Search Results (85)

Biosynthesized ZnO nanostructures were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), ultraviolet–visible (UV-vis) spectroscopy, and Fourier transform–infrared (FT-IR) spectroscopy. XRD confirmed a hexagonal wurtzite phase with an average crystallite size of 36.44 nm, while UV-vis spectroscopy showed a distinct absorption peak at 321 nm. The Zeta potential of the ZnO nanostructures was −24.28 mV, indicating high stability in suspension, which is essential for their dispersion and functionality in biological and environmental applications. The nematicidal activity of ZnO was evaluated in vitro at concentrations of 150, 300, 450, and 600 ppm, with the highest concentration achieving 75.71% mortality of second-stage juveniles (J2s) after 72 h. The calculated LC₅₀ values for the treatments were 270.33 ppm at 72 h. Additionally, molecular docking studies indicated significant interactions between the ZnO nanostructures and nematode proteins, HSP-90 and ODR1, supporting their potential nematicidal mechanism. This research highlights the effectiveness of neem leaf extract-mediated ZnO nanostructures as an eco-friendly, sustainable alternative for nematode control, presenting a promising solution for agricultural pest management. Full article

Plant-parasitic nematodes represent a significant threat to agriculture, causing substantial economic losses worldwide. Among the biological alternatives for their control, the genus Trichoderma has emerged as a promising solution for suppressing various nematode species. This article reviews key studies on the interaction between Trichoderma spp. and plant-parasitic nematodes, highlighting the most studied species such as Trichoderma harzianum, Trichoderma longibrachiatum, Trichoderma virens, and Trichoderma viride, mainly against the genera Meloidogyne, Pratylenchus, Globodera, and Heterodera. Trichoderma spp. act through mechanisms such as mycoparasitism, antibiosis, competition for space in the rhizosphere, production of lytic enzymes, and modulation of plant defense responses. They also produce metabolites that affect nematode mobility, reproduction, and survival, such as gliotoxin, viridin and cyclosporine A. In addition, they secrete enzymes such as chitinases, proteases, lipases, and glucanases, which degrade the cuticle of nematodes and their eggs. Furthermore, Trichoderma spp. induce systemic resistance in plants through modulation of phytohormones such as jasmonic acid, ethylene, salicylic acid and auxins. The use of Trichoderma in integrated nematode management enables its application in combination with crop rotation, organic amendments, plant extracts, and resistant varieties, thereby reducing the reliance on synthetic nematicides and promoting more sustainable and climate-resilient agriculture. Full article

This study evaluated the chemical properties of phosphocompost extracts and their effectiveness in inducing tomato seedlings resistance to Meloidogyne javanica. Phosphocomposts: Sugar beet phosphocompost (PC-SB: CP2), green waste phosphocompost (PC-GW: CP3), and olive mill waste phosphocompost (PC-OMW: CP4), were utilized to produce compost water extracts at concentrations of 1:5, 1:10, 1:20, and 1:100 g:mL and then applied as soil drenches for tomato seedlings one-week post-inoculation. The CP2 extract applied at a 1:5 dilution led to marked improvements in growth parameters, with plant height increasing by over 52.2%, shoot fresh biomass rising by approximately 52.44%, and shoot dry biomass showing a gain of 62.21%. Root biomass also rose by 33%. Chlorophyll a increased with CP4 at 1:5 and 1:100 (41.05% and 37.32%), chlorophyll b increased with CP3 at 1:5 and 1:10 (22.34% and 7.59%), while carotenes showed no variation. Polyphenols rose by 86.45–91.01% with CP2 from 1:5 to 1:20, and flavonoids increased by 64.90% with CP4 at 1:10. CP2 diminished the ultimate M. javanica population and reproduction factor by 171.43%, while CP4 at 1:20 decreased egg masses by 151.94%. The root gall index showed no variation. The chemical composition of phosphocomposts revealed that the strategic incorporation of diverse organic improvers (10%) in phosphocomposts yielded distinct nutrient signatures, with sugar beet waste enhancing PO₄³⁻ (12.91 mg/L) and secondary macronutrients, green waste optimizing NO₃⁻ (69.91 mg/L) and SO₄²⁻ (62.70 mg/L) availability, and olive mill waste producing superior micronutrient concentrations alongside dominant Ca (24.21 mg/L), K (392.50 mg/L), and P (9.17 mg/L) levels. Overall, the results underscore the potential of phosphocompost extracts as a viable, low-cost, and eco-friendly alternative to synthetic nematicides, offering a sustainable and resilient approach to M. javanica control while enhancing tomato plant growth. Full article

