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During a routine survey to establish a fungal inventory on broad-leaf deciduous trees in forests of the country, a black yeast-like species was repeatedly isolated from leaves of Acer pseudosieboldianum. Sequence comparisons using the ITS rDNA and LSU gene regions and morphological characteristics showed that the fungus isolated in this study was resided in a distinct lineage, indicating it as a novel species of Aureobasidium. This novel species is described here as Aureobasidium acericola sp. nov. The discovery of this fungus suggests that additional taxa residing in Aureobasidium are likely to be discovered in Korea and illustrates that further surveys and research should be planned to achieve this goal in the future

In 2020, severely infected fruit of pecan, Carya illinoiensis, showing distinct anthracnose symptoms were observed from pecan orchards in Uiseong (36°21'31.5"N 128°27'15.9"E) and Miryang (35°22'54.9"N 128°48'06.5"E) in South Korea. Visible symptoms occurred on fruit of the tree between June and July, which included dark, depressed and covered with irregularly shaped lesions. As the disease progressed, the lesions expanded and merged over time, leading to abscission of the fruit, which resulted in severe yield loss of pecan fruit. Of pecan varieties including Caddo, Giles and Peruque that were cultivated in each pecan orchard, Caddo appeared to be most susceptible to the disease. Estimated losses were approximately 30% and 70% for the Uiseong and Miryang pecan orchard, respectively. For pathogen isolation, ten symptomatic fruits of pecan were randomly collected and brought to the laboratory. The fruits were surface disinfested for 30 s with 70% ethanol and 1% sodium hypochlorite. These were then rinsed with sterile distilled water twice, placed in a humid chamber, and incubated at 25 ± 1°C with a photoperiod of 12 h. Acervuli filled with salmon-colored conidial masses were produced abundantly on the fruit a day after the incubation. Conidia were single celled, hyaline, cylindrical having rounded ends, smooth walls, guttulate, 15.5 to 17.7 µm long, and 3.4 to 4.8 µm wide (n = 20). Monoconidial isolates were made on 2% malt extract agar and incubated at 25°Ϲ for two weeks in the dark condition. Of those that were successfully retained, two representative isolates from each orchard were deposited in the culture collection (CDH) of the National Institute of Forest Science, Korea (Accession No. CDH2020-17-18). To ensure the identity of the pathogen, molecular identification was made based on three gene regions, the internal transcribed spacer (ITS) region of rDNA, beta-tubulin (TUB2) gene and a partial sequence of the actin (ACT), which were amplified with ITS1F/ITS4, T1/Bt2b and ACT-512F/ACT-783R, respectively (Weir et al. 2012). These were then submitted to GenBank with accession numbers of MW380423-24 for ITS, MW387129-30 for TUB2 and MW387127-28 for ACT. A BLAST search in GenBank revealed that the sequences showed high similarity to those of Colletotrichum siamense, which were identical to MT434615 and MT274214 for ITS and ACT, respectively, and 99.7% to MK967337 for TUB2. Phylogenetic analysis based on the maximum likelihood method further showed that the isolates recovered in this study clustered with C. siamense, confirming its identity. Pathogenicity was confirmed by inoculating living pecan trees. Healthy fruits from five trees were surface cleaned with cotton soaked in sterile water and air-dried. To inoculate the pathogen, three to five fruit per tree were wounded with a sterilized needle, and an aliquot of 10 μl of spore suspension (1.0 × 105 conidia/ml) of C. siamense (CDH2020-18) was dropped on each wound. To keep moisture, each treated fruit was enveloped by a plastic bag where the cotton soaked in sterile water had been placed. Controls were treated with sterile distilled water drops. The symptoms with dark, depressed and irregularly shaped lesions developed from all inoculated treatments six weeks after the inoculations, which were identical to those observed in the field. However, no symptom was observed on the control. Colletotrichum siamense was successfully re-isolated, fulfilling Koch's postulates. Taken together, it was confirmed that C. siamense is the causal agent of anthracnose on pecan. In Korea, C. siamense was reported causing anthracnose on apple, persimmon and plum (Farr and Rossman 2020). However, to our knowledge, this is the first report of anthracnose on pecan caused by C. siamense in Korea. To control the disease effectively, more attention should be paid to other regions of the country where the disease caused by the pathogen might occur.

