Search Results (55)

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

With the sustainable increase in agricultural productivity, the need for safer, environmentally friendly pesticide alternatives is also growing. Metabolites of microorganisms (bacteria, fungi, actinomycetes) are emerging as potential bioactive compounds for integrated pest and disease management. These compounds comprise amino acids, carbohydrates, lipids, organic acids, phenolics, peptides, alkaloids, polyketides, and volatile organic compounds. The majority of them have insecticidal, fungicidal, and nematicidal activities. In this review, the classifications, biosynthetic pathways, and ecological functions of primary and secondary metabolites produced by microorganisms are discussed, including their mechanisms of action, ranging from competition to systemic acquired resistance in host plants. The article highlights the importance of microbial genera (viz., Bacillus sp., Pseudomonas sp., Trichoderma sp., Streptomyces sp., etc.) in making chemicals and biopesticides for crop defense. We present the possible applications of microbial biosynthesis strategies and synthetic biology tools in bioprocess development, covering recent innovations in formulation, delivery, and pathway engineering to enhance metabolite production. This review emphasizes the significance of microbial metabolites in improving the plant immunity, yield performance, reduction in pesticide application, and the sustainability of an ecological, sustainable, and resilient agricultural system. Full article

Pine wilt disease (PWD), caused by the pine wood nematode (PWN, Bursaphelenchus xylophilus), poses a significant threat to global pine forests and calls for the development of innovative management strategies. Microbial control emerges as an effective, cost-efficient, and environmentally sustainable approach to eliminate the damage from PWD. This review consolidates molecular mechanisms in the microbiological control of PWD, which focus on three core strategies: microbial control activity against PWN, biological control of vector insects, and the enhancement of host tree resistance to nematode infections. The review thoroughly evaluates integrated control strategies in which microbial control is used in traditional management practices. Recent studies have pinpointed promising microbial agents for PWN control, such as nematophagous microorganisms, nematicidal metabolites, parasitic fungi that target vector insects, and microbes that boost plant resistance. In particular, the control potential of volatile organic compounds (VOCs) produced by microorganisms against PWN and the enhancement of pine resistance to PWN by microorganisms were emphasized. Moreover, we assessed the challenges and opportunities associated with the field application of microbiological control agents. We emphasized the feasibility of multi-strategy microbial integrated control, which provides a framework for future studies on microbial-based PWD control strategies. Full article

Bacillus halotolerans, a halophilic bacterial species of the genus Bacillus, is emerging as a biological control agent with immense potential for sustainable agriculture, particularly in extreme conditions and environmental rehabilitation. This review summarizes the current state of research on B. halotolerans, emphasizing its diverse applications in the biocontrol of plant pathogens, plant growth promotion under salinity stress, nematode management, and bioremediation. B. halotolerans utilizes several mechanisms such as the production of siderophores and phytohormones, secretion of exopolysaccharides, and the release of antifungal and nematicidal compounds, which allows it to mitigate both abiotic and biotic stresses in various crops, including wheat, rice, date palm, tomato, and others. In addition, genomic and metabolomic analyses have revealed its potential for secondary metabolite production that improves its antagonistic and growth-promoting traits. Despite significant progress, challenges remain in translating laboratory results into field applications. Future research should focus on formulating effective bioinoculants and field trials to maximize the practical utility of B. halotolerans for sustainable agriculture and environmental resilience. 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

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

Traditional pesticides are based on toxic compounds that can reduce biodiversity, degrade the environment, and contribute to less healthy living. Plant allelochemicals can provide more environmentally friendly and sustainable alternatives. Essential oils (EOs) are complex mixtures of plant secondary metabolites that show strong biological activities. In the present study, the EOs of Cymbopogon citratus were screened for activity against the pinewood nematode (PWN), the causal agent of pine wilt disease. To understand their nematicidal properties, EOs were fractioned into hydrocarbon molecules and oxygen-containing compounds, and their main compounds were acquired and tested separately against the PWN. The EO oxygen-containing molecules fraction was highly active against the PWN (EC₅₀ = 0.279 µL/mL), with citral and geraniol showing higher activities (EC₅₀ = 0.266 and 0.341 µL/mL, respectively) than emamectin benzoate (EC₅₀ = 0.364 µL/mL), a traditional nematicide used against the PWN. These compounds were additionally reported to be less toxic to non-target organisms (fish, invertebrates, and algae) and safer to human health (with higher reported toxicity thresholds) and predicted to exert fewer environmental impacts than traditional nematicides. Resorting to approved natural compounds can quickly leverage the development of sustainable alternatives to traditional nematicides. Full article

