Self-supported iron-doped cobalt-copper oxide heterostructures for efficient electrocatalytic denitrification.

The electrocatalytic reduction of nitrate ions (NO3-) to nitrogen gas (N2) has emerged as an effective approach for mitigating nitrate pollution in water bodies. However, the development of efficient and highly selective cathode materials remains challenging. Conventional copper-based catalysts often exhibit low selectivity because they strongly adsorb oxygen. In this study, a straightforward solvothermal and pyrolysis method was used to grow iron-doped cobalt-copper oxide heterogeneous structures on copper foam surfaces (Fe-CoO/CuO@CF). Then, the effects of the applied potential, initial NO3- concentration, Cl- concentration, electrolyte pH, and different catalysts on the catalyst performance were investigated. Compared with recently reported congeners, Fe-CoO/CuO@CF is less expensive and exhibits outstanding activity for NO3- reduction. Meanwhile, under a cathode potential of - 1.31 V vs. Ag/AgCl, Fe-CoO/CuO@CF degrades 98.6 % of NO3- in 200 min. In addition, when employing a method inspired by NH4+ removal by breakpoint chlorination, N2 selectivity over Fe-CoO/CuO@CF was raised from 10 % without Cl- to 99.7 % when supplemented with Cl-. The catalyst demonstrated excellent cyclic stability, maintaining a high electrocatalytic activity for the conversion of NO3- to N2 gas over eleven cycles. Moreover, Fe-CoO/CuO@CF enabled 63.7 % removal of NO3- from wastewater (50 mg/L NO3--N) prepared from natural water, with 100 % conversion to N2. Computational studies showed that iron doping decreased the free energy change of the intermediate of NO3- reduction reaction. This study provides an effective strategy for the electrochemical reduction of nitrate to nitrogen gas and offers good prospects for addressing nitrate pollution.

Recent Advances in Catalyst Design and Performance Optimization of Nanostructured Cathode Materials in Zinc-Air Batteries.

This review focuses on the advanced design and optimization of nanostructured zinc-air batteries (ZABs), with the aim of boosting their energy storage and conversion capabilities. The findings show that ZABs favor porous nanostructures owing to their large surface area, and this enhances the battery capacity, catalytic activity, and life cycle. In addition, the nanomaterials improve the electrical conductivity, ion transport, and overall battery stability, which crucially reduces dendrite growth on the zinc anodes and improves cycle life and energy efficiency. To obtain a superior performance, the importance of controlling the operational conditions and using custom nanostructural designs, optimal electrode materials, and carefully adjusted electrolytes is highlighted. In conclusion, porous nanostructures and nanoscale materials significantly boost the energy density, longevity, and efficiency of Zn-air batteries. It is suggested that future research should focus on the fundamental design principles of these materials to further enhance the battery performance and drive sustainable energy solutions.

The application of entomopathogenic nematode modified microbial communities within nesting mounds of the red imported fire ants, Solenopsis invicta.

Entomopathogenic microorganisms (e.g., fungi, bacteria, nematodes) have been widely used in biological control of soil-dwelling pests, including the red imported fire ant (RIFA), Solenopsis invicta, a notorious invasive pest worldwide. The application of large amounts of entomopathogenic microorganisms to soil may affect the indigenous soil microbial communities. However, reports about the effect of entomopathogenic nematodes (EPN) on soil microbial communities are very few. In this study, the effects of EPN on RIFA populations and microbial communities in mounds were investigated. Our results showed that the application of the EPN Steinernema carpocapsae. All strain on mounds efficaciously suppressed RIFA worker populations, without forming significantly more satellite mounds compared with the control treatment. The application of EPN did not impact the bacterial and fungal diversity in soils derived from the RIFA mounds. However, it slightly altered the taxonomic make-up of the bacterial communities, but significantly altered the taxonomic composition of fungal communities at the phylum, family, and genus levels. The abundances of some beneficial bacteria and fungi, such as Streptomyces, decreased, while those of plant and animal pathogenic bacteria and fungi, dramatically increased, after EPN treatment. On the other hand, the abundances of some entomopathogenic fungi, such as Fusicolla, Clonostachys, and Mortierella, increased. Redundancy analysis or canonical correspondence analysis revealed a positive correlation between the efficacious EPN control and the presence of the insect-resistant bacteria, Sinomonas, as well as entomopathogenic fungi Fusicolla and Mortierella. This suggests that the interactions between EPN and entomopathogenic fungi may play a role in the biological control of RIFA. Our discoveries shed light on the interactions among EPN, RIFA, and soil microbial communities, and emphasize a possible mutualistic relationship between EPN and entomopathogenic fungi in the biological control of RIFA.

