Antibiotic feeding changes the bacterial community of Chilo suppressalis and thereby affects its pesticide tolerance.

BACKGROUND: Owing to the widespread use of chemical pesticides to control agricultural pests, pesticide tolerance has become a serious problem. In recent years, it has been found that symbiotic bacteria are related to pesticides tolerance. To investigate the potential role of microorganisms in the pesticide tolerance of Chilo suppressalis, this study was conducted. RESULTS: The insect was fed with tetracycline and cefixime as the treatment group (TET and CFM, respectively), and did not add antibiotics in the control groups (CK). The 16S rDNA sequencing results showed that antibiotics reduced the diversity of C. suppressalis symbiotic microorganisms but did not affect their growth and development. In bioassays of the three C. suppressalis groups (TET, CFM, and CK), a 72 h LC50 fitting curve was calculated to determine whether long-term antibiotic feeding leads to a decrease in pesticide resistance. The CK group of C. suppressalis was used to determine the direct effect of antibiotics on pesticide tolerance using a mixture of antibiotics and pesticides. Indirect evidence suggests that antibiotics themselves did not affect the pesticide tolerance of C. suppressalis. The results confirmed that feeding C. suppressalis cefixime led to a decrease in the expression of potential tolerance genes to chlorantraniliprole. CONCLUSIONS: This study reveals the impact of antibiotic induced changes in symbiotic microorganisms on the pesticide tolerance of C. suppressalis, laying the foundation for studying the interaction between C. suppressalis and microorganisms, and also providing new ideas for the prevention and control of C. suppressalis and the creation of new pesticides.

Assessment of microbial flora and pesticidal effect of vermicast generated from Azadirachta indica (neem) for developing a biofertilizer-cum-pesticide as a single package.

The soil comprising organic matter, nutrients, serve as substrate for plant growth and various organisms. In areas where there are large plantations, there is a huge leaf litter fall. The leaf litter upon decomposition releases nutrients and helps in nutrient recycling, for which the soil engineers such as earthworms, ants and termites are important key players. In this context, the present study was conducted to assess the characteristics of the vermicast obtained by vermicomposting neem leaf litter in terms of microbial flora, plant growth promoting properties and antagonistic activities of the vermicast against phytopathogens. Vermicomposting of neem leaf litter was done using two epigeic earthworm species Eisenia fetida and Eudrilus eugeniae. The vermicast exhibited antagonistic potential against plant pathogens. Out of the four vermiwash infusions studied, the 75 % formulation reduced the disease incidence against mealybug by 82 % in the tree Neolamarkia cadamba. The result of the study suggests that vermicast made from neem leaf litter may be a potent combination of a biofertilizer and a pesticide.

Smart and Sustainable Crop Protection: Design and Evaluation of a Novel α-Amylase-Responsive Nanopesticide for Effective Pest Control.

In this study, an α-amylase-responsive controlled-release formulation was developed by capping polydopamine onto ß-cyclodextrin-modified abamectin-loaded hollow mesoporous silica nanoparticles. The prepared Aba@HMS@CD@PDA were subjected to characterization using various analytical techniques. The findings revealed that Aba@HMS@CD@PDA, featuring a loading rate of 18.8 wt %, displayed noteworthy release behavior of abamectin in the presence of α-amylase. In comparison to abamectin EC, Aba@HMS@CD@PDA displayed a significantly foliar affinity and improved rainfastness on lotus leaves. The results of field trail demonstrated a significantly higher control efficacy against Spodoptera litura Fabricius compared to abamectin EC at all concentrations after 7, 14, and 21 days of spaying, showcasing the remarkable persistence of Aba@HMS@CD@PDA. These results underscore the potential of Aba@HMS@CD@PDA as a novel and persistently effective strategy for sustainable on-demand crop protection. The application of nanopesticides can enhance the effectiveness and efficiency of pesticide utilization, contributing to more sustainable agricultural practices.

Quinoline Derivatives in Discovery and Development of Pesticides.

