Didymella gigantis sp. nov. Causing Leaf Spot in Korean Angelica

During a disease survey in October 2019, leaf spot symptoms with a yellow halo were observed on Korean angelica (Anglica gigas) plants grown in fields in Pyeongchang, Gangwon Province, Korea. Incidence of diseased leaves of the plants in the investigated fields ranged from 10% to 60%. Morphological and cultural characteristics of two single-spore isolates from the leaf lesions indicated that they belonged to the genus Didymella. Molecular phylogenetic analyses using combined sequences of LSU, ITS, TUB2, and RPB2 regions showed distinct clustering of the isolates from other Didymella species. In addition, the morphological and cultural characteristics of the isolates were somewhat different from those of closely related Didymella spp. Therefore, the novelty of the isolates was proved based on the investigations. Pathogenicity of the novel Didymella species isolates was confirmed on leaves of Korean angelica plants via artificial inoculation. This study reveals that Didymella gigantis sp. nov. causes leaf spot in Korean angelica.

Didymella acutilobae sp. nov. Causing Leaf Spot and Stem Rot in Angelica acutiloba

During disease surveys of Angelica acutiloba plants in Korea, leaf spot symptoms were observed in a field in Andong in July 2019, and stem rot symptoms in vinyl greenhouses in Yangpyeong in April 2020. Incidence of leaf spot and stem rot of the plants ranged from 10 to 20% and 5 to 30%, respectively. Morphological and cultural characteristics of fungal isolates from the leaf spot and stem rot symptoms fitted into those of the genus Phoma. Molecular phylogenetic analyses of two single-spore isolates from the symptoms using concatenated sequences of LSU, ITS, TUB2, and RPB2 genes authenticated an independent cluster from other Didymella (anamorph: Phoma) species. Moreover, the isolates showed different morphological and cultural characteristics in comparison to closely related Didymella species. These discoveries confirmed the novelty of the isolates. Pathogenicity of the novel Didymella species isolates was substantiated on leaves and stems of A. acutiloba through artificial inoculation. Thus, this study reveals that Didymella acutilobae sp. nov. causes leaf spot and stem rot in Angelica acutiloba.

Current Studies on Bakanae Disease in Rice: Host Range, Molecular Identification, and Disease Management

The seed borne disease such as bakanae is difficult to control. Crop yield loss caused by bakanae depending on the regions and varieties grown, ranging from 3.0% to 95.4%. Bakanae is an important disease of rice worldwide and the pathogen was identified as Fusarium fujikuroi Nirenberg (teleomorph: Gibberella fujikuroi Sawada). Currently, four Fusaria (F. fujikuroi, F. proliferatum, F. verticillioides and F. andiyazi) belonging to F. fujikuroi species complex are generally known as the pathogens of bakanae. The infection occurs through both seed and soil-borne transmission. When infection occurs during the heading stage, rice seeds become contaminated. Molecular detection of pathogens of bakanae is important because identification based on morphological and biological characters could lead to incorrect species designation and time-consuming. Seed disinfection has been studied for a long time in Korea for the management of the bakanae disease of rice. As seed disinfectants have been studied to control bakanae, resistance studies to chemicals have been also conducted. Presently biological control and resistant varieties are not widely used. The detection of this pathogen is critical for seed certification and for preventing field infections. In South Korea, bakanae is designated as a regulated pathogen. To provide highly qualified rice seeds to farms, Korea Seed & Variety Service (KSVS) has been producing and distributing certified rice seeds for producing healthy rice in fields. Therefore, the objective of the study is to summarize the recent progress in molecular identification, fungicide resistance, and the management strategy of bakanae.

Anti-Oomycete Activity and Pepper Root Colonization of Pseudomonas plecoglossicida YJR13 and Pseudomonas putida YJR92 against Phytophthora capsici

Previously, Pseudomonas plecoglossicida YJR13 and Pseudomonas putida YJR92 from a sequential screening procedure were proven to effectively control Phytophthora blight caused by Phytophthora capsici. In this study, we further investigated the anti-oomycete activities of these strains against mycelial growth, zoospore germination, and germ tube elongation of P. capsici. We also investigated root colonization ability of the bacterial strains in square dishes, including cell motility (swimming and swarming motilities) and biofilm formation. Both strains significantly inhibited mycelial growth in liquid and solid V8 juice media and M9 minimal media, zoospore germination, and germ tube elongation compared with Bacillus vallismortis EXTN-1 (positive biocontrol strain), Sphingomonas aquatilis KU408 (negative biocontrol strain), and MgSO4 solution (untreated control). In diluted (nutrient-deficient) V8 juice broth, the tested strain populations were maintained at >108 cells/ml, simultaneously providing mycelial inhibitory activity. Additionally, these strains colonized pepper roots at a 106 cells/ml concentration for 7 days. The root colonization of the strains was supported by strong swimming and swarming activities, biofilm formation, and chemotactic activity towards exudate components (amino acids, organic acids, and sugars) of pepper roots. Collectively, these results suggest that strains YJR13 and YJR92 can effectively suppress Phytophthora blight of pepper through direct anti-oomycete activities against mycelial growth, zoospore germination and germ tube elongation. Bacterial colonization of pepper roots may be mediated by cell motility and biofilm formation together with chemotaxis to root exudates.

Antifungal Activity of Thymol against Aspergillus awamori and Botrytis aclada Isolated from Stored Onion Bulbs

The antifungal activity of thymol against Aspergillus awamori F23 and Botrytis aclada F15 in onions was examined through direct treatment with amended media and gaseous treatment with I-plates (plastic plates containing central partitions). The protective and curative control efficacy of thymol was examined 24 h before and after the inoculation of onion bulbs with the fungal isolates. Mycelial growth, sporulation, and spore germination of the isolates were inhibited on potato dextrose agar amended with various concentrations of thymol or acetic acid (positive control). Overall, thymol produced a stronger inhibitory effect on the mycelial growth and development of the isolates than acetic acid. Following gaseous treatment in I-plates, mycelial growth, sporulation, and spore germination of the isolates were inhibited at higher concentrations of thymol or acetic acid; however, acetic acid showed a little effect on the sporulation and spore germination of the isolates. Following the treatment of onion bulbs with 1000 mg L^-1 of thymol 24 h before and after fungal inoculation, lesion diameter was greatly reduced compared with that following treatment with 0.5% ethanol (solvent control). Onion bulbs sprayed with thymol 24 h before fungal inoculation generally showed reduced lesion diameters by isolate F23 but not in isolate F15 compared with those sprayed 24 h after fungal inoculation. Collectively, thymol effectively inhibited the growth and development of A. awamori and B. aclada on amended media and in I-plates. In addition, spraying or fumigation of thymol is more desirable for effectively controlling these postharvest fungal pathogens during long-term storage conditions.

Biological Control of Oomycete Soilborne Diseases Caused by Phytophthora capsici, Phytophthora infestans, and Phytophthora nicotianae in Solanaceous Crops

Oomycete pathogens that belong to the genus Phytophthora cause devastating diseases in solanaceous crops such as pepper, potato, and tobacco, resulting in crop production losses worldwide. Although the application of fungicides efficiently controls these diseases, it has been shown to trigger negative side effects such as environmental pollution, phytotoxicity, and fungicide resistance in plant pathogens. Therefore, biological control of Phytophthora-induced diseases was proposed as an environmentally sound alternative to conventional chemical control. In this review, progress on biological control of the soilborne oomycete plant pathogens, Phytophthora capsici, Phytophthora infestans, and Phytophthora nicotianae, infecting pepper, potato, and tobacco is described. Bacterial (e.g., Acinetobacter, Bacillus, Chryseobacterium, Paenibacillus, Pseudomonas, and Streptomyces) and fungal (e.g., Trichoderma and arbuscular mycorrhizal fungi) agents, and yeasts (e.g., Aureobasidium, Curvibasidium, and Metschnikowia) have been reported as successful biocontrol agents of Phytophthora pathogens. These microorganisms antagonize Phytophthora spp. via antimicrobial compounds with inhibitory activities against mycelial growth, sporulation, and zoospore germination. They also trigger plant immunity-inducing systemic resistance via several pathways, resulting in enhanced defense responses in their hosts. Along with plant protection, some of the microorganisms promote plant growth, thereby enhancing their beneficial relations with host plants. Although the beneficial effects of the biocontrol microorganisms are acceptable, single applications of antagonistic microorganisms tend to lack consistent efficacy compared with chemical analogues. Therefore, strategies to improve the biocontrol performance of these prominent antagonists are also discussed in this review.

