RÉSUMÉ
To examine the impact of pre-harvest fungicide applications on the postharvest storage performance of tomato fruits, we measured the lycopene content, hardness, soluble solids content, rotting rate, and weight loss rate of the fruits, as well as conducted a sensory assessment. Protective and systematic fungicides were sprayed on tomatoes 20 days before harvest in order to prevent rotting and weight loss during storage. Our findings showed that, the fungicide-treated tomatoes had a significantly lower rotting rate of 16.00% and a weight loss rate of 3.96%. However the control group experienced 65.33% rotting rate and 6.90% weight loss rate on 12th days of storage. Out of the pre-harvest applications, 'Zineb' a protective fungicide significantly delayed the loss of hardness and soluble solids accumulation in tomato fruits during storage, but it had no significant effect on lycopene content. On the other hand, when comparing to the examined treatment, the systemic fungicides did not have any significant effect on the postharvest storage performance of tomato fruits. Sensory evaluation results indicated that systemic fungicides improved the aroma of the fruits, while protective fungicides had a greater impact on the appearance and juiciness of the fruits. This study offers a potential novel solution for preserving fruits and vegetables which have been frequently infected by phytopathogens during storage, and consequently mitigate/reduce postharvest losses.
Sujet(s)
Stockage des aliments , Fruit , Fongicides industriels , Lycopène , Solanum lycopersicum , Solanum lycopersicum/effets des médicaments et des substances chimiques , Solanum lycopersicum/microbiologie , Fongicides industriels/pharmacologie , Fruit/effets des médicaments et des substances chimiques , Fruit/microbiologie , Fruit/composition chimique , Stockage des aliments/méthodes , Lycopène/pharmacologie , Lycopène/analyse , Conservation aliments/méthodes , Caroténoïdes/analyseRÉSUMÉ
The Oomycetes fungus Phytophthora spp. which causes Abnormal leaf fall (ALF) disease poses a significant threat as one of the most devastating diseases affecting rubber trees in India. A total of 30 Phytophthora isolates were obtained from ALF-affected samples collected during the Southwest monsoon season of Kerala. The colony morphology of Phytophthora isolates revealed eight different types of growth patterns, with stellate, stellate striated, and petaloid patterns growing rapidly, whereas chrysanthemum pattern grew slowly. Sporangia were papillate to non-papillate in various shapes, and sporangiophores exhibited simple, simple sympodial, or irregularly branching patterns. Highly virulent isolates exhibited petaloid morphology and rapid growth rates. Regardless of their virulence, all isolates showed susceptibility to the fungicide metalaxyl. Under in vitro conditions, the highly virulent isolate (R17) from rubber caused severe infections in chili, brinjal, and tomato with brown water-soaked lesions. Sequence analysis and multi-locus phylogeny of Internal transcribed spacer (ITS), cCytochrome c oxidase 1 (COX 1), Heat shock protein 90 (HSP 90), and Ribosomal protein L10 (RPL 10) confirmed the pathogen as Phytophthora meadii. A comprehensive understanding of both morphological and molecular traits of P. meadii is crucial for precise identification and future genetic variability studies.
Sujet(s)
Hevea , Phylogenèse , Phytophthora , Maladies des plantes , Inde , Phytophthora/génétique , Phytophthora/classification , Maladies des plantes/microbiologie , Maladies des plantes/parasitologie , Hevea/microbiologie , Hevea/parasitologie , Typage par séquençage multilocus , Feuilles de plante/microbiologie , Feuilles de plante/parasitologie , Analyse de séquence d'ADN , Virulence , Espaceur de l'ADN ribosomique/génétique , Prévalence , Analyse de regroupements , Fongicides industriels/pharmacologie , Alanine/analogues et dérivésRÉSUMÉ
The use of plant genetic resources (PGR)-wild relatives, landraces, and isolated breeding gene pools-has had substantial impacts on wheat breeding for resistance to biotic and abiotic stresses, while increasing nutritional value, end-use quality, and grain yield. In the Global South, post-Green Revolution genetic yield gains are generally achieved with minimal additional inputs. As a result, production has increased, and millions of hectares of natural ecosystems have been spared. Without PGR-derived disease resistance, fungicide use would have easily doubled, massively increasing selection pressure for fungicide resistance. It is estimated that in wheat, a billion liters of fungicide application have been avoided just since 2000. This review presents examples of successful use of PGR including the relentless battle against wheat rust epidemics/pandemics, defending against diseases that jump species barriers like blast, biofortification giving nutrient-dense varieties and the use of novel genetic variation for improving polygenic traits like climate resilience. Crop breeding genepools urgently need to be diversified to increase yields across a range of environments (>200 Mha globally), under less predictable weather and biotic stress pressure, while increasing input use efficiency. Given that the ~0.8 m PGR in wheat collections worldwide are relatively untapped and massive impacts of the tiny fraction studied, larger scale screenings and introgression promise solutions to emerging challenges, facilitated by advanced phenomic and genomic tools. The first translocations in wheat to modify rhizosphere microbiome interaction (reducing biological nitrification, reducing greenhouse gases, and increasing nitrogen use efficiency) is a landmark proof of concept. Phenomics and next-generation sequencing have already elucidated exotic haplotypes associated with biotic and complex abiotic traits now mainstreamed in breeding. Big data from decades of global yield trials can elucidate the benefits of PGR across environments. This kind of impact cannot be achieved without widescale sharing of germplasm and other breeding technologies through networks and public-private partnerships in a pre-competitive space.
