• The Plant Pathology Journal
• /
• v.34 no.4
• /
• pp.341-346
• /
• 2018

The microbiome makes a significant contribution to plant health and endophytes may generate positive effects for the host. However, there is a limited knowledge available concerning the kiwifruit endophyte. Therefore, we discuss endophyte microbiome community structures among the kiwifruit cultivars. Total reads numbered 17620 in cv. Hayward, 11515 in cv. Haegeum and 13613 in cv. Jecygold. The number of OTUs was follows: 112 in cv. Hageum; and 87 in cvs. Hayward and Jecygold. Most of the identified OTUs were phylum Proteobacteria and it emerged that Actinobacteria, Firmicute and Bacteroidetes were mainly present. While the largest difference in Proteobacteria content is between cv. Haegeum and cv. Jecygold, they shared more OTUs than cv. Hayward. As well, this study revealed the presence of remarkably dominated OTU of Pseudomonas spp. in kiwifruit sap regardless of cultivars. To the best of our knowledge, this study is the first tone to investigate the kiwifruit endophyte-microbiome community.

• 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.

• Journal of Microbiology
• /
• v.42 no.3
• /
• pp.169-173
• /
• 2004

Enterobacter cloacae (strain PR2/7), a genetically modified endophyte(GME) in citrus plants, carrying different plasmids (pEC3.0/18, pCelE, pEglA and pGFP), was inoculated into Citrus sinensis seedlings under greenhouse conditions. The impact of this on the indigenous bacterial endophytic community was studied by analyses of 2 different morphologic groups. The germination rates of inoculated seeds were evaluated in greenhouse, and plasmid stability under in vitro conditions. Results demonstrated a great and diverse endophytic community inside plants, and specialization in tissue colonization by some bacterial groups, in different treatments. Shifts in seed germination rate were observed among treatments: in general, the PR2/7 harboring pEglA bacterial- clone significantly reduced seed germination, compared to the PR2/7 harboring pEC3.0/18 clone. This suggests that the presence of the pEglA plasmid changes bacteria-seed interactions. The endophytic community of citrus seedlings changed according to treatment. In seedlings treated with the PR2/7 with pEglA clone, the population of group II decreased significantly, within the context of the total endophytic community. These results indicate that the application of GMEs induces shifts in the endophytic bacterial community of citrus seedlings.

• The Plant Pathology Journal
• /
• v.39 no.4
• /
• pp.397-408
• /
• 2023

Fire blight disease, caused by Erwinia amylovora, is a devastating affliction in apple cultivation worldwide. Chemical pesticides have exhibited limited effectiveness in controlling the disease, and biological control options for treating fruit trees are limited. Therefore, a relatively large-scale survey is necessary to develop microbial agents for apple trees. Here we collected healthy apple trees from across the country to identify common and core bacterial taxa. We analyzed the endophytic bacterial communities in leaves and twigs and discovered that the twig bacterial communities were more conserved than those in the leaves, regardless of the origin of the sample. This finding indicates that specific endophytic taxa are consistently present in healthy apple trees and may be involved in vital functions such as disease prevention and growth. Furthermore, we compared the community metabolite pathway expression rates of these endophyte communities with those of E. amylovora infected apple trees and discovered that the endophyte communities in healthy apple trees not only had similar community structures but also similar metabolite pathway expression rates. Additionally, Pseudomonas and Methylobacterium-Methylorobrum were the dominant taxa in all healthy apple trees. Our findings provide valuable insights into the potential roles of endophytes in healthy apple trees and inform the development of strategies for enhancing apple growth and resilience. Moreover, the similarity in cluster structure and pathway analysis between healthy orchards was mutually reinforcing, demonstrating the power of microbiome analysis as a tool for identifying factors that contribute to plant health.

• The Plant Pathology Journal
• /
• v.38 no.4
• /
• pp.372-382
• /
• 2022

Soybean is an important source of protein and for a wide range of agricultural, food, and industrial applications. Soybean is being affected by Xanthomonas citri pv. glycines, a causal pathogen of bacterial pustule disease, result in a reduction in yield and quality. Diverse microbial communities of plants are involved in various plant stresses is known. Therefore, we designed to investigate the microbial community differentiation depending on the infection of X. citri pv. glycines. The microbial community's abundance, diversity, and similarity showed a difference between infected and non-infected soybean. Microbiota community analysis, excluding X. citri pv. glycines, revealed that Pseudomonas spp. would increase the population of the infected soybean. Results of DESeq analyses suggested that energy metabolism, secondary metabolite, and TCA cycle metabolism were actively diverse in the non-infected soybeans. Additionally, Streptomyces bacillaris S8, an endophyte microbiota member, was nominated as a key microbe in the healthy soybeans. Genome analysis of S. bacillaris S8 presented that salinomycin may be the critical antibacterial metabolite. Our findings on the composition of soybean microbiota communities and the key strain information will contribute to developing biological control strategies against X. citri pv. glycines.