Suppression of Ripe Rot on 'Zesy002' Kiwifruit with Commercial Agrochemicals

Ripe rot caused by Botryosphaeria dothidea is one of the serious diseases of postharvest kiwifruit. In order to control ripe rot on Actinidia chinensis cultivar 'Zesy002', several commercial agrofungicides were selected by an antifungal test on an artificial medium. Furthermore, disease suppression by the selected fungicides was evaluated on the kiwifruit by inoculation with a conidial suspension of B. dothidea. On the artificial media containing boscalid + fludioxonil was shown to be the most effective antifungal activity. However, in the bio-test pyraclostrobin + boscalid and iminoctadine-tris were the most effective agrochemicals on the fruit. On the other hand, the infection structures of B. dothidea on kiwifruit treated with pyraclostrobin + boscalid were observed with a fluorescent microscope. Most of the fungal conidia had not germinated on the kiwifruit treated with the agrochemicals whereas on the untreated fruit the fungal conidia had mostly germinated. Electron microscopy of the fine structures showed morphological changes to the conidia and branch of hyphae on the kiwifruit pre-treated with pyraclostrobin + boscalid, indicating its suppression effect on fungal growth. Based on this observation, it is suggested that ripe rot by B. dothidea may be suppressed through the inhibition of conidial germination on the kiwifruit treated with the agrochemicals.

In Vitro and In Vivo Inhibitory Effects of Gaseous Chlorine Dioxide against Fusarium oxysporum f. sp. batatas Isolated from Stored Sweetpotato: Study II

Chlorine dioxide (ClO₂) has been widely used as an effective disinfectant to control fungal contamination during postharvest crop storage. In this study, Fusarium oxysporum f. sp. batatas SP-f6 from the black rot symptom of sweetpotato was isolated and identified using phylogenetic analysis of elongation factor 1-α gene; we further examined the in vitro and in vivo inhibitory activities of ClO₂ gas against the fungus. In the in vitro medium tests, fungal population was significantly inhibited upon increasing the concentration and exposure time. In in vivo tests, spore suspensions were drop-inoculated onto sweetpotato slices, followed by treatment using various ClO₂ concentrations and treatment times to assess fungus-induced disease development in the slices. Lesion diameters decreased at the tested ClO₂ concentrations over time. When sweetpotato roots were dip-inoculated in spore suspensions prior to treatment with 20 and 40 ppm of ClO₂ for 0-60 min, fungal populations significantly decreased at the tested concentrations for 30-60 min. Taken together, these results showed that ClO₂ gas can effectively inhibit fungal growth and disease development caused by F. oxysporum f. sp. batatas on sweetpotato. Therefore, ClO₂ gas may be used as a sanitizer to control this fungus during postharvest storage of sweetpotato.

Complete genome sequence data of Flavobacterium anhuiense strain GSE09, a volatile-producing biocontrol bacterium isolated from cucumber (Cucumis sativus) root

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.

In Vitro and In Vivo Inhibitory Effects of Gaseous Chlorine Dioxide Against Diaporthe batatas Isolated from Stored Sweetpotato

Chlorine dioxide (ClO₂) can be used as an alternative disinfectant for controlling fungal contamination during postharvest storage. In this study, we tested the in vitro and in vivo inhibitory effects of gaseous ClO₂ against Diaporthe batatas SP-d1, the causal agent of sweetpotato dry rot. In in vitro tests, spore suspensions of SP-d1 spread on acidified potato dextrose agar were treated with various ClO₂ concentrations (1-20 ppm) for 0-60 min. Fungal growth was significantly inhibited at 1 ppm of ClO₂ treatment for 30 min, and completely inhibited at 20 ppm. In in vivo tests, spore suspensions were drop-inoculated onto sweetpotato slices, followed by ClO₂ treatment with different concentrations and durations. Lesion diameters were not significantly different between the tested ClO₂ concentrations; however, lesion diameters significantly decreased upon increasing the exposure time. Similarly, fungal populations decreased at the tested ClO₂ concentrations over time. However, the sliced tissue itself hardened after 60-min ClO₂ treatments, especially at 20 ppm of ClO₂. When sweetpotato roots were dip-inoculated in spore suspensions for 10 min prior to treatment with 20 and 40 ppm of ClO₂ for 0-60 min, fungal populations decreased with increasing ClO₂ concentrations. Taken together, these results showed that gaseous ClO₂ could significantly inhibit D. batatas growth and dry rot development in sweetpotato. Overall, gaseous ClO₂ could be used to control this fungal disease during the postharvest storage of sweetpotato.

Chryseobacterium phosphatilyticum sp. nov., a phosphate-solubilizing endophyte isolated from cucumber (Cucumis sativus L.) root

A bacterial strain, designated as ISE14^T, with Gram-stain-negative and non-motile rod-shaped cells, was isolated from the root of a cucumber plant collected in a field in Iksan, Republic of Korea and was characterized using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain ISE14^T represented a member of the genus Chryseobacterium and was closely related to Chryseobacterium viscerum 687B-08^T (16S rRNA gene sequence similarity of 98.50 %), Chryseobacterium lactis NCTC 11390^T (98.49 %), Chryseobacterium ureilyticum F-Fue-04IIIaaaa^T (98.49 %) and Chryseobacterium oncorhynchi 701B-08^T (98.04 %). Average nucleotide identity values between genome sequences of strain ISE14^T and the closely related species ranged from 81.44 to 83.15 %, which were lower than the threshold of 95 % (corresponding to a DNA-DNA hybridization value of 70 %). The DNA G+C content of strain ISE14^T was 36.3 mol%. The dominant fatty acids were iso-C15 : 0, summed feature 9 (iso-C17 : 1ω9c and/or C16 : 0 10-methyl), summed feature 3 (iso-C15 : 0 2-OH and/or C16 : 1ω7c) and iso-C17 : 0 3-OH. The major polar lipids were phosphatidylethanolamine, three unidentified aminolipids and eight unidentified lipids; the predominant respiratory quinone was MK-6. On the basis of the evidence presented in this study, strain ISE14^T can be distinguished from closely related species belonging to the genus Chryseobacterium. Thus, strain ISE14^T is a novel species of the genus Chryseobacterium, for which the name Chryseobacteriumphosphatilyticum sp. nov. is proposed. The type strain is ISE14^T (=KACC 19820^T=JCM 32876^T).

Effect of Temperature and Relative Humidity on Growth of Aspergillus and Penicillium spp. and Biocontrol Activity of Pseudomonas protegens AS15 against Aflatoxigenic Aspergillus flavus in Stored Rice Grains

In this study, we evaluated the effect of different temperatures (10, 20, 30, and 40 °C) and relative humidities (RHs; 12, 44, 76, and 98%) on populations of predominant grain fungi (Aspergillus candidus, Aspergillus flavus, Aspergillus fumigatus, Penicillium fellutanum, and Penicillium islandicum) and the biocontrol activity of Pseudomonas protegens AS15 against aflatoxigenic A. flavus KCCM 60330 in stored rice. Populations of all the tested fungi in inoculated rice grains were significantly enhanced by both increased temperature and RH. Multiple linear regression analysis revealed that one unit increase of temperature resulted in greater effects than that of RH on fungal populations. When rice grains were treated with P. protegens AS15 prior to inoculation with A. flavus KCCM 60330, fungal populations and aflatoxin production in the inoculated grains were significantly reduced compared with the grains untreated with strain AS15 regardless of temperature and RH (except 12% RH for fungal population). In addition, bacterial populations in grains were significantly enhanced with increasing temperature and RH, regardless of bacterial treatment. Higher bacterial populations were detected in biocontrol strain-treated grains than in untreated control grains. To our knowledge, this is the first report showing consistent biocontrol activity of P. protegens against A. flavus population and aflatoxin production in stored rice grains under various environmental conditions of temperature and RH.

