• BMB Reports
• /
• v.41 no.5
• /
• pp.376-381
• /
• 2008

The discovery of RNA silencing inhibition by virus encoded suppressors or low temperature leads to concerns about the stability of transgenic resistance. RNA-dependent RNA polymerase (RdRp) has been previously characterized to be essential for transgene-mediated RNA silencing. Here we showed that low temperature led to the inhibition of RNA silencing, the loss of viral resistance and the reduced expression of host RdRp homolog (NtRdRP1) in transgenic T4 progeny with untranslatable potato virus Y coat protein (PVY-CP) gene. Moreover, RNA silencing and the associated resistance were differently inhibited by potato virus X (PVX) and tobacco mosaic virus (TMV) infections. The increased expression of NtRdRP1 in both PVX and TMV infected plants indicated its general role in response to viral pathogens. Collectively, we propose that biotic and abiotic stress factors affect RNA silencing-mediated resistance in transgenic tobacco plants and that their effects target different steps of RNA silencing.

• The Plant Pathology Journal
• /
• v.38 no.3
• /
• pp.229-238
• /
• 2022

Fusarium wilt caused by Fusarium oxysporum f. sp. niveum (Fon) is the most serious soil-borne disease in the world and has become the main limiting factor of watermelon production. Reliable and quick detection and quantification of Fon are essential in the early stages of infection for control of watermelon Fusarium wilt. Traditional detection and identification tests are laborious and cannot efficiently quantify Fon isolates. In this work, a real-time polymerase chain reaction (PCR) assay has been described to accurately identify and quantify Fon in watermelon plants and soil. The FONRT-18 specific primer set which was designed based on identified specific sequence amplified a specific 172 bp band from Fon and no amplification from the other formae speciales of Fusarium oxysporum tested. The detection limits with primers were 1.26 pg/µl genomic DNA of Fon, 0.2 pg/ng total plant DNA in inoculated plant, and 50 conidia/g soil. The PCR assay could also evaluate the relationships between the disease index and Fon DNA quantity in watermelon plants and soil. The assay was further used to estimate the Fon content in soil after disinfection with CaCN₂. The real-time PCR method is rapid, accurate and reliable for monitoring and quantification analysis of Fon in watermelon plants and soil. It can be applied to the study of disease diagnosis, plant-pathogen interactions, and effective management.

• The Korean Journal of Mycology
• /
• v.49 no.3
• /
• pp.413-416
• /
• 2021

In July 2019, damping-off symptoms of young Fischer's ragwort (Ligularia fischeri) plants were observed in four vinyl greenhouses of a farmer located in Taebaek, Gangwon Province, Korea. This disease occurred in 20-30% of plants in the vinyl greenhouses investigated. Nine isolates of Rhizoctonia sp. were obtained from the diseased plants. All the isolates were identified as Rhizoctonia solani AG-2-2 (IIIB), based on morphological, cultural characteristics, and anastomosis test. Three isolates were used for artificial inoculation test on Fischer's ragwort. Pathogenicity of these isolates was confirmed on the plants with the inoculation tests. Damping-off symptoms observed on the inoculated plants were similar to those observed in the diseased plants in the vinyl greenhouses. This is the first report of R. solani AG-2-2 (IIIB) being the causative agent in damping-off in Fischer's ragwort.

• Research in Plant Disease
• /
• v.27 no.4
• /
• pp.187-191
• /
• 2021

Wilt symptoms were frequently observed in Korean blackberry (Rubus coreanus) plants grown in farmers' fields located in Gochang and Jeongeup, Jeonbuk Province, Korea during disease surveys in July 2020. The disease occurred in 10 of the 13 fields surveyed in the two locations. The incidence of diseased plants in the fields was 5-80%. Seven isolates of Fusarium sp. were obtained from the diseased plants and examined for their morphological and molecular characteristics. All the isolates belonged to Fusarium oxysporum species complex based on the morphological characteristics but were identified as F. cugenangense based on the molecular characteristics. Two isolates of F. cugenangense were tested for pathogenicity on Korean blackberry plants by artificial inoculation. Pathogenicity of the two isolates on the plants was confirmed with the inoculation tests, which showed wilt symptoms similar to those observed in the diseased plants in the fields investigated. This is the first report of F. cugenangense causing Fusarium wilt in Korean blackberry.

