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In March 2020, approximately 20% of leaves in a commercial oat field growing Avena sativa (cv. Samhan) in Jeongeup, Korea (35.3859°, 126.5607°), displayed leaf blight in the seedling stage of development. The lesions observed in 2020 were of a yellow discoloration that spread from the leaf tip downward with minimal brown delineation (Fig. S1A). These symptoms differed from the haloes delineated at the edges by extensive brown necrosis caused by Pseudomonas coronofaciens (Kim 2020a; Fig. S1C). To isolate the causal agent, 3-cm-long pieces of symptomatic leaves from ten different oat plants were disinfected by submersion in 70% ethanol for 5 min followed by immersion in 1% sodium hypochlorite for 5 min and rinsing extensively with sterile distilled water. The air-dried segments were transferred intact to nutrient agar, and only one colony type (yellow-colored, wet, with a shiny convex surface) was observed. After single colony isolation, three isolates from different 2020 field-grown diseased leaves, termed 2007, 2009, and 2011, were selected at random. The isolates produced fluorescent siderophores on King’s medium B and triggered a hypersensitive response (HR) when infiltrated into tobacco (cv. Xanthi) leaves (Fig. S1D). Multilocus sequence typing analysis with four housekeeping genes was used for taxonomic identification of these isolates (Maiden et al. 1998). The 16S rRNA sequences were amplified with the 27F/1492R universal primers (Weisburg et al. 1991). The primers for three housekeeping genes were designed using genome sequence of P. coronaficiens X-1 causing halo blight disease in Korea (NZ_CP050260.1, Kim, 2020b). The products obtained had sizes of 640 bp for gltA (using primers F: 5’-CCT GGT AGC CAA GAT GCC GAC-3’; R: 5’-CAA AGA TCA CGG TGA ACA TGC TGG-3’), 710 bp for gyrB (with primers F: 5’-TCG GCA GCC GAG GTC ATC ATG AC-3’; R: 5’-TTG TCT TTG GTC TGC GAG CTG AA-3’), and 870 bp for rpoD ( with primers F: 5’-GTG AAG GCG AAA TCG AAA TCG-3’; R: 5’-CCG ATG TTG CCT TCC TGG ATC AG-3’). The concatenated sequences (2,353 bp/2,376 bp) had 99% identity with the gene sequences from P. salomonii type strain (AY091528.1, NZ_FNOX01000003, LC486864.1, LC486849.1), but lesser identity (90%) with P. coronafaciens (Fig. S2). Pathogenicity of the Korean isolates was confirmed by fulfilling Koch’s postulates using leaves of 2 week-old greenhouse-grown ‘Samhan’ seedlings. Plants (n=50) were sprayed with 108 cfu/ml bacterial suspensions in water or with sterile water as controls. The plants were incubated for a week at 23 °C in 100% relative humidity under a 10 h light/14 h dark photoperiod. Five days after bacterial inoculation, yellow discoloration appeared at the leaf tips which progressed downward with time (Fig. S1B). Three bacterial isolates extracted from yellowed, inoculated leaves had 16S rRNA gene sequences identical to that of P. salomonii Korean isolates, 2007, 2009 and 2011, and they caused the anticipated symptoms when inoculated into oat leaves. These findings indicate that P. salomonii should be added to the potential pathogens of oats grown in Korea. Understanding whether spring weather conditions (warmth and humidity) boost this oat disease will help devise disease alert systems for farmers (Anderson 2004; Chakraborty 2005).

The fungal isolate Isaria javanica pf185 has potential as a mycopesticide because it demonstrates insecticidal activity against the green peach aphid and antifungal activity against Colletotrichum gloeosporioides. For commercialization of this isolate, determination of the optimal and least expensive culture conditions is required; however, these data are not currently available. This study describes the conditions for optimal development of conidia and production of metabolites for the biocontrol of the fungal pathogen. The optimal culture conditions were examined using cultures on solid agar and liquid media. High growth temperature enhanced spore formation but reduced antifungal activity in both solid and liquid media. The highest spore yield was obtained in a medium containing glucose as a carbon source and yeast extract as a nitrogen source. Soybean powder and wheat bran were effective nitrogen sources that promoted spore production and antifungal activity of the isolate. These results revealed the basic, cost-effective growth media for commercial production of a biopesticide with insecticidal and antifungal properties for use in integrated pest management.

