LL-DAP type and did not produce spores. After incubation of isolate NH 50 in yeast extract-malt extract-dextrose broth, antifungal compound NH-B1 that inhibited mycelial growth of some plant pathogenic fungi was purified from the methanol eluates of XAD-16 resins by a series of purification procedures, i.e., silica gel flash chromatography, C18 flash chromatography, Sephadex LH-20 column chromatography, silica gel medium pressure liquid chromatography (MPLC), C18 MPLC, and high pressure liquid chromatography (HPLC). UV spectrum and 1HNMR spectrum of antifungal compound NH-B1 dissolved in methanol were examined. The antibiotic NH-B1 showed the major peaks at 230 and 271.2nm. Based on the data of 1H-NMR spectrum, NH-B1 was confirmed to be an extremely complex polymer of sugars called polysaccharides. The antibiotic NH-B1 showed strong antifungal activity against Alternaria solani and Cercospora kikuchi, but weak activity against M. grisea.

• 한국작물학회지
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• 제29권1호
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• pp.50-54
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• 1984

하대두형 품종에 대하여 파종기를 달리하고 비닐멀칭을 했을 때 생육 및 수량에 미치는 영향을 규명코져 다마미도리 지두를 4월 13일부터 10일 간격으로 4파종기로 하고, 비닐로 멀칭과 무멀칭으로 하여 시험한 결과를 요약하면 다음과 같다. 1. 출현기는 멀칭을 할 경우 무멀칭에 비하여 촉진되어 4월 13일 파종구는 11일 축진되었다. 개화일수도 멀칭을 할 경우 평균 6일이 단축되었고, 4월 13일 파종구는 12일이 단축되었다. 2. 멀칭구는 무멀칭에 비하여 주경장이 컸으며, 주경절수 및 분지수도 많았을 뿐 아니라. l0a당 건경중도 많았다. 평균 100립중은 차가 없었다. 멀칭의 경우 늦게 파종한 구에서 주경장이 컸고, 주경절수 및 분지수도 많았을 뿐 아니라 건경중도 높았으며, 100립중도 무거웠다. 이러한 현상은 일찍 파종한구에서 미이라병의 리병입률이 높았기 때문이다. 무멀칭의 경우는 멀칭구와 같은 경향을 보이지는 않았다. 3. 멀칭구에서 미이라병의 리병입율이 높으면 자반병 리병입율은 낮아졌다. 무멀칭구는 멀칭구에서와 같은 경향은 보이지 않았다. 4. 멀칭구에서는 무멀칭구보다 평균 20％가 증수되었고, 파종기별로 보면 일찍 파종한 구에서 미이라병에 대한 리병정도가 심하여 수량이 낮았고, 늦게 파종한 구에서 수량이 높았다.

• 한국작물학회지
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• 제23권2호
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• pp.113-117
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• 1978

대두 자반병에 대하여 저항성인 계통 선발을 위한 Mass-screening technique를 확립하고 이 종자잡종법을 이용하여 수집재내종 및 각 품종의 저항성검정을 실시한 결과는 다음과 같다. 1. 조숙성인 수집재내종 50계통의 자반병 자연감염률과 종자접종에 의한 자주빛 색소 형성률간에 나타난 정의 상관관계는 r=0.121로서 고도의 유의성이 인정되었으며 이 종자접종법은 효과약인 Mass-screening technique으로서 방사선을 이용한 돌연변이육종에서 자반병저항성 계통선발에 이용가능성이 높았다. 2. 자반병 자연감염률이 극히 낮은 만숙성 수집재내종 85계통은 종자접종에 의하여 대부분이 이병성 반응을 보였으며 이는 포장에서의 만숙계통의 저항성이 유전적인 특성이기 보다는 병해도피 현상에 기인한 것으로 생각되었다. 3. 대두품종의 저항성검정에서 우리나라 대두 36품종을 비롯하여 일본과 대만의 각 16품종, 베트남 11품종, 필리핀 8품종 및 미국 38품종 등 대부분이 이병성이였고 미국품종인 Sac, Hill, Harosoy등이 비교적 저항성 이었다. 4. 각 지역에서 분리한 대두 자반병균 244 isolates 중에서 배지에서 자주빛 색소를 형성하지 않는 두 균주를 제외하고는 모두가 암조건에서는 감자한천배지에서, 광조건에서는 오트밀한친배지에서 자주빛 색소형성이 잘 되었으며 배지에서의 색소형성 정도는 종자에서의 병원성과 밀접한 상관이 있었다.