Biocontrol Activity of Volatile-Producing Bacillus megaterium and Pseudomonas protegens Against Aspergillus and Penicillium spp. Predominant in Stored Rice Grains: Study II

In our previous studies, Bacillus megaterium KU143, Microbacterium testaceum KU313, and Pseudomonas protegens AS15 have been shown to be antagonistic to Aspergillus flavus in stored rice grains. In this study, the biocontrol activities of these strains were evaluated against Aspergillus candidus, Aspergillus fumigatus, Penicillium fellutanum, and Penicillium islandicum, which are predominant in stored rice grains. In vitro and in vivo antifungal activities of the bacterial strains were evaluated against the fungi on media and rice grains, respectively. The antifungal activities of the volatiles produced by the strains against fungal development and population were also tested using I-plates. In in vitro tests, the strains produced secondary metabolites capable of reducing conidial germination, germ-tube elongation, and mycelial growth of all the tested fungi. In in vivo tests, the strains significantly inhibited the fungal growth in rice grains. Additionally, in I-plate tests, strains KU143 and AS15 produced volatiles that significantly inhibited not only mycelial growth, sporulation, and conidial germination of the fungi on media but also fungal populations on rice grains. GC-MS analysis of the volatiles by strains KU143 and AS15 identified 12 and 17 compounds, respectively. Among these, the antifungal compound, 5-methyl-2-phenyl-1H-indole, was produced by strain KU143 and the antimicrobial compounds, 2-butyl 1-octanal, dimethyl disulfide, 2-isopropyl-5-methyl-1-heptanol, and 4-trifluoroacetoxyhexadecane, were produced by strain AS15. These results suggest that the tested strains producing extracellular metabolites and/or volatiles may have a broad spectrum of antifungal activities against the grain fungi. In particular, B. megaterium KU143 and P. protegens AS15 may be potential biocontrol agents against Aspergillus and Penicillium spp. during rice grain storage.

Global transcriptome analysis identifies weight regain-induced activation of adaptive immune responses in white adipose tissue of mice

Objective:

Studies have indicated that weight regain following weight loss predisposes obese individuals to metabolic disorders; however, the molecular mechanism of this potential adverse effect of weight regain is not fully understood. Here we investigated global transcriptome changes and the immune response in mouse white adipose tissue caused by weight regain.

Design:

We established a diet switch protocol to compare the effects of weight regain with those of weight gain without precedent weight loss, weight loss maintenance and chow diet. We conducted a time course analysis of global transcriptome changes in gonadal white adipose tissue (gWAT) during the weight fluctuation. Co-expression network analysis was used to identify functional modules associated with the weigh regain phenotype. Immune cell populations in gWAT were characterized by flow-cytometric immunophenotyping. Metabolic phenotypes were monitored by histological analysis of adipose tissue and liver, and blood-chemistry and body weight/composition analyses.

Results:

In total, 952 genes were differentially expressed in the gWAT in the weight regain vs the weight gain group. Upregulated genes were associated with immune response and leukocyte activation. Co-expression network analysis showed that genes involved in major histocompatibility complex I and II-mediated antigen presentation and T-cell activation function were upregulated. Consistent with the transcriptome analysis results, flow cytometry demonstrated significant increases in subsets of T cells and proinflammatory M1 macrophages in the gWAT in the weight regain as compared to the weight gain group. In addition, upregulation of adaptive immune responses was associated with high incidence of adipocyte death and upregulation of high mobility group box 1, a well-known component of damage-associated molecular patterns.

Conclusions:

Our global transcriptome analysis identified weight regain-induced activation of adaptive immune responses in mouse white adipose tissue. Results suggest that activation of adipocyte death-associated adaptive immunity in adipose tissue may contribute to unfavorable metabolic effects of weight regain following weight loss.

Influence of Temperature and Water Activity on Deleterious Fungi and Mycotoxin Production during Grain Storage

Cereal grains are the most important food source for humans. As the global population continues to grow exponentially, the need for the enhanced yield and minimal loss of agricultural crops, mainly cereal grains, is increasing. In general, harvested grains are stored for specific time periods to guarantee their continuous supply throughout the year. During storage, economic losses due to reduction in quality and quantity of grains can become very significant. Grain loss is usually the result of its deterioration due to fungal contamination that can occur from preharvest to postharvest stages. The deleterious fungi can be classified based on predominance at different stages of crop growth and harvest that are affected by environmental factors such as water activity (aw) and eco-physiological requirements. These fungi include species such as those belonging to the genera Aspergillus and Penicillium that can produce mycotoxins harmful to animals and humans. The grain type and condition, environment, and biological factors can also influence the occurrence and predominance of mycotoxigenic fungi in stored grains. The main environmental factors influencing grain fungi and mycotoxins are temperature and aw. This review discusses the effects of temperature and aw on fungal growth and mycotoxin production in stored grains. The focus is on the occurrence and optimum and minimum growth requirements for grain fungi and mycotoxin production. The environmental influence on aflatoxin production and hypothesized mechanisms of its molecular suppression in response to environmental changes are also discussed. In addition, the use of controlled or modified atmosphere as an environmentally safe alternative to harmful agricultural chemicals is discussed and recommended future research issues are highlighted.

Biocontrol Activity of Volatile-Producing Bacillus megaterium and Pseudomonas protegens against Aspergillus flavus and Aflatoxin Production on Stored Rice Grains

In our previous study, three bacterial strains, Bacillus megaterium KU143, Microbacterium testaceum KU313, and Pseudomonas protegens AS15, were selected as effective biocontrol agents against Aspergillus flavus on stored rice grains. In this study, we evaluated the inhibitory effects of the volatiles produced by the strains on A. flavus growth and aflatoxin production on stored rice grains. The three strains significantly reduced mycelial growth of A. flavus in dual-culture assays compared with the negative control strain, Sphingomonas aquatilis KU408, and an untreated control. Of these tested strains, volatiles produced by B. megaterium KU143 and P. protegens AS15 markedly inhibited mycelial growth, sporulation, and conidial germination of A. flavus on agar medium and suppressed the fungal populations in rice grains. Moreover, volatiles produced by these two strains significantly reduced aflatoxin production in the rice grains by A. flavus. To our knowledge, this is the first report of the suppression of A. flavus aflatoxin production in rice grains using B. megaterium and P. protegens volatiles.

Chryseobacterium cucumeris sp. nov., an endophyte isolated from cucumber (Cucumis sativus L.) root, and emended description of Chryseobacterium arthrosphaerae

The Gram-stain-negative, yellow-pigmented, rod-shaped bacterial strain GSE06^T, isolated from the surface-sterilized root of a cucumber plant grown in a field in Gunsan, Korea, was characterized by not only cultural and morphological features but also physiological, biochemical and molecular analyses. Phylogenetic analyses based on 16S rRNA gene sequences revealed that strain GSE06^T was most closely related to species of the genus Chryseobacterium. Furthermore, strain GSE06^T exhibited the highest sequence similarities with the type strains Chryseobacterium indologenes ATCC 29897^T (98.9 %), Chryseobacterium gleum ATCC 35910^T (98.8 %), Chryseobacterium arthrosphaerae CC-VM-7^T (98.7 %), Chryseobacterium contaminans C26^T (98.5 %), Chryseobacterium artocarpi UTM-3^T (98.3 %), and Chryseobacterium gallinarum 100^T (97.9 %). Average nucleotide identity values between genome sequences of strain GSE06^T and the above-mentioned reference strains ranged from 81.2 to 86.9 %, which were lower than the threshold of 95 % (corresponding to a DNA-DNA reassociation value of 70 %). The DNA G+C content of strain GSE06^T was 36.1 mol%; the predominant respiratory quinone of the strain was MK-6. The major fatty acids were iso-C15 : 0, summed feature 9 (iso-C17 : 1ω9c), summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and iso-C17 : 0 3-OH. The major polar lipids were phosphatidylethanolamine, three aminolipids, one aminophospholipid, four glycolipids and one unidentified lipid. These results of phenotypic and genotypic characteristics could differentiate strain GSE06^T from closely related type strains belonging to the genus Chryseobacterium. Thus, strain GSE06^T is proposed as a representative of a novel species in the genus Chryseobacterium, Chryseobacterium cucumeris sp. nov. The type strain is GSE06^T (=KACC 18798^T=JCM 31422^T).