• Journal of Microbiology
• /
• v.45 no.1
• /
• pp.11-14
• /
• 2007

Over the last few years, the endophytic bacterial community associated with citrus has been studied as an important component interacting with Xylella fastidiosa, the causal agent of citrus variegated chlorosis(CVC). This bacterium may also colonize some model plants, such as Catharanthus roseus and Nicotiana clevelandii. In the present study, we compared the endophytic colonization of Citrus sinensis and Catharanthus rose us using the endophytic bacteria Klebsiella pneumoniae. We chose an appropriate strain, K. pneumoniae 342 (Kp342), labeled with the GFP gene. This strain was inoculated onto seedlings of C. sinensis and C. roseus. The isolation frequency was determined one week after the inoculation and the endophytic colonization of K. pneumoniae was observed using fluorescence microscopy. Although the endophytic bacterium was more frequently isolated from C. roseus than from C. sinensis, the colonization profiles for both host plants were similar, suggesting that C. roseus could be used as a model plant to study the interaction between endophytic bacteria and X. fastidiosa.

• Mycobiology
• /
• v.45 no.3
• /
• pp.150-159
• /
• 2017

This study analyzed the distribution of endophytic fungi in 3 coastal environments with different climatic, geographical, and geological characteristics: the volcanic islands of Dokdo, the East Sea, and the West Sea of Korea. The isolated fungal endophytes were characterized and analyzed with respect to the characteristics of their host environments. For this purpose, we selected common native coastal halophyte communities from three regions. Molecular identification of the fungal endophytes showed clear differences among the sampling sites and halophyte host species. Isolates were also characterized by growth at specific salinities or pH gradients, with reference to previous geographical, geological, and climate studies. Unlike the East Sea or West Sea isolates, some Dokdo Islands isolates showed endurable traits with growth in high salinity, and many showed growth under extremely alkaline conditions. A smaller proportion of West Sea coast isolates tolerate compared to the East Sea or Dokdo Islands isolates. These results suggest that these unique fungal biota developed through a close interaction between the host halophyte and their environment, even within the same halophyte species. Therefore, this study proposes the application of specific fungal resources for restoring sand dunes and salt-damaged agricultural lands and industrialization of halophytic plants.

• Journal of Microbiology and Biotechnology
• /
• v.24 no.3
• /
• pp.324-333
• /
• 2014

The Black Pine, Pinus thunbergii, is widely distributed along the eastern coast of Korea and its importance as a shelterbelt was highlighted after tsunamis in Indonesia and Japan. The root endophytic diversity of P. thunbergii was investigated in three coastal regions; Goseong, Uljin, and Busan. Fungi were isolated from the root tips, and growth rates of pure cultures were measured and compared between PDA with and without 3% NaCl to determine their saline resistance. A total of 259 isolates were divided into 136 morphotypes, of which internal transcribed spacer region sequences identified 58 species. Representatives of each major fungi phylum were present: 44 Ascomycota, 8 Zygomycota, and 6 Basidiomycota. Eighteen species exhibited saline resistance, many of which were Penicillium and Trichoderma species. Shoreline habitats harbored higher saline-tolerant endophytic diversity compared with inland sites. This investigation indicates that endophytes of P. thunbergii living closer to the coast may have higher resistance to salinity and potentially have specific relationships with P. thunbergii.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.06a
• /
• pp.161-161
• /
• 2017

Seed endophytes are very remarkable groups of bacteria for their unique abilities of being vertically transmitted and conserved. As plants attain hybrid vigor and heterosis in the process of crossbreeding, this might also lead to the changes in the community structure and diversity of plant endophytes in the hybrid plants ultimately affecting the endophytes of the seeds. It would be interesting to characterize how seed endophyte composition change over time. The objective of this study is to gain insights into the influence of natural crossbreeding and parental lineage in the seed bacterial endophytic communities of two pure inbred lines exploring contributions of the two most important sources of plant endophytes - colonization from external sources and vertical transmission via seeds. Total genomic DNA was isolated from rice seeds and bacterial DNA was selectively amplified by PCR. The diversity of endophytic bacteria was studied through Terminal-Restriction Fragment Length Polymorphism (T-RFLP) analysis. Diversity between the original parents and the pure inbred line may show significant differences in terms of richness, evenness and diversity indices. Heat maps reveal astonishing contributions of both or either parents (IR29 ${\times}$ Pokkali and AT401 ${\times}$ IR31868) in the shaping of the bacterial seed endophytes of the hybrid, FL478 and IC32, respectively. Most of the T-RFs of the subsequent pure inbred line could be traced to any or both of the parents. Comparison of common and genotype-specific T-RFs of parents and their offspring reveals that majority of the T-RFs are shared suggesting higher transmission of bacterial communities common to both parents. The parents influence the bacterial community of their offspring. Unique T-RFs of the offspring also suggest external sources of colonization particularly as the seeds are cultivated in different ecogeographical locations. This study showed that host parental lines contributed greatly in the shaping of bacterial seed endophytes of their offspring. It also revealed transmission and potential conservation of core seed bacterial endophytes that generally become the dominant microbiota in the succeeding generations of plant hosts.