Sujet(s)
Sécurité alimentaire , Amélioration des plantes , Maladies des plantes , Triticum , Triticum/génétique , Triticum/microbiologie , Maladies des plantes/microbiologie , Maladies des plantes/prévention et contrôle , Résistance à la maladie/génétique , Pandémies , Fongicides industriels , EnvironnementRÉSUMÉ
The uptake, translocation, and accumulation of mefentrifluconazole (MFZ), an innovative chiral triazole fungicide, in plants at the enantiomeric level are still unclear. Herein, we investigated the patterns and mechanisms of enantiomeric uptake, bioaccumulation, and translocation through several experiments. Rac-MFZ shows the strongest uptake and bioaccumulation capacity in wheat compared with its enantiomers, while S-(+)-MFZ has the highest translocation potential. Molecular docking provided evidence of the stronger translocation ability of S-(+)-MFZ than R-(-)-MFZ. Split-root experiments showed that MFZ and its enantiomers could undergo long-distance transport within the wheat. Active transport or facilitated and simple diffusion may be involved in the wheat uptake of MFZ. The limited acropetal translocation capability of MFZ may be attributed to the dominant uptake pathway of apoplastic. The concentrations of Rac-MFZ in different subcellular fractions varied greatly. In summary, this study provides novel insights for further understanding the behaviors of MFZ and its enantiomers in plants.
Sujet(s)
Fongicides industriels , Triazoles , Triticum , Triticum/métabolisme , Triticum/composition chimique , Triazoles/composition chimique , Triazoles/métabolisme , Fongicides industriels/métabolisme , Fongicides industriels/composition chimique , Stéréoisomérie , Transport biologique , Simulation de docking moléculaire , Racines de plante/métabolisme , Racines de plante/composition chimiqueRÉSUMÉ
Genome mining in association with the OSMAC (one strain, many compounds) approach provides a feasible strategy to extend the chemical diversity and novelty of natural products. In this study, we identified the biosynthetic gene cluster (BGC) of restricticin, a promising antifungal agent featuring a reactive primary amine, from the fungus Aspergillus sclerotiorum LZDX-33-4 by genome mining. Combining heterologous expression and the OSMAC strategy resulted in the production of a new hybrid product (1), along with N-acetyl-restricticin (2) and restricticinol (3). The structure of 1 was determined by spectroscopic data, including optical rotation and electronic circular dichroism (ECD) calculations, for configurational assignment. Compound 1 represents a fusion of restricticin and phytotoxic cichorin. The biosynthetic pathway of 1 was proposed, in which the condensation of a primary amine of restricticin with a precursor of cichorine was postulated. Compound 1 at 5 mM concentration inhibited the growth of the shoots and roots of Lolium perenne, Festuca arundinacea, and Lactuca sativa with inhibitory rates of 71.3 and 88.7% for L. perenne, 79.4 and 73.0% for F. arundinacea, and 58.2 and 52.9% for L. sativa. In addition, compound 1 at 25 µg/mL showed moderate antifungal activity against Fusarium fujikuroi and Trichoderma harzianum with inhibition rates of 22.6 and 31.6%, respectively. These results suggest that heterologous expression in conjunction with the OSMAC approach provides a promising strategy to extend the metabolite novelty due to the incorporation of endogenous metabolites from the host strain with exogenous compounds, leading to the production of more complex compounds and the acquisition of new physiological functions.