Microbe-Mediated Control of Mycotoxigenic Grain Fungi in Stored Rice with Focus on Aflatoxin Biodegradation and Biosynthesis Inhibition

Rice contaminated with fungal species during storage is not only of poor quality and low economic value, but may also have harmful effects on human and animal health. The predominant fungal species isolated from rice grains during storage belong to the genera Aspergillus and Penicillium. Some of these fungal species produce mycotoxins; they are responsible for adverse health effects in humans and animals, particularly Aspergillus flavus, which produces the extremely carcinogenic aflatoxins. Not surprisingly, there have been numerous attempts to devise safety procedure for the control of such harmful fungi and production of mycotoxins, including aflatoxins. This review provides information about fungal and mycotoxin contamination of stored rice grains, and microbe-based (biological) strategies to control grain fungi and mycotoxins. The latter will include information regarding attempts undertaken for mycotoxin (especially aflatoxin) bio-detoxification and microbial interference with the aflatoxin-biosynthetic pathway in the toxin-producing fungi.

Draft Genome Sequence of a Biocontrol Rhizobacterium, Chryseobacterium kwangjuense Strain KJ1R5, Isolated from Pepper (Capsicum annuum)

Strain KJ1R5 of the rhizobacterium ITALIC! Chryseobacterium kwangjuenseis an effective biocontrol agent against Phytophthora blight of pepper caused by a destructive soilborne oomycete, ITALIC! Phytophthora capsici Here, we present the draft genome sequence of strain KJ1R5, which contains genes related to biocontrol, plant growth promotion, and environmental stress adaptation.

Effect of X-irradiation on Citrus Canker Pathogen Xanthomonas citri subsp. citri of Satsuma Mandarin Fruits

Citrus canker caused by Xanthomonas citri subsp. citri (Xcc) is one of the most important bacterial diseases of citrus. Because citrus canker is not found in many countries including European Union and Australia, Xcc is strictly regulated in order to prevent its spread. In this study, the effects of X-irradiation on Xcc growth either in the suspension or on the surface of citrus fruits were investigated. The suspension containing 1×10(7) cfu/ml of Xcc was irradiated with different absorbed doses of X-irradiation ranging from 50 to 400 Gy. The results showed that Xcc was fully dead at 400 Gy of X-irradiation. To determine the effect of X-irradiation on quarantine, the Xcc-inoculated citrus fruits were irradiated with different X-ray doses at which Xcc was completely inhibited by an irradiation dose of 250 Gy. The D10 value for Xcc on citrus fruits was found to be 97 Gy, indicating the possibility of direct application on citrus quarantine without any side sterilizer. Beside, presence of Xcc on the surface of asymptomatic citrus fruits obtained from citrus canker-infected orchards was noted. It indicated that the exporting citrus fruits need any treatment so that Xcc on the citrus fruits should be completely eliminated. Based on these results, ionizing radiation can be considered as an alternative method of eradicating Xcc for export of citrus fruits.

Localization and projected role of phosphatidylinositol 4-kinases IIα and IIβ in inositol 1,4,5-trisphosphate-sensitive nucleoplasmic Ca²⁺ store vesicles

Phosphatidylinositol (PI) kinases are key molecules that participate in the phosphoinositide signaling in the cytoplasm. Despite the accumulating evidence that supports the existence and operation of independent PI signaling system in the nucleus, the exact location of the PI kinases inside the nucleus is not well defined. Here we show that PI4-kinases IIα and IIβ, which play central roles in PI(4,5)P2 synthesis and PI signaling, are localized in numerous small nucleoplasmic vesicles that function as inositol 1,4,5-trisphosphate (Ins(1,4,5)P3)-sensitive Ca(2+) stores. This is in accord with the past results that showed the localization of PI4(P)5-kinases that are essential in PI(4,5)P2 production and PI(4,5)P2 in nuclear matrix. Along with PI(4,5)P2 that also exists on the nucleoplasmic vesicle membranes, the localization of PI4-kinases IIα and IIβ in the nucleoplasmic vesicles strongly implicates the vesicles to the PI signaling as well as the Ins(1,4,5)P3-depenent Ca(2+) signaling in the nucleus. Accordingly, the nucleoplasmic vesicles indeed release Ca(2+) rapidly in response to Ins(1,4,5)P3. Further, the Ins(1,4,5)P3-induced Ca(2+) release studies suggest that PI4KIIα and IIβ are localized near the Ins(1,4,5)P3 receptor (Ins(1,4,5)P3R)/Ca(2+) channels on the Ca(2+) store vesicle membranes. In view of the widespread presence of the Ins(1,4,5)P3-dependent Ca(2+) store vesicles and the need to fine-control the nuclear Ca(2+) concentrations at multiple sites along the chromatin fibers in the nucleus, the existence of the key PI enzymes in the Ins(1,4,5)P3-dependent nucleoplasmic Ca(2+) store vesicles appears to be in perfect harmony with the physiological roles of the PI kinases in the nucleus.

Microscopical observation of inhibition-behaviors against Diaporthe citri by pre-treated with Pseudomonas putida strain THJ609-3 on the leaves of citrus plants

Citrus melanose is one of the most important diseases in orchards cultivating citrus in the world. Although the disease does not cause yield loss, the profitability of the infected fruits is often reduced in the fresh-market, resulting in economic loss. In this study, disease reduction was proven by pre-treatment with Pseudomonas putida strain THJ609-3. In order to illustrate mechanism of the disease reduction by the bacterial strain, the infection behaviors of Diaporthe citri and necrosis deposit of plant tissue were observed using a fluorescence microscope. On the leaves pre-treated with the strain THJ609-3, germination rates of D. citri conidia were significantly decreased compared to those of the untreated control. Scanning electron microscopical observations showed that bacterial cells were attached to the surface of fungal hyphae. Furthermore, morphological change of germ tubes of the conidia was detected. These results suggest that the disease reduction may be caused by the direct antifungal activity of the bacterial strain on the leaf surfaces.

Priming-mediated systemic resistance in cucumber induced by Pseudomonas azotoformans GC-B19 and Paenibacillus elgii MM-B22 against Colletotrichum orbiculare

Induced systemic resistance (ISR) can be activated by biotic agents, including root-associated beneficial bacteria to inhibit pathogen infection. We investigated priming-mediated ISR in cucumber induced by Pseudomonas azotoformans GC-B19 and Paenibacillus elgii MM-B22 against Colletotrichum orbiculare (causal fungus of anthracnose). In addition, we examined whether this ISR expression was bacterial density-dependent by assessing peroxidase activity in the presence and absence of the pathogen. As a result, root treatment with the ISR-eliciting strains GC-B19 and MM-B22 or the chemical inducer DL-β-amino-n-butyric acid (positive control) significantly inhibited fungal infection process (conidial germination and appressorium formation) and disease severity compared with the non-ISR-eliciting strain, Pseudomonas aeruginosa PK-B09 (negative control), and MgSO4 solution (untreated control). These treatments effectively induced rapid elicitation of hypersensitive reaction-like cell death with H2O2 generations, and accumulation of defense-related enzymes (β-1,3-glucanase, chitinase, and peroxidase) in cucumber leaves in the "primed" state against C. orbiculare. In addition, ISR expression was dependent on the bacterial cell density in the rhizosphere. This ISR expression was derived from the presence of sustained bacterial populations ranging from 10(4) to 10(6) cells/g of potting mix over a period of time after introduction of bacteria (10(6) to 10(10) cells/g of potting mix) into the rhizosphere. Taken together, these results suggest that priming-mediated ISR against C. orbiculare in cucumber can be induced in a bacterial density-dependent manner by Pseudomonas azotoformans GC-B19 and Paenibacillus elgii MM-B22.

The role as inoculum sources of Xanthomonas citri pv. citri surviving on the infected Satsuma mandarin fruits

Importing citrus fruits infected by Asiatic citrus canker caused by Xanthomonas citri pv. citri (Xcc) can act as an inoculum source for the disease epidemic in citrus canker-free countries. In this study, the pathogenicity of the causal agent of Asiatic citrus canker surviving on infected Satsuma mandarin fruits was evaluated. The washing solution of infected Satsuma mandarin fruits did not cause lesion formation on the citrus leaves. However, a typical citrus canker lesion was formed on the leaves after inoculation with higher concentrations of the inoculum from the washing solution (washing solution II). It indicated that the pathogenicity of the citrus canker surviving on the symptomatic Satsuma mandarin fruits was not changed. Scanning electron microscopic observation showed that the numbers of bacterial cells on the leaves of Satsuma mandarin which inoculated with the washing solution directly (washing solution I) was less compared to those of leaves inoculated with the washing solution II. This result spports that the pathogenicity of Xcc surviving on Satsuma mandarin fruits may not be changed but that the sucessful infection of citrus caker may depend on the concentration of the inoculum.