Separable alginate gel spheres encapsulated with La-Fe modified biochar for efficient adsorption of Sb(III) with high capacity.

Sb and its compounds have been widely used in various industrial applications. Therefore, the preparation of Sb adsorbents with easy recovery and excellent adsorption levels is an urgent problem that must be resolved. By calcining and treating La/Fe metal-organic frameworks (MOF) biochar as a precursor, a loaded La-Fe-modified water hyacinth biochar was synthesised and used as a filler to synthesise iron alginate composite gel spheres, MBC/algFe. Through a series of static adsorption experiments, the effects of different filler addition ratios, solution pH, reaction time, coexisting ions, and other factors on the adsorption of Sb(III) were investigated. According to the Langmuir model, the maximum adsorption capacity of MBC/algFe at 25 â„ƒ was 277.8 mg·g-1. The adsorption mechanism mainly involved hydrogen bonding and metal-organic complexation interactions.

Separable calcium sulphate modified biochar gel beads for efficient cadmium removal from wastewater.

This study outlines the synthesis of a novel, cost-effective composite material comprising calcium sulphate-modified biochar (Ca-BC) cross-linked with polyethyleneimine (PEI) and sodium alginate (SA), which was subsequently transformed into gel beads (Ca-BC@PEI-SA). These beads were engineered to enable effective cadmium ion (Cd(II)) adsorption from wastewater. Batch adsorption experiments were conducted to evaluate the effects of pH, contact time, temperature, and coexisting ions on adsorption performance. The isotherms and kinetics in the adsorption process were investigated. The results indicated that the removal of Cd(II) by Ca-BC@PEI-SA adheres more closely to the Langmuir model, with maximum adsorption capacities of 138.44 mg/g (15 °C), 151.98 mg/g (25 °C), and 165.56 mg/g (35 °C) at different temperatures. The pseudo-secondary model fit well with Cd(II) adsorption kinetics, suggesting that the removal process was a monolayer process controlled by chemisorption. Moreover, the mechanical strength of the Ca-BC@PEI-SA gel beads allowed easy recovery and reduced secondary contamination. In addition, the adsorption capacity remained nearly constant after four cycles. The main Cd(II) adsorption mechanisms involved surface complexation, ion exchange, and cation-π-bonding interactions.

Self-supported P-doped NiFe2O4 micro-sheet arrays for the efficient conversion of nitrite to ammonia.

The nitrite reduction reaction (NO2-RR) is an important process for eliminating toxic nitrites from water while simultaneously producing high-value ammonia under ambient conditions. For the aim to improve the NO2-RR efficiency, we designed a new synthetic strategy to prepare a phosphorus-doped three-dimensional NiFe2O4 catalyst loaded onto a nickel foam in-situ and evaluated its performance for the reduction of NO2- to NH3. The catalyst achieved a high Faradaic efficiency (FE) of 95.39%, and an ammonia (NH3) yield rate of 34788.51 µg h-1 cm-2 at - 0.45 V vs. RHE. A high NH3 yield rate and FE were maintained after 16 cycles at - 0.35 V vs. RHE in an alkaline electrolyte. This study provides a new direction for the rational design of highly stable electrocatalysts for the conversion of NO2- to NH3.

FAPbBr3@PbBr(OH) phosphor with high stability for anti-counterfeiting application via water induction.

