Lacticaseibacillus pabuli sp. nov., isolated from fermented cattle feed.

Strain BSF-3MT is a Gram-stain-positive, non-flagellated, facultative anaerobic and rod-shaped bacterium that was isolated from fermented feed collected at a cattle farm in the Daejeon region of the Republic of Korea. It was studied using polyphasic taxonomic methods. Using 16S rRNA gene sequences and the resulting phylogenetic tree, the strain was primarily identified as a member of the genus Lacticaseibacillus. Strain BSF-3MT contained a chromosome of 2.5 Mbp and a plasmid of 33.4 kbp. The G+C content of genomic DNA was 51.3 mol%. Strain BSF-3MT had the highest ortho-average nucleotide identity value of 73.7 % with Lacticaseibacillus songhuajiangensis 7-19T, its closest relative in the phylogenetic tree based on the 16S rRNA gene sequences and the phylogenomic tree based on up-to-date bacterial core genes. Based on the results of a polyphasic taxonomic study, strain BSF-3MT represents a novel species in the genus Lacticaseibacillus, for which the name Lacticaseibacillus pabuli sp. nov. is proposed. The type strain is BSF-3MT (=KACC 23028T=NBRC 116014T).

First Report of Alternaria alternata causing leaf spot on Chinese quince (Chaenomeles sinensis (Thouin) Koehne) in Korea.

The Chinese quince (Chaenomeles sinensis (Thouin) Koehne), belongs to the Rosaceae family, is widely distributed throughout Asia, including Republic of Korea. It is used as a traditional treatment for asthma, common cold, and dry pharynx. Numerous recent pharmacological studies on antiinfluenza, antioxidant, and antidiabetic properties have confirmed the medicinal properties of the Chinese quince fruit (Chun et al., 2012). In March 2022, leaf spots on Chinese quince, resulting in defoliation, were observed in Andong, Gyeongsangbuk Province, Korea (Fig. 1A). The disease symptoms are dark brown spots on leaves. Later, the chlorophyll is lost, causing the entire leaf to become wilted and fell off (Fig. 1B). To identify the pathogen, symptomatic leaves were brought to the laboratory, cut into small pieces, and surface-disinfected in 70% ethanol for 15 s and rinsed with sterile distilled water (SDW). The specimens were then treated with 1% NaOCl for 15 s, followed by rinsing with SDW. Thus, surface-disinfected tissues were placed onto potato dextrose agar (PDA) plates and incubated at 25°C for 7 d. A total of four isolates were obtained from the infected leaves. The colonies were transferred onto freshly prepared PDA plates by the single spore method for further purification. GYUN-10746 isolate was selected as the representative strain among the four isolates and deposited in the Korean Agricultural Culture Collection (KACC 410367). They initially produced white mycelia, which turned dark brown or pale brown at the center and beige at the periphery after 7 d (Fig. 1C and D). Conidiophores were pyriform, sometimes ovoid, or ellipsoidal and brown, measuring 30.8 ± 0.49 × 12.9 ± 0.26 µm (length × width) (n=100) (Fig. 1E). The morphological characteristics were consistent with those of Alternaria alternata (Woudenberg et al. 2015). For molecular identification, DNA was amplified using the following primers: ITS1/ITS4 (White et al. 1990), EF1-728F/EF1-986R (Carbone et al. 1999), Gpd-R/Gpd-F (Berbee et al. 1999), Alt a1-F/Alt a1-R (Hong et al. 2005) and rpb2F/rpb2R (Liu et al. 1999) by PCR. DNA sequences from all 4 isolates (GYUN-10746, GYUN-11193, GYUN-11194 and GYUN-11195) were identical. The ITS (OP594615), TEF1-α (OR327062), GAPDH (OR372157), Alt a 1 (OR327061), and RPB2 (OR352741) sequences from the representative isolate GYUN-10746 were 100% identical to those of previously identified A. alternate isolates. A phylogenetic tree was constructed using sequences of ITS, TEF1-α, GAPDH, Alt a l, and RPB2 to illustrate their relationship with A. alternata and related Alternaria species (Fig. 2). For the pathogenicity test, healthy Chinese quince branch containing leaves were inoculated with 7-day-old mycelial plugs of A. alternata, while leaves on a branch inoculated with PDA plugs alone served as a control group. Thus inoculated branches were incubated at 25°C for 7 d. Disease symptoms were developed on leaves of the branches inoculated with mycelial plugs of the fungal pathogen (Fig. 1F), while no symptoms developed on control group. The resulting leaf spots resembled those on the original infected plants. To confirm Koch's postulates, the pathogen was re-isolated from inoculated leaves with identical morphological and molecular characteristics. To the best of our knowledge, this is the first report of leaf spot caused by A. alternata in C. sinensis in Korea. The identification of the pathogen may provide pertinent information for the development of disease controlling strategies.

Mycoproteins and their health-promoting properties: Fusarium species and beyond.

