Salicylic acid (SA) is an essential plant growth regulator that functions as a signaling molecule in plants. The purpose of this study was to clarify how the exogenous application of SA counteracts aluminum stress-induced growth and biomass yield reduction in alfalfa exposed to aluminum (Al) stress. Two-week-old alfalfa seedlings were exposed to a combination of AlCl3 (0 μM, 50 μM and 100 μM, respectively) and SA (0.1 mM) for 72 hours. We observed, Al stress-induced plant growth inhibition and forage yield reduction are Al stress-dependent manner. A significant reduction of plant height (42.0-52.9%), leaf relative water content (13.0-21.4%), root length (35.4-48.7%), shoot fresh weight (31.2-25.9%), root fresh weight (15.4-23.3%), shoot dry weight (12.7-22.2%), roots dry weight (47.3 -53.5%), were observed in alfalfa. In contrast, SA alleviated the Al-stress and enhanced growth and biomass yield in alfalfa. This study provides useful information concerning the role of SA that counteracts aluminum stress-induced growth and yield reduction in alfalfa.

Soil acidity or alkalinity are serious limitations for crop production. The purpose of this study was to clarify the negative effects of extreme pH stress (low and high) on alfalfa vegetative growth (VG) and biomass accumulation (BA). Two-week-old alfalfa seedlings were exposed to different pH (4.0, 4.5, 7.0, 8.0 and 8.5, respectively) levels for 72 hours. Alfalfa grown at pH 4.0 and 8.5 significantly reduced VG and BA, wherein as neutral pH (7.0) comparably exhibited better growth and biomass yield. These results indicate that extreme acidic or alkaline level are critical limiting factors for growth and biomass yield in alfalfa.

The study conducted finite element analysis in advance to understand the natural frequency, con-ducted static structural analysis and analyzed stress behavior occurring on the boundary of wheel and rail when passing the straight line and curve line. According to the FEA, the wheel had natural frequency of 1st mode 238.4Hz to 10th mode 1,320Hz, and the rail had natural frequency of 457.4Hz to 619.7Hz. When looking at the correlated frequency range, the natural frequency of 4th~6th mode of wheel and 3rd~9th mode of rail track were correlated. As for the result of stress behavior translation occurring on the boundary of wheel and track, it was 53.4MPa when passing the curve line, which was 16MPa higher than when passing the straight line.

Minute pirate bug, Orius minutus (L.), is a native predator of many small insects such as aphid, scale, thrips, and mites in Korea. Seven chemical pesticides with lower ecotoxicity being used to control those pests were evaluated for acute toxicity against adult female O. minutus in glass scintillation vial assay. In the 1st batch experiment with three pesticides, flonicamid and buprofezin were least toxic whereas in the 2nd batch experiment with four pesticides spirotetramat and spiromesifen showed least toxicity. The corrected mortality of buprofezin and flonicamid became 100% on 55 and 47 h of exposure in 1st batch and that of spirotetramat and spiromesifen became 100% on 75 and 71 h of exposure in 2nd batch, respectively. In conclusion, flonicamid, buprofezin, spirotetramat, and spiromesifen was least toxic among the seven pesticides tested against adult female of O. minutus.

Trialeurodes vaporariorum is an important greenhouse pest worldwide. We compared the efficacy of a new strain of Beauveria bassiana (ARP14) with a commercialized one (GHA) against 2nd instar and 4th instar of T. vaporarioum. Those nymphs were exposed to the fungus in a concentration of 1×108 conidia/mL by leaf dipping method. There was no difference in mycosis rates at any observation time between the two strains in both 2nd (100.0%) and 4th instar (100.0%). Lethal median time (LT50) wasn't different between the two strains in both 2nd and 4th instar. In conclusion, the new B. bassiana strain (ARP14) would be a good candidate of mycoinsecticide for whitefly management.