Sujet(s)
Lactuca , Lolium , Lolium/génétique , Lolium/effets des médicaments et des substances chimiques , Lolium/croissance et développement , Lolium/métabolisme , Lactuca/effets des médicaments et des substances chimiques , Lactuca/génétique , Lactuca/croissance et développement , Famille multigénique , Festuca/génétique , Festuca/métabolisme , Festuca/microbiologie , Festuca/effets des médicaments et des substances chimiques , Festuca/croissance et développement , Fongicides industriels/pharmacologie , Fongicides industriels/composition chimique , Fongicides industriels/métabolisme , Protéines fongiques/génétique , Protéines fongiques/métabolisme , Protéines fongiques/composition chimique , Voies de biosynthèse , Racines de plante/génétique , Racines de plante/métabolisme , Racines de plante/croissance et développement , Racines de plante/effets des médicaments et des substances chimiques , Racines de plante/microbiologie , Structure moléculaire , Génome fongique , Ascomycota/génétique , Ascomycota/effets des médicaments et des substances chimiques , Ascomycota/métabolisme , Fusarium/effets des médicaments et des substances chimiques , Fusarium/génétique , Fusarium/croissance et développementRÉSUMÉ
The genus Phytophthora contains more than 100 plant pathogenic species that parasitize a wide range of plants, including economically important fruits, vegetables, cereals, and forest trees, causing significant losses. Global agriculture is seriously threatened by fungicide resistance in Phytophthora species, which makes it imperative to fully comprehend the mechanisms, frequency, and non-chemical management techniques related to resistance mutations. The mechanisms behind fungicide resistance, such as target-site mutations, efflux pump overexpression, overexpression of target genes and metabolic detoxification routes for fungicides routinely used against Phytophthora species, are thoroughly examined in this review. Additionally, it assesses the frequency of resistance mutations in various Phytophthora species and geographical areas, emphasizing the rise of strains that are resistant to multiple drugs. The effectiveness of non-chemical management techniques, including biological control, host resistance, integrated pest management plans, and cultural practices, in reducing fungicide resistance is also thoroughly evaluated. The study provides important insights for future research and the development of sustainable disease management strategies to counter fungicide resistance in Phytophthora species by synthesizing current information and identifying knowledge gaps.
Sujet(s)
Résistance des champignons aux médicaments , Fongicides industriels , Phytophthora , Maladies des plantes , Phytophthora/effets des médicaments et des substances chimiques , Phytophthora/génétique , Fongicides industriels/pharmacologie , Maladies des plantes/microbiologie , Maladies des plantes/prévention et contrôle , Maladies des plantes/parasitologie , Résistance des champignons aux médicaments/génétique , Mutation , AgricultureRÉSUMÉ
Infection of grapevines with the grey mold pathogen Botrytis cinerea results in severe problems for winemakers worldwide. Browning of wine is caused by the laccase-mediated oxidation of polyphenols. In the last decades, Botrytis management has become increasingly difficult due to the rising number of resistances and the genetic variety of Botrytis strains. During the search for sustainable fungicides, polyphenols showed great potential to inhibit fungal growth. The present study revealed two important aspects regarding the effects of grape-specific polyphenols and their polymerized oxidation products on Botrytis wild strains. On the one hand, laccase-mediated oxidized polyphenols, which resemble the products found in infected grapes, showed the same potential for inhibition of growth and laccase activity, but differed from their native forms. On the other hand, the impact of phenolic compounds on mycelial growth is not correlated to the effect on laccase activity. Instead, mycelial growth and relative specific laccase activity appear to be modulated independently. All phenolic compounds showed not only inhibitory but also inductive effects on fungal growth and/or laccase activity, an observation which is reported for the first time. The simultaneous inhibition of growth and laccase activity demonstrated may serve as a basis for the development of a natural botryticide. Yet, the results showed considerable differences between genetically distinguishable strains, impeding the use of a specific phenolic compound against the genetic variety of wild strains. The present findings might have important implications for future understanding of Botrytis cinerea infections and sustainable Botrytis management including the role of polyphenols.
Sujet(s)
Botrytis , Laccase , Oxydoréduction , Polyphénols , Vitis , Botrytis/effets des médicaments et des substances chimiques , Botrytis/croissance et développement , Botrytis/enzymologie , Laccase/métabolisme , Polyphénols/pharmacologie , Vitis/microbiologie , Mycelium/croissance et développement , Mycelium/effets des médicaments et des substances chimiques , Fongicides industriels/pharmacologie , Fongicides industriels/composition chimique , Vin/microbiologie , Maladies des plantes/microbiologieRÉSUMÉ
Flusilazole is a well-known triazole fungicide applied to various crops and fruits worldwide. Flusilazole residues are frequently detected in the environment, and many researchers have reported the hazardous effects of flusilazole on non-target organisms; however, the developmental toxicity of flusilazole has not been fully elucidated. In this study, we investigated flusilazole-induced developmental defects in zebrafish, which are used in toxicology studies to assess the toxic effects of chemicals on aquatic species or vertebrates. We confirmed that flusilazole exposure affected the viability and hatching rate of zebrafish larvae, and resulted in morphological defects, reduced body length, diminished eye and head sizes, and inflated pericardial edema. Apoptosis, oxidative stress, and inflammation were also observed. These factors interrupted the normal organ formation during early developmental stages, and transgenic models were used to identify organ defects. We confirmed the effects of flusilazole on the nervous system using olig2:dsRed transgenic zebrafish, and on the cardiovascular system using cmlc2:dsRed and fli1:eGFP transgenic zebrafish. Our results demonstrate the developmental toxicity of flusilazole and its mechanisms in zebrafish as well as the detrimental effects of flusilazole.