The rice root-knot nematode (RRKN), Meloidogyne graminicola Golden and Birchfield 1965, is a dangerous crop pest that affects rice production on a global scale. The largest rice-producing countries struggle with the impacts of RRKN infestation, namely, underdeveloped plants and a reduction in rice grain that can reach up to 70% of crop yield. In addition, the shift to strategies of sustainable pest management is leading to a withdrawal of some of the most effective pesticides, given the dangers they pose to the environment and human health. Volatile metabolites produced by plants can offer safer alternatives. The present study characterized the nematicidal activity of volatile phytochemicals against the RRKN and compared the most active with commercial nematicides concerning their safety to the environment and human health. Rice plants were used to grow large numbers of RRKNs for direct-contact bioassays. Mortality induced by the volatiles was followed for four days on RRKN second-stage juveniles. Of the 18 volatiles tested, carvacrol, eugenol, geraniol, and methyl salicylate showed the highest mortalities (100%) and were compared to traditional nematicides using (eco)toxicological parameters reported on freely available databases. While methyl salicylate had a faster activity, carvacrol had more lasting effects. When compared to synthetic nematicides, these volatile phytochemicals were reported to have higher thresholds of toxicity and beneficial ecotoxicological parameters. Ultimately, finding safer alternatives to traditional pesticides can lower the use of damaging chemicals in farming and leverage the transition to agricultural practices with a lower impact on biodiversity. Full article

Claviceptaceous endophytic fungi in the genus Epichloë mostly form a symbiotic relationship with cool-season grasses. Epichloë spp. are capable of producing bioactive alkaloids such as peramines, lolines, ergot alkaloids, and indole-diterpenes, which protect the host plant from herbivory by animals, insects, and nematodes. The host also benefits from enhanced tolerance to abiotic stresses, such as salt, drought, waterlogging, cold, heavy metals, and low nitrogen stress. The bioactive alkaloids produced can have both direct and indirect effects towards plant parasitic nematodes. Direct interaction with nematodes’ motile stages can cause paralysis (nematostatic effect) or death (nematicidal effect). Indirectly, the metabolites may induce host immunity which inhibits feeding and subsequent nematode development. This review highlights the different mechanisms through which this interaction and the metabolites produced have been explored in the suppression of plant parasitic nematodes and also how the specific interactions between different grass genotypes and endophyte strains result in variable suppression of different nematode species. An understanding of the different grass–endophyte interactions and their successes and failures in suppressing various nematode species is essential to enable the proper selection of grass–endophyte combinations to identify the alkaloids produced, concentrations required, and determine which nematodes are sensitive to which specific alkaloids. Full article

The management of plant-parasitic nematodes (PPNs) still relies on traditional nematicides that threaten the environment and human health. Novel solutions are urgently needed for PPN pest management that are effective while safeguarding non-target organisms. Volatile phytochemicals belong to a structurally diverse group of bioactive metabolites that are believed to hold safer environmental characteristics than synthetic pesticides. Nonetheless, not many studies have analysed the potential environmental benefits of shifting to these novel bionematicides. In the present study, 20 phytochemical volatiles with reported nematicidal activity were compared to traditional pesticides using specific parameters of environmental and human health safety available on applied online databases and predicted in silico through specialised software. Overall, the reviewed nematicidal phytochemicals were reportedly less toxic than synthetic nematicides. They were predicted to disperse to the air and soil environmental compartments and were reported to have a lower toxicity on aquatic organisms. On the contrary, the synthetic nematicides were reportedly toxic to aquatic organisms while showing a predicted high affinity to the water environmental compartment. As alternatives, β-keto or fatty acid derivatives, e.g., aliphatic alcohols or ketones, showed more adequate properties. This study highlights the importance of complementing studies on nematicidal activity with a risk assessment-based analysis to allow for a faster selection of nematicidal phytochemical volatiles and to leverage the development and implementation of bionematicides. Full article

The Cannabis species is one of the potent ancient medicinal plants acclaimed for its medicinal properties and recreational purposes. The plant parts are used and exploited all over the world for several agricultural and industrial applications. For many years Cannabis spp. has proven to present a highly diverse metabolomic profile with a pool of bioactive metabolites used for numerous pharmacological purposes ranging from anti-inflammatory to antimicrobial. Cannabis sativa has since been an extensive subject of investigation, monopolizing the research. Hence, there are fewer studies with a comprehensive understanding of the composition of bioactive metabolites grown in different environmental conditions, especially C. indica and a few other Cannabis strains. These pharmacological properties are mostly attributed to a few phytocannabinoids and some phytochemicals such as terpenoids or essential oils which have been tested for antimicrobial properties. Many other discovered compounds are yet to be tested for antimicrobial properties. These phytochemicals have a series of useful properties including anti-insecticidal, anti-acaricidal, anti-nematicidal, anti-bacterial, anti-fungal, and anti-viral properties. Research studies have reported excellent antibacterial activity against Gram-positive and Gram-negative multidrug-resistant bacteria as well as methicillin-resistant Staphylococcus aureus (MRSA). Although there has been an extensive investigation on the antimicrobial properties of Cannabis, the antimicrobial properties of Cannabis on phytopathogens and aquatic animal pathogens, mostly those affecting fish, remain under-researched. Therefore, the current review intends to investigate the existing body of research on metabolomic profile and anti-microbial properties whilst trying to expand the scope of the properties of the Cannabis plant to benefit the health of other animal species and plant crops, particularly in agriculture. Full article