Genetically modified (GM) plants have potential benefits in modern agriculture such as increasing yields and decreasing the use of chemicals. However, GM plants may cause unintended consequences of gene flow to indigenous plants or microbes and the detrimental effects on non-target organisms such as soil microbial communities. To investigate these possible unintended effects of GM plants, we conducted a 3-year field study using the transgenic pepper line H-15 carrying the coat protein gene (CMVP0-CP) of Cucumber mosaic virus (CMV) pathotype CMVP0, which is resistant to two CMV pathotypes CMVP0 and CMVP1, to assess its effects on soil fungal populations and communities. This study was conducted in two different fields using the plate counting method on selective media as well as polymerase chain reaction (PCR) and denaturing gradient gel electrophoresis analyses. In addition, we examined potential gene flow of CMVP0-CP from the transgenic line H-15 into the soil environment, including microflora, in the tested fields. We found little differences in the influence of the line H-15 compared with the inbred line P2377 (non-transgenic control) on the populations of fungal groups (total fungi, Aspergillus and Penicillium spp., Fusarium spp., and Trichoderma spp.), distribution of fungal genera, and fungal communities. Further, coat protein gene (CMVP0-CP) (PCR detection limit in soil = 1–10 pg) of the transgenic line was not detected in the soil samples of the tested fields. Taken together, the transgenic pepper line had no distinct impact on fungal populations and communities with no detection of CMVP0-CP gene flow from the transgenic line into the soil environment of the fields. Thus, the transgenic line H-15 might be little significantly harmful from the perspective of preserving soil fungal diversity; it could be a potential candidate for developing a commercial cultivar.

Flavobacterium anhuiense (previously identified as Flavobacterium johnsoniae) strain GSE09 is a volatile-producing bacterium that exhibits significant biocontrol activity against an oomycete pathogen, Phytophthora capsici, on pepper plants. Here, we report the complete genome sequence data of strain GSE09, isolated from surface-sterilized cucumber root. The genome consists of a circular 5,109,718-bp chromosome with a G + C content of 34.30%. A total of 4,138 complete coding sequences including 15 rRNA, 66 tRNA, 3 ncRNA, and 51 pseudogene sequences were retrieved. Thus, the genome sequence data of F. anhuiense GSE09 may facilitate the elucidation of many biological traits related to the biocontrol against plant pathogens. Keywords: Biocontrol, Complete genome sequence, EggNOG analysis, Flavobacterium anhuiense, Phytophthora capsici

Garlic (Allium sativum L.) is one of the oldest horticultural crops and an important element for cuisines worldwide, especially in Korea. After isolating several black aspergilli from brownish lesions with black spores on garlic bulbs, we identified a representative isolate GL-125 through molecular analysis of its internal transcribed spacer (ITS)1-5.8S rRNA-ITS2 region, β-tubulin gene, and calmodulin gene. Morphological features of GL-125 were also compared with those of the Aspergillus awamori type strain NRRL 4948T. As a result, GL-125 was identified as A. awamori by neighbor-joining and maximum-likelihood methods with the examined gene sequences. The macro-morphological (colony growth and color) and micro-morphological (stripes, vesicles, metulae, phialides, and conidia) features of GL-125 were also similar, compared with those of NRRL 4849T. Furthermore, we conducted pathogenicity tests for GL-125 and NRRL 4948T against garlic cloves, using pin-prick inoculation with spore suspensions. Both GL-125 and NRRL 4948T were pathogenic on garlic cloves producing brown to pinkish sunken, water-soaking lesions with white mycelia and black spores in the center. These isolates were successfully re-isolated from the lesions, thereby fulfilling Koch's postulates, whereas no fungal mycelia were isolated from water-inoculated cloves (control). The identities of the re-isolated mycelia were re-confirmed by sequence analyses of the previously examined genes. To the best of our knowledge, this is the first report of A. awamori as a fungal pathogen of garlic.