Sujet(s)
Animal génétiquement modifié , Apoptose , Fongicides industriels , Stress oxydatif , Triazoles , Danio zébré , Animaux , Stress oxydatif/effets des médicaments et des substances chimiques , Apoptose/effets des médicaments et des substances chimiques , Triazoles/toxicité , Fongicides industriels/toxicité , Embryon non mammalien/effets des médicaments et des substances chimiques , SilanesRÉSUMÉ
Cytochrome c oxidase (Cox) is a crucial terminal oxidase in the electron transport chain. In this study, we generated 14 Cox gene deletion or overexpression mutants in Fusarium graminearum. Fungicide sensitivity tests revealed that 11 Cox gene deletion mutants displayed resistance to pyraclostrobin, while 10 overexpression mutants showed hypersensitivity. RNA-Seq and RT-qPCR analyses demonstrated the upregulation of FgAox (alternative oxidase in F. graminearum), FgAod2, and FgAod5 (alternative oxidase deficiency in F. graminearum) in ΔFgCox4-2 and ΔFgCox17-75 mutants. In 11 Cox gene deletion mutants, FgAox expression was significantly upregulated, whereas in 10 Cox gene overexpression mutants, it was significantly downregulated. FgAox overexpression mutants exhibit resistance to pyraclostrobin, while FgAox deletion mutants show hypersensitivity to pyraclostrobin. FgAod2 and FgAod5 were identified as transcription factors for FgAox. Our findings reveal that FgCox influences pyraclostrobin sensitivity by regulating FgAox through FgAod2 and FgAod5. Understanding pyraclostrobin resistance mechanisms in F. graminearum could help develop better fungicide rotation and application strategies to manage resistance and guide the creation of new fungicides targeting different pathways.
Sujet(s)
Complexe IV de la chaîne respiratoire , Protéines fongiques , Fongicides industriels , Fusarium , Strobilurines , Facteurs de transcription , Fusarium/génétique , Fusarium/enzymologie , Strobilurines/pharmacologie , Protéines fongiques/génétique , Protéines fongiques/métabolisme , Fongicides industriels/pharmacologie , Facteurs de transcription/génétique , Facteurs de transcription/métabolisme , Complexe IV de la chaîne respiratoire/génétique , Complexe IV de la chaîne respiratoire/métabolisme , Maladies des plantes/microbiologie , Maladies des plantes/génétique , Régulation de l'expression des gènes fongiques , Oxidoreductases/génétique , Oxidoreductases/métabolismeRÉSUMÉ
Fusarium head blight (FHB) is a plant disease caused by various species of the Fusarium fungus. One of the major concerns associated with Fusarium spp. is their ability to produce mycotoxins. Mycotoxin contamination in small grain cereals is a risk to human and animal health and leads to major economic losses. A reliable site-specific precise Fusarium spp. infection early warning model is, therefore, needed to ensure food and feed safety by the early detection of contamination hotspots, enabling effective and efficient fungicide applications, and providing FHB prevention management advice. Such precision farming techniques contribute to environmentally friendly production and sustainable agriculture. This study developed a predictive model, Sága, for on-site FHB detection in wheat using imaging spectroscopy and deep learning. Data were collected from an experimental field in 2021 including (1) an experimental field inoculated with Fusarium spp. (52.5 m × 3 m) and (2) a control field (52.5 m × 3 m) not inoculated with Fusarium spp. and sprayed with fungicides. Imaging spectroscopy data (hyperspectral images) were collected from both the experimental and control fields with the ground truth of Fusarium-infected ear and healthy ear, respectively. Deep learning approaches (pretrained YOLOv5 and DeepMAC on Global Wheat Head Detection (GWHD) dataset) were used to segment wheat ears and XGBoost was used to analyze the hyperspectral information related to the wheat ears and make predictions of Fusarium-infected wheat ear and healthy wheat ear. The results showed that deep learning methods can automatically detect and segment the ears of wheat by applying pretrained models. The predictive model can accurately detect infected areas in a wheat field, achieving mean accuracy and F1 scores exceeding 89%. The proposed model, Sága, could facilitate the early detection of Fusarium spp. to increase the fungicide use efficiency and limit mycotoxin contamination.
