Mycobiota community and fungal species response to development stage and fire blight disease in apples

Fire blight disease, caused by the bacterial pathogen Erwinia amylovora, has been a significant concern for over 50 countries worldwide. The efficacy of chemical pesticides currently available for disease control is limited. To address this issue, research is being conducted to explore environmentally friendly control methods, particularly biological control using beneficial microorganisms. However, there is limited research on the apple microbiota community and minimal research has been conducted on fungal communities that may exhibit reliable performance in apple trees. Therefore, our objective was to analyze the fungal communities present in apples at different developmental stages and in different tissues, aiming to identify potential biological control agents for fire blight disease. Our findings indicate that the fungal communities present in apple buds, flowers and leaves play an important role in inhibiting the invasion of E. amylovora. Specifically, we propose GS11 and Lipomyces starkeyi as potential keystone taxa that respond to fire blight disease. These findings provide insights into the continuity and discontinuity of fungal community structure in different developmental stages of apples and offer predictions for potential biological control agents for fire blight disease

Evolution of Antibiotic Synthesis Gene Clusters in the Streptomyces globisporus TFH56, Isolated from Tomato Flower

Streptomyces species are known to produce various bioactive metabolites that can prevent plant diseases. Previously, the Streptomyces strain TFH56 was found to inhibit the gray mold pathogen, Botrytis cinerea, in tomato flower. In this study, the genome sequence of strain TFH56 was acquired using the Pacific Biosciences RS II platform. Three linear sequences (7.67 Mbp in total) were obtained. Based on average nucleotide identity, strain TFH56 was classified as Streptomyces globisporus, which is consistent with the presence of a linear chromosome and linear plasmids. Moreover, as with other examples of S. globisporus, the genome of strain TFH56 included a caryolan-1-ol synthase gene, a conprimycin synthetic gene cluster, and a lidamycin synthetic gene cluste

Transition from Ginseng Root Rot Disease-Conducive Soil to -Suppressive Soil Mediated by Pseudomonadaceae

ABSTRACT Ginseng is a popular medicinal herb with established therapeutic effects such as cardiovascular disease prevention, anticancer effects, and anti-inflammatory effects. However, the slow growth of ginseng due to soilborne pathogens has been a challenge for establishing new plantations. In this study, we investigated root rot disease associated with the microbiota in a ginseng monoculture model system. Our results showed that a collapse of the early microbiota community inhibiting root rot disease was observed before the disease became severe, and nitrogen fixation was necessary to support the initial microbiota community structure. Furthermore, changes in the nitrogen composition were essential for the suppression of pathogen activity in early monoculture soils. We hypothesize that Pseudomonadaceae, a population built up by aspartic acid, can inhibit the occurrence of root rot disease in ginseng and that specific management practices that maintain a healthy microbiome can be implemented to prevent and mitigate the disease. Our findings provide insights into the potential use of specific members of the microbiota for controlling root rot disease in ginseng cultivation. IMPORTANCE Understanding the initial soil microbiota and community shifts in a monoculture system is critical for developing disease-suppressive soils for crop production. The lack of resistance genes against soilborne pathogens in plants highlights the need for effective management strategies. Our investigation of root rot disease and initial microbiota community shifts in a ginseng monoculture model system provides valuable insight into the development of conducive soil into specific suppressive soil. With a thorough understanding of the microbiota in disease-conducive soil, we can work toward the development of disease-suppressive soil to prevent outbreaks and ensure sustainable crop production

Investigation of Fungal Strains Composition in Fruit Pollens for Artificial Pollination

Plants pollination are conducted through various pollinators such as wind, animals, and insects. Recently, the necessity for artificial pollination is drawing attention as the proportion of natural pollinators involved is decreasing over the years. Likewise, the trade in pollen for artificial pollination is also increasing worldwide. Through these imported pollens, many unknown microorganisms can flow from foreign countries. Among them, spores of various fungi present in the particles of pollen can be dispersed throughout the orchard. Therefore, in this study, the composition of fungal communities in imported pollen was revealed, and potential ecological characteristics of the fungi were investigated in four types of imported pollen. Top 10 operational taxonomic unit (OTU) of fungi were ranked among the following groups: Alternaria sp., Cladosporium sp., and Didymella glomerata which belong to many pathogenic species. Through FUNGuild analysis, the proportion of OTUs, which is assumed to be potentially plant pathogens, was higher than 50%, except for apple pollen in 2018. Based on this study of fungal structure, this information can suggest the direction of the pollen quarantine process and contribute to fungal biology in polle

Antioxidant and anti-inflammatory activities of N-((3,4-Dihydro-2H-benzo[h]chromene-2-yl)methyl)-4-methoxyaniline in LPS-induced BV2 microglial cells

Microglial activation is known to cause inflammation resulting in neurotoxicity in several neurological diseases. N-((3,4-Dihydro-2H-benzo[h]chromene-2-yl)methyl)-4-me-thoxyaniline (BL-M), a chromene derivative, was originally synthesized with the perspective of inhibiting nuclear factor-kappa B (NF-kappa B), a key regulator of inflammation. The present study evaluated the antioxidant and anti-inflammatory potential of BL-M in lipopolysaccharide (LPS)-stimulated BV2 microglial cells. Our results demonstrated that BL-M significantly inhibited the formation of 1,1-dipheny1-2-picrylhydrazyl radicals, as well as lipid peroxidation in rat brain homogenate in a concentration-dependent manner. In addition, it suppressed the generation of intracellular reactive oxygen species, and the levels of pro-inflammatory mediators including nitric oxide, tumor necrosis factor-alpha, and interleukin-6 in LPS-induced BV2 cells. Western blotting analyses revealed the inhibition of inhibitor of kappa B alpha (I kappa B alpha) phosphorylation and NF-kappa B translocation by BL-M in LPS-activated cells. Therefore, our study highlights marked antioxidant and anti-inflammatory activities of BL-M, and suggests that this compound may have a beneficial impact on various neurodegenerative diseases associated with inflammation

Development qRT-PCR Protocol to Predict Strawberry Fusarium Wilt Occurrence

Strawberry Fusarium wilt disease, caused by Fusarium oxysporum f. sp. fragariae, is the most devastating disease in strawberry production. The pathogen produces chlamydospores which tolerate against harsh environment, fungicide and survive for decades in soil. Development of detection and quantification techniques are regarded significantly in many soilborne pathogens to prevent damage from diseases. In this study, we improved specific-quantitative primers for F. oxysporum f. sp. fragariae to reveal correlation between the pathogen density and the disease severity. Standard curve r2 value of the specific-quantitative primers for qRT-PCR and meting curve were over 0.99 and 80.5°C, respectively. Over pathogen 105 cfu/g of soil was required to cause the disease in both lab and field conditions. With the minimum density to develop the wilt disease, the pathogen affected near 60% in nursery plantation. A biological control microbe agent and soil solarization reduced the pathogen population 2-fold and 1.5-fold in soil, respectively. The developed F. oxysporum f. sp. fragariae specific qRT-PCR protocol may contribute to evaluating soil healthiness and appropriate decision making to control the disease

Supplementary tables and figures from Caryolan-1-ol, an antifungal volatile produced by <i>Streptomyces</i> spp., inhibits the endomembrane system of fungi

Supplementary tables and figure