The effects of methyl jasmonate (MJ) and sodium nitroprusside (SNP) on ginsenoside production were investigated in ginseng adventitious roots. The role of nitric oxide (NO) production and reactive oxygen species (ROS) was also elucidated. Different concentrations of SNP were applied to ginseng adventitious roots. The highest accumulation of ginsenoside was recorded for 200 μM of SNP. Ginsenoside biosynthesis-related genes were highly induced by 100 μM MJ in combination with 200 μM of SNP compared to MJ alone , which subsequently led to higher ginsenoside accumulation after 72 h. For the first time, a full length NO-associated (NOA) cDNA clone was isolated and characterized from the embryogenic callus of ginseng with predicted localization in the mitochondria. The open reading frame was 1626 bp with a deduced amino acid sequence of 541 residues, which shared a high degree of homology with the NO associated protein from Solanum tuberosum. PgNOA showed higher transcript levels in treated roots with combined MJ and SNP compared to MJ alone. Increased production of NO was observed after addition of SNP to MJ-treated samples. There was no difference in transcript levels for lipoxygenase, a key enzyme in the jasmonic acid pathway in MJ- and SNP-treated roots compared to roots treated with MJ alone. The superoxide dismutase 1 (SOD1) gene was highly responsive to MJ and SNP treatment compared to treatment with MJ alone. SOD1 catalyzes the dismutation of toxic superoxide radicals into either molecular oxygen or hydrogen peroxide (H2O2) resulting in higher production of these products. H2O2 can be subsequently converted to water by the action of ascorbate peroxidase (APX), which was highly expressed in combined treatment with MJ and SNP compared to treatment with MJ alone. The results obtained here suggest that SNP enhanced the elicitation power of MJ for increased ginsenoside accumulation. Moreover, this process was mediated by a complex signal transduction network including NO biosynthesis and ROS generation.

The nutrient contents of pumpkins depend on many factors, including the species, climate, soil type, and plant part. The nutritional compositions of five pumpkin cultivars (red boujjang, mini hong, mini gold, boujjang, and yakhobak) were investigated. To analyze the nutrient contents of the edible parts, the other parts (seeds, skin, and stem) of each pumpkin were removed. The results showed that the proximate compositions of the edible parts of the pumpkins ranged from 74 to 87 g per 100 g for moisture, 1.6 to 3.2 g per 100 g for crude protein, 10.1 to 20.7 g per 100 g for carbohydrate content, and 2.0 to 3.4 g per 100 g for total dietary fiber. The proximate contents of the pumpkin samples were not significantly different. The thiamine contents of the pumpkins, except for red boujjang, varied from 0.03 to 0.15 mg per 100 g, but that of red boujjang had the highest level (0.60 mg per 100 g). The vitamin C contents of the pumpkins, except for boujjang, ranged from 13.0 to 14.0 mg per 100 g, but that of boujjang was the highest (49.0 mg per 100 g). In particular, yakhobak showed the highest total carotenoid and folate levels (279.5 and 74.0 μg per 100 g, respectively). These results will be useful for coming up with better pumpkin varieties through breeding, and established the nutrient compositions of pumpkins.

Ginsenosides are glycosylated triterpenes that are considered to be important pharmaceutically active components of the ginseng (Panax ginseng ‘Meyer’) plant, which is known as an adaptogenic herb. However, the regulatory mechanism underlying the biosynthesis of triterpene saponin through the mevalonate pathway in ginseng remains unclear. In this study, we characterized the role of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR) concerning ginsenoside biosynthesis. Through analysis of full-length complementary DNA, two forms of ginseng HMGR (PgHMGR1 and PgHMGR2) were identified as showing high sequence identity. The steady-state mRNA expression patterns of PgHMGR1 and PgHMGR2 are relatively low in seed, leaf, stem, and flower, but stronger in the petiole of seedling and root. The transcripts of PgHMGR1 were relatively constant in 3- and 6-year-old ginseng roots. However, PgHMGR2 was increased five times in the 6-year-old ginseng roots compared with the 3-year-old ginseng roots, which indicates that HMGRs have constant and specific roles in the accumulation of ginsenosides in roots. Competitive inhibition of HMGR by mevinolin caused a significant reduction of total ginsenoside in ginseng adventitious roots. Moreover, continuous dark exposure for 2 to 3 d increased the total ginsenosides content in 3-year-old ginseng after the dark-induced activity of PgHMGR1. These results suggest that PgHMGR1 is associated with the dark-dependent promotion of ginsenoside biosynthesis. We also observed that the PgHMGR1 can complement Arabidopsis (Arabidopsis thaliana) hmgr1-1 and that the overexpression of PgHMGR1 enhanced the production of sterols and triterpenes in Arabidopsis and ginseng. Overall, this finding suggests that ginseng HMGRs play a regulatory role in triterpene ginsenoside biosynthesis.