Organic-inorganic hybrid perovskite nanocrystals have become a very widely used as semiconductor light-emitting materials. However, perovskite nanocrystals face stability challenges, which is a key factor hindering their application. In this paper, by introducing water into the synthesis of formamidinium lead bromide (FAPbBr3) perovskite, ultra-stable FAPbBr3@PbBr(OH) fluorescent material was prepared. The photoluminescence intensity of the material after the addition of water increased 2.9 times compared with that before the addition of water. The excellent green fluorescence emission was still maintained after four cycles of wash-dry treatment. Meanwhile, it also exhibits good ultraviolet and thermal stability. The above enhanced performance of FAPbBr3nanocrystals is attributed the protection of PbBr(OH). In addition, the prepared material can be used in anti-counterfeit patterns. The anti-counterfeit patterns have good color rendering and the luminous color has a high dependence on temperature. Both of these features make it very valuable for various fluorescent anti-counterfeiting labels.

Effect of in-plane Mott-Schottky on the hydroxyl deprotonation in MoS2@Co3S4/NC heterostructure for efficient overall water splitting.

The development of clean energy sources such as hydrogen is indispensable for achieving the long-term goal of carbon neutrality by the mid-century. The utilization of renewable energy for power generation to electrolyze water for hydrogen production is one of the most desirable green hydrogen production methods. The cathode side of the decomposing water undergoes the oxygen precipitation reaction, and the oxygen precipitation mechanism can be divided into the adsorbed evolution mechanism (AEM) and lattice oxygen oxidation mechanism (LOM). Based on the adsorbed evolution mechanism (AEM), the deprotonation (DeP) process involving multiple electron transfers is central to determining the oxygen release. DeP is essentially a proton-transfer process that allows for the establishment of a bifunctional catalyst system with both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Consequently, an all-transition-metal-based MoS2@Co3S4/NC heterostructure was designed and constructed in this study for the efficient total decomposition of water. The MoS2@Co3S4/NC catalyst achieved the HER and OER current densities of 10 mA cm-2 at the low overpotential (56 mV, 243 mV) and showed excellent long-term durability among all samples. The Mott-Schottky effect is considered the driving force for the HER and DeP in the OER. This study proposes a rational design for bifunctionalized non-precious metal electrolytic water catalysts using the Mott-Schottky effect as a criterion.

Silencing a dehydration-responsive element-binding gene enhances the resistance of plants to a phloem-feeding herbivore.

Herbivore-induced plant defence responses share common components with plant responses to abiotic stresses. However, whether abiotic stress-responsive factors influence the resistance of plants to herbivores by regulating these components remains largely unknown. Here, we cloned a dehydration-responsive element-binding gene in rice, OsDREB1A, and investigated its role in the resistance of rice to the phloem-feeding herbivore, brown planthopper (BPH, Nilaparvata lugens), under normal and low temperatures. We found that OsDREB1A localized to the nucleus, and its transcripts in rice were up-regulated in response to BPH infestation, low temperatures and treatment with methyl jasmonate or salicylic acid. Silencing OsDREB1A changed transcript levels of two defence-related WRKY and two PLD genes, enhanced levels of jasmonic acid (JA), JA-isoleucine and abscisic acid, and decreased the ethylene level in rice; these changes subsequently enhanced the resistance of plants to BPH, especially at 17°C, by decreasing the hatching rate and delaying the development of BPH eggs. Moreover, silencing OsDREB1A increased the growth of rice plants. These findings suggest that OsDREB1A, which positively regulates the resistance of rice to abiotic stresses, negatively regulates the resistance of rice to BPH.

Spodoptera exigua Multiple Nucleopolyhedrovirus Increases the Susceptibility to Insecticides: A Promising Efficient Way for Pest Resistance Management.