The structural behavior and safety of a static load test fixture for a pylon and an external fuel tank of a fixed-wing aircraft currently being developed in South Korea are analyzed. The test loads are calculated via the flight loads applied on the external fuel tank and a whiffletree configuration; subsequently, they are used in the static analysis of the test fixture using the finite element method. Vulnerable components of the test fixture are identified by calculating the von Mises stress, and detailed structural behavior is analyzed. It is confirmed that most components of the test fixture exhibit a factor of safety of 3.0 or greater, which is determined by the calculated von Mises stress and the yield strength of the material. The proposed method is expected to be utilized in the structural integrity evaluation of a static test fixture for the external stores of an aircraft.

Certain chemical pesticides control plant diseases through induction of systemic resistance mechanisms. In this study, orysastrobin, a “quinone outside inhibitor” (QoI)-type commercial fungicide, decreased disease severity in the leaves of A. thaliana resulting from inoculation with P. syringae pv. tomato DC3000; protection from the orysastrobin treatment correlated with lowered bacterial populations in the plant tissue. The fungicide-induced cross protection to a bacterial pathogen was at the same level as that given by foliar treatment with beta-aminobutyric acid (BABA), an inducer of salicylic acid (SA) - defense pathway, leading to induced resistance for this pathogen. Although another chemical inducer of the SA-pathway, benzo-(1,2,3)-thiadiazole-7-carbothioic acid S-methyl ester (BTH), induced the marker gene for the salicylic acid (SA) pathway PR1a, there was no induction with orysastrobin or methyl jasmonate treatments. However, orysastrobin induced AtVSP1.2, in the JA-pathway and PDF1.2 in the ET defense pathway. These findings suggested that the fungicide, orysastrobin, induced resistance to the pathogenic pseudomonad. Because orysastrobin induced the JA/ET defense pathways, applications of this strobilurin-type fungicide have the potential to protect plants from a large array of pathogens and abiotic stresses.

A new hybrid non-ribosomal peptide-polyketide antibiotic (serratamid) for phytoprotection was isolated from the ethyl acetate layer of tryptic soy agar culture of the soil bacterium Serratia plymuthica C1 through bioassay-guided fractionation. Its chemical structure was elucidated using instrumental analyses, such as mass and nuclear magnetic resonance spectrometry. Serratamid showed antibacterial activity against 15 phytopathogenic bacteria, with minimum inhibitory concentration (MIC) values ranging from 0.244 to 31.25 μg/mL. In vitro, it displayed strong antibacterial activity against Ralstonia solanacearum and four Xanthomonas spp., with MIC values (0.244-0.488 μg/mL) superior to those of streptomycin sulfate, oxolinic acid, and oxytetracycline. Further, serratamid and the ethyl acetate layer of S. plymuthica C1 effectively reduced bacterial wilt caused by R. solanacearum on tomato seedlings and fire blight caused by Erwinia on apple fruits in a dose-dependent manner. These results suggest that serratamid is a promising candidate as a potent bactericide for controlling bacterial diseases.

Gas turbine power generation is relatively minor in terms of pollutant emissions, such as nitrogen oxides or sulfur oxides, as compared to thermal power generation using coal or petroleum. This is because of the use of liquefied natural gas, known as an eco-friendly power generation solution. Large gas turbines used for power generation are suitable for the power load demanded by modern society, which fluctuates very much with respect to power consumption because it takes only about 10–20 min to reach the entire output from the start-up. A large gas turbine used for power generation is a rotating machine that features a high degree of difficulty in mechanical design due to its fast start-up characteristics, structural complexity, and high operating temperature, while also emphasizing stability. Customers are demanding operational reliability as a prerequisite before evaluating the performance of a gas turbine. It is very important to design and verify the rotor dynamics sufficiently and accurately from the design stage prior to fabrication in light of that it is very difficult to change the rotor dynamics characteristics once the design is completed and finished. Many researchers are trying to improve the design completeness, but the researches that actually design and verify the power generation gas turbine are limited only to a few manufacturers with the original technology, so there is little verification of actual gas turbine. In this paper, rotor dynamics analysis and verification of a 270 MW class DGT-300H gas turbine rotor newly developed by DHI. To verify the center tie-rod type rotor design of a large gas turbine for power generation, which was conceptually designed using in-house design tools, a 1/5 scaled model was designed by applying the dynamic scaling law. In order to verify the suitability of the applied tie-rod design, the characteristics of the variation of the natural frequency with the variation of the pre-tightening force were tested in order to confirm the dynamic proper pre-tightening force. The design of the scaled model rotor was created, the model was designed and fabricated, and the natural frequencies were analyzed and tested to confirm the validity of the design method and the suitability of the analysis results. After the design of the large gas turbine rotor for 270 MW class power generation, the natural frequencies of the rotor before the blade installation were analyzed and the suitability of the design was verified by implementing a vibration test of the rotor before blade installation.