Species of the genus Chryseobacterium belonging to the family Flavobacteriaceae are nonmotile, yellow-pigmented, and rod-shaped bacteria, some of which were frequently isolated from soil or plant-related materials. Here, we present draft genome sequences of three type strains of Chryseobacterium , which contain genes related to plant growth promotion, colonization, or stress adaptation.

A representative isolate KU53 of the predominant Penicillium species was obtained from rice samples from rice processing complexes of National Agricultural Cooperative Federation in Korea. In this study, isolate KU53 was identified by its morphological and molecular characteristics. The macro- and microscopic characteristics of isolate KU53 were compared with the P. fellutanum reference isolate KCTC16913 on different media; isolate KU53 was generally identical to those of the reference isolate KCTC16913. In a molecular-based identification, the β-tubulin and translation elongation factor 1-alpha sequences of isolate KU53 was most closely related to those of P. fellutanum. Thus, isolate KU53 from stored rice could be identified as P. fellutanum, some isolates of which are known to produce mycotoxin-related metabolites. To our knowledge, this is the first detection of P. fellutanum from stored rice in Korea.

We evaluated microbial populations and aflatoxin production in unhulled and white rice from rice processing complexes of the National Agricultural Cooperative Federation in five regions in Korea and identified three predominant Aspergillus species. Fungal and bacterial populations in rice samples were significantly different between regions in 2007. Aflatoxins were also detected and varied at the levels of 2.45 - 3.43 ng per g unhulled rice grain and 1.29 - 2.09 ng per g white rice grain. Unhulled rice generally detected higher level of aflatoxins than white rice regardless of sampling regions; however, no significant differences were found in Anseong and Cheonan in 2005 and Cheonan and Gimpo in 2007. Aflatoxin production between sampling regions was not different regardless of rice type and sampling year. Although the fungal diversity was highly distinct from region to region, three Aspergillus isolates were predominant in the rice samples; thus, representative isolates AC317, AF57, and AF8 were selected and identified based on their morphological and molecular characteristics. Consequently, isolates AC317, AF57, and AF8 were identified as A. candidus, A. flavus, and A. fumigatus, respectively. These fungi can produce mycotoxins that are harmful for consumers and thus it is important to detect and reduce the population of storage fungi in rice.

We have previously obtained a representative isolate KU101 of the predominant Penicillium species from rice under indoor storage conditions. In this study we attempted to characterize isolate KU101 using its morphological and molecular characteristics. When the micro- and macroscopic characteristics of isolate KU101 were compared with the P. islandicum reference isolate KCCM 34763, isolate KU101 was generally identical to those of isolate KCCM 34763, however, isolate KU101 grew faster and produced more orange to red pigments than isolate KCCM 34763. In a molecular-based identification, the nuclear sequence of the ITS1-5.8S-ITS2 region of isolate KU101 was most closely related to that of P. islandicum. Therefore, these results indicated that isolate KU101 from stored rice could be identified as P. islandicum, some isolates of which are known to produce mycotoxins.