Ruta graveolens L. has been described as possessing antifungal and nematicidal activity. Among the bioactive compounds present in this plant, alkaloids and furanocoumarins have attracted considerable attention. The aim of this study was to evaluate the in vitro biological activity of extracts from rue enriched in bioactive compounds against Fusarium oxysporum, F. circinatum, and Meloidogyne incognita, and to correlate the chemical profile of the extracts with their biological activities. Six extracts with contrasting chemical profiles, obtained by pressurized liquid extraction and supercritical fluid extraction using green solvents, were selected for biological evaluation. The highest F. oxysporum growth inhibition was achieved with the extracts enriched in fatty acids and furanocoumarins at concentrations of 4, 8, and 16 mg/mL, while for F. circinatum, the highest growth inhibition was obtained using the extract enriched in terpenes at 16 mg/mL; moreover, the six extracts evaluated caused mortality in M. incognita. Therefore, enriched extracts of R. graveolens might be considered as an alternative for pathogen control on economically important crops such as potatoes, tomatoes, and onions, among others. Correlations between biological activities and chemical compositions suggest the importance of fatty acids against F. oxysporum, fatty acids and terpenes against F. circinatum, and alkaloids, coumarins, and furanocoumarins for M. incognita. Full article

In the frame of a “greener agriculture”, the development of new natural pesticides that are safer than their synthetic counterparts is gaining ground. Nonetheless, the origin of their nature does not necessarily imply their eco-friendliness. Hence, specific ecotoxicological studies are needed, with products being subjected to hazard and consequent risk assessment, for registration purposes. We have previously described on the strong nematicidal activity of Melia azedarach (chinaberry), Petroselinum crispum (parsley) and Eruca sativa (rocket) against the nematode Meloidogyne incognita. With this study the effect of the above-mentioned nematicidal botanicals on Eisenia fetida, Enchytraeus albidus, Daphnia magna and Danio rerio (Zebrafish) is reported, being all model organisms for the study of ecotoxicology of pesticides under registration. The implemented protocols are according to the OECD standards used for the evaluation of formulates under authorization. NOEC values were estimated to be higher than the highest concentrations assessed as recommended by OECD guidelines (≥1000 mg test item/kg dry soil). According to the presented results, all tested botanical nematicidals proved ecofriendly, not hindering the reproduction of juvenile worms of Eisenia fetida, and Enchytraeus albidus. Notably, Petroselinum crispum exhibited beneficial effects on reproduction of Eisenia fetida, as the number of juveniles increased. M. azedarach extract demonstrated moderate toxicity to zebrafish embryos (LC₅₀ was 51.41 ± 1.67 mg/L), yet it did not elicit adverse effects on the zebrafish liver. Thus, chinaberry, parsley and rocket are promising to be developed into new “green” nematicides. Full article

Plant-parasitic nematodes are highly damaging pests responsible for heavy losses in a considerable number of plant crops. Common pest management strategies rely on the use of synthetic chemical nematicides, which have led to serious concerns regarding their impact on human health and the environment. The essential oils (EOs) obtained from aromatic plant species can provide a good source of agents for the sustainable control of nematodes, due to higher biodegradability, generally low toxicity for mammals, fish, and birds, and lower bioaccumulation in the environment. This study aimed to evaluate the nematicidal and nematostatic properties of EOs extracted from plant species relevant to Macaronesia flora or with widespread use as culinary herbs in Mediterranean cuisine. Eighteen EOs were chemically characterized and evaluated by direct contact and hatching bioassays on the root-knot nematode Meloidogyne javanica. The EOs that showed a significant effect on M. javanica second-stage juveniles’ (J2) mortality (≥40%) were also used in chemotaxis assays. From the eighteen EOs, seven showed strong nematicidal activity (>80%) and hatching inhibition. The chemotaxis assays revealed that only Mentha pulegium exhibited repellent behavior for M. javanica J2, and the rest of EOs had attractive behavior. Furthermore, EOs were assessed against the root-lesion nematode Pratylenchus penetrans and the pinewood nematode Bursaphelenchus xylophilus. Cinnamomum burmanni was the EO with the highest nematicidal activity for the three nematode species. Among the terpene-rich EOs, high mortality values and hatching inhibition for M. javanica were observed for the carvacrol chemotype Origanum vulgare, albeit with low activity for P. penetrans and B. xylophilus. Mentha pulegium, mainly composed of monoterpene ketones and monoterpenoids, demonstrated moderate-to-high mortality activity (from 30% for P. penetrans to 99% for M. javanica) for the three nematode species. Full article