In 2019, symptoms of Botrytis mold on the peony (Paeonia lactiflora Pall.) 'Sarah Bernhardt' were observed during a survey of the commercial greenhouses of Gangjin County, South Korea. The initial symptoms, small brown spots, were observed mainly at the leaf margins. The lesions extended to the interior of leaves forming irregular spots in which abundant conidia developed. Fungal colonies were obtained from surface-sterilized tissue excised from growing edges of the lesions that were transferred to potato dextrose agar. Melanized irregular sclerotia were formed in these colonies after 40 days at 8°C. Molecular phylogeny based on sequences of genes for glyceraldehyde-3-phosphate dehydrogenase, heat-shock protein 60, and RNA polymerase subunit II were highest for the PBC-2 isolate to the type strains of Botrytis cinerea, rather than other Botrytis species associated with peony diseases. Following Koch's postulates, healthy Sarah Bernhardt plants were inoculated with a foliar application of conidial suspensions of the isolate PBC-2. Following incubation under humidity with a 12 hr photoperiod for 7 days, symptoms developed on the leaf margins that were identical to those observed in the greenhouses. This study is the first report of Botrytis blight caused by B. cinerea on peonies grown in commercial greenhouses in South Korea.

We have studied magnetic behaviors of water-quenched 5 wt.% (Fe, Ti) particle-doped MgB2 compared with those of air-cooled one. Generally, grain refinement is achieved by water quenching, which means increases of grain boundaries in a superconductor. We inspected that the increased grain boundary density of a superconductor influenced the kinds of flux-pinning effects on the field dependence of magnetization. As a result, grain boundaries are served as a pinning centers on a higher magnetic field (2.5–6.0 T) whereas they are served as a pathway to facilitate movements of fluxes pinned on volume defects at a lower field (0.2–2.0 T). As inspecting characteristics of grain boundaries, it is understood that they have a flux-pinning effect as well as a flux-penetrating promotion effect. By using TEM, we confirmed that the width of grain boundary in MgB2 is approximately 1 nm, which is not wide enough to pin several flux quanta across the width. As temperature increases, the flux-pinning effect of water-quenched 5 wt.% (Fe, Ti) particle-doped MgB2 decreases significantly when compared with that of air-cooled one. The behavior was because flux-pinning effect of grain boundaries decreases and flux-penetrating promotion effect of them increases, which are considered to be caused by increased coherence length of the superconductor.

In this study, a yo-yo vibrational energy harvesting device that can adjust its resonant frequency to the desired excitation frequency using geometrical control is proposed and investigated. The device employs a spring system, suspended proof mass, and set of reels and gears to convert translational input into rotational motion to power its generator. The spring system is composed of two symmetrical oblique springs, and its stiffness and the resonant frequency of the proposed harvester varies with the oblique angle between these springs. The characteristics of the oblique spring system are investigated accordingly, and it is shown that there exists a lower limit of stiffness; therefore, the achievable frequency bandwidth of the harvester can be determined. The method used to design the proposed tunable energy harvester so that it satisfies the desired frequency bandwidth is then provided. A prototype of the device was built and tested on a vibration table, and its performance is illustrated via a comparison with the results of numerical calculations. The results indicate that the proposed device is capable of harnessing the kinetic energy of the ocean waves.

Pseudomonas chlororaphisisolates have been studied intensively for their beneficial traits.P. chlororaphisspecies function as probiotics in plants and fish, offering plants protection against microbes, nematodes and insects. In this review, we discuss the classification ofP. chlororaphisisolates within four subspecies; the shared traits include the production of coloured antimicrobial phenazines, high sequence identity between housekeeping genes and similar cellular fatty acid composition. The direct antimicrobial, insecticidal and nematocidal effects ofP. chlororaphisisolates are correlated with known metabolites. Other metabolites prime the plants for stress tolerance and participate in microbial cell signalling events and biofilm formation among other things. Formulations ofP. chlororaphisisolates and their metabolites are currently being commercialized for agricultural use.

