• Molecules and Cells
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• 제25권3호
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• pp.323-331
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• 2008

Plants are continually exposed to a variety of potentially pathogenic microbes, and the interactions between plants and pathogenic invaders determine the outcome, disease or disease resistance. To defend themselves, plants have developed a sophisticated immune system. Unlike animals, however, they do not have specialized immune cells and, thus all plant cells appear to have the innate ability to recognize pathogens and turn on an appropriate defense response. Using genetic, genomic and biochemical methods, tremendous advances have been made in understanding how plants recognize pathogens and mount effective defenses. The primary immune response is induced by microbe-associated molecular patterns (MAMPs). MAMP receptors recognize the presence of probable pathogens and evoke defense. In the co-evolution of plant-microbe interactions, pathogens gained the ability to make and deliver effector proteins to suppress MAMP-induced defense responses. In response to effector proteins, plants acquired R-proteins to directly or indirectly monitor the presence of effector proteins and activate an effective defense response. In this review we will describe and discuss the plant immune responses induced by two types of elicitors, PAMPs and effector proteins.

• 한국토양비료학회지
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• 제45권4호
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• pp.622-627
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• 2012

The processes to determine the composition, dynamics, and activity of infection mechanisms by the rhizosphere microflora have attracted the interest of scientists from multiple disciplines although considerable progress of the infection pathways and plant-pathogen interactions by soil borne fungal pathogens have been made. Soilborne pathogens are confined within a three-dimensional matrix of mineral soil particles, pores, organic matter in various stages of decomposition and a biological component. Among the physical and chemical properties of soils soil texture and matric water potential may be the two most important factors that determine spread exudates by soil borne fungal pathogens, based on the size of the soil pores. Pathogenic invasion of plant roots involves complex molecular mechanisms which occur in the diffuse interface between the root and the soil created by root exudates. The initial infection by soilborne pathogens can be caused by enzymes which breakdown cell wall layers to penetrate the plant cell wall for the fungus. However, the fate and mobility of the exudates are less well understood. Therefore, it needs to develop methods to control disease caused by enzymes produced by the soilborne pathogens by verifying many other possible pathways and mechanisms of infection processes occurring in soils.

• 식물병연구
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• 제20권3호
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• pp.189-195
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• 2014

Genetic engineering is being used to enhance disease resistance and nutritional value of crops including rice plant. Considering the fast-growing agricultural biotechnology and rapidly increasing global area of transgenic crops, the risk evaluation on environment is necessary. In this study, we surveyed the difference of disease occurrence between transgenic rice variety, Iksan526 transformed with peanut stilbene synthase gene and non-transgenic rice varieties, Dongjin and Nampyeong in the field. Moreover, the possibility of gene transfer from transgenic rice to bacterial and fungal pathogens was investigated. The results of this study indicated that there was no significant difference in the occurrence and severity of the diseases between Iksan526 and Dongjin or Nampyeong. In addition, the results suggested that rice pathogen, such as Xanthomonas oryzae pv. oryzae, Rhizoctonia solani and Magnaporthe grisea did not take up stilbene synthase and bar genes under natural conditions. Moreover the transformed DNA was not transferred to the pathogens even in repetitive contacts.

• The Plant Pathology Journal
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• 제28권1호
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• pp.20-31
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• 2012

Endophytic bacterial communities of tidal flat plants antagonistic to oomycete plant pathogens were studied by the isolation of 256 root colonizing endophytic bacteria from surface-disinfected root tissues of six plants ($Rosa$ $rugosa$, $Suaeda$ $maritima$, $Vitex$ $rotundifolia$, $Carex$ $scabrifolia$, $Glehnia$ $littoralis$ and $Elymus$ $mollis$) growing in a tidal flat area of Namhae Island, Korea. To understand the antagonistic potential, an $in$ $vitro$ antagonistic assay was performed to characterize and identify strains that were antagonistic to the oomycete plant pathogens $Phytophthora$ $capsici$ and $Pythium$ $ultimum$ from the total population. Nine percent of the total number of isolated bacteria exhibited in vitro inhibitory activity against target plant pathogenic oomycetes. Taxonomic and phylogenetic placement of the antagonistic bacteria was investigated by analysis of the 16S rRNA gene sequences. The sequence analysis classified the antagonistic strains into four major classes of the domain bacteria ($Firmicutes$, ${\alpha}-Proteobacteria$, ${\gamma}-Proteobacteria$ and $Actinomycetes$) and 10 different genera. Further production of secondary metabolites, hydrolytic enzymes and plant growth promoting traits were determined for the putative new species of antagonistic endophytic bacteria. These new strains could not be identified as known species of ${\alpha}-Proteobacteria$, and so may represent novel bacterial taxa. The unexpected high antagonistic bacterial diversity associated with the tidal flat plants may be indicative of their importance in tidal flat plants as a promising source of novel antimicrobial compounds and biocontrol agents.

