Search Results (15)

This research focuses on the removal of emerging contaminants (CEC) present in synthetic aqueous matrices. Azole compounds were selected as CEC of interest due to their persistence and toxicity, particularly the triazole and oxazole groups. These compounds are also trace contaminants listed in the proposed revision of Directive 91/271/EEC on urban wastewater treatment and the 3rd European Union Observation List (Implementing Decision EU 2020/116), highlighting their regulatory importance. The draft Directive includes the implementation of quaternary treatments to achieve the highest possible removal rates of micropollutants. Among the technologies used on a large scale are some advanced oxidation processes (AOP), often combined with adsorption on activated carbon (AC). Laboratory-scale pilot plants have been designed and operated in this research, including UV photolysis and oxidation with H₂O₂ and adsorption with GAC. The results demonstrate that UV photolysis is able to remove all the selected CECs except fluconazole, reaching eliminations higher than 86% at high doses of 31.000 J/m². Treatment by H₂O₂ achieved removals of 4 to 55%, proving to be ineffective in the degradation of persistent compounds when acting as a single technology. Adsorption by AC is improved with longer contact times, reaching removals above 80% for benzotriazole and methyl benzotriazole at short contact times, followed by sulfamethoxazole and tebuconazole. Fluconazole had a mean adsorption capacity at low contact times, while metconazole and penconazole showed low adsorption capacities. Full article

The development of innovative and effective strategies to combat fungal pathogens is critical to sustainable crop protection. Fungicides have been used for over two centuries, with traditional copper- and sulfur-based formulations still in use due to their broad-spectrum, multisite mode of action, which minimizes the risk of pathogen resistance. In contrast, modern systemic fungicides, though potent, often target a single site of action, leading to the accelerated emergence of resistant fungal strains. This study explores synergistic interactions between chitosan (CS) and selected fungicides, focusing on their antifungal activity against Fusarium graminearum. Among the fungicides tested, azoxystrobin (Amistar) exhibited the highest 44.88 synergy score when combined with CS (30 kDa, degree of deacetylation ≥ 90), resulting in significantly improved antifungal efficacy. Furthermore, the combination of CS and Amistar with double-stranded RNA (dsRNA) targeting selected ABC transporter genes further amplified antifungal activity by silencing genes critical for fungal tolerance to treatment. This dual synergy highlights the potential of RNA interference (RNAi) as both a functional tool to investigate fungal physiology and an effective antifungal strategy. These findings reveal a promising and environmentally friendly approach to mitigate resistance while improving fungal control. Furthermore, the remarkable synergy between azoxystrobin and CS presents a novel mechanism with significant potential for sustainable agricultural applications, which warrants further investigation to elucidate its molecular basis. Full article

Wheat sharp eyespot is a prevalent soil-borne disease that causes substantial economic losses in agriculture. Metconazole, a new triazole broad-spectrum fungicide, has demonstrated effective control of soil-borne diseases. Multi-walled carbon nanotubes (MWCNTs) are an innovative adsorbent material known for their large surface area and high absorptive capacity. This study identifies MWCNTs as the optimal adsorption material for metconazole, achieving an adsorption rate of 85.27% under optimal conditions (stirring time of 30 min and feeding ratio of 6:1). The optimized formula consists of 1.5% dispersant sodium wood, 1% emulsifier BY-112, 2% AEO-15, 3% glycol, 3% filmogen, and 4% red dyes. A 0.5% MWCNT–metconazole suspension concentrate for seed coating (FSC) significantly enhances the inhibitory effect of metconazole on wheat growth and promotes root development. At the tillering stage, a coating ratio of 1:100 shows a marked impact on wheat growth, and MWCNTs can improve the control effect of metconazole to Rhizoctonia cerealis. This work offers a novel approach for applying metconazole in a wheat suspension concentrate for seed coating. Full article

