• The Plant Pathology Journal
• /
• v.40 no.3
• /
• pp.299-309
• /
• 2024

The rice blast disease, caused by the fungal pathogen, Magnaporthe oryzae (syn. Pyricularia oryzae), poses a significant threat to the global rice production. Understanding how this disease impacts the plant's microbial communities is crucial for gaining insights into host-pathogen interactions. In this study, we investigated the changes in communities of bacterial and fungal endophytes inhabiting different compartments in healthy and diseased plants. We found that both alpha and beta diversities of endophytic communities do not change significantly by the pathogen infection. Rather, the type of plant compartment appeared to be the main driver of endophytic community structures. Although the overall structure seemed to be consistent between healthy and diseased plants, our analysis of differentially abundant taxa revealed the specific bacterial and fungal operational taxonomic units that exhibited enrichment in the root and leaf compartments of infected plants. These findings suggest that endophyte communities are robust to the changes at the early stage of pathogen infection, and that some of endophytes enriched in infected plants might have roles in the defense against the pathogen.

• Mycobiology
• /
• v.49 no.4
• /
• pp.385-395
• /
• 2021

Fungal endophytes have been recorded in various plant species with a richness of diversity, and their presence plays an essential role in host plant protection against biotic and abiotic stresses. This study applied the Illumina MiSeq sequencing platform based on the amplification of fungal ribosomal ITS2 region to analyze fungal endophytic communities of two oak species (Quercus mongolica and Q. serrata) with different oak wilt disease susceptibilities in Korea. The results showed a total of 230,768 sequencing reads were obtained and clustered at a 97% similarity threshold into 709 operational taxonomic units (OTUs). The OTUs of Q. serrata were higher than that of Q. mongolica with the number of 617 OTUs and 512 OTUs, respectively. Shannon index also showed that Q. serrata had a significantly higher level of fungal diversity than Q. mongolica. Total of OTUs were assigned into 5 fungal phyla, 17 classes, 60 orders, 133 families, 195 genera, and 280 species. Ascomycota was the dominant phylum with 75.11% relative abundance, followed by Basidiomycota with 5.28%. Leptosillia, Aureobasidium and Acanthostigma were the most abundant genera detected in Q. serrata with the average relative abundance of 2.85, 2.76, and 2.19%, respectively. On the other hand, Peltaster, Cladosporium and Monochaetia were the most common genera detected in Q. mongolica with the average relative abundance of 4.83, 3.03, and 2.87%, respectively. Our results indicated that fungal endophytic communities were significantly different between two oak species and these differences could influence responses of host trees to oak wilt disease caused by Raffaelea quercus-mongolicae.

• Mycobiology
• /
• v.28 no.3
• /
• pp.115-118
• /
• 2000

To determine the degree of variability among the host plant species in their abilities to become colonized by arbuscular mycorrhizal fungi (AMF), the inoculum for AMF was collected from the various sites in Korea and was inoculated to the three horticultural plants; Tagetes patula, Torenia fournieri, and Salvia splendens. After 4-month growth under greenhouse, mycorrhizal root colonization rates and spore density were measured. The roots of T. patula showed higher colonization rate than both plants of T. fournieri and Salvia splendens. The mycorrhizal root colonization was influenced by both of the AM fungal inoculum and the host species or their interactions. The combination of the host and fungal species was suggested to be important for the application of AMF to horticultural crops.

• 한국균학회소식:학술대회논문집
• /
• 2015.05a
• /
• pp.20-20
• /
• 2015

Endophytic fungi are microorganisms inhabiting living plant tissues without causing apparent harm to the host. They are drawing increasing attention due to their ability to produce various bioactive compounds as well as their effects on host growth and resistance to biotic and abiotic stresses. As a first step to assess biodiversity of plant associated fungi in Korea and the following evaluation on diverse biological activities, we are collecting endophytic fungi from plant in wild followed by systematic long-term storage in liquid nitrogen. Molecular identification using ITS sequences was also incorporated for pure culture by hyphal tip isolation. As of April 2015, about 1,400 fungal strains had been isolated from about 170 plant taxa. Fungal isolates belonging to Pleosporales, Diaporthales, Glomerellales, Hypocreales, and Xylariales were the most abundant. These collections are being used for several complementary researches, including screening of isolates with novel bioactive compounds or conferring drought stress resistance, phylogenetic and genomic study. Genome sequencing was performed for 3 isolates, one Xylaria sp. strain JS573 producing griseofulvin, an antifungal compound, and two Fusarium spp. strains JS626 and JS1030, which are assumed to be new species found in Korea. More detailed analysis on these genomes will be presented. These collections and genome informations will serve as invaluable resources for identifying novel bioactive materials in addition to expand our knowledge on fungal biodiversity.