Finding highly active molecular scaffold structures is always the key research content of new pesticide discovery. In the research and development of new pesticides, the discovery of new agricultural molecular scaffold structures and new targets still faces great challenges. In recent years, quinoline derivatives have developed rapidly in the discovery of new agriculturally active molecules, especially in the discovery of fungicides. The unique quinoline scaffold has many advantages in the discovery of new pesticides and can provide innovative and feasible solutions for the discovery of new pesticides. Therefore, we reviewed the use of quinoline derivatives and their analogues as molecular scaffolds in the discovery of new pesticides since 2000. We systematically summarized the agricultural biological activity of quinoline compounds and discussed the structure-activity relationship (SAR), physiological and biochemical properties, and mechanism of action of the active compounds, hoping to provide ideas and inspiration for the discovery of new pesticides.

The impacts of water quality on the amphibian chytrid fungal pathogen: A systematic review.

The pathogenic fungus Batrachochytrium dendrobatidis has caused declines of amphibians worldwide. Yet our understanding of how water quality influences fungal pathogenicity is limited. Here, we reviewed experimental studies on the effect of water quality on this pathogen to determine which parameters impacted disease dynamics consistently. The strongest evidence for protective effects is salinity which shows strong antifungal properties in hosts at natural levels. Although many fungicides had detrimental effects on the fungal pathogen in vitro, their impact on the host is variable and they can worsen infection outcomes. However, one fungicide, epoxiconazole, reduced disease effects experimentally and likely in the field. While heavy metals are frequently studied, there is weak evidence that they influence infection outcomes. Nitrogen and phosphorous do not appear to impact pathogen growth or infection in the amphibian host. The effects of other chemicals, like pesticides and disinfectants on infection were mostly unclear with mixed results or lacking an in vivo component. Our study shows that water chemistry does impact disease dynamics, but the effects of specific parameters require more investigation. Improving our understanding of how water chemistry influences disease dynamics will help predict the impact of chytridiomycosis, especially in amphibian populations affected by land use changes.

Mimicking natural deterrent strategies in plants using adhesive spheres.

With a continuous increase in world population and food production, chemical pesticide use is growing accordingly, yet unsustainably. As chemical pesticides are harmful to the environment and developmental resistance in pests is increasing, a sustainable and effective pesticide alternative is needed. Inspired by nature, we mimic one defense strategy of plants, glandular trichomes, to shift away from using chemical pesticides by moving toward a physical immobilization strategy via adhesive particles. Through controlled oxidation of a biobased starting material, triglyceride oils, an adhesive material is created while monitoring the reactive intermediates. After being milled into particles, nanoindentation shows these particles to be adhesive even at low contact forces. A suspension of particles is then sprayed and found to be effective at immobilizing a target pest, thrips, Frankliniella occidentalis. Small arthropod pests, like thrips, can cause crop damage through virus transfer, which is prevented by their immobilization. We show that through a scalable fabrication process, biosourced materials can be used to create an effective, sustainable physical pesticide.

Chalcones-Features, Identification Techniques, Attributes, and Application in Agriculture.

This review article is a comprehensive and current overview on chalcones, covering their sources, identification methods, and properties with a particular focus on their applications in the agricultural sector. The widespread use of synthetic pesticides has not only led to increased resistance among weeds and pests, resulting in economic losses, but it has also raised significant health concerns due to the overuse of these chemicals. In line with the European Green Deal 2030 and its Farm to Fork strategy, there is a targeted 50% reduction in the use of chemical pesticides by 2030, emphasizing a shift towards natural alternatives that are more environmentally sustainable and help in the restoration of natural resources. Chalcones and their derivatives, with their herbicidal, fungicidal, bactericidal, and antiviral properties, appear to be ideal candidates. These naturally occurring compounds have been recognized for their beneficial health effects for many years and have applications across multiple areas. This review not only complements the previous literature on the agricultural use of chalcones but also provides updates and introduces methods of detection such as chromatography and MALDI technique.