Sujet(s)
Apprentissage profond , Grains comestibles , Fusarium , Maladies des plantes , Triticum , Triticum/microbiologie , Fusarium/isolement et purification , Grains comestibles/microbiologie , Grains comestibles/composition chimique , Maladies des plantes/microbiologie , Contamination des aliments/analyse , Mycotoxines/analyse , Fongicides industriels/analyseRÉSUMÉ
Tebuconazole (TEB) is a common triazole sterol demethylation inhibitor fungicide utilized to manage a variety of diseases in crops like cereals, fruits, and vegetables. The aim of this work was to assess the effects of TEB on the structure of the cerebellum in adult albino rats and possible protective impact of co-administration of Gallic acid (GA). Four groups of forty adult male albino rats were randomly selected, and the rats in group I received corn oil through daily gavage for 4 weeks. Group II received GA dissolved in the normal saline at a dose of 100 mg/kg through daily gavage for 4 weeks, group III administered with TEB dissolved in corn oil at its acceptable daily intake dose (0.02 mg/kg body weight) through daily gavage for 4 weeks, group IV rats received both TEB and GA. For light microscopic, ultrastructural, and immunohistochemical investigations, cerebellar specimens were prepared. TEB exposure led to neuronal damage in the form of degenerated Purkinje cells with vacuolated cytoplasm, areas of lost Purkinje cells, the basket cells appeared vacuolated with degenerated neuropil, the granule cells clumped with congested areas between them, dilated cerebellar islands, weak positive bcl2 immunoreactions in the Purkinje cells, and numerous GFAP-positive astrocytes. GA mitigated TEB-mediated histological changes in the cerebellar cortex. We concluded that TEB caused Purkinje neurons in the rat cerebellar cortex to degenerate and undergo apoptosis. GA had a neuroprotective benefit against TEB toxicity in the rat cerebellar cortex.
Sujet(s)
Cervelet , Fongicides industriels , Acide gallique , Triazoles , Animaux , Mâle , Rats , Cervelet/effets des médicaments et des substances chimiques , Cervelet/anatomopathologie , Acide gallique/pharmacologie , Triazoles/pharmacologie , Triazoles/toxicité , Fongicides industriels/toxicité , Immunohistochimie , Neuroprotecteurs/pharmacologieRÉSUMÉ
Colletotrichum spp. is a phytopathogen causing anthracnose in a variety of tropical fruits. Strategies used to control postharvest diseases in tropical fruits typically rely on the use of synthetic fungicides, which have stimulated the emergence of resistant pathogens. Safer alternative strategies to control anthracnose in tropical fruits have been described in the literature. This review presents and discusses the main innovative interventions concerning the application of sustainable alternative strategies in the postharvest control of pathogenic Colletotrichum species in tropical fruits, with a particular emphasis on the studies published in the last 5 years. The available studies have shown the use of various methods, including physical barriers, natural antimicrobials, and biological control with antagonistic microorganisms, to reduce anthracnose lesion severity and incidence in tropical fruits. The available literature showed high inhibitory activity in vitro, reduced anthracnose incidence and lesion diameter, and total disease inhibition in tropical fruits. Most studies focused on the inhibition of Colletotrichum gloeosporioides on avocado, papaya, and mango, as well as of Colletotrichum musae on banana; however, the inhibition of other Colletotrichum species was also demonstrated. The application of emerging sustainable alternative methods, including natural antimicrobial substances, also stimulated the induction of defense systems in tropical fruits, including enzymatic activity, such as polyphenol oxidase, peroxidase, and phenylalanine ammonia-lyase. The retrieved data helped to understand the current state of the research field and reveal new perspectives on developing efficient and sustainable intervention strategies to control pathogenic Colletotrichum species and anthracnose development in tropical fruits.
Sujet(s)
Colletotrichum , Fruit , Maladies des plantes , Fruit/microbiologie , Maladies des plantes/microbiologie , Maladies des plantes/prévention et contrôle , Conservation aliments/méthodes , Climat tropical , Fongicides industriels/pharmacologieRÉSUMÉ
Fungicides undergo rapid metabolism and are excreted in the urine. There are few methods for screening these ubiquitous compounds, which have a high potential for human exposure. High-resolution mass spectrometry (HRMS) is a suitable technique to assess fungicide exposures; however, there is a lack of spectral libraries for fungicide annotation and in particular for downstream metabolites. We created spectral libraries for 32 fungicides for suspect screening. Fungicide standards were administered to mice, and 24-h urine was analyzed using hydrophilic interaction and reversed-phase chromatography coupled to hybrid quadrupole-orbitrap mass spectrometry. Suspect metabolite MS2 spectra for library creation were selected based on the ratio of exposed-to-control mouse urine. MS2 libraries were applied to urine collected from female university students (n = 73). Several tetraconazole and tebuconazole metabolites were detected in 3% (2/73) of the samples. The creation of comprehensive suspect screening MS2 libraries is a useful tool to detect fungicide exposure for human biomonitoring.