Fungicides play an important role in crop protection, but they have also been shown to adversely affect non-target organisms, including those living in the aquatic environment. The aim of the present study is to combine experimental and computational approaches to evaluate the effects of flutriafol, metconazole, myclobutanil, tebuconazole, tetraconazole and triticonazole on aquatic model organisms and to obtain information on the effects of these fungicides on Lemna minor, a freshwater plant, at the molecular level. The EC₅₀ (the half-maximum effective concentration) values for the growth inhibition of Lemna minor in the presence of the investigated fungicides show that metconazole (EC₅₀ = 0.132 mg/L) and tetraconazole (EC₅₀ = 0.539 mg/L) are highly toxic, tebuconazole (EC₅₀ = 1.552 mg/L), flutriafol (EC₅₀ = 3.428 mg/L) and myclobutanil (EC₅₀ = 9.134 mg/L) are moderately toxic, and triticonazole (EC₅₀ = 11.631 mg/L) is slightly toxic to this plant. The results obtained with the computational tools TEST, ADMETLab2.0 and admetSAR2.0 also show that metconazole and tetraconazole are toxic to other aquatic organisms: Pimephales promelas, Daphnia magna and Tetrahymena pyriformis. A molecular docking study shows that triazole fungicides can affect photosynthesis in Lemna minor because they strongly bind to C43 (binding energies between −7.44 kcal/mol and −7.99 kcal/mol) and C47 proteins (binding energies between −7.44 kcal/mol and −8.28 kcal/mol) in the reaction center of photosystem II, inhibiting the binding of chlorophyll a to these enzymes. In addition, they can also inhibit glutathione S-transferase, an enzyme involved in the cellular detoxification of Lemna minor. Full article

Rice blast, caused by the filamentous fungus Pyricularia oryzae, has long been one of the major threats to almost all rice-growing areas worldwide. Metconazole, 5-(4-chlorobenzyl)-2, 2-dimethyl-1-(1H-1, 2, 4-triazol-1-ylmethyl) cyclopentanol, is a lipophilic, highly active triazole fungicide that has been applied in the control of various fungal pathogens of crops (cereals, barley, wheat), such as the Fusarium and Alternaria species. However, the antifungal activity of metconazole against P. oryzae is unknown. In this study, metconazole exhibited broad spectrum antifungal activities against seven P. oryzae strains collected from rice paddy fields and the wild type strain P131. Scanning electron microscopic analysis and fluorescein diacetate staining assays revealed that metconazole treatment damaged the cell wall integrity, cell membrane permeability and even cell viability of P. oryzae, resulting in deformed and shrunken hyphae. The supplementation of metconazole in vitro increased fungal sensitivity to different stresses, such as sodium dodecyl sulfate, congo red, sodium chloride, sorbitol and oxidative stress (H₂O₂). Metconazole could inhibit key virulence processes of P. oryzae, including conidial germination, germ tube elongation and appressorium formation. Furthermore, this chemical prevented P. oryzae from infecting barley epidermal cells by disturbing appressorium penetration and subsequent invasive hyphae development. Pathogenicity assays indicated a reduction of over 75% in the length of blast lesions in both barley and rice leaves when 10 μg/mL of metconazole was applied. This study provides evidence to understand the antifungal effects of metconazole against P. oryzae and demonstrates its potential in rice blast management. Full article

Fusarium species are common plant pathogens that cause serious crop losses worldwide. Fusarium spp. colonize not only the main host plants, crops, but also alternative hosts. The effectiveness of fungicide use in disease management ranges from very successful to possibly promoting the growth of the pathogen. Triazole fungicides are widely used to control these pathogens due to their broad-spectrum activity and systemic nature. This paper reviews the sensitivity of 40 Fusarium strains isolated from weeds, non-gramineous plants, and spring wheat to metconazole, prothioconazole, and tebuconazole. The effect of fungicides was determined by the percentage inhibition of F. graminearum, F. culmorum, F. sporotrichioides, and F. avenaceum fungal mycelial growth. The 50% effective concentration (EC50) values of all isolates on metconazole were lower than 2.9 mg L⁻¹, prothioconazole EC50 ranged from 0.12 to 23.6 mg L⁻¹, and tebuconazole ranged from 0.09 to 15.6 mg L⁻¹. At 0.00025–0.025 mg L⁻¹, the fungicides were ineffective, except for the growth of the F. avenaceum species. It was observed that isolates from weeds were more sensitive to low concentrations of fungicide than isolates from crop plants. In general, information is scarce regarding the comparison of fungicide resistance in Fusarium isolates from weed and crop plants, making this study an additional contribution to the existing knowledge base. Full article

