• Toxicological Research
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• 제29권2호
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• pp.143-147
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• 2013

Cyanogenic glycosides are HCN-producing phytotoxins; HCN is a powerful and a rapidly acting poison. It is not difficult to find plants containing these compounds in the food supply and/or in medicinal herb collections. The objective of this study was to investigate the distribution of total cyanide in nine genera (Dolichos, Ginkgo, Hordeum, Linum, Phaseolus, Prunus, Phyllostachys, Phytolacca, and Portulaca) of edible plants and the effect of the processing on cyanide concentration. Total cyanide content was measured by ion chromatography following acid hydrolysis and distillation. Kernels of Prunus genus are used medicinally, but they possess the highest level of total cyanide of up to 2259.81 $CN^-$/g dry weight. Trace amounts of cyanogenic compounds were detected in foodstuffs such as mungbeans and bamboo shoots. Currently, except for the WHO guideline for cassava, there is no global standard for the allowed amount of cyanogenic compounds in foodstuffs. However, our data emphasize the need for the guidelines if plants containing cyanogenic glycosidesare to be developed as dietary supplements.

• 농업과학연구
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• 제29권2호
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• pp.91-97
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• 2002

식물병원균 Bipolaris sorokiniana 배양 추출물로부터 이탈리안 라이그라스 및 논피의 유근신장을 억제하는 활성물질을 분리 정제하여 각종 기기분석을 통하여 화학구조를 결정하였다. 이들 화합물들은 분자식이 $C_8H_8O_3$인 benzenoid 화합물인 3-methoxybenzoic acid와 3-hydroxy benzoic acid methyl ester로 숙주식물의 유근신장을 1000ppm에서 90% 이상 저해하였다. 이들 화합물은 식물체의 잎과 줄기에서 분리되어 항균활성 및 항류마티스 활성이 있음이 보고된바 있으나 B. sorokiniana로부터 분리되어 제초활성에 관하여 보고하기는 본 논문이 처음이다.

• 한국잡초학회지
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• 제14권3호
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• pp.192-198
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• 1994

잡초병원균 Drechslera portulacae가 생산하는 식물독소를 단리하여 그 화학구조를 결정한 결과, zeaenol으로서 동정하였다. Zeaenol은 기지 물질이나 지금까지 입체화학적인 면에서는 불명인 채 남아있었으며, 본 연구에서 처음으로 그 입체구조를 명백하게 하였다. 또한, 잡초방제적인 측면에서 식물독소의 활용가능성을 찾기 위하여 zeaenol의 제초활성을 조사하였다. 그 결과, 식용피 및 어저귀의 유묘의 초장에 대한 억제효과는 보여주지 않았으나, $3{\times}10^{-5}M$의 처리구에서 식용피 및 어저귀의 유근의 생장을 대조구에 비해 각각 22.8%, 54.8% 억제하였다.

• Applied Biological Chemistry
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• 제39권3호
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• pp.241-244
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• 1996

Drechslera siccans의 배양 추출물로부터 이탈리안 라이그라스 (Lolium multiflorum Lam.) 뿌리의 생육저해 활성을 나타내는 물질을 분리정제한 다음에 2차원 NMR을 포함한 각종 기기분석을 이용하여 구조를 결정하였다. Siccanol(1)이라고 명명한 이 화합물의 분자식은 $C_{25}H_{38}_{4}$이었으며 100ppm에서 숙주 식물중의 하나인 이탈리안 라이그라스에 대하여 100%의 저해 활성을 나타내었다.