In this study, the sensitivity of Magnaporthe oryzae isolates from different geographic areas in Korea to two phosphorothiolate (PTL) fungicides, edifenphos and iprobenfos, was determined. A total of 1080 M. oryzae isolates were collected from rice-cultivating fields in 11 locations throughout Korea in 1997 and 1998. The minimum inhibitory concentrations (MICs) of edifenphos (20 μg a.i. ml −1 ) and iprobenfos (55 μg a.i. ml −1 ) against seven representative sensitive isolates of M. oryzae were determined from the dose-response curves, and the MICs were then used as single discriminatory concentrations for the detection of fungicide resistance. Of the 1080 tested isolates, the isolates less sensitive to edifenphos and iprobenfos were 57 and 84%, respectively, and 53% of the isolates were less sensitive to both fungicides. Approximately 11% of all tested isolates showed no growth at the MICs of the tested fungicides. Isolates with a relative mycelial growth of 0.05 to edifenphos occurred at the greatest frequency (33%); isolates with a relative growth of 0.3 to iprobenfos occurred at the greatest frequency (23%). The frequency distribution of isolates sensitive to either edifenphos or iprobenfos varied with geographic location. The two-sample median test yielded high medians in the Kwangju and Chonju isolates for edifenphos, and in the Kwangju, Donghae, and Yangyang isolates for iprobenfos, but low medians in the Kangnung isolates for edifenphos and in the Kangnung, Gwangju, and Chunchon isolates for iprobenfos, respectively, as compared to the isolates from the other locations. Analysis of Spearman's rank correlation test showed a significantly positive relationship ( r = 0.490, P M. oryzae populations collected from different geographic areas in Korea, and isolates less sensitive to these fungicides exhibit cross-resistance with each other.

This research was conducted to evaluate fungal and bacterial populations in unhulled and brown rice under indoor storage conditions, and to examine the relationship between microbial populations and environmental conditions such as temperature and relative humidity. The temperature and relative humidity of the storage room ranged from and 23.3% to 44.2%, respectively. Total fungal and bacterial populations remained relatively stable over the storage period. Predominant fungi included Aspergillus candidus, A. flavus, A. fumigatus, and Penicillium spp.; the predominant bacteria were Bacillus, Microbacterium, Sphingomonas, and Methylobacterium spp. Total fungi and bacteria were not significantly correlated with either unhulled (r

This study was to examine the efficacy of a root-dipping application of antagonistic bacterial strains for the control of Phytophthora blight of pepper caused by P. capcisi, and to evaluate their plant growth-promoting effects in the field in 2005 and 2006. The candidate antagonistic rhizobacterial strains CCR04, CCR80, GSE09, ISE13, and ISE14 were treated by dipping plant roots with bacterial suspensions prior to transplanting. The candidate rhizobacterial strains CCR04, CCR80, GSE09, and ISE14 significantly (P

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Stored rice was collected from rice processing complexes of National Agricultural Cooperative Federation of 11 regions in Korea to evaluate the occurrence of fungi and bacteria and to identify the predominant fungi and bacteria to the genus levels. Most rice samples generally produced the higher levels of fungi and bacteria than white rice. The occurrence of fungi and bacteria varied in various locations of Korea. Among fungi observed, Aspergillus spp. and Penicillium spp. were dominant in the samples and Aspergillus spp. were observed more frequently than Penicillium spp. Predominant bacteria from rice and white rice samples tentatively belonged to the Genus Bacillus, Pectobacterium, Pantoea, and Microbacterium according to BIOLOG and FAME analyses. The results of this study showed that rice in Korea was contaminated in a relatively high level by two dominant storage fungi such as Aspergillus spp. and Penicillium spp. In addition, occurrence of mycotoxins in rice by the fungi could be possible and thus it is necessary to control the storage fungi.

An unusual lon mutation (called lonR9) is dominant over the wild-type gene, which encodes the ATP-dependent protease La (Lon) in Escherichia coli, when present in multicopy plasmids. Here, we cloned and sequenced lonR9, and showed that the mutant gene carries a single point mutation in its open reading frame, which leads to replacement of Glu614 by Lys. The LonR9 protein and its poly-His-tagged form were purified to apparent homogeneity. Both of the purified proteins were capable of inhibiting the ATP-dependent proteolysis and the protein-activated ATP hydrolysis by protease La. Furthermore, the His-tagged LonR9 protein was found to form mixed oligomeric complexes with protease La, upon analysis by chromatography on a metal-chelating column. These results suggest that the phenotypic dominance of the lonR9 mutant is due to the formation of mixed oligomeric complexes between LonR9 and protease La, in which the defective components prevent the function of the wild-type subunits.