Chryseobacterium kwangjuense sp. nov., isolated from pepper (Capsicum annuum L.) root

The yellow-pigmented, Gram-stain-negative, rod-shaped bacterium KJ1R5T was isolated from the root of a pepper plant grown in a field in Kwangju, Korea. Strain KJ1R5T was characterized by physiological, biochemical, and molecular genetic analyses. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain KJ1R5T was most closely related to members of the genus Chryseobacterium , and that the strain exhibited the highest similarities with type strains of Chryseobacterium vrystaatense (97.0 %) and Chryseobacterium rhizosphaerae (97.1 %). DNA–DNA hybridization reassociation values between strain KJ1R5T and type strains of C. vrystaatense KACC 11675T and C. rhizosphaerae KACC 14918T were 46.9 and 38.4 %, respectively. The DNA G+C content of KJ1R5T is 40.2 mol%. The predominant respiratory quinone of KJ1R5T was menaquinone MK-6; major cellular fatty acids were iso-C15 : 0, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), iso-C17 : 1ω9c, and iso-C17 : 0 3-OH. On the basis of these phenotypic and genotypic characteristics, the strain significantly differed from representative strains belonging to the genus Chryseobacterium . Thus, we propose that strain KJ1R5T represents a novel species of the genus Chryseobacterium , named Chryseobacterium kwangjuense sp. nov. The type strain is KJ1R5T ( = KACC 13029T = JCM 15904T).

Biocontrol of Phytophthora Blight and Anthracnose in Pepper by Sequentially Selected Antagonistic Rhizobacteria against Phytophthora capsici

We previously developed a sequential screening procedure to select antagonistic bacterial strains against Phytophthora capsici in pepper plants. In this study, we used a modified screening procedure to select effective biocontrol strains against P. capsici; we evaluated the effect of selected strains on Phytophthora blight and anthracnose occurrence and fruit yield in pepper plants under field and plastic house conditions from 2007 to 2009. We selected four potential biocontrol strains (Pseudomonas otitidis YJR27, P. putida YJR92, Tsukamurella tyrosinosolvens YJR102, and Novosphingobium capsulatum YJR107) among 239 bacterial strains. In the 3-year field tests, all the selected strains significantly (P < 0.05) reduced Phytophthora blight without influencing rhizosphere microbial populations; they showed similar or better levels of disease suppressions than in metalaxyl treatment in the 2007 and 2009 tests, but not in the 2008 test. In the 2-year plastic house tests, all the selected strains significantly (P < 0.05) reduced anthracnose incidence in at least one of the test years, but their biocontrol activities were variable. In addition, strains YJR27, YJR92, and YJR102, in certain harvests, increased pepper fruit numbers in field tests and red fruit weights in plastic house tests. Taken together, these results indicate that the screening procedure is rapid and reliable for the selection of potential biocontrol strains against P. capsici in pepper plants. In addition, these selected strains exhibited biocontrol activities against anthracnose, and some of the strains showed plant growth-promotion activities on pepper fruit.

Oxygen-vacancy-induced orbital reconstruction of Ti ions at the interface of LaAlO3/SrTiO3 heterostructures: a resonant soft-X-ray scattering study

Resonant soft-x-ray scattering measurements have been performed to investigate interface electronic structures of (LaAlO(3)/SrTiO(3)) superlattices. Resonant scattering intensities at superlattice reflections show clear evidence of degeneracy lifting in t(2g) states of interface Ti ions. Polarization dependence of intensities indicates the energy of d(xy) states is lower by ~1 eV than two other t(2g) states. The energy splitting is insensitive to epitaxial strain. The orbital reconstruction is induced by oxygen vacancies and confined to the interface within two unit cells, indicating charge compensation at the polar interfaces.

Root treatment with rhizobacteria antagonistic to Phytophthora blight affects anthracnose occurrence, ripening, and yield of pepper fruit in the plastic house and field

We previously selected rhizobacterial strains CCR04, CCR80, GSE09, ISE13, and ISE14, which were antagonistic to Phytophthora blight of pepper. In this study, we investigated the effects of root treatment of rhizobacteria on anthracnose occurrence, ripening, and yield of pepper fruit in the plastic house and field in 2008 and 2009. We also examined the effects of volatiles produced by the strains on fruit ripening and on mycelial growth and spore development of Colletotrichum acutatum and Phytophthora capsici in the laboratory, identifying the volatile compounds by gas chromatography-mass spectrometry (GC-MS). In the house tests, all strains significantly (P < 0.05) reduced anthracnose incidence on pepper fruit; strains GSE09 and ISE14 consistently produced higher numbers of pepper fruit or increased the fresh weight of red fruit more than the controls in both years. In the field tests, all strains significantly (P < 0.05) reduced anthracnose occurrence on either green or red pepper fruit; strain ISE14 consistently produced higher numbers or increased fresh weights of red fruit more than the controls in both years. In the laboratory tests, volatiles produced by strains GSE09 and ISE13 only stimulated maturation of pepper fruit from green (unripe) to red (ripe) fruit; the volatiles of certain strains inhibited the growth and development of C. acutatum and P. capsici. On the other hand, GC-MS analysis of volatiles of strains GSE09 and ISE13 revealed 17 distinct compounds in both strains, including decane, dodecane, 1,3-di-tert-butylbenzene, tetradecane, 2,4-di-tert-butylphenol, and hexadecane. Among these compounds, 2,4-di-tert-butylphenol only stimulated fruit ripening and inhibited growth and development of the pathogens. Taken together, strains GSE09 and ISE14 effectively reduced anthracnose occurrence and stimulated pepper fruit ripening and yield, possibly via bacterial volatiles. Therefore, these two strains could be potential agents for controlling Phytophthora blight and anthracnose, and for increasing fruit ripening and yield. To our knowledge, this is the first report of volatiles such as 2,4-di-tert-butylphenol produced by rhizobacteria being related to both fruit ripening and pathogen inhibition.

Biocontrol activity and primed systemic resistance by compost water extracts against anthracnoses of pepper and cucumber

We investigated direct and indirect effects of compost water extracts (CWEs) from Iljuk-3, Iljuk-7, Shinong-8, and Shinong-9 for the control of anthracnoses caused by Colletotrichum coccodes on pepper and C. orbiculare on cucumber. All tested CWEs significantly (P < 0.05) inhibited in vitro conidial germination and appressorium formation of the fungal pathogens; however, DL-β-amino-n-butyric acid (BABA) failed to inhibit the conidial development of the pathogens. Direct treatments of the CWEs and BABA on pepper and cucumber leaves at 1 and 3 days before or after inoculation significantly (P < 0.05) reduced anthracnose severities; Iljuk-3, Shinong-9, and BABA for pepper and Iljuk-7 for cucumber had more protective activities than curative activities. In addition, root treatment of CWEs suppressed anthracnoses on the plants by the pathogens; however, CWE treatment on lower leaves failed to reduce the diseases on the upper leaves of the plants. The CWE root treatments enhanced not only the expression of the pathogenesis-related (PR) genes CABPR1, CABGLU, CAChi2, CaPR-4, CAPO1, and CaPR-10 in pepper and PR1-1a, PR-2, PR-3, and APOX in cucumber but also the activity of β-1,3-glucanase, chitinase, and peroxidase and the generation of hydrogen peroxide in pepper and cucumber under pathogen-inoculated conditions. However, the CWE treatments failed to induce the plant responses under pathogen-free conditions. These results indicated that the CWEs had direct effects, reducing anthracnoses by C. coccodes on pepper leaves and C. orbiculare on cucumber leaves through protective and curative effects. In addition, CWE root treatments could induce systemic resistance in the primed state against pathogens on plant leaves that enhanced PR gene expression, defense-related enzyme production, and hydrogen peroxide generation rapidly and effectively immediately after pathogen infection. Thus, the CWEs might suppress anthracnoses on leaves of both pepper and cucumber through primed (priming-mediated) systemic resistance.