• The Plant Pathology Journal
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• 제27권1호
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• pp.14-19
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• 2011

Early blight of potato, caused by Alternaria solani, is a ubiquitous disease in many countries around the world. Our previous screening of several Iranian potato cultivars found that significant variation in resistance phenotypes exists between two cultivars: resistant 'Diamond' and susceptible 'Granula'. Our previous analysis of five different pathogen isolates also identified varying degrees of aggressiveness regardless of the host cultivar. Here, a bioassay was used to study the role of liquid culture exudates produced in vitro on pathogenicity and elicitation of disease symptomology in seedlings as well as detached leaves. Responses of host genotypes to the exudates of the two A. solani isolates were significantly different. Detached leaves of the resistant cultivar 'Diamond' elicited fewer symptoms to each isolate when compared to the susceptible cultivar 'Granula'. Interestingly, the phytotoxicity effect of the culture filtrate from the more aggressive isolate A was higher than from isolate N suggesting an increased concentration or strength of the toxins produced. Our results are significant because they indicate a correlation between symptoms elicited by A. solani phytotoxins and their aggressiveness on the host.

• ALGAE
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• 제36권2호
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• pp.91-109
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• 2021

The occurrence of benthic dinoflagellates, many of which are known to be toxic, is a critical concern for scientists, government officers, and people in the aquaculture, dining, and tourism industries. The interest in these dinoflagellates in countries with temperate climate is increasing because tropical or subtropical species introduced into temperate waters by currents are able to survive the winter season in the new environment owing to global warming. Recently, several species from the benthic dinoflagellate genera Amphidinium, Coolia, Ostreopsis, Gambierdiscus, and Prorocentrum have been reported in the waters of the South and East Sea of Korea. The advent of the benthic dinoflagellates in Korean waters is especially important because raw or slightly cooked seaweeds, which may harbor these benthic dinoflagellates, as well as raw fish, which can be potentially intoxicated by phytotoxins produced by some of these benthic dinoflagellates, are part of the daily Korean diet. The recent increase in temperature of Korean coastal waters has allowed for the expansion of benthic dinoflagellate species into these regions. In the present study, we reviewed the species, distribution, and toxicity of the benthic dinoflagellates that have been reported in Korean waters. We also provided an insight into the ecological and socio-economic importance of the occurrence of benthic dinoflagellates in Korean waters.

• The Plant Pathology Journal
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• 제31권3호
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• pp.245-251
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• 2015

Alternative hosts increase the difficulty of disease management in crops because these alternate hosts provide additional sources of primary inoculum or refuges for diversity in the pathogen gene pool. Agropyron cristatum (crested wheatgrass), Bromus inermis (smooth bromegrass), Pascopyrum smithii (western wheatgrass), Stipa viridula (green needlegrass), and Thinopyrum intermedium (intermediate wheatgrass), commonly identified in range, prairie, verge, and soil reclamation habitats, serve as additional hosts for Pyrenophora tritici-repentis, the cause of tan spot in wheat (Triticum aestivum L.). A. cristatum (five lines), B. inermis (seven lines), P. smithii (four lines), S. viridula (two lines), and T. intermedium (six lines) were tested for their reactions to 30 representative P. tritici-repentis isolates from races 1-5. Plants were grown until the two-three-leaf stage in a greenhouse, inoculated individually with the 30 isolates, held at high humidity for 24 h, and rated after 7 days. All lines developed lesion types 1-2 (resistant) based on a 1-5 rating scale. Also, leaves from an additional plant set were infiltrated with two host selective toxins, Ptr ToxA as a pure preparation and Ptr ToxB as a dilute crude culture filtrate. All lines were insensitive to the toxins. Results indicate that these grass hosts have a limited or nonsignificant role in tan spot epidemiology on wheat in the northern Great Plains. Additionally, the resistant reactions demonstrated by the grass species in this research indicate the presence of resistance genes that can be valuable to wheat breeding programs for improving wheat resistance to P. tritici-repentis.