This study describes the numerical simulation results of aluminum/carbon-fiber-reinforced plastic (CFRP) hybrid joint parts using the explicit finite-element solver LS-DYNA, with a focus on capturing the failure behavior of composite laminates as well as the adhesive capacity of the aluminum–composite interface. In this study, two types of adhesive modeling techniques were investigated: a tiebreak contact condition and a cohesive zone model. Adhesive modeling techniques have been adopted as a widely commercialized model of structural adhesives to simulate adhesive failure based on fracture mechanics. CFRP was studied with numerical simulations utilizing LS-DYNA MAT54 to analyze the crash capability of aluminum/CFRP. To evaluate the simulation model, the results were compared with the force–displacement curve from numerical analysis and experimental results. A parametric study was conducted to evaluate the effect of different fracture toughness values used by designers to predict crash capability and adhesive failure of aluminum/CFRP parts.

Serratia plymuthica C-1, a biocontrol agent, was isolated from soil collected from a mountain forest in Korea. Previous studies have shown that certain strains of S. plymuthica cause root rot disease in ginseng. To the best of our knowledge, this is the first report of the sequence of the circular chromosome of S. plymuthica C-1, which plays a dual role by causing root rot in ginseng and exhibiting biocontrol activity. The findings of this study will assist in analyzing the genes associated with the pathogenicity and biocontrol properties of S. plymuthica.

Pseudomonas coronafaciens X-1 was isolated from halo blight lesions on oat leaves in Korea. Currently, no genome resource on the oat halo blight pathogen is available. Here, the complete genome sequence of this strain, containing a circular chromosome and one circular megaplasmid is reported. This is the first genome sequence of the oat halo blight pathogen and will contribute to our understanding of the pathogenicity and ecological aspects of the halo blight pathogen and the interactions between P. coronafaciens and oats.

We have investigated the structural, electrical, and magnetic properties of oxychalcogenide LaREO2Bi3Ag0.6Sn0.4S6 (RE = Pr and Nd) superconductors. The LaREO2Bi3Ag0.6Sn0.4S6 (RE = Pr and Nd) samples are composed of a single La2O2Bi3AgS6 phase without any impurity phase. The superconducting onset temperature of LaREO2Bi3Ag0.6Sn0.4S6 (RE = Pr and Nd) is $\sim $ 4.1 K, which is slightly higher than 2.8 K observed for La2O2Bi3Ag0.6Sn0.4S6.

A smart tire monitoring system uses tire information, such as temperature, pressure, acceleration, force, tire-road friction coefficient, in real time to monitor the driving safety of cars. A vibration energy harvester for a smart tire monitoring system converts the tire dynamic strain energy into electrical energy which is the power source of the wireless sensor module. The self-powered wireless sensor module consists of an electro-magnetic type energy harvester, a power conversion circuit, an acceleration sensor and a radio communication circuit. This research is focused on achieving high energy conversion efficiency, lightweight design, and long durability of the harvester because it is located at the inner surface of tire where extremely high pressure and acceleration exist. The energy harvester was made in a cylindrical shape with a length of 35 mm. The manufactured harvester was 9.4 g, the casing 10.8 g, the battery 2.6 g, the wireless acceleration sensor module 1.1 g, and the power conversion circuit module 1.2 g. So, the total weight of the wireless sensor module was less than 27 g. The monitoring system receives an acceleration signal from the wireless sensor module which is attached to the inner surface of a tire. An operating test of the monitoring system was carried out by using the tire driving test equipment. The average output power of the energy harvester was measured as about 5.7 mW at 60 km/h. The wireless sensor module was operated during about 11700 km (60 km / h * 6.5 h / day * 30 day). The test results showed that the energy harvester has sufficient power to maintain the operation of the wireless sensor module, and the sensor module has a sufficient durability.

The aim of this study is to optimize the electromagnetic vibration energy harvesters with typical cylindrical shape considering the aspect ratio. In the optimization procedure, voltage and power, which are two key factors of energy harvesting systems, are mainly considered in the three types of electromagnetic vibration energy harvester according to various aspect ratios. We then investigate the optimum design parameters in each case. The results show that there is an optimum aspect ratio that maximizes the output voltage and power for the same volume. We also find that the optimum design parameters for each aspect ratio have a relatively constant value regardless of the aspect ratio. An experimental study is also conducted to verify the simulation results of the design optimization, and it clearly confirms that the proposed optimization result matches the experimental results well.