Spodoptera exigua is a polyphagous pest of diverse crops and causes considerable economic losses. The overuse of chemical insecticides for controlling this pest results in insecticide resistance, environmental pollution and toxicity to other non-target organisms. Therefore, a sustainable and efficient way for pest management is urgently required. In this study, laboratory bioassays of eleven commonly used insecticides, the specific entomopathogen of S. exigua (Spodoptera exigua multiple nucleopolyhedrovirus, SeMNPV), and SeMNPV-insecticide combinations against the S. exigua laboratory population and two field populations were tested. Our results indicated that the two field populations had developed resistance to almost half of the tested insecticides, while SeMNPV had good virulence in all populations. Interestingly, the combined use of SeMNPV enhanced the toxicity of the tested insecticides against all populations to a different extent and considerably reduced the insecticide resistance of S. exigua field populations or even recovered the susceptibility to above insecticides. Furthermore, the field trial showed that the combined application of SeMNPV contributed to promoting the control efficacy of emamectin benzonate and chlorfenapyr. These results provide a promising efficient way for pest resistance management and an environmentally friendly approach for controlling S. exigua with the combined application of nucleopolyhedroviruses and insecticides.

Nanomanganese cobaltate-decorated halloysite nanotubes for the complete degradation of ornidazole via peroxymonosulfate activation.

Peroxymonosulfate (PMS) driven by halloysite nanotubes (HNTs) modified with nanomanganese cobaltate (MnCo2O4) generates reactive oxygen species (ROS) that offer high degradation efficiency and mineralization rates for many typical antibiotic pollutants, such as ornidazole (ONZ). The experimental results show that halloysite nanotubes (HNTs) modified with nanomanganese cobaltate (MnCo2O4@HNTs denoted as MCO@HNTs) can degrade ONZ completely over a wide pH range (6.08-11.00) with little influence of the pH value. MCO@HNTs + PMS exhibited higher catalytic activity and lower Co- and Mn-ion leaching rates. It also showed a strong anti-interference effect on natural lake water and anions. Additionally, PMS can be quickly activated and consumed in natural lakes to avoid secondary pollution. The roasting of MCO@HNTs showed good catalytic activity and stability after degrading ONZ. The combination of ion quenching and electron paramagnetic resonance (EPR) analysis illustrated that the MCO@HNTs + PMS system had a strong oxidation capacity, and the produced singlet oxygen (1O2) was the main ROS for ONZ degradation. The degradation pathway of ONZ via the MCO@HNTs + PMS system was proposed based on the types of intermediates determined via liquid chromatography-mass spectrometry (LC-MS). This comprehensive study shows the preparation of a simple, environmentally friendly, and cheap PMS activation catalyst that has practical application value in the treatment of antibiotic wastewater and provides a focus on actual water testing with residual amount of PMS.

Characterization of Indoxacarb Resistance in the Fall Armyworm: Selection, Inheritance, Cross-Resistance, Possible Biochemical Mechanisms, and Fitness Costs.

The fall armyworm, Spodoptera frugiperda (J.E. Smith), is a voracious insect pest that is difficult to control due to resistance to insecticides and Bt proteins. We assessed cross-resistance, resistance mechanism, and fitness costs based on the life history traits of S. frugiperda. We established an S. frugiperda strain selected for resistance to indoxacarb (Ind-SEL) from a field-collected population and an unselected strain, Ind-UNSEL. Results indicated that after 24 generations of selection, the resistance to indoxacarb was increased by 472.67-fold as compared to the Ind-UNSEL. There was high cross-resistance to deltamethrin (31.23-fold) with very low or negligible cross-resistance to chlorantraniliprole, emamectin benzoate, and/or methoxyfenozide in the Ind-SEL population. Butoxide synergist increased susceptibility to indoxacarb, indicating that P450 enzymes may be involved in indoxacarb resistance. Significantly longer developmental time of larvae extended pupal duration, shorter adult longevity, and lower fecundity were observed in Ind-SEL as compared with the Ind-UNSEL population. The Net reproductive rate (R0) was the only growth parameter that differs between crosses of Ind-SEL♂ × Ind-UNSEL♀ (176 ± 46) and Ind-SEL♀ × Ind-UNSEL♂ (328 ± 57). On the other hand, all population growth parameters differ between Ind-SEL and Ind-UNSEL strains. Our work contributes to the growing body of research that demonstrates the importance of strain genetics in fitness cost experiments and helps resistance management programs make decisions.