Evidence for the existence of secretory granule (dense-core vesicle)-based inositol 1,4,5-trisphosphate-dependent Ca2+ signaling system in astrocytes

BACKGROUND

The gliotransmitters released from astrocytes are deemed to play key roles in the glial cell-neuron communication for normal function of the brain. The gliotransmitters, such as glutamate, ATP, D-serine, neuropeptide Y, are stored in vesicles of astrocytes and secreted following the inositol 1,4,5-trisphosphate (IP3)-induced intracellular Ca2+ releases. Yet studies on the identity of the IP3-dependent intracellular Ca2+ stores remain virtually unexplored.

PRINCIPAL FINDINGS

We have therefore studied the potential existence of the IP3-sensitive intracellular Ca2+ stores in the cytoplasm of astrocytes using human brain tissue samples in contrast to cultured astrocytes that had primarily been used in the past. It was thus found that secretory granule marker proteins chromogranins and secretogranin II localize in the large dense core vesicles of astrocytes, thereby confirming the large dense core vesicles as bona fide secretory granules. Moreover, consistent with the major IP3-dependent intracellular Ca2+ store role of secretory granules in secretory cells, secretory granules of astrocytes also contained all three (types 1, 2, and 3) IP3R isoforms.

SIGNIFICANCE

Given that the secretory granule marker proteins chromogranins and secretogranin II are high-capacity, low-affinity Ca2+ storage proteins and chromogranins interact with the IP3Rs to activate the IP3R/Ca2+ channels, i.e., increase both the mean open time and the open probability of the channels, these results imply that secretory granules of astrocytes function as the IP3-sensitive intracellular Ca2+ store.

Biocontrol activity and induction of systemic resistance in pepper by compost water extracts against Phytophthora capsici

We investigated the effects of water extracts of composts (CWE) from commercial compost facilities for controlling root and foliar infection of pepper plants by Phytophthora capsici. Among 47 CWE tested, CWE from composts Iljuk-3, Iljuk-7, Shinong-8, and Shinong-9 significantly (P < 0.05) inhibited zoospore germination, germ tube elongation, mycelial growth, and population of P. capsici. All selected CWE significantly (P < 0.05) reduced the disease incidence and severity in the seedling and plant assays compared with the controls. However, there were no significant differences in zoospore germination, disease incidence, and disease severity between treatments of untreated, autoclaved, and filtered CWE. In addition, CWE significantly (P < 0.05) suppressed leaf infection of P. capsici through induced systemic resistance (ISR) in plants root-drenched with CWE. The tested CWE enhanced the expression of the pathogenesis-related genes, CABPR1, CABGLU, CAChi2, CaPR-4, CAPO1, or CaPR-10 as well as beta-1,3-glucanase, chitinase, and peroxidase activities, which resulted in enhanced plant defense against P. capsici in pepper plants. Moreover, the CWE enhanced the chemical and structural defenses of the plants, including H(2)O(2) generation in the leaves and lignin accumulation in the stems. The CWE could also suppress other fungal pathogens (Colletotrichum coccodes in pepper leaves and C. orbiculare in cucumber leaves) through ISR; however, it failed to inhibit other bacterial pathogens (Xanthomonas campestris pv. vesicatoria in pepper leaves and Pseudomonas syringae pv. lachrymans in cucumber leaves). These results suggest that a heat-stable chemical(s) in the CWE can suppress root and foliar infection by P. capsici in pepper plants. In addition, these suppressions might result from direct inhibition of development and population of P. capsici for root infection, as well as indirect inhibition of foliar infection through ISR with broad-spectrum protection.

Overexpression of lipid transfer protein (LTP) genes enhances resistance to plant pathogens and LTP functions in long-distance systemic signaling in tobacco

The lipid signal is essential for the activation of plant defense responses, but downstream components of the signaling pathway are still poorly defined. To investigate the biological functions of pepper lipid transfer protein (LTP), we carried out virus-induced gene silencing (VIGS) in pepper, constitutive expression of CALTPs and grafting experiments in the tobacco plant. Suppression of endogenous CALTPI and CALTPII by VIGS, respectively, resulted in enhanced susceptibility to Xanthomonas campestris pv. vescatoria and pepper mosaic mottle virus in pepper. On the other hand, the constitutive expression of CALTPI and CALTPII genes in tobacco plants showed enhanced resistance to oomycete pathogen, Phytophthora nicotianae and bacterial pathogen, Pseudomonas syringae pv. tabaci. Enhanced resistance is found to be associated with the enhanced CALTP transcript levels in the independent transgenic CALTPI or II tobacco lines. Induced resistance responses in grafted scion leaves revealed that LTP plays a role in long-distance systemic signaling in plants.

Allelic variation of the Waxy gene in foxtail millet [Setaria italica (L.) P. Beauv.] by single nucleotide polymorphisms

The Waxy (Wx) gene product controls the formation of a straight chain polymer of amylose in the starch pathway. Dominance/recessiveness of the Wx allele is associated with amylose content, leading to non-waxy/waxy phenotypes. For a total of 113 foxtail millet accessions, agronomic traits and the molecular differences of the Wx gene were surveyed to evaluate genetic diversities. Molecular types were associated with phenotypes determined by four specific primer sets (non-waxy, Type I; low amylose, Type VI; waxy, Type IV or V). Additionally, the insertion of transposable element in waxy was confirmed by ex1/TSI2R, TSI2F/ex2, ex2int2/TSI7R and TSI7F/ex4r. Seventeen single nucleotide polymorphims (SNPs) were observed from non-coding regions, while three SNPs from coding regions were non-synonymous. Interestingly, the phenotype of No. 88 was still non-waxy, although seven nucleotides (AATTGGT) insertion at 2,993 bp led to 78 amino acids shorter. The rapid decline of r (2) in the sequenced region (exon 1-intron 1-exon 2) suggested a low level of linkage disequilibrium and limited haplotype structure. K (s) values and estimation of evolutionary events indicate early divergence of S. italica among cereal crops. This study suggested the Wx gene was one of the targets in the selection process during domestication.

Biological evaluation of neopeptins isolated from a Streptomyces strain

BACKGROUND

Microbial secondary metabolites are a rich source of antifungal agents and have merit as alternatives to synthetic fungicides. To develop disease control agents against powdery mildew, the lipopeptide antibiotic neopeptins were identified from the culture broth of a Streptomyces sp., and in vivo control efficacy of the compounds was evaluated on cucumber plants under glasshouse conditions.

RESULTS

The Streptomyces sp. KNF2047 antagonistic against powdery mildew development in cucumber plants was isolated from a soil sample. Antifungal compounds were purified from the culture broth and identified as neopeptin A and B. In vitro microtitre assays revealed the inhibitory activities of the compounds in the range 128-512 microg mL(-1) against the mycelial growth of Alternaria mali, Botrytis cinerea, Cladosporium cucumerinum, Colletotrichum lagenarium, Didimella bryoniae and Magnaporthe grisea. Although neither compound showed remarkable in vitro antifungal activity against other plant pathogenic fungi, a mixture of neopeptins (484 mg of neopeptin A and 290 mg of neopeptin B per gram of partially purified powder) showed potent protective and curative activity against cucumber powdery mildew in vivo. The disease control activity of the neopeptins at a concentration of 2.4 mg L(-1) was 92.1%, which was similar to that of the commercial fungicide fenarimol (89.3% at 63 mg L(-1)) and that of the commercial biocontrol agent Actinovate (67.4% at 2 x 10(7) cfu L(-1)).

CONCLUSION

Neopeptin mixtures isolated from Streptomyces sp. KNF2047 showed potent disease control activity against powdery mildew development on cucumber plants. .