Endolichenic fungi represent an important ecological group of microorganisms that form associations with photobionts in the lichen thallus. These endofungi that live in and coevolve with lichens are known for synthesizing secondary metabolites with novel structures and diverse chemical skeletons making them an unexplored microbial community of great interest. As part of our search for new phytoprotectants, in this work, we studied the endolichenic fungus Xylaria sp. isolated from the lichen Hypogymnia tubulosa, which grows as an epiphyte on the bark of the endemic Canarian tree Pinus canariensis. From the extract of the liquid fermentation, we isolated two unreported piliformic derivatives, (+)-9-hydroxypiliformic acid (1) and (+)-8-hydroxypiliformic acid (2), along with four previously reported compounds, (+)-piliformic acid (3), hexylaconitic acid A anhydride (4), 2-hydroxyphenylacetic acid (5), and 4-hydroxyphenylacetic acid (6). Their structures were elucidated based on NMR and HRESIMS data. The extract and the isolated compounds were tested for their insect antifeedant (Myzus persicae, Rhopalosiphum padi, and Spodoptera littoralis), antifungal (Alternaria alternata, Botrytis cinerea, and Fusarium oxysporum), nematicidal (Meloidogyne javanica), and phytotoxic effects on mono- and dicotyledonous plant models (Lolium perenne and Lactuca sativa). Compounds 4, 5, and 6 were effective antifeedants against M. persicae and 4 was also active against R. padi. Moreover, 3 and 4 showed antifungal activity against B. cinerea and 4 was the only nematicidal. The extract had a strong phytotoxic effect on L. sativa and L. perenne growth, with compounds 3, 4, and 5 identified as the phytotoxic agents, while at low concentrations compounds 3 and 4 stimulated L. sativa root growth. Full article

The most common and damaging plant parasitic nematodes are root-knot nematodes (RNK). Although hemp has been clearly infected by RNK, little information is available regarding the extent of the damage and losses caused. In addition, no information is available concerning hemp seed extracts’ activity against RNK. In the current research, a greenhouse experiment was developed to evaluate the infection effect of five RKN species (Meloidogyne javanica, M. incognita, M. arenaria, M. hapla, and M. luci) in nine industrial hemp varieties (Fedora 17, Ferimon 12, Futura 75, Santhica 27, Santhica 70, KC Dora, KC Zuzana, Zenit, and USO 31), as was a laboratory experiment to evaluate the nematicidal activity of aqueous and water extracts of hemp seeds against second-stage juveniles (J2s) of M. javanica. The results revealed that the five evaluated Meloidogyne species were pathogenic to hemp plants. The lowest shoot weights were recorded in plants that were inoculated with M. javanica and M. luci (4.65 and 4.53 g, respectively). As for the root system, the most severe damage of the roots was detected in M. incognita-infected plants, presenting the lowest root weight (1.72 g). Regarding hemp varieties, the most susceptible were USO 31, Fedora 17, Ferimon 12, and Zenit, while Futura 75 hosted the lowest nematode numbers, including the lowest values of females per gram of root (10.66), number of egg masses per gram of root (4.70), and fecundity (33.68 eggs per egg mass). Moreover, this research showed that aqueous and ethanolic hemp seed extracts can control M. javanica. After 24, 48, 72, and 96 h of exposure to high concentrations (250–2000 ppm) of ethanolic and aqueous extracts, the J2s were permanently paralyzed; however, at low concentrations, only the ethanolic extract was effective. The ethanolic extract paralyzed J2s at concentrations higher than 62.5 ppm and reduced the egg hatching by up to 76% compared to the control treatment. In general, the efficacy of the aqueous extract was considerably lower than that of the ethanolic extract. Full article