Filamentous fungal mycoproteins have gained increasing attention as sustainable alternatives to animal and plant-based proteins. This comprehensive review summarizes the nutritional characteristics, toxicological aspects, and health-promoting effects of mycoproteins, focusing on those derived from filamentous fungi, notably Fusarium venenatum. Mycoproteins are characterized by their high protein content, and they have a superior essential amino acid profile compared to soybeans indicating excellent protein quality and benefits for human nutrition. Additionally, mycoproteins offer enhanced digestibility, further highlighting their suitability as a protein source. Furthermore, mycoproteins are rich in dietary fibers, which have been associated with health benefits, including protection against metabolic diseases. Moreover, their fatty acids profile, with significant proportions of polyunsaturated fatty acids and absence of cholesterol, distinguishes them from animal-derived proteins. In conclusion, the future of mycoproteins as a health-promoting protein alternative and the development of functional foods relies on several key aspects. These include improving the acceptance of mycoproteins, conducting further research into their mechanisms of action, addressing consumer preferences and perceptions, and ensuring safety and regulatory compliance. To fully unlock the potential of mycoproteins and meet the evolving needs of a health-conscious society, continuous interdisciplinary research, collaboration among stakeholders, and proactive engagement with consumers will be vital.

A phase Ia/Ib study of novel anti-ErbB3 monoclonal antibody, barecetamab (ISU104) in refractory solid cancers and monotherapy or in combination with cetuximab in recurrent or metastatic head and neck cancer.

We evaluated the safety, tolerability, pharmacokinetics and antitumor activity of barecetamab monotherapy and combination cetuximab therapy in patients with advanced solid cancers, especially head and neck cancer (HNC). Part 1 was a 3 + 3 dose-escalation study in which 15 patients received barecetamab at 1, 3, 5, 10 and 20 mg/kg intravenously (IV) on days 1 and 28 and weekly in patients with advanced solid cancer. Part 2 was a dose-expansion study including two patient groups with advanced HNC, including six patients receiving barecetamab at 20 mg/kg IV every 3 weeks and 12 patients receiving barecetamab and cetuximab (400 mg/m2 on day 1 followed by 250 mg/m2 every week). No dose-limiting toxicities (DLTs) were observed. Maximum serum target engagement was reached with trough levels of doses ≥3 mg/kg IV weekly. Common adverse drug reactions were diarrhea, stomatitis, dermatitis acneiform and decreased appetite. One durable complete response of more than 17 months was observed, and the overall response and disease control rates were 36.4% (4/11) and 81.1% (9/11), respectively, in the combination therapy group. In conclusion, DLT was not observed in barecetamab at 1 to 20 mg/kg. The recommended phase II dose was determined to be 20 mg/kg triweekly. Barecetamab and in cetuximab combination was well tolerated and demonstrated meaningful antitumor effects.

Melaminivora suipulveris sp. nov., isolated from pigpen dust.

A bacterial strain designated SC2-9T was isolated from the dust collector of a pigpen located in Wanju-gun, Jeollabuk-do, Republic of Korea. Cells were strictly aerobic, Gram-stain-negative, flagellated and rod-shaped. The strain was catalase- and oxidase-positive, and grew optimally 28-30 °C, pH 8.0 and 0 % NaCl (w/v). Phylogenetic analysis based on 16S rRNA gene sequences showed 99.1 and 98.3 % similarities to Melaminivora jejuensis KBB12T and Melaminivora alkalimesophila CY1T, and revealing less than 97 % similarity to other validly named species. The genomic DNA G+C content of strain SC2-9T was 68.2 %. The orthologous average nucleotide identity and dDDH values of strain SC2-9T with the closest species Melaminivora jejuensis KCTC 32230T were 85.6 and 29.3 %, respectively. The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, three unidentified aminolipids and one unidentified lipid. The major fatty acids (>10 %) were summed feature 3 (C16 : 1 ω6c and/or C16 : 1 ω7c), C16 : 0 and summed feature 8 (C18 : 1 ω6c and/ or C18 : 1 ω7c). The predominant isoprenoid quinone was ubiquinone-8. Based on phenotypic, chemotaxonomic and phylogenetic data, strain SC2-9T should be assigned as a novel species of the genus Melaminivora, for which the name Melaminivora suipulveris sp. nov. is proposed. The type strain is SC2-9T (=KACC 19310T=NBRC 113103T).

Brevibacillus ruminantium sp. nov., isolated from cow faeces.

An aerobic, Gram-stain-positive, rod-shaped, endospore-forming bacterial strain, designated BB3-R1T, was isolated from cow faeces sampled in Daejeon, Republic of Korea. Growth was observed at 25-45 °C (optimum, 35-40 °C) and pH 7.0-9.0 (optimum, pH 8.0), with up to 3 % (w/v) NaCl (optimum, 0 % NaCl). blast analysis of 16S rRNA gene sequences revealed the highest sequence similarity of strain BB3-R1T to Brevibacillus borstelensis NRRL NRS-818T (98.8 %) followed by Brevibacillus panacihumi JCM 15085T (97.5 %). According to 16S rRNA gene and whole-genome based phylogenetic trees, strain BB3-R1T clustered with Brevibacillus composti FJAT-54423T and B. borstelensis NRRL NRS-818T. OrthoANI and dDDH values of strain BB3-R1T with the closely related strains were lower than 77.5 and 26.8 %, respectively. The major menaquinones and polar lipids of the strain were MK-7 and phosphatidylmonomethylethanolamine, diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine, respectively. The major fatty acids (>10 %) were C14 : 0 iso, C15 : 0 iso, C15 : 0 anteiso and C16 : 1 ω7c alcohol. The cell-wall peptidoglycan contained cross-linked meso-diaminopimelic acid (type A1 gamma). The phenotypic, chemotaxonomic and genotypic data obtained in this study showed that the strain represents a novel species of the genus Brevibacillus, for which the name Brevibacillus ruminantium sp. nov. (type strain BB3-R1T=KACC 22663T=NBRC 115962T) is proposed.