Recent Advances and Outlook of Benzopyran Derivatives in the Discovery of Agricultural Chemicals.

Scaffold structures, new mechanisms of action, and targets present enormous challenges in the discovery of novel pesticides. The discovery of new scaffolds is the basis for the continuous development of modern agrochemicals. Identification of a good scaffold such as triazole, carbamate, methoxy acrylate, pyrazolamide, pyrido-pyrimidinone mesoionic, and bisamide often leads to the development of a new series of pesticides. In addition, pesticides with the same target, including the inhibitors of succinate dehydrogenase (SDH), oxysterol-binding-protein, and p-hydroxyphenyl pyruvate dioxygenase (HPPD), may have the same or similar scaffold structure. Recent years have witnessed significant progress in the discovery of new pesticides using natural products as scaffolds or bridges. In recent years, there have been increasing reports on the application of natural benzopyran compounds in the discovery of new pesticides, especially osthole and coumarin. A systematic and comprehensive review of benzopyran active compounds in the discovery of new agricultural chemicals is helpful to promote the discussion and development of benzopyran active compounds. Therefore, this work systematically reviewed the research and application of benzopyran derivatives in the discovery of agricultural chemicals, summarized the antiviral, herbicidal, antibacterial, fungicidal, insecticidal, nematicidal and acaricidal activities of benzopyran active compounds, and discussed the structural-activity relationship and mechanism of action. In addition, some active fragments were recommended to further optimize the chemical structure of benzopyran active compounds based on reference information.

Adhesion Peptide-Functionalized Biobased Microgels for Controlled Delivery of Pesticides.

Widespread use of plant protection agents in agriculture is a major cause of pollution. Apart from active ingredients, the environmental impact of auxiliary synthetic polymers should be minimized if they are highly persistent. An alternative to synthetic polymers is the use of natural polysaccharides, which are abundant and biodegradable. In this study, we explore pectin microgels functionalized with anchor peptides (P-MAPs) to be used as an alternative biobased pesticide delivery system. Using copper as the active ingredient, P-MAPs effectively prevented infection of grapevine plants with downy mildew under semi-field conditions on par with commercial copper pesticides. By using anchor peptides, the microgels tightly bind to the leaf surface, exhibiting excellent rain fastness and prolonged fungicidal activity. Finally, P-MAPs are shown to be easily degradable by enzymes found in nature, demonstrating their negligible long-term impact on the environment.

Encapsulated allyl isothiocyanate improves soil distribution, efficacy against soil-borne pathogens and tomato yield.

BACKGROUND: Crop quality, yield and farmer income are reduced by soil-borne diseases, nematodes and weeds, although these can be controlled by allyl isothiocyanate (AITC), a plant-derived soil fumigant. However, its efficacy against soil-borne pathogens varies, mainly because of its chemical instability and uneven distribution in the soil. Formulation modification is an effective way to optimize pesticide application. We encapsulated AITC in modified diatomite granules (GR) and measured the formulation's loading content and stability, environmental fate and efficacy against soil-borne pathogens, and its impact on the growth and yield of tomatoes. RESULTS: We observed that an AITC loading content in the granules of 27.6% resulted in a degradation half-life of GR that was 1.94 times longer than 20% AITC emulsifiable concentrate in water (EW) and shorter than AITC technical (TC) grade. The stable and more even distribution of GR in soil resulted in relatively consistent and acceptable control of soil-borne pathogens. Soil containing AITC residues that remained 10-24 days after GR fumigation were not phytotoxic to cucumber seeds. GR significantly reduced soil-borne pest populations, and tomato growth and yield increased as AITC dosage increased. GR containing an AITC dose of 20 g m-2 effectively controlled pathogens in soil for about 7 months and improved tomato yield by 108%. CONCLUSION: Our research demonstrates the benefits of soil fumigation with loaded AITC over other formulations for effective pest control, and improved tomato plant growth and fruit yield. Fumigant encapsulation appears to be a useful method to improve pest and disease control, environmental performance and fumigant commercial sustainability. © 2024 Society of Chemical Industry.