Root-knot nematodes (RKNs) are pathogens that endanger a wide range of crops and cause serious global agricultural losses. In this study, we investigated metabolites of the endoparasitic fungus Harposporium anguillulae YMF1.01751, with the expectation of discovering valuable Meloidogyne incognita biocontrol compounds. Based on results obtained by a liquid chromatograph coupled to a mass spectrometer (LC-MS) of crude extracts under five culture conditions and their nematicidal activity against M. incognita, corn meal agar (CMA) medium was determined as the scale-up fermentation medium. Twelve metabolites (1–12) were isolated from the fermentation products, and compound 1 was identified to be a new cyclic tetrapeptide. The activity assay results showed that phenylacetic acid (11) had good nematicidal activity at 400 μg/mL, and the mortalities of M. incognita were 89.76% and 96.05% at 12 and 24 h, respectively, while the mortality of canthin-6-one (2) against M. incognita was 44.26% at 72 h. In addition, the results of chemotaxis activity showed that 1-(1H-indol-3-yl)ethanone (10) possessed attraction activity towards M. incognita. At the tested concentrations, cyclo-(Arg-Pro) (4) and cyclo-(Val-Ile) (7) showed an avoidant response to M. incognita. This study provides insight into the nematode-active compounds of H. anguillulae origin and offers new opportunities for the development of RKN biocontrol products. Full article

The search for natural product-based biopesticides from endophytic fungi is an effective tool to find new solutions. In this study, we studied a pre-selected fungal endophyte, isolate YCC4, from the paleoendemism Persea indica, along with compounds present in the extract and the identification of the insect antifeedant and nematicidal ones. The endophyte YCC4 was identified as Phyllosticta sp. by molecular analysis. The insect antifeedant activity was tested by choice bioassays against Spodoptera littoralis, Myzus persicae, and Rhopalosiphum padi, and the in vitro and in vivo mortality was tested against the root-knot nematode Meloidogyne javanica. Since the extract was an effective insect antifeedant, a strong nematicidal, and lacked phytotoxicity on tomato plants, a comprehensive chemical study was carried out. Two new metabolites, metguignardic acid (4) and (-)-epi-guignardone I (14), were identified along the known dioxolanones guignardic acid (1), ethyl guignardate (3), guignardianones A (5), C (2), D (7), and E (6), phenguignardic acid methyl ester (8), the meroterpenes guignardone A (9) and B (10), guignarenone B (11) and C (12), (-)-guignardone I (13), and phyllomeroterpenoid B (15). Among these compounds, 1 and 4 were effective antifeedants against S. littoralis and M. persicae, while 2 was only active on the aphid M. persicae. The nematicidal compounds were 4, 7, and 8. This is the first report on the insect antifeedant or nematicidal effects of these dioxolanone-type compounds. Since the insect antifeedant and nematicidal activity of the Phyllosticta sp. extract depend on the presence of dioxolanone components, future fermentation optimizations are needed to promote the biosynthesis of these compounds instead of meroterpenes. Full article

PWD (pine wilt disease) is a devastating forest disease caused by the Bursaphelenchus xylophilus, which is the major invasive species in Asian and European countries. To control this disease, fumigation, pesticide injection, and clear cutting of epidemic trees have been widely used. But these management strategies have many limitations in terms of the effectiveness and environmental impacts, especially for the overuse of chemical pesticides. Thus, PCs (phytochemicals), the various compounds extracted from plants, have drawn extensive attention owing to their special characteristics, including abundant sources, low toxicity, high efficacy, and easy degradation. This review provides an overview of the current status of using PCs as alternative approaches to manage PWD. It discusses the efficacy of various PCs, the factors influencing their nematicidal activity, and their mechanism of action against B. xylophilus. These results will reveal the application of PCs in combating these devastating diseases and the necessity for further research. Full article