Frateuria soli sp. nov. and Frateuria edaphi sp. nov., isolated from greenhouse soil.

Two bacterial strains, designated 5GH9-11T and 5GH9-34T, were isolated from greenhouse soil sampled in Wanju-gun, Jeollabuk-do, Republic of Korea. Both strains formed yellow colonies and were aerobic, rod-shaped and flagellated. The 16S rRNA gene sequence similarity between 5GH9-11T and 5GH9-34T was 98.6 %. Strain 5GH9-11T showed the highest sequence similarities to Dyella thiooxydans ATSB10T (98.1 %) and Frateuria aurantia DSM 6220T (97.7 %) while strain 5GH9-34T revealed the highest sequence similarity to F. aurantia DSM 6220T (98.3 %) and D. thiooxydans ATSB10T (98.3 %). Phylogenetic analysis on the basis of the 16S rRNA gene sequence showed that strains 5GH9-11T and 5GH9-34T formed a robust cluster with Frateuria flava MAH-13T and Frateuria terrea NBRC 104236T. The phylogenomic tree also showed that strains 5GH9-11T and 5GH9-34T formed a robust cluster with F. terrea DSM 26515T and F. flava MAH-13T. Strain 5GH9-11T showed the highest orthologous average nucleotide identity (OrthoANI; 88.5 %) and digital DNA-DNA hybridization (dDDH) values (35.5 %) with F. flava MAH-13T, and strain 5GH9-34T revealed highest OrthoANI (88.1 %) and dDDH (34.2 %) values with F. flava MAH-13T. The orthoANI and dDDH values between strain 5GH9-11T and 5GH9-34T were 87.7 and 33.9 %, respectively. Their major respiratory quinone was ubiquinone 8, and the major cellular fatty acids were iso-C16 : 0, summed feature 9 (iso-C17 : 1 ω9c and/or C16 : 0 10-methyl) and iso-C15 : 0. The major polar lipids of both strains were composed of large or moderate amounts of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, an unidentified aminolipid and an unidentified aminophospholipid. Based on these data, strains 5GH9-11T and 5GH9-34T should represent two independent novel species of Frateuria, for which the names Frateuria soli sp. nov. (type strain 5GH9-11T=KACC 16943T=JCM 35197T) and Frateuria edaphi sp. nov. (type strain 5GH9-34T=KACC 16945T=JCM 35198T) are proposed.

Five novel Hymenobacter species isolated from air: Hymenobacter cellulosilyticus sp. nov., Hymenobacter cellulosivorans sp. nov., Hymenobacter aerilatus sp. nov., Hymenobacter sublimis sp. nov. and Hymenobacter volaticus sp. nov.

Five Hymenobacter strains isolated from air samples collected from the Suwon and Jeju regions of the Republic of Korea were studied using polyphasic taxonomic methods. Using 16S rRNA gene sequences and the resulting phylogenetic tree, the strains were primarily identified as members of the genus Hymenobacter. Digital DNA-DNA hybridization values and average nucleotide identities values for species delineation (70 and 95-96 %, respectively) between the five strains and their nearest type strains indicated that each strain represented a novel species. All strains were aerobic, Gram-stain-negative, mesophilic, rod-shaped and catalase- and oxidase-positive, with red to pink coloured colonies. The genome sizes of the five strains varied from 4.8 to 7.1 Mb and their G+C contents were between 54.1 and 59.4 mol%. Based on their phenotypic, chemotaxonomic and genotypic characteristics, we propose to classify these isolates into five novel species within the genus Hymenobacter for which we propose the names, Hymenobacter cellulosilyticus sp. nov., Hymenobacter cellulosivorans sp. nov., Hymenobacter aerilatus sp. nov., Hymenobacter sublimis sp. nov. and Hymenobacter volaticus sp. nov., with strains 5116 S-3T (=KACC 21925T=JCM 35216T), 5116 S-27T (=KACC 21926T=JCM 35217T), 5413 J-13T (=KACC 21928T=JCM 35219T), 5516 S-25T (=KACC 21931T=JCM 35222T) and 5420 S-77T (=KACC 21932T=JCM 35223T) as the type strains, respectively.

Spirosoma oryzicola sp. nov., isolated from dried rice husk.