Comparison and Functional Analysis of Odorant-Binding Proteins and Chemosensory Proteins in Two Closely Related Thrips Species, Frankliniella occidentalis and Frankliniella intonsa (Thysanoptera: Thripidae) Based on Antennal Transcriptome Analysis.

Two closely related thrips species, Frankliniella occidentalis and Frankliniella intonsa, are important pests on agricultural and horticultural crops. They have several similarities, including occurrence patterns, host range, and aggregation pheromone compounds. However, there are very few reports about the chemosensory genes and olfactory mechanisms in these two species. To expand our knowledge of the thrips chemosensory system, we conducted antennal transcriptome analysis of two thrips species, and identified seven odorant-binding proteins (OBPs) and eight chemosensory proteins (CSPs) in F. occidentalis, as well as six OBPs and six CSPs in F. intonsa. OBPs and CSPs showed high sequence identity between the two thrips species. The RT-qPCR results showed that the orthologous genes FoccOBP1/3/4/5/6, FintOBP1/3/4/6, FoccCSP1/2/3, and FintCSP1/2 were highly expressed in male adults. Molecular docking results suggested that orthologous pairs FoccOBP4/FintOBP4, FoccOBP6/FintOBP6, and FoccCSP2/FintCSP2 might be involved in transporting the major aggregation pheromone compound neryl (S)-2-methylbutanoate, while orthologous pairs FoccOBP6/FintOBP6, FoccCSP2/FintCSP2, and FoccCSP3/FintCSP3 might be involved in transporting the minor aggregation pheromone compound (R)-lavandulyl acetate. These results will provide a fundamental basis for understanding the molecular mechanisms of pheromone reception in the two thrips species.

Star-shaped porous nitrogen-doped metal-organic framework carbon as an electrochemical platform for sensitive determination of Cd(II) in environmental and tobacco samples.

In this study, cetyltrimethylammonium bromide and zeolitic imidazolate framework-8 (ZIF-8) were first assembled via the chemical co-precipitation, and high-quality carbon-based metal-free nanomaterials were synthesized using a heat-treatment process. The internal and morphological characteristics of hexagonal Star ZIF-8 were investigated using scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The electrochemical sensor with a good response to Cd(II) was prepared via square-wave anodic stripping voltammetry (SWASV) with Star ZIF-8 nanomaterial-modified glassy carbon electrodes. The main parameters were adjusted to obtain the optimal stripping response and a wide linear range. Concurrently, under the calculation of SWASV, the sensitivity of Star ZIF-8-Nafion/GCE to Cd(II) was increased by five orders of magnitude (0.5-230 µg/L), and the determination level was even low to 0.48 µg/L. Based on the high anti-interference ability and stability of the sensor, the application potential of Star ZIF-8 carbon-based metal-free nanomaterials for the detection of trace Cd(II) in was confirmed.

Mesoporous carbon decorated with MIL-100(Fe) as an electrochemical platform for ultrasensitive determination of trace cadmium and lead ions in surface water.

In this work, MIL-100(Fe)-decorated mesoporous carbon powders (MC@MIL-100(Fe)) were prepared by in situ growth of MIL-100(Fe) on the surface of ZIF-8 framework-based mesoporous carbons (MC). The hybrid material was characterized using SEM equipped with EDS mapping for morphology investigation, X-ray photoelectron spectroscopy for chemical valence analysis, and X-ray diffraction for crystal structure determination. The developed sensor separated from the traditional bismuth film decoration, and simultaneously, MC@MIL-100(Fe) was applied for the first time to electrochemically detect trace amounts of Pb(II) and Cd(II). The fabricated MC@MIL-100(Fe)-based electrochemical sensor showed excellent response to the target analytes at -0.55 and - 0.75 V for lead and cadmium ions, respectively. By adjusting some measurement parameters, that is, the loading concentration of MC@MIL-100(Fe), acidity of the HAc-NaAc buffer (ABS), deposition potential, and deposition time, the analytical performance of the proposed electrochemical sensor was examined by exploring the calibration curve, repeatability, reproducibility, stability, and anti-interference under optimized conditions. The response current of the proposed MC@MIL-100(Fe) electrochemical sensor showed a well-defined linear relationship in the concentration ranges of 2-250 and 2-270 µg·L-1 for Cd(II) and Pb(II), respectively. In addition, the detection limits of the sensor for Cd(II) and Pb(II) were 0.18 and 0.15 µg L-1, respectively, which are well below the World Health Organization (WHO) drinking water guideline value. The MC@MIL-100(Fe) can be potentially used as an electrochemical platform for monitoring heavy metals in surface water, with satisfactory results.