Sujet(s)
Surveillance biologique , Fongicides industriels , Fongicides industriels/métabolisme , Fongicides industriels/urine , Humains , Femelle , Animaux , Souris , Surveillance biologique/méthodes , Spectrométrie de masse/méthodes , Adulte , Spectrométrie de masse en tandem/méthodes , Jeune adulteRÉSUMÉ
Succinate dehydrogenase (SDH) has been considered an ideal target for discovering fungicides. To develop novel SDH inhibitors, in this work, 31 novel benzothiazol-2-ylthiophenylpyrazole-4-carboxamides were designed and synthesized using active fragment exchange and a link approach as promising SDH inhibitors. The findings from the tests on antifungal activity indicated that most of the synthesized compounds displayed remarkable inhibition against the fungi tested. Compound Ig N-(2-(((5-chlorobenzo[d]thiazol-2-yl)thio)methyl)phenyl)-3-(difluoromethyl)-1-methyl-1H-yrazole-4-carboxamide, with EC50 values against four kinds of fungi tested below 10 µg/mL and against Cercospora arachidicola even below 2 µg/mL, showed superior antifungal activity than that of commercial fungicide thifluzamide, and specifically compounds Ig and Im were found to show preventative potency of 90.6% and 81.3% against Rhizoctonia solani Kühn, respectively, similar to the positive fungicide thifluzamide. The molecular simulation studies suggested that hydrophobic interactions were the main driving forces between ligands and SDH. Encouragingly, we found that compound Ig can effectively promote the wheat seedlings and the growth of Arabidopsis thaliana. Our further studies indicated that compound Ig could stimulate nitrate reductase activity in planta and increase the biomass of plants.
Sujet(s)
Antienzymes , Fongicides industriels , Pyrazoles , Succinate Dehydrogenase , Succinate Dehydrogenase/antagonistes et inhibiteurs , Succinate Dehydrogenase/métabolisme , Fongicides industriels/pharmacologie , Fongicides industriels/composition chimique , Fongicides industriels/synthèse chimique , Relation structure-activité , Antienzymes/pharmacologie , Antienzymes/composition chimique , Antienzymes/synthèse chimique , Pyrazoles/pharmacologie , Pyrazoles/composition chimique , Pyrazoles/synthèse chimique , Rhizoctonia/effets des médicaments et des substances chimiques , Rhizoctonia/croissance et développement , Simulation de docking moléculaire , Benzothiazoles/composition chimique , Benzothiazoles/pharmacologie , Protéines fongiques/antagonistes et inhibiteurs , Protéines fongiques/métabolisme , Protéines fongiques/composition chimique , Ascomycota/effets des médicaments et des substances chimiques , Ascomycota/enzymologie , Structure moléculaireRÉSUMÉ
In this paper, we present analytical methodologies for the determination of the thiazolidine fungicide flutianil (trade name GATTEN) and its primary metabolite OC56635 in hemp cannabis matrices. A total of nine crop matrices were tested: whole seed, fiber, flower buds, hemp hearts, hemp seed oil, hemp meal, hemp flour, ethanol extracted CBD resin (CBD-E), and supercritical CO2 extracted CBD resin (CBD-C). Processing of the CBD-E and CBD-C crop fractions was carried out in-house using methods detailed herein. Field sample analysis utilized sequential extractions, stacked solid phase extraction (SPE) column cleanups, and evaporation to prepare the samples for LC-MS/MS quantitation. Method validations for each fraction were carried out using untreated hemp matrices over a minimum of three levels, with lowest levels of method validation (LLMV) of 0.010 µg/g for all fractions except the CBD resins, for which LLMV was 0.020 µg/g. Flutianil-treated samples from nine field sites were collected from several crop production regions and analyzed to determine the distribution of incurred flutianil and OC56635 residues within the different hemp matrices. This data was generated in support of nationwide registration with the United States Environmental Protection Agency (USEPA).
Sujet(s)
Cannabis , Fongicides industriels , Spectrométrie de masse en tandem , Cannabis/composition chimique , Spectrométrie de masse en tandem/méthodes , Fongicides industriels/analyse , Fongicides industriels/composition chimique , Résidus de pesticides/analyse , Chromatographie en phase liquide à haute performance/méthodes , Extraction en phase solide/méthodes , Contamination des aliments/analyse , Graines/composition chimique ,RÉSUMÉ
Understanding the stereoselective bioactivity of chiral pesticides is crucial for accurately evaluating their effectiveness and optimizing their use. Isopyrazam, a widely used chiral SDHI fungicide, has been studied for its antifungal activity only at the racemic level. Therefore, to clarify the highly bioactive isomers, the stereoselective bioactivity of isopyrazam isomers against four typical phytopathogens was studied for the first time. The bioactivity ranking of the isomers was trans-1S,4R,9R-(+)-isopyrazam > cis-1R,4S,9R-(+)-isopyrazam > trans-1R,4S,9S-(-)-isopyrazam > cis-1S,4R,9S-(-)-isopyrazam. SDH activity was assessed by molecular docking simulation and actual detection to confirm the reasons for stereoselective bioactivity. The results suggest that the stereoselective bioactivity of isopyrazam is largely dependent on the differential binding ability of each isomer to the SDH ubiquitin-binding site, located within a cavity formed by the iron-sulfur subunit, the cytochrome b560 subunit, and the cytochrome b small subunit. Moreover, to reveal the molecular mechanism of isopyrazam stereoselectively affecting mycelial growth, the contents of succinic acid, fumaric acid, and ATP were measured. Furthermore, by measuring exospore polysaccharides and oxalic acid content, it was determined that 1S,4R,9R-(+)- and 1R,4S,9R-(+)-isopyrazam more strongly inhibited the ability of Sclerotinia sclerotiorum to infect plants. The findings provided essential data for the development of high-efficiency isopyrazam fungicides and offered a methodological reference for analyzing the enantioselective activity mechanism of SDHI fungicides.