Strain RHs26T is an aerobic, Gram-stain-negative, non-flagellated and rod- or filamentous-shaped (1.0-1.1×2.3-50 µm) bacterium that was isolated from dried rice husk. It was positive for oxidase and catalase, hydrolysed starch and Tween 80, and weakly hydrolysed CM-cellulose. The strain grew at temperatures between 10 and 37 °C (optimum, 28 °C), in 0-1 % NaCl (optimum, 0 %) and at pH 6.0-9.0 (optimum, pH 7.0-8.0). The predominant membrane fatty acids were summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c), C16 : 1 ω5c, iso-C15 : 0 and iso-C17 : 0 3-OH. The major polar lipids were phosphatidylethanolamine, an unidentified aminolipid, two unidentified aminophospholipids and two unidentified lipids. The predominant quinone was menaquinone MK-7. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain RHs26T belongs to the genus Spirosoma, presenting the highest sequence similarity to Spirosoma agri S7-3-3T (95.8 %). The genomic DNA G+C content of strain RHs26T was 49.5 %. Strain RHs26T showed the highest orthologous average nucleotide identity (OrthoANI) and digital DNA-DNA hybridization (dDDH) values of 76.4 % and 20.0 % with S. agri KCTC 52727T while sharing OrthoANI and dDDH values of 74.6 % and 19.2 % with Spirosoma terrae KCTC 52035T, the closest relative in the phylogenomic tree. Based on the results of a polyphasic taxonomic study, strain RHs26T represents a novel species in the genus Spirosoma, for which the name Spirosoma oryzicola sp. nov. is proposed. The type strain is RHs26T (=JCM 35224T=KACC 17318T).

Genome-wide identification of GH9 gene family and the assessment of its role during fruit abscission zone formation in Vaccinium ashei.

KEY MESSAGE: The genomic location and stage-specific expression pattern of GH9 genes reveal their critical roles during fruit abscission zone formation in Vaccinium ashei. Glycosyl hydrolase family 9 (GH9) cellulases play a crucial role in both cellulose synthesis and hydrolysis during plant growth and development. Despite this importance, there is currently no study on the involvement of GH9-encoding genes, specifically VaGH9s, in abscission zone formation of rabbiteye blueberries (Vaccinium ashei). In this study, we identified a total of 61 VaGH9s in the genome, which can be classified into 3 subclasses based on conserved motifs and domains, gene structures, and phylogenetic analyses. Our synteny analysis revealed that VaGH9s are more closely related to the GH9s of Populus L. than to those of Arabidopsis, Vitis vinifera, and Citrus sinensis. In silico structural analysis predicted that most of VaGH9s are hydrophilic, and localized in cell membrane and/or cell wall, and the variable sets of cis-acting regulatory elements and functional diversity with four categories of stress response, hormone regulation, growth and development, and transcription factor-related elements are present in the promoter sequence of VaGH9s genes. Transcriptomic analysis showed that there were 22 differentially expressed VaGH9s in fruit abscission zone tissue at the veraison stage, and the expression of VaGH9B2 and VaGH9C10 was continuously increased during fruit maturation, which were in parallel with the increasing levels of cellulase activity and oxidative stress indicators, suggesting that they are involved in the separation stage of fruit abscission in Vaccinium ashei. Our work identified 22 VaGH9s potentially involved in different stages of fruit abscission and would aid further investigation into the molecular regulation of abscission in rabbiteye blueberries fruit.

First Report of Cladosporium cladosporioides Causing Leaf Spot of Aralia cordata var. continentalis in Korea.

Aralia cordata var. continentalis (Kitag), commonly known as Japanese spikenard, is an upright herbaceous perennial medicinal plant effective in relieving pain. It is also consumed as a leafy vegetable. Leaf spots and blight symptoms on A. cordata resulting in defoliation were observed in July 2021 from a research field with a disease incidence of nearly 40-50% from 80 plants in Yeongju, Korea. Brown spots with chlorotic halos first appear on the upper leaf surface (Fig. 1A). In the later stage, spots enlarge and coalesce; resulting in the leaves to dry-off (Fig. 1B). To isolate the causal agent, small pieces of diseased leaves displaying the lesion were surface-sterilized by 70% ethanol for 30 s and rinsed twice with sterile distilled water (SDW). Later, the tissues were crushed in a sterile 2.0-ml Eppendorf tube with a rubber pestle in SDW. The suspension was serially diluted and spread on potato dextrose agar (PDA) medium, incubated at 25°C for 3 days. A total of 3 isolates were obtained from the infected leaves. Pure cultures were obtained by the monosporic culture technique (Choi et al. 1999). After 2 to 3 days of incubation with a 12-h photoperiod, the fungus initially produced gray mold colonies in olive color, and the edges of the mold appeared white with a velvety texture after 20 days (Fig. 1C). Microscopic observations revealed small, single-celled, rounded, and pointed conidia that measured 6.67 ± 0.23 µm × 4.18 ± 0.12 µm (length × width) (n=40 spores) (Fig. 1D). On the basis of its morphology, the causal organism was identified as Cladosporium cladosporioides (Torres et al. 2017). For molecular identification, pure colonies of three single-spore isolates were used for DNA extraction. A fragment of the ITS, ACT, and TEF1-α were amplified using the primers ITS1/ITS4 (Zarrin et al. 2016), ACT-512F/ACT-783R, and EF1-728F/EF1-986R, respectively, by PCR (Carbone et al. 1999). The DNA sequences from all three isolates (GYUN-10727, GYUN-10776, and GYUN-10777) were identical. The resulting ITS (ON005144), ACT (ON014518), and TEF1-α (OQ286396) sequences from the representative isolate GYUN-10727 were 99 to 100% identical to the C. cladosporioides (ITS: KX664404, MF077224; ACT: HM148509; TEF1-α: HM148268, HM148266). The phylogenetic dendrogram was constructed from the comparative analysis of ITS, ACT, and TEF1-α gene sequences, showing the relationship between Cladosporium cladosporioides and related Cladosporium species (Fig. 2). The isolate GYUN-10727 has been deposited in Korean Agricultural Culture Collection (KACC 410009), and used as a representative strain in this study. For the pathogenicity test, healthy fresh leaves (3 leaves per plant) of 3-months-old A. cordata plants in pots were spray inoculated with conidial suspensions (1 × 104 conidia/mL) of GYUN-10727, which was obtained from a 7-day-old PDA culture. Leaves sprayed with SDW were considered as control. After 15 days of incubation at 25°C ± 5°C under greenhouse conditions, necrotic lesions were observed on the inoculated A. cordata leaves, while control leaves did not develop any disease symptoms. The experiment was performed twice with three replicates (pots) per treatment. The pathogen was re-isolated from the symptomatic A. cordata leaves, but not from control plants, to fulfill Koch's postulates. The re-isolated pathogen was identified by PCR. Cladosporium cladosporioides has been reported to cause diseases in sweet pepper (Krasnow et al. 2022) and garden peas (Gubler et al. 1999). To our knowledge, this is the first report of C. cladosporioides causing leaf spots of A. cordata in Korea. The identification of this pathogen will help develop strategies to efficiently control the disease in A. cordata.