Construction and Single-Crystal Structures of N-Isoxazolin-5-ylcarbonylindole Derivatives, and Their Pesticidal Activities and Toxicology Study.

To explore natural product-based pesticide candidates, a series of indole derivatives containing the isoxazoline skeleton at the N-1 position were synthesized by 1,3-dipolar [2 + 3] cycloaddition reaction. Their structures were characterized by melting points (mp), infrared (IR) spectra, proton nuclear magnetic resonance spectra (1H NMR), carbon-13 nuclear magnetic resonance spectra (13C NMR), and high resolution mass spectrometry (HRMS). The single-crystal structures of five compounds were presented. Against Tetranychus cinnabarinus Boisduval, compound 3b showed greater than 3.8-fold acaricidal activity of indole and good control effects under glasshouse conditions. Against Aphis citricola Van der Goot, compounds 3b and 3q exhibited 48.3- and 36.8-fold aphicidal activity of indole and 6-methylindole, respectively. Particularly, compound 3b showed good bioactivities against T. cinnabarinus and A. citricola. Against Eriosoma lanigerum Hausmann, compound 3h and 3i showed 2.1 and 1.9 times higher aphicidal activity compared to indole. Furthermore, the construction of the epidermal cuticle layer of 3b-treated carmine spider mites was distinctly damaged, which ultimately led to their death.

A Smart Pesticide-Controlled Release Platform with Dual Stimuli-Responsive Functions for Enhanced Treatment of Plant Black Shank.

Realizing controllable input of botanical pesticides is conducive to improving pesticide utilization, reducing pesticide residues, and avoiding environmental pollution but is extremely challenging. Herein, we constructed a smart pesticide-controlled release platform (namely, SCRP) for enhanced treatment of tobacco black shank based on encapsulating honokiol (HON) with mesoporous hollow structured silica nanospheres covered with pectin and chitosan oligosaccharide (COS). The SCRP has a loading capacity of 12.64% for HON and could effectively protect HON from photolysis. Owing to the pH- and pectinase-sensitive property of the pectin, the SCRP could smartly release HON in response to a low pH or a rich pectinase environment in the black shank-affected area. Consequently, the SCRP effectively inhibits the infection of P. nicotianae on tobacco with a controlled rate for tobacco black shank of up to 87.50%, which is mainly due to the SCRP's capability in accumulating ROS, changing cell membrane permeability, and affecting energy metabolism. In addition, SCRP is biocompatible, and the COS layer enables SCRP to show a significant growth-promoting effect on tobacco. These results indicate that the development of a stimuli-responsive controlled pesticide release system for plant disease control is of great potential and value for practical agriculture production.

Combined effects of polyethylene microplastics and carbendazim on Eisenia fetida: A comprehensive ecotoxicological study.

Microplastic (MP) pollution is becoming an emerging environmental concern across aquatic and terrestrial ecosystems. Plastic mulching and the use of pesticides in agriculture can lead to microplastics and agrochemicals in soil, which can result in unintended exposure to non-target organisms. The combined toxicity of multiple stressors represents a significant paradigm shift within the field of ecotoxicology, and its exploration within terrestrial ecosystems involving microplastics is still relatively limited. The present study investigated the combined effects of polyethylene MP (PE-MP) and the agrochemical carbendazim (CBZ) on the earthworm Eisenia fetida at different biological levels of organization. While E. fetida survival and reproduction did not exhibit significant effects following PE-MP treatment, there was a reduction in cocoon and hatchling numbers. Notably, prolonged exposure revealed delayed toxicity, leading to substantial growth impairment. Exposure to CBZ led to significant alterations in the endpoints mentioned above. While there was a decrease in cocoon and hatchling numbers, the combined treatment did not yield significant effects on earthworm reproduction except at higher concentrations. However, lower concentrations of PE-MP alongside CBZ induced a noteworthy decline in biomass content, signifying a form of potentiation interaction. In addition, concurrent exposure led to synergistic effects, from oxidative stress to modifications in vital organs such as the body wall, intestines, and reproductive structures (spermathecae, seminal vesicles, and ovarian follicles). The comparison of multiple endpoints revealed that seminal vesicles and ovarian follicles were the primary targets during the combined exposure. The research findings suggest that there are variable and complex responses to microplastic toxicity in terrestrial ecosystems, especially when combined with other chemical stressors like agrochemicals. Despite these difficulties, the study implies that microplastics can alter earthworms' responses to agrochemical exposure, posing potential ecotoxicological risks to soil fauna.