This study investigated the degradation characteristics and conducted a risk assessment of four pesticides (Diniconazole, Dinotefuran, Metconazole, and Tebuconazole) in the leaves and roots of radish. Radish was cultivated in two greenhouse fields, and samples were collected at 0, 1, 2, 3, 5, 7, and 10 days after pesticide application. Sample analysis was performed using LC-MS/MS, and the recovery rates ranged from 70.1% to 118.6%. The biological half-life of Diniconazole was found to be 6.2 days (leaf and root), Dinotefuran was 5.3 days (leaf) and 4.6 days (root), Metconazole was 9.3 days (leaf) and 3.2 days (root), and Tebuconazole was 8.0 days (leaf) and 5.1 days (root). After comparing the maximum residue limits (MRL) of each pesticide in Korea with the residues during the pre-harvest interval (PHI), Diniconazole showed a Hazard quotient (HQ) exceeding 1, indicating potential risks for true consumers. Furthermore, Tebuconazole showed an HQ of 0.3 or higher, indicating a significant level of risk. Full article

The beach vitex (Vitex rotundifolia L.), a member of the Lamiaceae family, is a salt-tolerant, woody perennial common in coastal areas worldwide. Plant–fungal association was monitored in the shoreline forest area of Wando Island in Korea in 2020, and leaf samples showing leaf spot disease were collected. Eight fungal isolates were recovered from the samples on PDA and identified based on the morphological characteristics and multilocus molecular phylogeny. Among the eight isolates, four were identified as Alternaria alternata, two as Fusarium humuli, one as Colletotrichum aenigma, and one as Stagonosporopsis caricae. Pathogenicity tests of the fungal isolates on the detached leaves of beach vitex revealed that S. caricae CMML20–2 and A. alternata (CMML20–7, CMML20–8, CMML20–9, and CMML20–10) caused disease lesions while the other species did not. The fungal species S. caricae, C. aenigma, and F. humuli are the first reported in the host worldwide, and S. caricae and F. humuli are first reported in Korea. In vitro fungicide sensitivity assays were carried out based on a measurement of diametrical mycelial growth on media amended with different doses of the fungicides fludioxonil, metconazole, and fluxapyroxad. Fungicide sensitivity varied significantly among the species, and the A. alternata and S. caricae isolates were more sensitive to fluxapyroxad than the other isolates. Our study contributes to the understanding of fungal diversity in forest mycology and demonstrates that pathogenic fungi including A. alternata and S. caricae might accelerate decline in leaf health. Full article

Strawberry crown rot is a serious fungal disease that poses a great threat to strawberry production in the growth cycle. The dominant pathogens of strawberry crown rot pathogens were different in different periods. The main pathogen of strawberry crown rot at the seedling stage is unclear. In this study, 74 Colletotrichum spp. were isolated from 100 strawberry plants at the seedling stage. Based on the morphological observations and phylogenetic analysis of multiple genes (ACT, CAL, CHS, GAPDH, and ITS), all 74 tested isolates were identified as C. gloeosporioides species complex, including 69 isolates of C. siamense and 5 isolates of C. fructicola. Colletotrichum siamense is the main pathogen of strawberry crown rot at the seedling stage in Zhejiang, China. The sterol demethylation inhibitors (DMIs) were used to control strawberry crown rot, and their target was the CYP51 gene. The role of the homologous CYP51 gene in growth, reproduction, pathogenicity, and sensitivity to DMI fungicides in C. siamense has not been determined. Our study found that the pathogenicity of CsCYP51A deletion mutants to strawberry leaves and stems was weakened. The hyphae growth rate of CsCYP51B deletion mutants was significantly slower than that of the wild type, but the sporulation and appressorium production rates increased. CsCYP51B deletion mutants had significantly increased pathogenicity to the stem. Deletion of CsCYP51A led to increased sensitivity to prothioconazole, ipconazole, hexaconazole, triadimefon, prochloraz, tebuconazole, metconazole, propiconazole, and difenoconazole. CsCYP51B deletion mutants were more insensitive. Our results indicate that the effect of the homologous CsCYP51 gene on hyphae growth, pathogenicity, and sensitivity to DMI fungicides differs. Full article