• 한국균학회소식:학술대회논문집
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• 한국균학회 2016년도 춘계학술대회 및 임시총회
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• pp.33-33
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• 2016

Mycotoxins are toxic secondary metabolites produced by fungi. They can be present in where agricultural-based commodities are contaminated with toxigenic fungi. These mycotoxins cause various toxicoses in human and livestock when consumed. Small grains including corn, barley, rice or wheat are frequently contaminated with mycotoxins due to infection mainly by toxigenic Fusarium species and/or under environment favorable to fungal growth. One of the most well-known Fusarium toxin groups in cereals is trichothecenes consisting of many toxic compounds. Deoxynivalenol (DON), nivalenol (NIV), T-2 toxin, and various derivatives belong to this group. Zearalenone and fumonisin (FB) are also frequently produced by many species of the same genus. In order to monitor Korean cereals for contamination with Fusarium and other mycotoxigenic fungal species as well, barley, corn, maize, rice grains, and soybean were collected from fields at harvest or during storage for several years. The fungal colonies outgrown from the grain samples were identified based on morphological and molecular characteristics. Trichothecene chemotypes of Fusarium species or presence of FB biosynthetic gene were determined using respective diagnostic PCR to predict possible toxin production. Heavy grain contamination with fungi was detected in barley, rice and wheat. Predominant fungal genus of barley and wheat was Alternaria (up to 90%) while that of rice was Fusarium (~40%). Epicoccum also appeared frequently in barley, rice and wheat. While frequency of Fusarium species in barley and wheat was less than 20%, the genus mainly consisted of Fusarium graminearum species complex (FGSC) which known to be head blight pathogen and mycotoxin producer. Fusarium composition of rice was more diverse as FGSC, Fusarium incarnatum-equiseti species complex (FIESC), and Fusarium fujikuroi species complex (FFSC) appeared all at considerable frequencies. Prevalent fungal species of corn was FFSC (~50%), followed by FGSC (<30%). Most of FFSC isolates of corn tested appeared to be FB producer. In corn, Fusarium graminearum and DON chemotype dominate within FGSC, which was different from other cereals. Soybeans were contaminated with fungi less than other crops and Cercospora, Cladosporium, Alternaria, Fusarium etc. were detected at low frequencies (up to 14%). Other toxigenic species such as Aspergillus and Penicillium were irregularly detected at very low frequencies. Multi-year survey of small grains revealed dominant fungal species of Korea (barley, rice and wheat) is Fusarium asiaticum having NIV chemotype.

• 한국육종학회지
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• 제41권1호
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• pp.36-39
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• 2009

녹두 신품종 "다현"은 전남11호와 AV-1-3-34-2를 작물과 학원에서 인공교배하고 전라남도농업기술원에서 2006년에 육성되었다. "다현"의 생육습성은 직립, 잎 모양은 심장형, 백축색은 녹색, 성숙기에 꼬투리는 검고 곧으며, 종피는 광택이 없는 녹색이다. 개체당협수는 21.0개로 표준품종인 "어울녹두"보다 4.0개 많고, 경장은 57 cm, 천립중은 48 g, 나물수율은 표준품종보다 5% 많다. "다현"의 바이러스, 갈색무늬병, 흰가루병 및 도복에 대한 포장저항성은 강하고 평균 수량은 1.90 ton/ha으로 표준품종보다 17% 많다.