• The Plant Pathology Journal
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• 제37권6호
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• pp.505-511
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• 2021

Interaction of a pathogen with its host plant requires both flexibility and rapid shift in gene expression programs in response to environmental cues associated with host cells. Recently, a growing volume of data on the diversity and ubiquity of internal RNA modifications has led to the realization that such modifications are highly dynamic and yet evolutionarily conserved system. This hints at these RNA modifications being an additional regulatory layer for genetic information, culminating in epitranscriptome concept. In plant pathogenic fungi, however, the presence and the biological roles of RNA modifications are largely unknown. Here we delineate types of RNA modifications, and provide examples demonstrating roles of such modifications in biology of filamentous fungi including fungal pathogens. We also discuss the possibility that RNA modification systems in fungal pathogens could be a prospective target for new agrochemicals.

• The Plant Pathology Journal
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• 제18권4호
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• pp.216-220
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• 2002

Seed decay of soybean caused by Diaporthe phaseolorum, Colletotrichum truncatum and Cercospora kikuchii is a serious disease when soybean is harvested under warm and wet weather conditions. Benomyl has been used for controlling the disease, however, benomyl application may be limited due to common occurrence of resistance. The efficacy of 21 fungicides against the pathogens was evaluated in vitro. Among the fungicides tested, benomyl, carbendazim, fluazinam, iprodione+propineb, thiophanate-methyl, and triflumizole were found effective and were evaluated for their ability to control the seed pathogens. Fluazinam completely inhibited mycelial growth at a concentration of 100 $\mu\textrm{g}$/$\textrm{m}{\ell}$ for D. phaseolorum; and at a concentration of 500 $\mu\textrm{g}$/$\textrm{m}{\ell}$ for C. truncatum and C. kikuchii. $EC_90$ values of fluazinam were similar to that of benomyl. Because fluazinam, iprodione+propineb, and triflumizole were found effective against the seed pathogens, these were subjected for field-testing. Suppression of pod and seed infection by fluazinam and iprodione+propineb was as high as that of benomyl without any reduction in agronomic characters of soybean. This study shows that fluazinam and iprodione+propineb may be used in combination with benomyl to control seed pathogens, manage resistance, and ensure production of high quality soybean seeds.

• The Plant Pathology Journal
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• 제16권5호
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• pp.286-289
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• 2000

Mechanol extracts of three cold-tolerant eucalyptus trees-Eucalyptus darlympleana, E. gunnii and E. unigera were screened for antimicrobial activity against twenty two phyto-pathogenic fungi and six food-borne bacterial pathogens. E. unigera showed the antagonistic activity against all the tested pathogens. Among the tested fungal pathogens, Pythium species were highly sensitive to the leaf extracts. Especially, P. vanterpoolii, a causal agent of leaf blight in creeping bentgrass (Agrostis palustris), was completely inhibited by the extracts. The eucalyptus extracts were also effective in inhibiting the fungal growth of Botrytis cinerea and Phomopsis sp. isolated from the lesions of kiwifruit soft rot during post-harvest storage. Escherichia coli O-157 was less sensitive to the inhibition than the other bacterial pathogens tested. It was likely that Gram positive bacteria-Bacillus subtilis and Streptococcus mutans were more sensitive to the eucalyptus extracts than Gram negative bacteria-Escherichia coli, Salmonella enteritidis and Pseudomonas aeruginosa. Our findings suggest that the cold-tolerant eucalyptus species have antimicrobial properties that can serve the development of novel fungitoxic agents or food preservatives.

• The Plant Pathology Journal
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• 제16권2호
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• pp.90-97
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• 2000

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• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 1999년도 임시총회 및 추계 학술발표회
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• pp.54.3-54
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• 1999

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2004년도 The 2004 KSPP Annual Meeting & International Symposium
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• pp.68-69
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• 2004

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