Insulin/IGF signaling (IIS) regulates multiple physiological processes such as larval growth, reproduction, and life span in many organisms including legume pod borer, Maruca vitrata (Lepidoptera: Crambidae). RNA interference of IIS components, insulin receptor (InR) and Forkhead Box O (FOXO), impaired larval growth and female reproduction. To further validate the physiological roles of InR and FOXO, we generated knock-out (KO) mutants using CRISPR/Cas9-mediated genome-editing technology. Both KO mutants exhibited delayed larval growth and reduced pupal and adult body sizes. In conclusion, these results demonstrated the critical role of insulin signaling (IIS) pathway to control M. vitrata growth and development.

Spodoptera litura Fabricius is the serious, polyphagous pest of various crops. Due to the high resistant to most of chemical pesticides, it is hard to control S. litura in the fields. We investigated the virulence of four entomopathogenic nematodes (EPNs) in each larval stage. All EPNs were more effective to younger larvae than older larvae. Mortality, larval penetration rate and reproduction rate were significantly higher in H. indica, S. carpocapsae and S. longicaudum than the H. bacteriophora. Three high effective EPNs induced complete mortality of first instar larvae within 48 h, but of fifth instar larvae within 72 h. These EPNs also highly effective to control S. litura in pot assay. Thus, H. indica, S. carpocapsae and S. longicaudum, can be used as efficient biological control agents of S. litura.

Naturally occurring plant toxins, such as benzoates, have been shown to have insecticidal effects on some pest insects. In this study three commercially available benzoates, methyl benzoate (MB), ethyl benzoate (EB), and vinyl benzoate (VB), were assessed for their contact toxicity against Aphis gossypii Glover and its lacewing predator Chrysoperla carnea Stephens. Toxicity of 1% MB, EB, and VB showed 100%, 85% and 60% mortality of A. gossypii at 24 h. In addition, a mixture of MB and EB showed higher synergistic effect than mixtures of MB+VB or EB+VB against A. gossypii. Toxicity at 1% concentration of three benzoates against A. gossypii showed lower toxicity against the larvae of C. carnea after 72 h of exposure than A. gossypii. Our result suggest that benzoates have high potential as environmentally safe biopesticides for A. gossypii control.

A specific serotonin receptor (Se-5HTR) has been identified in the beet armyworm, Spodoptera exigua and classified into 5-HT7 type. Se-5HTR expression was up-regulated in hemocytes and fat body in response to immune challenge. As being a GPCR, this receptor is presumably coupled with intracellular trimeric Gαs protein activating cAMP-dependent protein kinase (PKA) pathway to regulate several cellular functions. RNA interference (RNAi) of Se-5HTR as well as its downstream signal proteins exhibited significant suppression in cellular immune responses including nodulation and phagocytosis. Application of inhibitors to the signaling cascade suppressed the immune responses as well. To validate the Se-5HTR involvement in mediating cellular immunity, 5-HTR knock-out mutants were developed using CRISPR-Cas9 technique and suffered significant developmental anomalies.

We present the analysis of KMT-2016-BLG-0212, a low flux-variation (Iflux−var ∼ 20 mag) microlensing event, which is in a high-cadence (Γ = 4hr −1) field of the three-telescope Korea Microlensing Telescope Network (KMTNet) survey. The event shows a short anomaly that is incompletely covered due to the brief visibility intervals that characterize the early microlensing season when the anomaly occurred. We show that the data are consistent with two classes of solutions, characterized respectively by low-mass brown-dwarf (q = 0.037) and sub-Neptune (q < 10−4) companions. Future high-resolution imaging should easily distinguish between these solutions.

In this study, Tröger’s Base (TB) chemistry is exploited to introduce tunable microporosity in commercially available polyimide membranes. Considering that TB is a rigid, V-shaped and bridged alicyclic amine, there have been notable reports on accessing feasibility in TB for gas separation membrane applications. However, this presentation shows a different but much viable preparation approach in comparison to the already reported ones. This approach only requires commercially available monomers with two preparation steps, thus it can accommodate scalable and practical productions. Five different kinds of homopolymers and six copolymers were explored to demonstrate structure-property-performance relationships and to evaluate practical applicability towards industrial level.