Presence of secretogranin II and high-capacity, low-affinity Ca2+ storage role in nucleoplasmic Ca2+ store vesicles

Chromogranins and secretogranins have traditionally been known as marker proteins of secretory granules that contain the highest concentrations of cellular calcium, reaching approximately 40 mM. In addition, chromogranin B was also shown to exist in the nucleus, localizing in the putative inositol 1,4,5-trisphosphate (IP3)-sensitive nucleoplasmic Ca2+ store vesicles. Chromogranins A (CGA) and B (CGB) are high-capacity, low-affinity Ca2+ binding proteins, binding 30-90 mol of Ca2+/mol with dissociation constants (Kd) of 1.5-4 mM. Yet the Ca2+-binding property of secretogranins has not been studied. Here, we show the localization of secretogranin II (SgII) in the nucleus, more specifically, in the IP3-sensitive nucleoplasmic Ca2+ store vesicles along with CGB and the IP3 receptors. We have also determined the Ca2+-binding property of SgII and found that SgII binds 61 mol of Ca2+/mol (910 nmol Ca2+/mg) with a Kd of 3.0 mM at the intragranular pH 5.5 and 30 mol of Ca2+/mol (440 nmol Ca2+/mg) with a Kd of 2.2 mM at a near-physiological pH 7.5. Chromogranin B also bound 50 mol of Ca2+/mol (670 nmol Ca2+/mg) with a Kd of 3.1 mM at pH 7.5. Given the high-capacity, low-affinity Ca2+-binding property of SgII and its presence in the IP3-sensitive nucleoplasmic Ca2+ store vesicles, these results suggest that SgII may function in the storage and control of Ca2+ in the nucleus through its interaction with CGB in the nucleoplasmic vesicles.

Comparison of and chromogranin effect on inositol 1,4,5-trisphosphate sensitivity of cytoplasmic and nucleoplasmic inositol 1,4,5-trisphosphate receptor/Ca2+ channels

The nucleus also contains the inositol 1,4,5-trisphosphate receptor (IP3R)/Ca2+ channels in the nucleoplasm proper independent of the nuclear envelope or the cytoplasm. The nuclear IP3R/Ca2+ channels were shown to be present in small IP3-dependent nucleoplasmic Ca2+ store vesicles, yet no information is available regarding the IP3 sensitivity of nuclear IP3R/Ca2+ channels. Here, we show that nuclear IP3R/Ca2+ channels are 3-4-fold more sensitive to IP3 than cytoplasmic ones in both neuroendocrine PC12 cells and nonneuroendocrine NIH3T3 cells. Given the presence of phosphoinositides and phospholipase C and the importance of IP3-mediated Ca2+ signaling in the nucleus, the high IP3 sensitivity of nuclear IP3R/Ca2+ channels seemed to reflect the physiological needs of the nucleus to finely control the IP3-dependent Ca2+ concentrations. It was further shown that the IP3R/Ca2+ channels of secretory cells are 7-8-fold more sensitive to IP3 than those of nonsecretory cells. This difference appeared to result from the presence of secretory cell marker protein chromogranins (thus secretory granules) in secretory cells; expression of chromogranins in NIH3T3 cells increased the IP3 sensitivity of both nuclear and cytoplasmic IP3R/Ca2+ channels by approximately 4-6-fold. In contrast, suppression of chromogranin A expression in PC12 cells changed the EC50 of IP3 sensitivity for cytoplasmic IP3R/Ca2+ channels from 17 to 47 nM, whereas suppression of chromogranin B expression changed the EC50 of cytoplasmic IP3R/Ca2+ channels from 17 to 102 nM and the nuclear ones from 4.3 to 35 nM. Given that secretion is the major function of secretory cells and is under a tight control of intracellular Ca2+ concentrations, the high IP3 sensitivity appears to reflect the physiological roles of secretory cells.

Populations of fungi and bacteria associated with samples of stored rice in Korea

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.

Fabrication of fluorine-doped diamond-like carbon stamps for UV nanoimprint lithography

Two fluorine-doped diamond-like carbon (F-DLC) stamps with sub-100 nm line patterns were fabricated using a direct etching method. These were applied successfully to ultraviolet (UV) nanoimprint lithography without requiring an anti-adhesion layer coating. Tests were performed to determine the optimum fluorine concentration for the F-DLC stamps. The ideal stamp material consisted of 25 at.% F-DLC with a contact angle of 85°, UV transmittance of 16.4-26.8%, and hardness of 4.5 GPa. The O(2) plasma etch rate of the DLC was increased considerably by the fluorine doping, making it comparable to the etch rate of polymethyl methacrylate (PMMA). Thus, only PMMA was used as the etch mask in the fabrication of the stamps.

Overexpression of a pepper basic pathogenesis-related protein 1 gene in tobacco plants enhances resistance to heavy metal and pathogen stresses

A pepper gene, CABPR1, which encodes basic pathogenesis-related protein 1, has been reported to be strongly induced after ethephon treatment, wounding, and tobacco mosaic virus infection. The potential role of CABPR1 in tolerance of biotic or abiotic stresses was examined in transgenic Nicotiana tabacum cv. xanthi plants. Overexpression of CABPR1 in tobacco plants enhanced tolerance not only to heavy metal stresses, but also to the oomycete pathogen Phytophthora nicotianae, and the bacterial pathogens Ralstonia solanacearum and Pseudomonas syringae pv. tabaci. RT-PCR revealed that the CABPR1 transgene increased expression of the PR-Q and glutathione S-transferase genes, but decreased expression of the PR-1a and thaumatin genes. Moreover, these transgenic lines exhibited significant decreases in total peroxidase activity and transcription level, suggesting that overexpression of CABPR1 in tobacco cells altered the balance of redox systems. Redox imbalance in transgenic lines may lead to H(2)O(2) accumulation, triggering tolerance to biotic and abiotic stresses.

Identification of pathogen-responsive regions in the promoter of a pepper lipid transfer protein gene (CALTPI) and the enhanced resistance of the CALTPI transgenic Arabidopsis against pathogen and environmental stresses

The 5' flanking region of the CALTPI gene, which encodes a basic lipid transfer protein, was isolated and characterized from the genomic DNA of Capsicum annuum. Four different regions of the promoter sequence of the CALTPI gene were fused to the beta-glucuronidase (GUS) coding region. In an Agrobacterium-mediated transient expression assay, the transcriptional activations of the promoter deletions were examined in tobacco leaves after infection with Pseudomonas syringae pv. tabaci, and treatment with ethylene and salicylic acid. The -808 bp region of the CALTPI gene promoter sequence exhibited full promoter activity. The W-box and ERE-box elements, which are essential for induction by all signals, were localized in the region between -555 bp and -391 bp upstream of the translation initiation site. A CALTPI transgene was then introduced under the control of the 35S promoter into the Arabidopsis ecotype Col-0. Transgenic Arabidopsis lines expressing the CALTPI gene developed rapidly compared to the wild-type plants, indicating that CALTPI may be involved in plant development. Overexpression of the CALTPI gene enhanced the resistance against infection by P. syringae pv. tomato and Botrytis cinerea. The transgenic plants expressing the CALTPI gene also showed high levels of tolerance to NaCl and drought stresses at various vegetative growth stages. No transcription of the PR-1, PR-2, PR-5, thionin, and RD29A genes was observed in untreated leaf tissues of the transgenic plants. The enhanced resistance to pathogen and environmental stresses in transgenic Arabidopsis correlated with the enhanced expression of the CALTPI gene.

The three-dimensional microstructure of the trabecular bone in the mandible

This study investigated the three dimensional (3D) trabecular microstructure of the alveolar and basal bone in the mandible using micro-CT and compared the morphometric values of the different sites. Ten specimens were prepared and scanned using a micro-CT system. Both the alveolar and basal trabecular bone of the premolar region in the mandible were measured for the structural analysis. Cross-sectional 1024x1024 pixel images were created. From the two-dimensional (2D) images produced, 3D structural images were reconstructed. After scanning the specimen, the volumes of interest (VOI) of the alveolar and basal bone regions were selected from the 3D reconstruction images, and the structural parameters such as bone volume fraction, bone surface density, trabecular thickness, trabecular separation, trabecular number and structural model index were analyzed. The trabecular structure showed a marked variation within the sites of the specimen, especially in the basal trabecular bone inferior to the mandibular canal. In both the alveolar and basal bone regions, a mixture of both plate-like and rod-like structures was observed. The alveolar region showed a more compact, plate-type trabecular structure than the basal regions. In parametric comparison with the basal bone, the alveolar bone generally had a higher bone volume fraction, bone trabecular thickness and trabecular number, and lower bone surface density, trabecular separation and structural model index. The alveolar bone consisted of a compact bone structure with a large amount of thick plate-type trabecular bone, which was effectively resistant to the masticatory forces. As the measurements were made closer to the basal bone, a loose structure was observed with lower bone volume and fewer, thin, rod-like trabeculae.