Sujet(s)
Ascomycota , Fongicides industriels , Simulation de docking moléculaire , Fongicides industriels/pharmacologie , Fongicides industriels/composition chimique , Stéréoisomérie , Ascomycota/effets des médicaments et des substances chimiques , Ascomycota/croissance et développement , Ascomycota/composition chimique , Protéines fongiques/composition chimique , Protéines fongiques/métabolisme , Succinate Dehydrogenase/antagonistes et inhibiteurs , Succinate Dehydrogenase/métabolisme , Succinate Dehydrogenase/composition chimique , Pyridines/composition chimique , Pyridines/pharmacologie , Relation structure-activité , Maladies des plantes/microbiologie , Monoterpènes de type norbornane , PyrazolesRÉSUMÉ
BACKGROUND: The Fusarium head blight caused by Fusarium graminearum results in reduced crop yields and the potential for vomitoxin contamination, which poses a risk to both human and livestock health. The primary method of control relies on the application of chemical fungicides. RESULTS: The current study found that the tebuconazole sensitivity of 165 F. graminearum isolates collected from the Huang-Huai-Hai region of China between 2019 and 2023 ranged from 0.005 to 2.029 µg/mL, with an average EC50 value of 0.33 ± 0.03 µg/mL. The frequency distribution conformed to a unimodal curve around the mean, and therefore provides a useful reference for monitoring the emergence of tebuconazole resistance in field populations of F. graminearum. No cross-resistance was detected between tebuconazole and other unrelated fungicides such as flutriafol, propiconazole and fluazinam, but there was a clear negative cross-resistance with triazole fungicides including fludioxonil, epoxiconazole, hexaconazole, and metconazole. Analysis of five tebuconazole-resistant mutants produced under laboratory conditions indicated that although the mycelial growth of the mutants were significantly (p < 0.05) reduced, spore production and germination rates could be significantly (p < 0.05) increased. However, pathogenicity tests confirmed a severe fitness cost associated with tebuconazole resistance, as all of the mutants completely loss the ability to infect host tissue. Furthermore, in general the resistant mutants were found to have increased sensitivity to abiotic stress, such as ionic and osmotic stress, though not to Congo red and oxidative stress, to which they were more tolerant. Meanwhile, molecular analysis identified several point mutations in the CYP51 genes of the mutants, which resulted in two substitutions (I281T, and T314A) in the predicted sequence of the FgCYP51A subunit, as well as seven (S195F, Q332V, V333L, L334G, M399T, E507G, and E267G) in the FgCYP51C subunit. In addition, it was also noted that the expression of the CYP51 genes in one of the mutants, which lacked point mutations, was significantly up-regulated in response to tebuconazole treatment. CONCLUSIONS: These results provide useful data that allow for more rational use of tebuconazole in the control of F. graminearum, as well as for more effective monitoring of fungicide resistance in the field.