This study was designed to investigate the possibility that mtDNA mutations might arise in inflammatory or chronically damaged nasal polyp tissue from 23 patients. Thirteen patients (57%) displayed nasal polyp tissue-specific mtDNA mutations in the hypervariable segment of the control region and cytochrome b gene, which were not found in the corresponding blood cells and/or adjacent normal tissue. Nasal polyp tissue-specific length heteroplasmic mutations were also detected in nucleotide position (np) 303–315 homopolymeric poly C track (39%), np 514–523 CA repeats (17%) and np 16184–16193 poly C track (30%). The average mtDNA copy number was about three times higher in nasal polyp tissue than in the corresponding peripheral blood cells and adjacent non-polyp tissues. The level of reactive oxygen species (ROS) was significantly higher in the nasal polyp tissues compared to those from the corresponding samples. High level of ROS in nasal polyp tissue may contribute to development of mtDNA mutations, which may play a crucial role in the vicious cycle of pathophysiology of nasal polyps.

HslVU is an ATP-dependent protease consisting of two multimeric components: the HslU ATPase and the HslV peptidase. SulA, which is an inhibitor of cell division and has high tendency of aggregation, is degraded by HslVU protease. Here we show that HslU plays a role not only as a regulatory component for the HslV-mediated proteolysis but also as a molecular chaperone. Purified HslU prevented aggregation of SulA in a concentration-dependent fashion. This chaperone activity required oligomerization of HslU subunits, which could be achieved by ATP-binding or in the presence of high HslU protein concentrations. hsl mutation reduced the SulA-mediated inhibition of cell growth and this effect could be reversed upon overproduction of HslU, suggesting that HslU promotes the ability of SulA to block cell growth through its chaperone function. Thus, HslU appears to have two antagonistic functions: one as a chaperone for promotion of the ability of SulA in cell growth inhibition by preventing SulA aggregation and the other as the regulatory component for elimination of SulA by supporting the HslV-mediated degradation.

HslVU is an ATP-dependent protease consisting of two multimeric components, the HslU ATPase and the HslV peptidase. To gain an insight into the role of HslVU in regulation of cell division, the reconstituted enzyme was incubated with SulA, an inhibitor of cell division in Escherichia coli, or its fusion protein with maltose binding protein (MBP). HslVU degraded both proteins upon incubation with ATP but not with its non-hydrolyzable analog, ATPγS, indicating that the degradation of SulA requires ATP hydrolysis. The pulse-chase experiment using an antibody raised against MBP-SulA revealed that the stability of SulA increased in hsl mutants and further increased in lon/hsl double mutants, indicating that SulA is an in vivo substrate of HslVU as well as of protease La (Lon). These results suggest that HslVU in addition to Lon plays an important role in regulation of cell division through degradation of SulA.

Background: The effect of methyl jasmonate (MJ) on ginsenoside production in different organs of ginseng (Panax ginseng Meyer) was evaluated after the whole plant was dipped in an MJ-containing solution. MJ can induce the production of antioxidant defense genes and secondary metabolites in plants. In ginseng, MJ treatment in adventitious root resulted in the increase of dammarenediol synthase expression but a decrease of cycloartenol synthase expression, thereby enhancing ginsenoside biosynthesis. Although a previous study focused on the application of MJ to affect ginsenoside production in adventitious roots, we conducted our research on entire plants by evaluating the effect of exogenous MJ on ginsenoside production with the aim of obtaining new approaches to study ginsenoside biosynthesis response to MJ in vivo. Methods: Different parts of MJ-treated ginseng plants were analyzed for ginsenoside contents (fine root, root body, epidermis, rhizome, stem, and leaf) by high-performance liquid chromatography. Results: The total ginsenoside content of the ginseng root significantly increased after 2 d of MJ treatment compared with the control not subjected to MJ. Our results revealed that MJ treatment enhances ginsenoside production not in the epidermis but in the stele of the ginseng root, implying transportation of ginsenosides from the root vasculature to the epidermis. Application of MJ enhanced protopanaxadiol (PPD)-type ginsenosides, whereas chilling treatment induced protopanaxatriol (PPT)-type ginsenosides. Conclusion: These findings indicate that the production of PPD-type and PPT-type ginsenosides is differently affected by abiotic and biotic stresses in the ginseng plant, and they might play different defense mechanism roles.