• Korean Journal of Soil Science and Fertilizer
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• v.50 no.4
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• pp.215-225
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• 2017

Kiwifruit is prone to damage by frost in the harvest season and the occurrence of postharvest diseases. Accordingly, new cultivars overcoming these disadvantages have been developed. Compared to existing cultivars, studies on diseases in new cultivars are very limited. Thus, goal of this study was investigation of fungal infection occurrences in new cultivars. Kiwifruit was harvested in 2014 and 2015 year, respectively. In both years, cvs. Goldone and Redvita showed more resistance against fungal infection but cv. Gamrok was more sensitive compared with cv. Hayward. Major fungi were identified as Botryosphaeria dothidea, Phomopsis sp., Alternaria alternata and Nigrospora sp. Firmness and soluble solids content were also influenced by the occurrences. This study's findings are important for providing practical information on new cultivars in the kiwifruit industry.

• Mycobiology
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• v.30 no.4
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• pp.233-239
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• 2002

The main aim of this study is to evaluate the efficiency of two biologically active compounds(Strom and F-760) in control of wheat root rot disease and its causal organisms. Fusarium graminearum, F. oxysporum, F. solani and Bipolaris sorokiniana were used as target organisms. In vitro, the two compounds showed fungicidal effect on all investigated pathogens resulted in suppression of radial growth and mycelial dry weight of them. Under greenhouse conditions, treatment of wheat grains with either Strom or F-760 before cultivation significantly reduced the percent of disease distribution as well as the mean disease rating of plants in both seedling and flowering stages. Fresh and dry weights of plants as well as water maintenance capacity were increased as the result of applying these compounds as seed dressing. Also data showed that the membrane stability of plants was injured as a result of infection with all investigated organisms, while this injury was alleviated when F-760 and Strom were applied. The $K^+$ efflux and the leakage of UV absorbing metabolites was stimulated with fungal infection. However, F-760 and Storm treatment partially retarded the stimulatory effect on leakage of $K^+$ and UV-absorbing metabolites of fungal infected plants. On the other side, the fungal infection had inhibitory effects on pigment fractions(chlorophyll a, b, and carotenoids) biosynthesis in wheat leaves. This retarding effect was partially or completely alleviated as the grains were treated with the applied compounds.

• Journal of Microbiology and Biotechnology
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• v.19 no.1
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• pp.11-16
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• 2009

Magnaporthe oryzae, the causal agent of rice blast, forms a specialized infection structure, called an appressorium, which is crucial for penetration and infection of the host plant. Pharmacological data suggest that calcium/calmodulindependent signaling is involved in appressorium formation in this fungus. To understand the role of the calcium/calmodulin-activated protein phosphatase on appressorium formation at the molecular level, MCNA, a gene encoding the catalytic subunit of calcineurin, was functionally characterized in M. oryzae. Transformants expressing sense/antisense RNA of MCNA exhibited significant reductions in mycelial growth, conidiation, appressorium formation, and pathogenicity. cDNA of MCNA functionally complemented a calcineurin disruptant strain (cmp1::LEU2 cmp2::HIS3) of Saccharomyces cerevisiae. These data suggest that calcineurin A plays important roles in signal transduction pathways involved in the infection-related morphogenesis and pathogenicity of M. oryzae.

• The Plant Pathology Journal
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• v.37 no.3
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• pp.268-279
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• 2021

Citrus scab, caused by the fungal pathogen Elsinoë fawcettii, is one of the most important fungal diseases affecting Citrus spp. Citrus scab affects young tissues, including the leaves, twigs, and fruits, and produces severe fruit blemishes that reduce the market value of fresh fruits. To study the molecular responses of satsuma mandarin (C. unshiu) to E. fawcettii, plant hormone-related gene expression was analyzed in response to host-compatible (SM16-1) and host-incompatible (DAR70024) isolates. In the early phase of infection by E. fawcettii, jasmonic acid- and salicylic acid-related gene expression was induced in response to infection with the compatible isolate. However, as symptoms advanced during the late phase of the infection, the jasmonic acid- and salicylic acid-related gene expression was downregulated. The gene expression patterns were compared between compatible and incompatible interactions. As scabs were accompanied by altered tissue growth surrounding the infection site, we conducted gibberellic acid- and abscisic acid-related gene expression analysis and assessed the content of these acids during scab symptom development. Our results showed that gibberellic and abscisic acid-related gene expression and hormonal changes were reduced and induced in response to the infection, respectively. Accordingly, we propose that jasmonic and salicylic acids play a role in the early response to citrus scab, whereas gibberellic and abscisic acids participate in symptom development.

• Journal of the Korean Orthopaedic Association
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• v.54 no.1
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• pp.52-58
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• 2019