Plant-parasitic nematodes (PPNs) are highly damaging pests responsible for heavy losses in worldwide productivity in a significant number of important plant crops. Common pest management strategies rely on the use of synthetic chemical nematicides, which have led to serious concerns regarding their impacts on human health and the environment. Plant natural products, or phytochemicals, can provide a good source of agents for sustainable control of PPNs, due to their intrinsic characteristics such as higher biodegradability, generally low toxicity for mammals, and lower bioaccumulation in the environment. In this work, the nematicidal activity of 39 phytochemicals was determined against the root-lesion nematode (RLN) Pratylenchus penetrans using standard direct and indirect contact methodologies. Overall, the RLN was tolerant to the tested phytochemicals at the highest concentration, 2 mg/mL, seldom reaching full mortality. However, high activities were obtained for benzaldehyde, carvacrol, 3-octanol, and thymol, in comparison to other phytochemicals or the synthetic nematicide oxamyl. These phytochemicals were seen to damage nematode internal tissues but not its cuticle shape. Also, the environmental and (eco)toxicological parameters reported for these compounds suggest lower toxicity and higher safety of use than oxamyl. These compounds appear to be good candidates for the development of biopesticides for a more sustainable pest management strategy. Full article

This research was designed to investigate the metabolite profiling, phenolics, and flavonoids content as well as the potential nematicidal properties of decoction (ZpDe), orange-yellow resin (ZpRe) and essential oil (ZpEO) from Argentinean medicinal plant Zuccagnia punctata Cav. Additionally, the antioxidant and antibacterial properties of ZpDe and ZpEO were determined. Metabolite profiling was obtained by an ultrahigh-resolution liquid chromatography MS analysis (UHPLC-ESI-QTOF/OT-MS-MS) and GCMS. The nematicidal activity was assayed by a standardized method against Meloidogyne incognita. The antioxidant properties were screened by four methods: (2,2-diphenyl-1-picrylhydrazyl assay (DPPH), Trolox equivalent antioxidant activity assay (TEAC), ferric-reducing antioxidant power assay (FRAP), and lipid peroxidation in erythrocytes (ILP). The antibacterial activity was evaluated according to the Clinical and Laboratory Standards Institute (CLSI) rules. The ZpDe, ZpRe and ZpEO displayed a strong nematicidal activity with an LC₅₀ of 0.208, 0.017 and 0.142 mg/mL, respectively. On the other hand, the ZpDe showed a strong DPPH scavenging activity (IC₅₀ = 28.54 µg/mL); ILP of 87.75% at 250 µg ZpDe/mL and moderated antimicrobial activity. The ZpEO showed promising activity against a panel of yeasts Candida albicans and non-albicans (ATCC and clinically isolated) with MIC values from 750 to 1500 µg/mL. The ZpDe showed a content of phenolics and flavonoid compounds of 241 mg GAE/g and 10 mg EQ/g, respectively. Fifty phenolic compounds were identified in ZpDe by ultrahigh-resolution liquid chromatography (UHPLC–PDA– Q-TOF-MS) analysis, while forty-six phenolic compounds were identified in ZpRe by UHPLC-ESI-Q-OT-MS-MS and twenty-nine in ZpEO using a GC-MS analysis, updating the knowledge on the chemical profile of this species. The results support and standardize this medicinal plant mainly as a potential environmentally friendly and sustainable bionematicide for the control of Argentinean horticultural crops including tomatoes and peppers and as a source of antimicrobial and antioxidant compounds which could be further explored and exploited for potential applications. Full article

The substance fenbendazole is included in the composition of many anthelmintic drugs, in which the “chemical stability” parameter is one of the main characteristics when obtaining permission for the use of drugs in veterinary practice. Fenbendazole is characterized by low solubility in water and therefore the content of the substance is overestimated in its preparations, which increases the cost of the drug as well as the safety risks of pharmacotherapy. The possibilities of mechanochemical modification of fenbendazole were evaluated in order to improve the solubility index. During the mechanical processing treatment of the substance in the presence of polymeric substances, solid dispersions are formed, which have increased solubility and high anthelmintic activity. The inclusion in these dispersions of the third component, which is succinic acid, did not significantly change the solubility of fenbendazole. In all these dispersions, the substance remained unchanged both during the preparation of its solid dispersions and during their storage. When fenbendazole is modified in an organic solvent medium, the substance is partially converted into oxfendazole, which is one of its metabolites. The chemical stability of fenbendazole was confirmed via HPLC/MS and NMR spectroscopy. The anthelmintic activity of these compositions was evaluated and it was found that they have a high nematicidal activity. Full article