• 한국토양비료학회지
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• 제24권1호
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• pp.17-21
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• 1991

연작지(連作地) 토양(土壤)의 pH저하(低下)의 원인(原因)에 대(對)하여 수행(遂行)한 시험결과(試驗結果)를 요약(要約)하면 다음과 같다. 1. 연작연수(連作年數)가 증가(增加)할수록 독소물질(毒素物質)의 함량(含量)이 증가(增加)하였으며, 독소물질(毒素物質)의 증가(增加)가 pH를 저하(低下)시켰다. 2. 독소물질(毒素物質)에 의한 pH저하율(低下率)이 증류수와 수도수에서는 높았으나 토양(土壞)에서는 이온들의 간섭(干涉)에 의해 저하율(低下率)이 낮았다. 3. 작물(作物)의 발아(發芽)에 미치는 독소물질(毒素物質)의 영향(影響)은 benzoic acid가 p-hyd roxybenzoic acid보다 컸으며 benzoic acid 300ppm 이상(以上)에서는 발아(發芽)되지 않았다. 4. acetone으로 독소물질(毒素物質)을 추출해낸 연작지(連作地) 토양(土壤)에서는 pH가 비연작토양(非連作土壤)과 거의 같았으며 참깨의 생육(生育)도 비연작토(非連作土)의 생육(生育)정도까지 회복(回復)되었다.

• 한국잡초학회지
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• 제14권3호
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• pp.184-191
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• 1994

잡초병원균 Drechslera portulacae는 기주식물인 쇠비름(Portulaca oleracea)에만 병징을 발현하는 식물독소를 생산한다는 사실을 발견하여 병원성에 관여하는 물질을 D. portulacae의 배양여액 중에서 정제 단리한 후 기기분석한 결과, 그 화학구조를 methyldihydroxyzearalenone으로 동정하였다. 또한, methyldihydroxyzearalenone의 제초활성은 시험초종인 식용피(E. crus-gall) 및 어저귀(A. avicennae)를 대상으로 조사되였다. 그 결과, 식용피 유묘의 초장에 대한 억제효과는 나타나지 않았으며 근생장에 있어서 $3{\times}10^{-5}M$ 처리시 대조구에 비해 35.7%의 억제를 보였다. 한편, 어저귀에서는 유묘의 초장 및 근장에 대한 억제효과가 인정되었으며 그 정도는 유근에서 심하여 $3{\times}10^{-5}M$ 처리구에서 근생장을 72.6% 억제시켰다. Methyldihydroxyzearalenone의 제초활성은 식용피보다 어저귀에서 높게 나타났다.

• The Plant Pathology Journal
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• 제39권1호
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• pp.88-107
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• 2023

In the present investigation, bacterial isolates from infected apple trees causing apple canker during winter were studied in the northern Gyeongbuk Province, Korea. The pathogen was identified as Pseudomonas syringae pv. syringae (Pss) through various physiological and biochemical characterization assays such as BIOLOG, gas chromatography of fatty acid methyl esters, and 16S rRNA. Bioassays for the production of phytotoxins were positive for syringopeptin and syringomycin against Bacillus megaterium and Geotrichum candidum, respectively. The polymerase chain reaction (PCR) method enabled the detection of toxin-producing genes, syrB1, and sypB in Pss. The differentiation of strains was performed using LOPAT and GATTa tests. Pss further exhibited ice nucleation activity (INA) at a temperature of -0.7℃, indicating an INA⁺ bacterium. The ice-nucleating temperature was -4.7℃ for a non-treated control (sterilized distilled water), whereas it was -9.6℃ for an INA^- bacterium Escherichia coli TOP10. These methods detected pathogenic strains from apple orchards. Pss might exist in an apple tree during ice injury, and it secretes a toxin that makes leaves yellow and cause canker symptoms. Until now, Korea has not developed antibiotics targeting Pss. Therefore, it is necessary to develop effective disease control to combat Pss in apple orchards. Pathogenicity test on apple leaves and stems showed canker symptoms. The pathogenic bacterium was re-isolated from symptomatic plant tissue and confirmed as original isolates by 16S rRNA. Repetitive element sequence-based PCR and enterobacterial repetitive intergenic consensus PCR primers revealed different genetic profiles within P. syringae pathovars. High antibiotic susceptibility results showed the misreading of mRNA caused by streptomycin and oxytetracycline.