Transcriptomic Analysis of Heat Stress Response in Brassica rapa L. ssp. pekinensis with Improved Thermotolerance through Exogenous Glycine Betaine.

Chinese cabbage (Brassica rapa L. ssp. pekinensis) is sensitive to high temperature, which will cause the B. rapa to remain in a semi-dormancy state. Foliar spray of GB prior to heat stress was proven to enhance B. rapa thermotolerance. In order to understand the molecular mechanisms of GB-primed resistance or adaptation towards heat stress, we investigated the transcriptomes of GB-primed and non-primed heat-sensitive B. rapa 'Beijing No. 3' variety by RNA-Seq analysis. A total of 582 differentially expressed genes (DEGs) were identified from GB-primed plants exposed to heat stress relative to non-primed plants under heat stress and were assigned to 350 gene ontology (GO) pathways and 69 KEGG (Kyoto Encyclopedia of Genes and Genomes) pathways. The analysis of the KEGG enrichment pathways revealed that the most abundantly up-regulated pathways were protein processing in endoplasmic reticulum (14 genes), followed by plant hormone signal transduction (12 genes), ribosome (8 genes), MAPK signaling pathway (8 genes), homologous recombination (7 genes), nucleotide excision repair metabolism (5 genes), glutathione metabolism (4 genes), and ascorbate and aldarate metabolism (4 genes). The most abundantly down-regulated pathways were plant-pathogen interaction (14 genes), followed by phenylpropanoid biosynthesis (7 genes); arginine and proline metabolism (6 genes); cutin, suberine, and wax biosynthesis (4 genes); and tryptophan metabolism (4 genes). Several calcium sensing/transducing proteins, as well as transcription factors associated with abscisic acid (ABA), salicylic acid (SA), auxin, and cytokinin hormones were either up- or down-regulated in GB-primed B. rapa plants under heat stress. In particular, expression of the genes for antioxidant defense, heat shock response, and DNA damage repair systems were highly increased by GB priming. On the other hand, many of the genes involved in the calcium sensors and cell surface receptors involved in plant innate immunity and the biosynthesis of secondary metabolites were down-regulated in the absence of pathogen elicitors in GB-primed B. rapa seedlings. Overall GB priming activated ABA and SA signaling pathways but deactivated auxin and cytokinin signaling pathways while suppressing the innate immunity in B. rapa seedlings exposed to heat stress. The present study provides a preliminary understanding of the thermotolerance mechanisms in GB-primed plants and is of great importance in developing thermotolerant B. rapa cultivars by using the identified DEGs through genetic modification.

Spirosoma rhododendri sp. nov., isolated from a flower of royal azalea (Rhododendron schlippenbachii).

A Gram-negative, non-motile, strictly aerobic and rod- or filamentous-shaped strain, CJU-R4T, was isolated from a flower of royal azalea (Rhododendron schlippenbachii) collected in the Republic of Korea. Strain CJU-R4T was catalase-positive and oxidase-negative, and grew at 15-33 °C (optimum, 28-20 °C), at pH 5.0-8.0 (optimum, pH 7.0-8.0), and in the presence of 0-1 % NaCl (w/v; optimum, 0 %). Strain CJU-R4T had the highest 16S rRNA gene sequence similarity to Spirosoma oryzae RHs22T (96.6 %), revealing less than 93 % sequence similarity to other type strains. Phylogenetic and phylogenomic analysis also revealed strain CJU-R4T formed a robust cluster with S. oryzae RHs22T. The major fatty acids were summed feature 3 (comprising C16 : 1 ω7c and/or C16 : 1 ω6c; 33.0 %), C16 : 1 ω5c (22.1 %), iso-C15 : 0 (12.6 %) and C16 : 0 (10.7 %). The polar lipids were composed of phosphatidylethanolamine, three unidentified aminophospholipids, one unidentified phospholipid and four unidentified lipids. Menaquinone-7 was detected as the sole respiratory quinone. The genomic DNA G+C content was 55.2 mol%. The average nucleotide identity and digital DNA-DNA hybridization values between strain CJU-R4T and Spirosoma oryzae DSM 28354T were 81.5 and 23.9 %, respectively. Based on the results of the phenotypic and genotypic analyses, strain CJU-R4T is considered to represent a novel species of the genus Spirosoma, for which the name Spirosoma rhododendri sp. nov. is proposed. The type strain is CJU-R4T (=KACC 21264T=NBRC 114513T).