Multi-Stimuli-Responsive, Topology-Regulated, and Lignin-Based Nano/Microcapsules from Pickering Emulsion Templates for Bidirectional Delivery of Pesticides.

The increasing demand for improving pesticide utilization efficiency has prompted the development of sustainable, targeted, and stimuli-responsive delivery systems. Herein, a multi-stimuli-responsive nano/microcapsule bidirectional delivery system loaded with pyraclostrobin (Pyr) is prepared through interfacial cross-linking from a lignin-based Pickering emulsion template. During this process, methacrylated alkali lignin nanoparticles (LNPs) are utilized as stabilizers for the tunable oil-water (O/W) Pickering emulsion. Subsequently, a thiol-ene radical reaction occurs with the acid-labile cross-linkers at the oil-water interface, leading to the formation of lignin nano/microcapsules (LNCs) with various topological shapes. Through the investigation of the polymerization process and the structure of LNC, it was found that the amphiphilicity-driven diffusion and distribution of cyclohexanone impact the topology of LNC. The obtained Pyr@LNC exhibits high encapsulation efficiency, tunable size, and excellent UV shielding to Pyr. Additionally, the flexible topology of the Pyr@LNC shell enhances the retention and adhesion of the foliar surface. Furthermore, Pyr@LNC exhibits pH/laccase-responsive targeting against Botrytis disease, enabling the intelligent release of Pyr. The in vivo fungicidal activity shows that efficacy of Pyr@LNC is 53% ± 2% at 14 days postspraying, whereas the effectiveness of Pyr suspension concentrate is only 29% ± 4%, and the acute toxicity of Pyr@LNC to zebrafish is reduced by more than 9-fold compared with that of Pyr technical. Moreover, confocal laser scanning microscopy shows that the LNCs can be bidirectionally translocated in plants. Therefore, the topology-regulated bidirectional delivery system LNC has great practical potential for sustainable agriculture.

A study of integrated pest management models with instantaneous and non-instantaneous impulse effects.

The occurrence of pests and diseases during agricultural production affects the quality and quantity of agricultural products. It is important to evaluate the impact of various factors on pests to achieve optimal results of integrated pest management (IPM) during its implementation. In this paper, we considered the transient and non-transient effects of chemical control on pests and the effects on natural enemies at different times, and developed a corresponding pest control model. Detailed studies and comparisons were conducted for spraying pesticides either more or less frequently as compared to strategies for releasing natural enemies. The threshold conditions for global asymptotic stabilization of the pest extinction period solution was obtained. Using two-parameter and sensitivity analysis techniques, the parameters affecting the variation of the threshold were discussed. By comparing these two pest control strategies, we found the existence of optimal application and release frequencies. Finally, in order to control pests below the economic threshold level, the state-dependent pest model was numerically investigated. The results show that the presence or absence of chemical control of pests can depend on the values taken for the parameters in the model. Based on this information, pest control experts can make decisions about the best spraying time and the best release rate.

Design, Synthesis, and Biological Activities of Novel Coumarin Derivatives as Pesticide Candidates.