Fusarium head blight (FHB) is one of the most important diseases of barley in Manitoba province (western Canada), and other major barley producing regions of the world. Little is known about the Fusarium species and mycotoxin spectra associated with FHB of barley in Manitoba. Hence, barley grain samples were collected from 149 commercial fields from 2017 to 2019, along with information on respective cropping history, and analyzed with respect to Fusarium species spectra, abundance, chemotype composition, and mycotoxin profiles. Fusarium poae was the predominant Fusarium species associated with FHB of barley in Manitoba, followed by F. graminearum, and F. sporotrichioides; F. equiseti and F. avenaceum were also detected but at low levels. F. poae strains with the nivalenol (NIV) chemotype and F. graminearum strains with 3-acetyl deoxynivalenol (3-ADON) and 15-acetyl deoxynivalenol (15-ADON) chemotypes were commonly detected in the barley grain samples. Nivalenol (597.7, 219.1, and 412.4 µg kg⁻¹) and deoxynivalenol (DON) (264.7, 56.7, and 65.3 µg kg⁻¹) were the two most prevalent mycotoxins contaminating Manitoba barley in 2017, 2018 and 2019, respectively. A substantially higher DON content was detected in grain samples from barley fields with cereals as a preceding crop compared to canola and flax. Furthermore, F. poae proved less sensitive to four triazole fungicides (metconazole, prothioconazole+tebuconazole, tebuconazole, and prothioconazole) than F. graminearum. Findings from this research will assist barley producers with improved understanding of FHB threat levels and optimizing practices for the best management of FHB in barley. Full article

In the Czech Republic, demethylation inhibitors (DMIs) are used both as fungicides in controlling phoma stem canker and as growth regulators. This heavy use can result in the development of resistant isolates. A total of 45 and 286 Leptosphaeria maculans isolates were tested in vitro, using the mycelial growth and microtiter plate assays, respectively. The objective was to determine the sensitivity of L. maculans isolates collected in the Czech Republic to the fungicides tetraconazole, metconazole, and prochloraz. The mean EC₅₀ values with the mycelial growth plate method were 1.33, 0.78, and 0.40 µg mL⁻¹ for tetraconazole, metconazole, and prochloraz, respectively. The mean EC₅₀ values for the microtiter plate assay were 3.01, 0.44, and 0.19 µg mL⁻¹ for tetraconazole, metconazole, and prochloraz, respectively. All three fungicides also had high variation factors that may be due to inserts in the ERG11 promoter region. In addition, cross sensitivity among the three fungicides was observed. Overall, the high variation factors and the PCR (polymerase chain reaction) results observed in this study could signify the presence of resistant isolates in L. maculans Czech populations, especially in isolates tested for sensitivity to tetraconazole. Full article

Triazole fungicides can manifest toxicity to a wide range of non-target organisms. Within this study we present a systematic review of the effects produced on the soil microbiota and activity of soil enzymes by the following triazole fungicides: cyproconazole, difenoconazole, epoxiconazole, flutriafol, hexaconazole, metconazole, myclobutanil, paclobutrazole, propiconazole, tebuconazole, tetraconazole, triadimenol, triadimefon, and triticonazole. Known effects of the triazole fungicides on the soil activity are dose dependent. High doses of triazole fungicides strongly affects the structure of the microbial communities in soil and usually decrease the soil microbial population and the activities of enzymes found in soil. Full article