Arachidicoccus terrestris sp. nov., isolated from greenhouse soil.

A Gram-stain-negative, aerobic, non-motile, rod-shaped or occasionally filamentous-shaped bacterial strain, designated 5GH13-10T, was isolated from greenhouse soil sampled in Yeoju-si, Republic of Korea. Colonies were milky-coloured, round and convex, and catalase- and oxidase-positive. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain 5GH13-10T was related to the genus Arachidicoccus and had highest 16S rRNA gene sequence identity with Arachidicoccus rhizosphaerae Vu-144T (98.4 %). The major cellular fatty acids were iso-C15 : 0, iso-C15 : 1 G, iso-C17 : 0 3-OH and summed feature 3 (C16 : 1 ω6c and/or C16 : 1 ω7c). The predominant quinone was menaquinone MK-7, and the polar lipids were composed of phosphatidylethanolamine, one unidentified aminolipid, three unidentified aminophospholipids, one unidentified phospholipid and five unidentified lipids. The genomic DNA G+C content of strain 5GH13-10T was 43.8 mol%. The average nucleotide identity values between strain 5GH13-10T and the closely related species Arachidicoccus ginsenosidivorans Gsoil 809T, Arachidicoccus rhizosphaerae Vu-144T and Archidicoccus soli KIS59-12T were 74.86, 74.74 and 69.52 %, and the digital DNA-DNA hybridization values were 20.0, 19.8 and 18.6 %, respectively. Combined phenotypic, phylogenetic and genomic data demonstrated that strain 5GH13-10T is representative of a novel species of the genus Arachidicoccus, for which we propose the name Arachidicoccus terrestris sp. nov. (type strain 5GH13-10T=KACC 18014T=NBRC 113162T).

Duganella dendranthematis sp. nov. and Massilia forsythiae sp. nov., isolated from flowers.

Two aerobic, Gram-stain-negative, motile, mesophilic, rod-shaped and catalase-positive bacterial strains designated AF9R3T and GN2-R2T were isolated from flowers collected in the Republic of Korea. Strain AF9R3T grew at 4-33 °C, pH 4.0-9.0 and with 0-1 % NaCl (w/v), and strain GN2-R2T grew at 10-33 °C, pH 4.0-9.0 and with 0-1 % NaCl (w/v). Phylogenetic analysis on the basis of 16S rRNA gene sequences indicated that strains AF9R3T and GN2-R2T belonged to the genera Duganella and Massilia, respectively, showing high sequence similarity to Duganella levis CY42WT (99.4 %) and Massilia putida 6 NM-7T (98.0 %), respectively. Both strains contained summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c) and C16 : 0 as the major fatty acids, and ubiquinone Q-8 as the predominant quinone. Strain AF9R3T had diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine, and strain GN2-R2T comprised diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and an unidentified phospholipid as the major polar lipids. Orthologous average nucleotide identity and digital DNA-DNA hybridization values of strain AF9R3T to its closest relative D. levis CY42WT were 92.6 and 56.5 %, and those of strain GN2-R2T to its closest relative M. putida 6 NM-7T were 81.4 and 24.8 %. Based on genotypic and phenotypic data, strains AF9R3T and GN2-R2T are considered to represent novel species of the genus Duganella and Massilia, respectively, for which the names Duganella dendranthematis sp. nov. (type strain AF9R3T=KACC 21258T=NBRC 114510T) and Massilia forsythiae sp. nov. (type strain GN2-R2T=KACC 21261T=NBRC 114511T) have been proposed.

Cohnella herbarum sp. nov., isolated from wild grass fermentation broth.

A novel strictly aerobic, Gram-stain-positive, rod-shaped, motile, endospore-forming, white-coloured bacterium, designated strain MFER-1T, was isolated from a fermented liquor of wild grasses sampled in the Republic of Korea. The respiratory quinone of strain MFER-1T was menaquinone-7 and its major cellular fatty acids were anteiso-C15 : 0 (55.3 %), iso-C16 : 0 (17.5 %) and C16 : 0 (12.1 %). The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, four unidentified aminophospholipids and an unidentified phospholipid. The 16S rRNA gene sequence of strain MFER-1T showed similarity of 98.1 % to 'Cohnella cholangitidis' 1 605-214T and below 98.0 % sequence similarity to the other Cohnella species. The phylogenomic tree indicated that strain MFER-1T formed a reliable cluster with several Cohnella species. The estimated genome size of strain MFER-1T was 8.52 Mb. Genomic DNA G+C content was 50.7mol%. The orthologous average nucleotide identity, digital DNA-DNA hybridization and amino acid identity values of strain MFER-1T with the most closely related species 'Cohnella cholangitidis' 1 605-214T were 78.7, 23.0 and 79.6 %, respectively. Based on the phenotypic, chemotaxonomic and phylogenetic results, strain MFER-1T should represent a novel species of the genus Cohnella, for which the name Cohnella herbarum sp. nov. is proposed, with strain MFER-1T (=KACC 21 257T=NBRC 114 628T) as the type strain.