In the course of our ongoing research targeting the identification of potential biocontrol agents from entomopathogenic fungi (EPF), we explored a solid-state rice fungal extract of Blackwellomyces roseostromatus BCC56290 derived from infected lepidopteran larvae. Chemical and biological prospections afforded four unprecedentedly reported natural products differentiated into a dimeric naphthopyran bioxanthracene ES-242 derivative (1) and three cyclodepsipeptides (2–4) in addition to two known cyclodepsipeptides, cardinalisamides B (5) and C (6). Chemical structures of the isolated compounds were elucidated through comprehensive 1D/2D NMR and HR-ESI-MS data together with comparisons to the reported literature. The absolute configuration of the isolated cyclodepsipeptides was determined using Marfey’s method. All isolated compounds were assessed for their antimicrobial, cytotoxic, and nematicidal activities with some compounds revealing significant activities. Full article

Plant-parasitic nematodes (PPNs) reduce the high profitability of many crops and degrade their quantitative and qualitative yields globally. Traditional nematicides and other nematode control methods are being used against PPNs. However, stakeholders are searching for more sustainable and effective alternatives with limited side effects on the environment and mankind to face increased food demand, unfavorable climate change, and using unhealthy nematicides. This review focuses on upgrading the pre-procedures of PPN control as well as novel measures for their effective and durable management strategies on economically important crops. Sound and effective sampling, extraction, identification, and counting methods of PPNs and their related microorganisms, in addition to perfecting designation of nematode–host susceptibility/resistance, form the bases for these strategies. Therefore, their related frontiers should be expanded to synthesize innovative integrated solutions for these strategies. The latter involve supplanting unsafe nematicides with a new generation of safe and reliable chemical nematicidal and bionematicidal alternatives. For better efficacy, nematicidal materials and techniques should be further developed via computer-aided nematicide design. Bioinformatics devices can reinforce the potential of safe and effective biocontrol agents (BCAs) and their active components. They can delineate the interactions of bionematicides with their targeted PPN species and tackle complex diseases. Also, the functional plan of nematicides based on a blueprint of the intended goals should be further explored. Such goals can currently engage succinate dehydrogenase, acetylcholinesterase, and chitin deacetylase. Nonetheless, other biochemical compounds as novel targets for nematicides should be earnestly sought. Commonly used nematicides should be further tested for synergistic or additive function and be optimized via novel sequential, dual-purpose, and co-application of agricultural inputs, especially in integrated pest management schemes. Future directions and research priorities should address this novelty. Meanwhile, emerging bioactivated nematicides that offer reliability and nematode selectivity should be advanced for their favorable large-scale synthesis. Recent technological means should intervene to prevail over nematicide-related limitations. Nanoencapsulation can challenge production costs, effectiveness, and manufacturing defects of some nematicides. Recent progress in studying molecular plant–nematode interaction mechanisms can be further exploited for novel PPN control given related topics such as interfering RNA techniques, RNA-Seq in BCA development, and targeted genome editing. A few recent materials/techniques for control of PPNs in durable agroecosystems via decision support tools and decision support systems are addressed. The capability and effectiveness of nematicide operation harmony should be optimized via employing proper cooperative mechanisms among all partners. Full article

Nematodes have a negative impact on crop production and yield. The use of synthetic formulations to control plant parasitic nematodes carries both environmental and human health risks. As these agrochemicals are gradually being phased out, recent research has been focused on finding more environmentally friendly, plant-based alternatives. This study aims to investigate the effectiveness of botanicals, used alone or in artificial blends, in paralyzing Meloidogyne incognita second-stage juveniles (J2s) immersed in test solutions or exposed to vapors. We tested thymol, trans-anethole, and two lavender essential oils, referred to as LEOA and LEOB, which vary in their flower and stem compositions. We also employed in our study Melia azedarach aqueous extract (MWE), already proven to have considerable nematicidal activity. According to our findings, all treatments used individually exhibited considerable efficacy, even LEOA and LEOB first reported herein. In addition, all blends exhibited significant synergism, and the best-performing were trans-anethole/thymol, being synergic to paralyzing J2s for up to two days, and trans-anethole/LEOB as well as trans-anethole/MWE, provoking irreversible paralysis since the first day of J2 immersion in test solutions. Most importantly, the blend of trans-anethole with LEOA displayed the best effective synergism against M. incognita both for immersion and fumigation methods. Lastly, the chemical composition analysis displayed linalyl acetate and β-linalool as the major components of LEOA and β-linalool and eucalyptol as the major components of LEOB. Full article