The chitinase-producing bacterium, Paenibacillus elgii HOA73, is a biocontrol agent that limits the damage caused to plants by microbial pathogens, insects, and nematodes. However, the mechanisms involved in the biocontrol of plant diseases by HOA73 have not been determined. The objective of this study was to elucidate the role of extracellular chitinase obtained from isolate HOA73 in the control of the fungal pathogen Botrytis cinerea, the causative agent of gray mold in tomato. The HOA73 strain grew efficiently in a chitin-containing broth and produced chitin oligomers through chitinase activity; protease, lipase, and Fe-chelating siderophores were also secreted by the bacterium. Cultures containing intact bacteria inhibited B. cinerea conidia germination to a greater extent than did the bacterial cells alone or the cell-free culture supernatant. The antifungal activity increased with culture age and was heat-sensitive because of chitinase-mediated production of long-chain chitin oligomers. The biocontrol efficacy of undiluted bacterial cultures against gray mold in tomato was comparable to that of a standard fungicide. This study demonstrated that P. elgii HOA73 bacterial cultures grown on chitin-based minimal medium may be an effective formulation for the integrated control of gray mold.

We present the data showing that overexpression of the Arabidopsis zinc finger homeodomain protein ZHD5 promotes shoot regeneration and confers other cytokinin-associated phenotypes. To isolate protein factors that bind to the promoter element of ABF2, which is a key regulator of ABA responsive gene expression, we carried out yeast-one-hybrid screen. Four zinc finger homeodomain (ZF-HD) protein genes were identified from the screen. Expression study showed that one of the ZF-HD proteins, ZHD5, is induced by various cytokinins (CKs). We generated and analyzed ZHD5 overexpression (OX) lines to study its function. Our results revealed that ZHD5 promoted shoot regeneration efficiency significantly, obviating CK requirement. Other CK-related phenotypes, such as enhanced cell proliferation and pathogen resistance, were also observed. At the molecular level, changes in the expression levels of a number of genes relevant to the phenotypes were observed. Collectively, our results provde strong evidence that ZHD5 is involved in shoot regeneration and other aspects of CK response.

Dual biocontrol of both insects and plant pathogens has been reported for certain fungal entomopathogens, including Beauveria bassiana and Lecanicillum spp. In this study, we demonstrate, for the first time, the dual biocontrol potential of two fungal isolates identified by morphological and phylogenetic analyses as Isaria javanica. Both these isolates caused mortality in the greater wax moth, and hence can be considered entomopathogens. Spores of the isolates were also pathogenic to nymphs of the green peach aphid (Myzus persicae), with an LC50 value of 107 spores/mL 4 days after inoculation and an LT50 of 4.2 days with a dose of 108 spores/mL. In vitro antifungal assays also demonstrated a strong inhibitory effect on the growth of two fungi that are pathogenic to peppers, Colletotrichum gloeosporioides and Phytophthora capsici. These results indicate that I. javanica isolates could be used as novel biocontrol agents for the simultaneous control of aphids and fungal diseases, such as anthracnose and Phytophthora blight, in an integrated pest management framework for red pepper.

An effective bioformulation of mixtures of chitin-degrading bacteria has been used successfully to control plant diseases and nematodes. In this study, the bioformulation approach was assessed to control damping-off disease of ginseng. In pot experiments with soils infested with dapming-off pathogens of ginseng, root-drenchings of Chrobacterium sp. C-61, Lysobacterium enzymogenes C-3, and mixture of two bacterial strains grown in chitin minimal medium were signficantly increased emergence of seeds and reduced damping-off disease incidence of seedlings. Efficacy of the bioformulated product depended on the dose and timing of application. In two-year-old ginseng field, the high control efficacies were achieved by soil drenching of two times with an undiluted product or three times with a 10-fold diluted product. In a To-jik nursery (self soil nursery), biocontrol efficacy of the undiluted product against damping-off disease were similar to that of a seed dressing with fungicide, Tolclofos-methyl WP. These results suggest that the bioformulated product containing Chromobacterium sp. C-61 and L. enzymogenes C-3 could be an effective approach to control of ginseng damping-off disease.

A plethora of compounds stimulate protective mechanisms in plants against microbial pathogens and abiotic stresses. Some defense activators are synthetic compounds and trigger responses only in certain protective pathways, such as activation of defenses under regulation by the plant regulator, salicylic acid (SA). This review discusses the potential of naturally occurring plant metabolites as primers for defense responses in the plant. The production of the metabolites, hexanoic acid and melatonin, in plants means they are consumed when plants are eaten as foods. Both metabolites prime stronger and more rapid activation of plant defense upon subsequent stress. Because these metabolites trigger protective measures in the plant they can be considered as “vaccines” to promote plant vigor. Hexanoic acid and melatonin instigate systemic changes in plant metabolism associated with both of the major defense pathways, those regulated by SA- and jasmonic acid (JA). These two pathways are well studied because of their induction by different microbial triggers: necrosis-causing microbial pathogens induce the SA pathway whereas colonization by beneficial microbes stimulates the JA pathway. The plant’s responses to the two metabolites, however, are not identical with a major difference being a characterized growth response with melatonin but not hexanoic acid. As primers for plant defense, hexanoic acid and melatonin have the potential to be successfully integrated into vaccination-like strategies to protect plants against diseases and abiotic stresses that do not involve man-made chemicals.