Chryseobacterium oryzae sp. nov. and Chryseobacterium suipulveris sp. nov., isolated from Andong sikhye and pigpen dust, respectively.

Two Gram-stain-negative, aerobic, mesophilic, rod-shaped bacteria, ADR-1T and SC2-2T, were isolated from Andong sikhye and dust in a pigpen, respectively. The phylogenetic tree on the basis of 16S rRNA gene sequences showed that strains ADR-1T and SC2-2T were members of the genus Chryseobacterium and revealed the highest sequence similarities to Chryseobacterium binzhouense LM2T (97.6 %) and Chryseobacterium koreense Chj707T (94.9 %), respectively. Phylogenomic treeing using 92 core genes clearly indicated that strain ADR-1T clustered with Chryseobacterium echinoideorum CC-CZW010T, Chryseobacterium binzhouense LM2T and Chryseobacterium taihuense CGMCC 1.10941T, and strain SC2-2T formed a compact cluster with Chryseobacterium koreense CCUG 49689T. The digital DNA-DNA hybridization (dDDH) and orthologous average nucleotide identity (ANI) values of strain ADR-1T with the closely related species of the genus Chryseobacterium were ≤24.4 % and ≤80.7 %, and those of strain SC2-2T were ≤24.0 % and ≤77.8 %, respectively, which are well below the cut-off values of species discrimination (>70 % dDDH and >95-96 % ANI). The only respiratory quinone in both strains was menaquinone 6. The polar lipid profile of strain ADR-1T comprised phosphatidylethanolamine, four unidentified aminolipids and three unidentified lipids, while strain SC2-2T contained phosphatidylethanolamine, two unidentified aminolipids, one unidentified aminophospholipid and five unidentified polar lipids. The major fatty acids (>10 %) of strain ADR-1T were iso-C15 : 0, summed feature 9 (iso-C17 : 1 ω9c and/or C16 : 0 10-methyl), iso-C17 : 0 3-OH and summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c), and those of strain SC2-2T were iso-C15 : 0 and anteiso-C15 : 0. On the basis of the results of phenotypic and phylogenetic analyses, strains ADR-1T and SC2-2T represent two distinct novel species in the genus Chryseobacterium, for which the names Chryseobacterium oryzae sp. nov. (type strain ADR-1T=KACC 19311T=NBRC 113104T) and Chryseobacterium suipulveris sp. nov. (type strain SC2-2T=KACC 19313T=NBRC 113106T) are proposed.

Ferruginibacter albus sp. nov., isolated from a mountain soil, and Mucilaginibacter robiniae sp. nov., isolated from a black locust flower, Robinia pseudoacacia.

Two bacterial strains, designated KIS38-8T and F39-2T, were isolated from a mountain soil sample and a black locust flower (Robinia pseudoacacia) in Republic of Korea, respectively. The phylogenetic tree based on 16S rRNA gene sequences showed that strain KIS38-8T was classified into the genus Ferruginibacter with the highest sequence similarity to Ferruginibacter lapsinanis HU1-HG42T (96.6 %), and strain F39-2T was grouped into the genus Mucilaginibacter with the highest sequence similarity to Mucilaginibacter daejeonensis Jip 10T (97.6 %). Orthologous average nucleotide identity and digital DNA-DNA hybridization values between strain KIS38-8T and closely related Ferruginibacter strains were less than 72 and 19 %, respectively, while those values between strain F39-2T and closely related Mucilaginibacter strains were less than 73 and 21 %, respectively. The DNA G+C contents of strain KIS38-8T and F39-2T were 36.4 and 41.4 mol%, respectively. On the basis of the phenotypic and genotypic evidence, strains KIS38-8T and F39-2T are considered to represent novel species of the genus Ferruginibacter and Mucilaginibacter, respectively, for which the names Ferruginibacter albus sp. nov. (type strain KIS38-8T=KACC 17328T=NBRC 113101T) and Mucilaginibacter robiniae sp. nov. (type strain F39-2T=KACC 19733T=JCM 33062T) have been proposed.

Blue mold rot caused by Penicillium expansum on Polygonatum odoratum var. pluriflorum.