Wheat is one of the global strategic crops and ranks third in terms of cereals production. Wheat crops are exposed to many fungal infections during their cultivation stages, some of which have the ability to secrete a number of toxic secondary metabolites that threaten the quality of the grains, consumer health, producer economics, and global trade exchange. Fifty-four random samples were collected from wheat which originated from different countries. The samples included 14 types of soft wheat to study the extent of their contamination with deoxynivalenol (DON) and T-2 toxin by auto-ELISA technology and r-biopharm microtiter plate. All samples were contaminated with DON toxin except one sample, and the values ranged between 40.7 and 1018.8 µg/kg⁻¹. The highest contamination rates were in Lithuanian wheat and the lowest was in Indian wheat. Meanwhile, the highest average level of T-2 toxin contamination was in Lithuanian wheat grains with 377.4 µg/kg⁻¹, and the lowest average was 115.3 µg/kg⁻¹ in Polish wheat. GC-MS/MS and multiple reaction monitoring mode (MRM) were used to detect 15 triazole derivatives in the collected samples, which may be used to combat fungal diseases on wheat during the growing season. Only 9 derivatives were found: simeconazole, penconazole, hexaconazole, cyproconazole, diniconazole, tebuconazole, metconazole, fenbuconazole, and difenoconazole. These derivatives varied according to the origin of the wheat samples as well as their concentration, whereas another 6 derivatives were not detected in any samples. A direct inverse relationship was found between the DON concentration in the samples and the residues of simeconazole, penconazole, diniconazole, tebuconazole, metconazole, fenbuconazole, and difenoconazole, and the T-2 toxin showed the same relationship except for tebuconazole. The safe and rational use of some triazole derivatives may be a new approach and a promising strategy to not only reduce plant diseases and their problems, but also to get rid of some mycotoxins as grain contaminants. Full article

Azole resistance is an emerging problem in patients with aspergillosis. The role of fungicides for resistance development and occurrence is not fully elucidated. EUCAST reference MICs of 17 fungicides (11 azoles and 6 others), five azole fungicide metabolites and four medical triazoles were examined against two reference and 28 clinical isolates of A. fumigatus, A. flavus and A. terreus with (n = 12) and without (n = 16) resistance mutations. Eight/11 azole fungicides were active against wild-type A. fumigatus, A. flavus and A. terreus, including four (metconazole, prothioconazole-desthio, prochloraz and imazalil) with low MIC₅₀ (≤2 mg/L) against all three species and epoxiconazole, propiconazole, tebuconazole and difenoconazole also against wild-type A. terreus. Mefentrifluconazole, azole metabolites and non-azole fungicides MICs were >16 mg/L against A. fumigatus although partial growth inhibition was found with mefentrifluconazole. Moreover, mefentrifluconazole and axozystrobin were active against wild-type A. terreus. Increased MICs (≥3 dilutions) were found for TR₃₄/L98H, TR₃₄⁽³⁾/L98H, TR₄₆/Y121F/T289A and G432S compared to wild-type A. fumigatus for epoxiconazole, propiconazole, tebuconazole, difenoconazole, prochloraz, imazalil and metconazole (except G432S), and for prothioconazole-desthio against TR₄₆/Y121F/T289A, specifically. Increased MICs were found in A. fumigatus harbouring G54R, M220K and M220R alterations for five, one and one azole fungicides, respectively, compared to MICs against wild-type A. fumigatus. Similarly, increased MICs wer found for A. terreus with G51A, M217I and Y491H alterations for five, six and two azole fungicides, respectively. Azole fungicides showed activity against wild-type A. fumigatus, A. terreus and A. flavus, but not against all mutant isolates, suggesting the environmental route of azole resistance may have a role for all three species. Full article

Developed and validated analytical methods for the determination of a wide spectrum of pesticide residues in honey and honeybee samples after the modification of QuEChERS extraction in combination with gas chromatography–tandem quadrupole mass spectrometry (GC-MS/MS) and liquid chromatography–tandem quadrupole mass spectrometry (LC-MS/MS) were discussed and compared. The developed methods were evaluated regarding the utilized equipment and reagents using Eco-Scale and compared in terms of extraction time, accuracy, precision, sensitivity and versatility, with similar procedures. The results proved that the QuEChERS protocol in combination with LC and GC techniques fulfills the requirements of green analytical chemistry, so it can be used as a tool in environmental monitoring. The recovery was 85–116% for honey and 85.5–103.5% for honeybee samples. The developed methods were successfully applied in monitoring real samples collected from three districts of Pomerania in Poland. Analysis of real samples revealed the presence of the following pesticides: bifenthrin, fenpyroximate, methidathione, spinosad, thiamethoxam, triazophos, metconazole and cypermethrin at levels higher than the MRLs established by the EU. Full article