Sujet(s)
Résistance des champignons aux médicaments , Fongicides industriels , Fusarium , Triazoles , Triazoles/pharmacologie , Fusarium/effets des médicaments et des substances chimiques , Fusarium/physiologie , Fongicides industriels/pharmacologie , Résistance des champignons aux médicaments/génétique , Maladies des plantes/microbiologie , Chine , MutationRÉSUMÉ
Excessive usage of biologically toxic fungicides and their matrix materials poses a serious threat to public health. Leveraging fungicide carriers with inherent pathogen inhibition properties is highly promising for enhancing fungicide efficacy and reducing required dosage. Herein, a series of coacervates have been crafted with lignin and surfactin, both of which are naturally derived and demonstrate substantial antifungal properties. This hierarchically assembled carrier not only effectively loads fungicides with a maximum encapsulation efficiency of 95% but also stably deposits on hydrophobic leaves for high-speed impacting droplets. Intriguingly, these coacervates exhibit broad spectrum fungicidal activity against eight ubiquitous phytopathogens and even act as a standalone biofungicide to replace fungicides. This performance can significantly reduce the fungicide usage and be further strengthened by an encapsulated fungicide. The inhibition rate reaches 87.0% when 0.30 mM pyraclostrobin (Pyr) is encapsulated within this coacervate, comparable to the effectiveness of 0.80 mM Pyr alone. Additionally, the preventive effects against tomato gray mold reached 53%, significantly surpassing those of commercial adjuvants. Thus, it demonstrates that utilizing biosurfactants and biomass with intrinsic antifungal activity to fabricate fully biobased coacervates can synergistically combine the functions of a fungicide carrier and antifungal agent against phytopathogens and guarantee environmental friendliness. This pioneering approach provides deeper insights into synergistically enhancing the effectiveness of agrochemicals from multiple aspects, including fungicide encapsulation, cooperative antifungal action, and droplet deposition.
Sujet(s)
Antifongiques , Lignine , Tests de sensibilité microbienne , Lignine/composition chimique , Lignine/pharmacologie , Antifongiques/pharmacologie , Antifongiques/composition chimique , Fongicides industriels/pharmacologie , Fongicides industriels/composition chimique , Lipopeptides/composition chimique , Lipopeptides/pharmacologie , Vecteurs de médicaments/composition chimique , Strobilurines/pharmacologie , Strobilurines/composition chimique , Pesticides/composition chimique , Pesticides/pharmacologie , Solanum lycopersicum/microbiologie , Solanum lycopersicum/effets des médicaments et des substances chimiques , Taille de particuleRÉSUMÉ
In agricultural environments, bees are routinely exposed to combinations of pesticides. For the most part, exposure to these pesticide mixtures does not result in acute lethal effects, but we know very little about potential sublethal effects and their consequences on reproductive success and population dynamics. In this study, we orally exposed newly emerged females of the solitary bee Osmia cornuta to environmentally-relevant levels of acetamiprid (a cyano-substituted neonicotinoid insecticide) singly and in combination with tebuconazole (a sterol-biosynthesis inhibitor (SBI) fungicide). The amount of feeding solution consumed during the exposure phase was lowest in bees exposed to the pesticide mixture. Following exposure, females were individually marked and released into oilseed rape field cages to monitor their nesting performance and assess their reproductive success. The nesting performance and reproductive success of bees exposed to the fungicide or the insecticide alone were similar to those of control bees and resulted in a 1.3-1.7 net population increases. By contrast, bees exposed to the pesticide mixture showed lower establishment, shortened nesting period, and reduced fecundity. Together, these effects led to a 0.5-0.6 population decrease. Female establishment and shortened nesting period were the main population bottlenecks. We found no effects of the pesticide mixture on nest provisioning rate, offspring body weight or sex ratio. Our study shows how sublethal pesticide exposure may affect several components of bee reproductive success and, ultimately, population growth. Our results calls for a rethinking of pollinator risk assessment schemes, which should target not only single compounds but also combinations of compounds likely to co-occur in agricultural environments.
Sujet(s)
Fongicides industriels , Insecticides , Néonicotinoïdes , Reproduction , Triazoles , Animaux , Abeilles/effets des médicaments et des substances chimiques , Abeilles/physiologie , Femelle , Insecticides/toxicité , Reproduction/effets des médicaments et des substances chimiques , Fongicides industriels/toxicité , Triazoles/toxicité , Néonicotinoïdes/toxicité , Croissance démographique , Pyridines/toxicitéRÉSUMÉ
Carbamate is a key structural motif in the development of fungicidal compounds, which is still promising and robust in the discovery of green pesticides. Herein, we report the synthesis and evaluation of the fungicidal activity of 35 carbamate derivatives, among which 19 compounds were synthesized in our previous report. These derivatives were synthesized from aromatic amides in a single step, which was a green oxidation process for Hofmann rearrangement using oxone, KCl and NaOH. Their chemical structures were characterized by 1H NMR, 13C NMR and high-resolution mass spectrometry. Their antifungal activity was tested against seven plant fungal pathogens. Many of the compounds exhibited good antifungal activity in vitro (inhibitory rate > 60% at 50 µg/mL). Compound 1ag exhibited excellent broad-spectrum antifungal activities with inhibition rates close to or higher than 70% at 50 µg/mL. Notably, compound 1af demonstrated the most potent inhibition against F. graminearum, with an EC50 value of 12.50 µg/mL, while compound 1z was the most promising candidate fungicide against F. oxysporum (EC50 = 16.65 µg/mL). The structure-activity relationships are also discussed in this paper. These results suggest that the N-aryl carbamate derivatives secured by our green protocol warrant further investigation as potential lead compounds for novel antifungal agents.