Food security is an important issue in the 21st century; preventing and controlling crop diseases and pests are the key to solve this problem. The creation of new pesticides based on natural products is an important and effective method. Herein, coumarins were selected as parent structures, and a series of their derivatives were designed, synthesized, and evaluated for their antiviral activities, fungicidal activities, and insecticidal activities. We found that coumarin derivatives exhibited good to excellent antiviral activities against tobacco mosaic virus (TMV). The antiviral activities of I-1, I-2a, I-4b, II-2c, II-2g, II-3, and II-3b are better than that of ribavirin at 500 µg/mL. Molecular docking research showed that these compounds had a strong interaction with TMV CP. These compounds also showed broad-spectrum fungicidal activities against 14 plant pathogenic fungi. The EC50 values of I-1, I-2a, I-3c, and II-2d are in the range of 1.56-8.65 µg/mL against Rhizoctonia cerealis, Physalospora piricola, Sclerotinia sclerotiorum, and Pyricularia grisea. Most of the compounds also displayed good insecticidal activities against Mythimna separata. Pesticide-likeness analysis showed that these compounds are following pesticide-likeness and have the potential to be developed as pesticide candidates. The present work lays a foundation for the discovery of novel pesticide lead compounds based on coumarin derivatives.

(4Z)-Lachnophyllum Lactone, a Metabolite with Phytotoxic and Antifungal Activity against Pests Affecting Mediterranean Agriculture: A New Versatile and Easy Scalable Parallel Synthesis.

A methodology for the total and modulable synthesis of (4Z)-lachnophyllum lactone (1), on a gram scale, is reported for the first time. The present work started with the design of a retrosynthetic pathway for the target compound, with the key step identified in Pd-Cu bimetallic cascade cross-coupling cyclization. (4Z)-Lachnophyllum lactone (1) is an acetylenic furanone previously isolated, in a low amount, from the organic extract of the autotrophic weedConyza bonariensis. Tested against the stem parasitic weed Cuscuta campestris in a seedling growth bioassay, (4Z)-lachnophyllum lactone (1) showed almost 85% of inhibitory activity up to 0.3 mM in comparison with the control. At the same concentration, the compound displayed radicle growth inhibitory activity of the root parasitic weeds Orobanche minor and Phelipanche ramosa higher than 70 and 40%, respectively. Surprisingly, the compound showed a high percentage of inhibition, up to 0.1 mM, on C. bonariensis seed germination too. This versatile synthetic strategy was also used to obtain two further natural analogues, namely, (4E)-lachnophyllum lactone (8) and (4Z,8Z)-matricaria lactone (9), that showed, in most cases, the same inhibitory trend with slight differences, highlighting the importance of the stereochemistry and unsaturation of the side chain. Furthermore, all of the compounds showed antifungal activity at 1 mM reducing the mycelial growth of the olive pathogen Verticillium dahliae. The design and implementation of scalable and modulable total synthesis on a gram scale of acetylenic furanones allow the production of a large amount of these natural products, overcoming the limit imposed by isolation from natural sources. The results of the present study pave the way for the development of ecofriendly bioinspired pesticides with potential application in agrochemical practices as alternative to synthetic pesticides.

"One-Pot" Method Preparation of Dendritic Mesoporous Silica-Loaded Matrine Nanopesticide for Noninvasive Administration Control of Monochamus alternatus: The Vector Insect of Bursapherenchus xylophophilus.

Monochamus alternatus is an important stem-boring pest in forestry. However, the complex living environment of Monochamus alternatus creates a natural barrier to chemical control, resulting in a very limited control effect by traditional insecticidal pesticides. In this study, a stable pesticide dendritic mesoporous silica-loaded matrine nanopesticide (MAT@DMSNs) was designed by encapsulating the plant-derived pesticide matrine (MAT) in dendritic mesoporous silica nanoparticles (DMSNs). The results showed that MAT@DMSNs, sustainable nanobiopesticides with high drug loading capacity (80%) were successfully constructed. The release efficiency of DMSNs at alkaline pH was slightly higher than that at acidic pH, and the cumulative release rate of MAT was about 60% within 25 days. In addition, the study on the toxicity mechanism of MAT@DMSNs showed MAT@DMSNs were more effective than MAT and MAT (0.3% aqueous solutions) in touch and stomach toxicity, which might be closely related to their good dispersibility and permeability. Furthermore, MAT@DMSNs are also involved in water transport in trees, which can further transport the plant-derived insecticides to the target site and improve its insecticidal effect. Meanwhile, in addition, the use of essential oil bark penetrants in combination with MAT@DMSNs effectively avoids the physical damage to pines caused by traditional trunk injections and the development of new pests and diseases induced by the traditional trunk injection method, which provides a new idea for the application of biopesticides in the control of stem-boring pests in forestry.