• Proceedings of the Korean Society of Agricultural Engineers Conference
• /
• 2001.10a
• /
• pp.417-420
• /
• 2001

The monitoring system for maintaining on-site wastewater treatment plants(Biofilter) was developed. Proposed system applied PLC(Programmable Logic Controller) technique. In process of development, the research against the monitoring parameters which will be able to represent condition and operation of the plants was accomplished. These parameters are ORP(Oxidation-Reduction Potential), Water Level, Pump and Power on/off. Also, to measure, collect, transfer and display these parameters, DMU(Data Measurement Unit), MCU(Main Controller Unit) and Display Board were produced.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.14 no.2
• /
• pp.59-81
• /
• 2011

The flora of the Sinpyeong and Churyeong stream were listed 324 taxa; 87 families, 227 genera, 289 species, 1 subspecies, 31 varieties and 3 forms. The Sinpyeong stream were 249 taxa and Churyeong stream were 221 taxa. Based on the rare plants (IUCN) by the Korea Forest Service and Korea National Arboretum were recorded; Penthorum chinense (Crassulaceae), etc. and endemic plants, 6 taxa; Weigela subsessilis (Caprifoliaceae), Lycoris flavescens (Amarylidaceae), etc. Based on the specific plants by floral region were total 12 taxa (3.7% of all 324 taxa of flora); Monochoria korsakowi (Pontederiaceae), etc. in class III. 10 taxa (Salix glandulosa (Salicaceae), Ulmus parvifolia (Ulmaceae), Impatiens noli-tangere (Balsaminaceae), Grewia biloba var. parviflora (Tiliaceae), Nymphoides peltata (Gentianaceae), Actinostemma lobatum (Cucurbitaceae), Cirsium pendulum (Compositae), Microstegium japonicum (Gramineae), etc.) in class I. Based on the naturalized plants, 51 taxa and ecosystem disturbing wild plants, 6 taxa (Rumex acetosella, Sicyos angulatus, Aster pilosus, Ambrosia artemisiaefolia, Hypochaeris radicata, Paspalum distichum var. distichum) and naturalization rate was 15.7% of all 324 taxa of flora, urbanization index was 18.8% of all 271 taxa of naturalized plants. Based on the hydrophytes, 23 taxa and emergent hydrophytes were 17 taxa, floating-leaved hydrophytes were 3 taxa, submergent hydrophytes were 2 taxa, free-floating hydrophytes was Spirodela polyrhiza.

• The Plant Pathology Journal
• /
• v.25 no.3
• /
• pp.299-301
• /
• 2009

Powdery mildew symptoms were frequently on plants of goat's-beard (Aruncus dioicus var. kamtschaticus) found cultivated in the island Ulleungdo in June 2008. The symptoms appeared as powdery mycelial colonies and dark brown cleistothecia on leaves, petioles, stems and budding flowers of the plant. Incidence of the disease was as high as 50-80% in the goat's-beard fields. Specimens of the diseased plants were collected and examined for morphological characteristics of the causal fungus. On the basis of morphological characteristics of the conidial stage and the teleomorph, the fungus was identified as Podosphaera ferruginea. This is the first report of goat's-beard powdery mildew caused by Podosphaera ferruginea in Korea.

• 한국균학회소식:학술대회논문집
• /
• 2009.10a
• /
• pp.41-43
• /
• 2009

• Korean Journal of Environmental Agriculture
• /
• v.34 no.4
• /
• pp.282-287
• /
• 2015

BACKGROUND: The current study was carried out to investigate Cd, Hg, Pb and As contaminations in 222 commercial medicinal plants and to estimate the potential health risk through dietary intake of commercial medicinal plants in Korea.METHODS AND RESULTS: The Cd, Hg, Pb, and As in medicinal plants were analyzed by ICP/MS and mercury analyzer.The potential health risk was estimated using risk assessment tools. Total amount of Cd in medicinal plants with 29% samples exceeded the standard limit legislated in 'Pharmaceutical Affairs Act' while all plant samples were lower than the standard limit value for As, Hg, and Pb. However, when applying the standard limit for root vegetable (fresh weight) in the Food Sanitation Act, four samples exceeded the standard limit of Pb. For health risk assessment, the values of cancer risk probability were 0.3~5.9×10^-7which were less than the acceptable cancer risk of 10^-6~10^-4for regulatory purpose. Also, Hazard quotientvalues were lower than 1.0.CONCLUSION: Therefore, these results demonstrated that human exposure to Cd, Hg, Pb, and As through dietary intake of commercial medicinal plants might notcause adverse health effects although some medicinal plants were higher than the standard limit values for Cd and Pb.

• The Plant Pathology Journal
• /
• v.22 no.4
• /
• pp.360-363
• /
• 2006

Efficacy of plant growth promoting rhizobacteria(PGPR) Bacillus vallismortis strain EXTN-1 has been proved in eliciting induced systemic resistance(ISR) in several crops. The present paper described the beneficial effects of EXTN-1 in potato as increase in yield and chlorophyll content, and plant protection against Potato Virus Y and X(PVY & PVX). EXTN-1 induced systemic resistance to the plants resulting in significant disease suppression in the field. Also the plants under treatment with EXTN-1 had higher chlorophyll content. The bacterized plants had significantly higher yields over the untreated control plants. The strain induced activation of defense genes, PR-1a and PDF 1.2 in transgenic tobacco model, which indicated the possible role of both SA, and JA pathways in EXTN-1 mediated plant protection against crop diseases.