• Journal of Ginseng Research
• /
• v.36 no.3
• /
• pp.327-333
• /
• 2012

Fungal endophytes were isolated from 1-, 2-, 3-, and 4-year-old ginseng roots (Panax ginseng Meyer) cultivated in Korea. The isolated fungal endophytes were identified based on sequence analysis of the internal transcribed spacer and morphological characterization by microscopic observations. A total of 81 fungal endophytes were isolated from 24 ginseng roots. Fungal endophytes were classified into 9 different fungal species and 2 unknown species. Ginseng roots that were 1-, 2-, 3-, and 4-years old were colonized by 2, 6, 8, and 5 species of fungal endophytes, respectively. While Phoma radicina was the most frequent fungal endophyte in 2-, 3-, and 4-year-old ginseng roots, Fusarium solani was the dominant endophyte in 1-year-old ginseng roots. The colonization frequencies (CF) varied with the host age. The CF were 12%, 40%, 31%, and 40% for 1-, 2-, 3-, and 4-year-old ginseng roots, respectively. We found a variety of fungal endophytes that were distributed depending on the age of ginseng plants.

• The Plant Pathology Journal
• /
• v.37 no.3
• /
• pp.268-279
• /
• 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 Applied Biological Chemistry
• /
• v.42 no.1
• /
• pp.45-47
• /
• 1999

Two phytotoxic compounds were isolated from a culture of Exserohilum monoceras Inu-1, a fungal pathogen of Barnyard grass. The structure was determined by spectroscopic analyses including 2D NMR experiments. During the isolation procedure, the toxic components were monitored by the assay using Italian ryegrass (Lolium multiflorum Lam.), a host plant of the pathogen. The compounds inhibited the root growth of the host plant seedlings at a level of 100 ppm. While no substantial inhibition was observed even at 300 ppm in non-host plant seedlings such as lettuce and tomato.

• The Korean Journal of Mycology
• /
• v.51 no.4
• /
• pp.419-428
• /
• 2023

Several endophytic fungal strains were isolated from Taxus cuspidata and identified by molecular analysis of the internal transcribed spacer and RNA polymerase II second largest subunit. This study aimed to determine the relative abundance and compare the species diversity of endophytic fungal communities within needle leaves and twigs. We identified a total of 49 endophytic fungal species. Notably, two species, Trichoderma dingleyae and Xylaria cubensis, were discovered to be previously unrecorded in Korea. The fungal communities in both plant tissues demonstrated distinct species composition. Differences were observed in the relative abundance and species diversity index between needle leaves and twigs. Our findings suggest that the host plant tissues influence the species diversity of endophytic fungal communities.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.20 no.5
• /
• pp.1126-1134
• /
• 2006

Human fungal infections are uncommon in normally healthy persons, being confined to conditions such as candidiasis (thrush) and dermatophyte skin infections such as athlete's foot. However, in the immunocompromised host, a variety of normally mild or nonpathogenic fungi can cause potentially fatal infections. Furthermore, the relativeease with which people can now visit 'exotic' countries provides the means for unusual fungal infections to be imported into this country. Mycoses appear in many different forms and areas. Fungal infections or mycoses are classified depending on the degree of tissue involvement and mode of entry into the host. These are Cutaneous, Subcutaneous, Systemic, and Opportunistic. Cutaneous mycoses specially appears symptoms on the skin. They are treated by amphotericinB, nystatin, grycelfulvin, micronazole and ketaconazole, etc, but these medicines are been careful about using, because most of them have serious side effects and toxicities. So, on the purpose of finding safe novel medicines, we have researched oriental medicines and search them to treat mycoses. In oriental medicines treating mycoses, we pay attention to orient applications that directly have an effect on disorder lesions. Oriental applications consists of various herbs and have a lot of forms, so we try to classify them as herbs and forms

• The Plant Pathology Journal
• /
• v.37 no.6
• /
• pp.505-511
• /
• 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.