Down-Regulation of P450 Genes Enhances Susceptibility to Indoxacarb and Alters Physiology and Development of Fall Armyworm, Spodoptera frugipreda (Lepidoptera: Noctuidae).

The fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith), is a pest of many important crops globally. Effective control is challenging, with the pest exhibiting resistance to different synthetic pesticides across various groups. However, the mechanisms employed by resistant insects for overexpression of relevant detoxification genes remain unclear. The activity of detoxification enzymes was investigated in this study. Additionally, using RNA interference (RNAi), a functional analysis was completed of two P450s genes in an indoxacarb resistant population of fall armyworms. Elevated resistance levels (resistance ratio = 31.37-fold) in indoxacarb-selected populations of FAW were observed after 14 generations. The qRT-PCR showed higher expression of two cytochrome P450 genes, CYP321A7 and CYP6AE43, in this selected population compared to the control population. RNAi was applied to knock down the P450 dsCYP321A7 and dsCYP6AE43 genes in the FAW larvae. Droplet feeding of the dsRNAs (CYP321A7 and CYP6AE43) via an artificial diet significantly increased mortality rates in the indoxacarb treated population. A shorter larval developmental time of FAW was detected in all dsRNAs-fed larvae. Correspondingly, larval mass was reduced by dsRNAs in indoxacarb resistant populations of fall armyworm. Larval feeding assays demonstrate that dsRNAs targeting, specifically of CYP321A7 and CYP6AE43 enzymes, could be a beneficial technique in the management of indoxacarb resistant populations. Further study on the potential use of dsRNA and its application should be conducted in efforts to counter the development of resistance in FAW against various insecticides in the field.

Molecular characterization and functional analysis of cytochrome P450-mediated detoxification CYP302A1 gene involved in host plant adaptation in Spodoptera frugieprda.

The fall armyworm (FAW) Spodoptera frugiperda is a destructive and polyphagous pest of many essential food crops including maize and rice. The FAW is hard to manage, control, or eradicate, due to its polyphagous nature and voracity of feeding. Here, we report the characterization and functional analysis of the detoxification gene CYP302A1 and how S. frugieprda larvae use a detoxification mechanism to adapt host plants. Results demonstrated that CYP302A1 expression levels were much higher in midgut tissue and the older S. frugiperda larvae. Our current studies revealed the enhanced P450 activity in the midguts of S. frugiperda larvae after exposure to rice plants as compared to corn plants and an artificial diet. Furthermore, higher mortality was observed in PBO treated larvae followed by the exposure of rice plants as compared to the corn plant. The dsRNA-fed larvae showed downregulation of CYP302A1 gene in the midgut. At the same time, higher mortality, reduced larval weight and shorter developmental time was observed in the dsRNA-fed larvae followed by the exposure of rice plant as compared to the corn plant and DEPC-water treated plants as a control. These results concluded that the inducible P450 enzyme system and related genes could provide herbivores with an ecological opportunity to adapt to diverse host plants by utilizing secondary compounds present in their host plants.

Silencing an E3 Ubiquitin Ligase Gene OsJMJ715 Enhances the Resistance of Rice to a Piercing-Sucking Herbivore by Activating ABA and JA Signaling Pathways.