Polygonatum odoratum var. pluriflorum, called "Dunggulle", is cultivated in East Asia to obtain rhizomes. In Korea and China, these rhizomes are used in traditional teas, health beverages, and herbal medicines (Zhao and Li, 2015). In 2019, Dunggulle was cultivated in 47 hectares, with an annual output of 120M/T in Korea. In November 2020, Dunggulle rhizomes with symptoms of blue mold rot were observed at a Dunggulle farm storage (36°06'01''N, 127°29'20''E) in Geuman, Korea, where the temperature ranged from 9 to 13°C, with an average humidity of 70%. The disease incidence was 2 to 3% out of 200 rhizomes across all markets surveyed. The disease begins with a greenish blue mold covering the rhizome surface (30 to 60%), followed by rhizome rot with a dark brown color as the disease progresses. Leading edges of the rotten rhizome pieces were sterilized with 1% NaOCl and 70% ethanol and placed on MEA (Malt Extract Agar) with penicillin G and streptomycin (both 50 µg/mL). After 7 days of incubation at 25°C, greenish-blue colonies appeared, from which a monospore was isolated. A representative isolated strain was deposited in the Korean Agricultural Culture Collection (KACC, Wanju, Korea) with Acc. No. KACC 49832. The strain grew slowly on MEA at 25°C (8 to 18 mm diam. after 7 days), producing greenish blue conidia. The conidiophores were hyaline and mostly terverticillate; the branches were appressed against the main axis; the stipes were smooth-walled; and the metulae were cylindrical, 10 to 13 × 2.7 to 3.2 µm, with 6 to 10 flask-shaped phialides, measured 9 to 12 × 2.7 to 3.1 µm. The conidia were globose or subglobose and 2.8 to 4.1 µm diam. These morphological characteristics fit well with the description of Penicillium expansum (Frisvad & Samson, 2004). Genomic DNA was extracted from the mycelia of the KACC 49832 MEA plate. ITS rDNA, beta-tubulin (BenA), and calmodulin (CaM) gene regions were sequenced for identification (Houbraken et al., 2020), and the rsulting sequences were deposited in GenBank (Acc. Nos. MZ189258, MZ226688, and MZ226689, respectively). Comparison with the GenBank sequences revealed that the Korean isolate was highly similar to P. expansum (ITS rDNA 99.8%, BenA 98.6%, and CaM 97.8%). Phylogenetic results based on the maximum-likelihood analysis revealed that KACC 49832 was grouped with P. expansum. To demonstrate pathogenicity, 10 µL of conidial suspension (1.3 × 105 conidia/mL) was dropped on the surface of three Dunggulle rhizomes scratched with a syringe needle. For the control, sterile water was applied on three control rhizomes. All rhizomes were surface-sterilized as referred above before being sprayed and dried. All inoculated and control rhizomes were kept in incubator at 25°C and 90-95% relative humidity. After a week, the inoculated points showed symptoms similar to those of the initial infection, whereas controls remained symptomless. The re-isolated fungus matched KACC 49832 based on morphological and sequence analyses, thereby fulfilling Koch's postulates. The experiment was performed three times. To our knowledge, this is the first report of P. expansum as a Dunggulle rhizome pathogen in Korea. As this pathogen is known to produce patulin, a carcinogenic fungal metabolite, further studies on the mycotoxicity of the infected rhizomes are required. This report might help manage the storage conditions of Dunggulle rhizomes to prevent the blue mold rot.

Enhanced Resistance to Sclerotinia sclerotiorum in Brassica rapa by Activating Host Immunity through Exogenous Verticillium dahliae Aspf2-like Protein (VDAL) Treatment.

Sclerotinia stem rot caused by Sclerotinia sclerotiorum is one of the most destructive diseases in Brassica rapa. Verticillium dahliae Aspf2-like protein (VDAL) is a secretory protein of V. dahliae which has been shown to enhance the resistance against fungal infections in several plants. Nonetheless, the molecular mechanisms of VDAL-primed disease resistance are still poorly understood. In this study, we performed physiological, biochemical, and transcriptomic analyses of Brassica rapa in order to understand how VDAL confers resistance to S. sclerotiorumn infections in plants. The results showed that foliar application of VDAL significantly reduced the plaque area on leaves inoculated with S. sclerotiorum. It also enhanced antioxidant capacity by increasing activities of superoxide dismutase (SOD), peroxidase (POD), peroxidase (APX), glutathione reductase (GR), protoporphyrinogen oxidase (PPO), and defense-related enzymes ß-1,3-glucanase and chitinase during the infection periods. This occurred in parallel with significantly reduced relative conductivity at different periods and lower malondialdehyde (MDA) content as compared to sole S. sclerotiorum inoculation. Transcriptomic analysis showed a total of 146 (81 up-regulated and 65 down-regulated) differentially expressed genes (DEGs) in VDAL-treated leaves compared to the control. The most enriched three Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were the mitogen-activated protein kinase (MAPK) signaling pathway, plant hormone signal transduction, and plant-pathogen interaction, all of which were associated with plant immunity. DEGs associated with MAPK and hormone signal transduction pathways were ethylene response sensor ERS2, EIN3 (Ethylene Insensitive3)-binding F-box protein 2 (EBF2), ethylene-responsive transcription factor ERF94, MAPK 9 (MKK9), protein phosphatase 2C (PP2C37), auxin-responsive proteins (AUX/IAA1 and 19), serine/threonine-protein kinase CTR1, and abscisic acid receptors (PLY 4 and 5). Among the DEGs linked with the plant-pathogen interaction pathway were calmodulin-like proteins (CML5, 24, 27), PTI1-like tyrosine protein kinase 3 (Pti13) and transcription factor MYB30, all of which are known to play key roles in pathogen-associated molecular pattern (PAMP)-triggered immunity and effector-triggered immunity (ETI) for hypersensitive response (HR), cell wall reinforcement, and stomatal closure in plants. Overall, VDLA treatment triggered repression of the auxin and ABA signaling pathways and de-repression of the ethylene signaling pathways in young B. rapa seedlings to increase plant innate immunity. Our results showed that VDAL holds great potential to enhance fungal disease resistance in B. rapa crop.