Purpose: Fungal periprosthetic joint infection (PJI) is a rare but devastating complication following total knee arthroplasty (TKA). On the other hand, a standardized procedure regarding an accurate treatment of this serious complication of knee arthroplasty is lacking. The clinical progress of staged reimplantation in patients who had fungus-related PJI after TKA was reviewed retrospectively. Materials and Methods: Ten patients who had a fungal related PJI after TKA between 2006 and 2017 using staged reimplantation surgery were reviewed. These patients were compared with 119 patients who had a PJI in the same period. The failure rate of infection control, intravenous antimicrobial using the period, and the clinical results were evaluated by comparing the range of motion and Korean knee score (KKS) between pre-staged reimplantation and the last follow-up. Results: In the fungal infection group, 7 out of 10 cases (70.0%) had failed in infection control using staged reimplantation and in the non-fungal group, 7 out of 119 cases (5.9%) had failed (p=0.04). In the non-fungal group, the mean duration of antibiotics was 6.2 weeks. In the fungus group, the mean duration of antibiotics was 15.3 weeks, which was 9.1 weeks longer (p<0.001). The range of motion of the knee was increased in the two groups (p=0.265). At the last follow-up, the KKS was 71.01 points in the non-fungal group and 61.3 points in the fungal group (p=0.012). Erythrocyte sedimentation rate and C-reactive protein (CRP) decreased in the two groups, but the CRP was significantly different in the two groups (p=0.007). Conclusion: The treatment of fungus-related PJIs using staged reimplantation showed uneven clinical progress and unsatisfactory clinical improvements compared to non-fungal PJI. Therefore, it is necessary to consider the use of an antifungal mixed cement spacer at resection arthroplasty and oral antifungal agent after reimplantation.

• Journal of Ginseng Research
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• v.28 no.3
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• pp.149-156
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• 2004

The objectives of this study were to investigate the morphology of mycorrhizal roots, and the effects of root age and soil texture on the mycorrhizal infection in ginseng (Panax ginseng C. A. Meyer) growing in Korea. Ginseng roots at ages of two to six years were collected from fields in late June. Their infection by arbuscular mycorrhizal fungi(AMF) was studied by clearing the roots and staining fungal hyphae with trypan blue. Root infection varied greatly depending on the developmental stages of young roots. Young tertiary roots, in diameter of smaller than 0.8 mrn, formed during the current growing season had root hairs and were frequently and in some cases heavily infected by AMF. Hyphal coils and arbuscules were abundant, while vesicles were rarely observed. Older secondary or tertiary roots in diameter of bigger than 1.0 mm with fully differentiated primary xylem formed during the previous growing season had no root hairs, and were not infected at all. The rates of mycorrhizal infection in the young tertiary roots were not affected by the age of the ginseng plants, suggesting that fungal populations might have not much changed during the aging of the cultivated fields up to six years. The differences in the infection rates among the different ages of ginseng were caused by differences in the amount of young tertiary roots in the samples. Soil texture, either sandy loam or clay loam, did not affect the rate of root infection. There were large variations in the infection rates among the different farms and locations within a farm. It strongly suggested that infection rates of the ginseng roots by AMF would be influenced by the practice of the farmers, possibly by avoiding consecutive planting, introduction of new topsoil, and the ways of handling the soil before transplanting the ginseng, such as fumigation or sterilization that might have affected indigenous inoculum sources of the AMF.

• Korean Journal of Plant Tissue Culture
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• v.26 no.3
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• pp.177-182
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• 1999

A fungal infection assay between normal and transgenic potato harboring chitinase gene in cultivar Belchip was investigated. In the first stage of experiment, seven transgenic lines having 12cm tall were tested for their resistance against potato late blight pathogen Phytophthora infestans by infection with the zoospores, artificially, Susceptibility to potato late blight infection could be classified into three types based on the rate. In terms of resistance to the disease, two lines were higher, two lines were more suppressive, and three lines were similar as compared with the control. In the following experiment, only 2 risistant lines and 1 suppressed line were used to confirm the resistance again. The results of both experiments were similar. Furthermore, two highly resistant transgenic lines grown in field exhibited a higher resistance than control under the conditions of natural ocurrence of the fungal disease.

• The Plant Pathology Journal
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• v.37 no.2
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• pp.87-98
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• 2021

To establish an infection, fungal pathogens must recognize diverse signals from host surfaces. The rice blast fungus, Magnaporthe oryzae, is one of the best models studying host-pathogen interactions. This fungus recognizes physical or chemical signals from the host surfaces and initiates the development of an infection structure called appressorium. Here, we found that protein MoAfo1(appressorium formation, MGG_10422) was involved in sensing signal molecules such as cutin monomers and long chain primary alcohols required for appressorium formation. The knockout mutant (ΔMoafo1) formed a few abnormal appressoria on the onion and rice sheath surfaces. However, it produced normal appressoria on the surface of rice leaves. MoAfo1 localized to the membranes of the cytoplasm and vacuole-like organelles in conidia and appressoria. Additionally, the ΔMoafo1 mutant showed defects in appressorium morphology, appressorium penetration, invasive growth, and pathogenicity. These multiple defects might be partially due to failure to respond properly to oxidative stress. These findings broaden our understanding of the fungal mechanisms at play in the recognition of the host surface during rice blast infection.

• Mycobiology
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• v.29 no.2
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• pp.65-72
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• 2001

• The Plant Pathology Journal
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• v.33 no.1
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• pp.80-86
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• 2017

One of the major problems in strawberry production is difficulty in diagnosis of anthracnose caused by Colletotrichum acutatum or Glomerella cingulata in latent infection stage. We here developed a diagnostic tool for the latent infection consisting of initial culturing of fungi, DNA extraction, synthesis of PCR-amplified probes and microtube hybridization (MTH) using a macroarray. The initial culturing step is convenient to lure the fungi out of the plant tissues, and to extract PCR-inhibitor-free DNA directly from fungal hyphae. For specific detection of the fungi, PCR primers were designed to amplify the fungal MAT1-2 gene. The subsequent MTH step using the PCR products as probes can replace the laborious electrophoresis step providing us sequence information and high-throughput screening. Using this method, we have conducted a survey for a few thousands nursery plants every year for three consecutive years, and finally succeeded in eliminating latent infection in the third year of challenge.