The RING-type E3 ubiquitin ligases play an important role in plant growth, development, and defense responses to abiotic stresses and pathogens. However, their roles in the resistance of plants to herbivorous insects remain largely unknown. In this study, we isolated the rice gene OsJMJ715, which encodes a RING-domain containing protein, and investigated its role in rice resistance to brown planthopper (BPH, Nilaparvata lugens). OsJMJ715 is a nucleus-localized E3 ligase whose mRNA levels were upregulated by the infestation of gravid BPH females, mechanical wounding, and treatment with JA or ABA. Silencing OsJMJ715 enhanced BPH-elicited levels of ABA, JA, and JA-Ile as well as the amount of callose deposition in plants, which in turn increased the resistance of rice to BPH by reducing the feeding of BPH and the hatching rate of BPH eggs. These findings suggest that OsJMJ715 negative regulates the BPH-induced biosynthesis of ABA, JA, and JA-Ile and that BPH benefits by enhancing the expression of OsJMJ715.

Comprehensive Metabolome and Volatilome Analyses in Eggplant and Tomato Reveal Their Differential Responses to Tuta absoluta Infestation.

The South American tomato pinworm, Tuta absoluta, is one of the most destructive insect pests in Solanaceae crops, particularly in tomatoes. Current methods of management have proven somewhat effective but still require a more efficacious management strategy to limit its havoc on crop yield. Tomato is much more predisposed to T. absoluta as compared with other plants such as eggplants, but the underlying causes have not been fully determined. We conducted this study to unravel the volatile organic compounds (VOCs) and primary/secondary metabolites that account for the differential response of tomatoes and eggplants to T. absoluta infestation. We performed widely targeted comparative metabolome and volatilome profiling by ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) and headspace solid-phase microextraction coupled to gas chromatography-mass spectrometry (HS-SPME/GC-MS), respectively, on eggplants and tomatoes under control and T. absoluta infestation conditions. Overall, 141 VOCs and 797 primary/secondary metabolites were identified, largely dominated by aldehyde, alcohols, alkanes, amine, aromatics, a heterocyclic compound, ketone, olefin, phenol, and terpenes. Most of the VOCs and primary/secondary metabolites from the terpene class were largely differentially regulated in eggplants compared with tomatoes. Eggplants emitted several compounds that were lower or completely absent in tomatoes either under control conditions or after T. absoluta infestation. The results from an electroantennogram showed that 35 differentially accumulated VOCs could elicit female T. absoluta response, implying that these volatile compounds significantly alter the behavior of this pest. These findings demonstrated that differentially accumulated metabolites and volatile compounds play major roles in eggplant resistance to T. absoluta infestation as these compounds were regulated upon attack by T. absoluta. Our findings can assist in integrated pest management efforts by developing appropriate control measures against T. absoluta in Solanaceae production.

Behavioral and Physiological Plasticity Provides Insights into Molecular Based Adaptation Mechanism to Strain Shift in Spodoptera frugiperda.

How herbivorous insects adapt to host plants is a key question in ecological and evolutionary biology. The fall armyworm, (FAW) Spodoptera frugiperda (J.E. Smith), although polyphagous and a major pest on various crops, has been reported to have a rice and corn (maize) feeding strain in its native range in the Americas. The species is highly invasive and has recently established in China. We compared behavioral changes in larvae and adults of a corn population (Corn) when selected on rice (Rice) and the molecular basis of these adaptational changes in midgut and antennae based on a comparative transcriptome analysis. Larvae of S. frugiperda reared on rice plants continuously for 20 generations exhibited strong feeding preference for with higher larval performance and pupal weight on rice than on maize plants. Similarly, females from the rice selected population laid significantly more eggs on rice as compared to females from maize population. The most highly expressed DEGs were shown in the midgut of Rice vs. Corn. A total of 6430 DEGs were identified between the populations mostly in genes related to digestion and detoxification. These results suggest that potential adaptations for feeding on rice crops, may contribute to the current rapid spread of fall armyworm on rice crops in China and potentially elsewhere. Consistently, highly expressed DEGs were also shown in antennae; a total of 5125 differentially expressed genes (DEGs) s were identified related to the expansions of major chemosensory genes family in Rice compared to the Corn feeding population. These results not only provide valuable insight into the molecular mechanisms in host plants adaptation of S. frugiperda but may provide new gene targets for the management of this pest.