Inflammatory orbital pseudotumor with infratemporal fossa extension mimicking temporomandibular joint dysfunction

Inflammatory orbital pseudotumor is a benign space-occupying lesion of unknown origin that involves all or part of the fatty tissue within the orbit. Occasionally the disease may extend into the middle cranial, the pterygopalatine, and the infratemporal fossa through the various foramina of the orbit, although extension into the infratemporal fossa is very rare. We present a case which extends into the infratemporal fossa through the inferior orbital fissure, resulting in presenting symptoms mimicking temporomandibular joint dysfunction.

Knowledge and attitudes of Korean parents towards their son's circumcision: a nationwide questionnaire study

OBJECTIVE

To evaluate knowledge about the foreskin and circumcision, and to understand the attitudes of parents to circumcision in Korea, where circumcision in childhood is widely practised with no particular religious or medical background.

SUBJECTS AND METHODS

A nationwide study involving questionnaires was conducted on 5500 parents with at least one son attending elementary school. Responses were obtained from one of the parents.

RESULTS

The response rate was 76.1% (4183); circumcision was most common in boys when aged 11 years, followed by neonatal circumcision. Of the parents, 91.3% believed that circumcision is necessary, while 2.1% believed it to be unnecessary. The principal reasons given for circumcision were 'to improve penile hygiene' (82.4%), followed by 'to improve future sexual potency' (7.5%). Among those who did not believe circumcision to be necessary, the most common reason was the expectation of spontaneous retraction of the prepuce with age (55.1%). Most (88.4%) of the parents believed that smegma is not a clean material, and is infected by microorganisms. Most parents (80.6%) thought that circumcision would prevent genital tract infection of the future spouse. Peer pressure was one of the most influential factors in deciding upon circumcision; 41.9% of the parents were anxious that their child might be ridiculed by his peer group unless he was circumcised, while 27.4% of the parents believed that their child might be ridiculed if he was circumcised. Mothers were more positive about circumcision than fathers (P < 0.05). Parents with a higher education and higher socio-economic status were also more positive about circumcision (P < 0.05). Mothers were prone to emphasize improved sexual potency (P < 0.05). There was no significant difference in response between urban and rural areas.

CONCLUSION

This study indicates that common beliefs held by parents about the prepuce or circumcision differ significantly from current medical knowledge, and these beliefs have a major influence on the practice of circumcision in Korea. More clinical research on the natural history of the foreskin is needed, and it is critical that both children and parents are informed about the potential benefits and disadvantages of circumcision.

Cloning and characterization of a type II integral transmembrane protein gene, Itm2c, that is highly expressed in the mouse brain

An Itm2C cDNA encoding a member of the mouse type II integral transmembrane protein (Itm2) was cloned from a mouse 13.5 days' post-coitum (dpc) embryonic head cDNA library. The nucleotide sequence and protein prediction analyses indicate that the membrane topology of the mouse Itm2c is a type II integral transmembrane protein with the N-terminus being intracellular and C-terminus, which is considered as either an extracellular or a luminal organelle domain. The predicted protein consists of 269 amino acids with a calculated Mr of 30,482 and a theoretical pI of 8.83. A putative N-glycosylation site was identified at amino acid 171, Asn. The single N-glycosylation site is conserved in the three members of the family in both mice and humans. The amino acid sequence of Itm2C is 41 and 49% identical to those of mouse Itm2A and Itm2B, respectively. A single approximately 2.1 kb transcript was detected with different levels in all of the tissues examined by Northern blot analysis. The Itm2c was highly expressed in both adult and postimplantation embryonic brains, although weak or moderate signals were also detected in other adult tissues. Among the tissues examined, RT-PCR analyses in various adult tissue shows that the Itm2c expression is highest in the adult brain. The results from this study suggest that the cloned Itm2c is a member of the Itm2 family that is specifically expressed in adult brains, unlike other members.

Isolation of neuronal precursors from differentiating P19 embryonal carcinoma cells by neuronal T alpha 1-promoter-driven GFP

The induction of pluripotent P19 embryonal carcinoma (EC) cells with retinoic acid results in their differentiation into cells that resemble neurons, glia, and fibroblasts. To isolate and enrich the developing neurons from heterogeneously differentiating P19 EC cells, we used a recently introduced protocol combining the expression of green fluorescent protein (GFP) driven by a tissue-specific promoter and fluorescence-activated cell sorting. Cells were transfected with the gene for GFP, which is under the control of the neuronal T alpha 1 tubulin promoter. After four days of retinoic acid treatment, GFP was specifically detected in cells undergoing neuronal differentiation. Sorting of fluorescent differentiating P19 EC transfectants yielded populations highly enriched in neuronal precursors and neurons. Immunoreactivity for nestin and neurofilament was observed in 80 and 25% of the sorted cell population, respectively. These results demonstrate that differentiated neuronal precursor cells can be efficiently isolated from differentiating pluripotent embryonic cells in vitro, suggesting that this method can reproducibly provide homogeneous materials for further studies on neurogenesis.

Dendritic cell-tumor coculturing vaccine can induce antitumor immunity through both NK and CTL interaction

Immunization of dendritic cells (DC) pulsed with tumor antigen can activate tumor-specific cytotoxic T lymphocytes (CTL) that are responsible for protection and regression. We show here that immunization with bone marrow-derived DC cocultured with tumor cells can induce a protective immunity against challenges to viable tumor cells. In this study, we further investigated the mechanism by which the antitumor activity was induced. Immunization of mice with DC cocultured with murine colon carcinoma. CT-26 cells, augmented CTL activity against the tumor cells. Concomitantly, an increase in natural killer (NK) cell activity was also detected in the same mice. When DC were fixed with paraformaldehyde prior to coculturing with tumor cells, most of the CTL and NK cell activity diminished, indicating that DC are involved in the process of presenting the tumor antigen(s) to CTL. NK cell depletion in vivo produced markedly low tumor-specific CTL activity responsible for tumor prevention. In addition, RT-PCR analysis confirmed the high expression of INF-gamma mRNA in splenocytes after vaccination with DC cocultured with tumors, but low expression in splenocytes from NK-depleted mice. Most importantly, the tumor protective effect rendered to DC by the coculturing with CT-26 cells was not observed in NK-depleted mice, which suggests that DC can induce an antitumor immune response by enhancing NK cell-dependent CTL activation. Collectively, our results indicate that NK cells are required during the priming of cytotoxic T-cell response by DC-based tumor vaccine and seem to delineate a mechanism by which DC vaccine can provide the desired immunity.

Apoptosis-linked gene 2 binds to the death domain of Fas and dissociates from Fas during Fas-mediated apoptosis in Jurkat cells

Apoptosis-linked gene 2 (ALG-2) is a member of the family of Ca(2+)-binding proteins with penta-EF-hand and is essential for the execution of apoptosis by various signals including Fas activation. We studied the regulation of ALG-2 during Fas-mediated apoptosis in Jurkat cells. The 22-kDa ALG-2 protein is cleaved and becomes a 19-kDa protein after Fas activation. The appearance of 19-kDa ALG-2 protein increases for 4 h after treatment with 200 ng/ml of anti-Fas Ab treatment and gradually degrades afterward. Confocal microscopic analysis showed that ALG-2 translocated from the plasma membrane to the cytosol during Fas-mediated apoptosis. Therefore, we examined if ALG-2 interacts with Fas. The protein-protein interaction of ALG-2 with Fas was demonstrated using yeast two-hybrid assays as well as in vitro GST pull-down assay. Endogenous ALG-2 was immunoprecipitated with anti-Fas Ab in Jurkat cells without Fas activation. However, the endogenous ALG-2 was no longer immunoprecipitated with anti-Fas Ab 2 h after anti-Fas Ab treatment. This study, for the first time, presents a direct molecular connection of ALG-2 to apoptosis by its direct interaction with Fas, and enlists ALG-2 as a new member of posttranslationally modified proteins during Fas-mediated apoptotic process.