Biological control is an important process for sustainable plant production, and this trait is found in many plant-associated microbes. This study reviews microbes that could be formulated into pesticides active against various microbial plant pathogens as well as damaging insects or nematodes. The focus is on the beneficial microbes that colonize the rhizosphere where, through various mechanisms, they promote healthy plant growth. Although these microbes have adapted to cohabit root tissues without causing disease, they are pathogenic to plant pathogens, including microbes, insects, and nematodes. The cocktail of metabolites released from the beneficial strains inhibits the growth of certain bacterial and fungal plant pathogens and participates in insect and nematode toxicity. There is a reinforcement of plant health through the systemic induction of defenses against pathogen attack and abiotic stress in the plant; metabolites in the beneficial microbial cocktail function in triggering the plant defenses. The review discusses a wide range of metabolites involved in plant protection through biocontrol in the rhizosphere. The focus is on the beneficial firmicutes and pseudomonads, because of the extensive studies with these isolates. The review evaluates how culture conditions can be optimized to provide formulations containing the preformed active metabolites for rapid control, with or without viable microbial cells as plant inocula, to boost plant productivity in field situations.

Background: Clinically, steroids have been used for hearing preservation both topically and systemically during cochlear implantation.Objective: This study compared steroid efficacy for hearing pre...

The integration of a complex of pathways involving growth promotion and stress tolerance in response to bacterial volatile organic compounds (VOCs) is remarkable in enhancing plant health. VOCs are emitted from microbes associated with the plant. In this chapter, we focus on the mechanisms involving the array of structurally diverse VOCs that are active in maintaining a balance for the plant under abiotic and biotic stress. Certain VOCs boost plant growth, act as direct deterrents of pests, or are activators of systemic plant defense mechanisms. The responses to the VOCs involved in plant health engage many different trophic levels and advantageously can occur at distance from the original signal. Thus, VOC sensing has a holistic aspect for plant welfare.

Background An entomopathogenic fungus, Isaria javanica pf185, causes mortality in nymphs of the green peach aphid and inhibits the growth of fungal plant pathogens. However, the metabolites of pf185 involved in these antifungal and aphicidal activities are unknown. This study was performed to identify the metabolites with these activities. Results An antifungal metabolite was purified by repetitive column chromatography and preparative high-performance liquid chromatography. Based on data from mass spectrometry and nuclear magnetic resonance, the active metabolite was identified as dibutyl succinate. The minimum concentration of dibutyl succinate to inhibit germination of conidia of the cause of anthracnose, Colletotrichum acutatum, was 4 mg mL-1 . Dibutyl succinate at 2 µg mL-1 inhibited mycelial growth. It also had strong aphicidal activity against the nymphs of the green peach aphid, Myzus persicae, median lethal concentration (LC50) of 306 mg L-1 at 24 h exposure, and median lethal time (LT50) of 14.5 h at 388 mg L-1 exposure. Conclusion This is the first report indicating that a single metabolite, dibutyl succinate, from the beneficial fungus I. javanica, has potential for use in integrated pest management to inhibit both insect and fungal plant pathogens. © 2018 Society of Chemical Industry.

Pseudomonas chlororaphis O6 induces systemic tolerance in plants against drought stress. A volatile, 2R, 3R-butanediol, produced by the bacterium causes partial stomatal closure, thus, limiting water loss from the plant. In this study, we report that applications of extracellular polymeric substances (EPS) from P. chlororaphis O6 to epidermal peels of leaves of Arabidopsis thaliana also reduce the size of stomatal openings. Growth of A. thaliana seedlings with applications of the EPS from P. chlororaphis O6 reduced the extent of wilting when water was withheld from the plants. Fluorescence measurements showed photosystem II was protected in the A. thaliana leaves in the water stressed EPS-exposed plants. These findings indicate that P. chlororaphis O6 has redundancy in traits associated with induction of mechanisms to limit water stress in plants.