3-(Methylthio)Propionic Acid from Bacillus thuringiensis Berliner Exhibits High Nematicidal Activity against the Root Knot Nematode Meloidogyne incognita (Kofoid and White) Chitwood.

Root knot nematodes cause serious damage to global agricultural production annually. Given that traditional chemical fumigant nematicides are harmful to non-target organisms and the environment, the development of biocontrol strategies has attracted significant attention in recent years. In this study, it was found that the Bacillus thuringiensis Berliner strain NBIN-863 exhibits strong fumigant nematicidal activity and has a high attraction effect on Meloidogyne incognita (Kofoid and White) Chitwood. Four volatile organic compounds (VOCs) produced by NBIN-863 were identified using solid-phase microextraction and gas chromatography-mass spectrometry. The nematicidal activity of four VOCs, namely, N-methylformamide, propenamide, 3-(methylthio)propionic acid, and phenylmalonic acid, was detected. Among these compounds, 3-(methylthio)propionic acid exhibited the highest direct contact nematicidal activity against M. incognita, with an LC50 value of 6.27 µg/mL at 24 h. In the fumigant bioassay, the mortality rate of M. incognita treated with 1 mg/mL of 3-(methylthio)propionic acid for 24 h increased to 69.93%. Furthermore, 3-(methylthio)propionic acid also exhibited an inhibitory effect on the egg-hatching of M. incognita. Using chemotaxis assays, it was determined that 3-(methylthio)propionic acid was highly attractive to M. incognita. In pot experiments, the application of 3-(methylthio)propionic acid resulted in a reduction in gall numbers, decreasing the number of galls per gram of tomato root from 97.58 to 6.97. Additionally, the root length and plant height of the treated plants showed significant increases in comparison with the control group. The current study suggests that 3-(methylthio)propionic acid is a novel nematicidal virulence factor of B. thuringiensis. Our research provides evidence for the potential use of NBIN-863 or its VOCs in biocontrol against root knot nematodes.

JAK/STAT signaling regulated intestinal regeneration defends insect pests against pore-forming toxins produced by Bacillus thuringiensis.

A variety of coordinated host-cell responses are activated as defense mechanisms against pore-forming toxins (PFTs). Bacillus thuringiensis (Bt) is a worldwide used biopesticide whose efficacy and precise application methods limits its use to replace synthetic pesticides in agricultural settings. Here, we analyzed the intestinal defense mechanisms of two lepidopteran insect pests after intoxication with sublethal dose of Bt PFTs to find out potential functional genes. We show that larval intestinal epithelium was initially damaged by the PFTs and that larval survival was observed after intestinal epithelium regeneration. Further analyses showed that the intestinal regeneration caused by Cry9A protein is regulated through c-Jun NH (2) terminal kinase (JNK) and Janus tyrosine kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathways. JAK/STAT signaling regulates intestinal regeneration through proliferation and differentiation of intestinal stem cells to defend three different Bt proteins including Cry9A, Cry1F or Vip3A in both insect pests, Chilo suppressalis and Spodoptera frugiperda. Consequently, a nano-biopesticide was designed to improve pesticidal efficacy based on the combination of Stat double stranded RNA (dsRNA)-nanoparticles and Bt strain. This formulation controlled insect pests with better effect suggesting its potential use to reduce the use of synthetic pesticides in agricultural settings for pest control.