Search

This study investigates a novel antimicrobial peptide AtR905 derived from the endophytic fungus Aspergillus terreus , which was successfully expressed in Bacillus subtilis , purified, and characterized, and highlighted as a promising potential biocontrol agent against various plant pathogens. The results indicated AtR905 exhibited broad-spectrum antimicrobial activities against key pathogens such as Ralstonia solanacearum and Clavibacter michiganensis with very low minimal inhibitory concentrations (MICs). Stability tests confirmed that AtR905 retains its antimicrobial properties under varying thermal, pH, and UV conditions. The Oxford Cup test indicated that AtR905 showed obvious fungicidal activity against six plant pathogenic fungi, especially Rhizoctonia solani and Botrytis cinerea . Additionally, in vivo experimental demonstrated AtR905 could effectively control the B. cinerea on tobacco leaves and R. solanacearum on tomato plants. Scanning electron microscopy revealed significant membrane disruption in bacterial cells treated with AtR905. These findings suggest that AtR905 is a promising candidate for sustainable plant disease management, potentially reducing the reliance on chemical pesticides and mitigating the issue of antibiotic resistance in agricultural settings. Further research is needed to evaluate the long-term field applicability and ecological impacts of AtR905.

The exacerbation of plant fungal diseases necessitates the development of new fungicides to prevent outbreaks. In this study, five novel isoindoline-2-yl putrescines (ISPs) were synthesized, and their synthetic procedures and gram-scale preparation were explored. When tested at 50 μg mL -1 , ISPs did not significantly inhibit mycelial growth on agar plates. However, at 100 μg mL -1 , they demonstrated remarkable in vivo efficacy in mitigating Botrytis cinerea infection, especially ISP3 showed curative and protective activities of 91.9 % and 92.6 %, respectively. Moreover, ISP3 also effectively halted lesion expansion of gray mold, Sclerotic rot, and Fusarium scabs, while inducing excessive malformed top mycelial branches of B. cinerea and Sclerotinia sclerotiorum, suppressing sclerotia formation in S. sclerotiorum, and triggering autophagic vacuolization with numerous autophagosomes in the mycelia of these fungi. Molecular docking revealed that ISP3 effectively bound to the active site of BcAtg3, forming hydrogen bonds with Ser279, Gly343, Asp370, and Asp13, along with establishing a stable salt bridge with Asp13. Furthermore, ISP3 possessed favorable ADMET properties. These findings highlight ISP3 as a promising antifungal candidate through autophagy activation., (© 2024 Wiley-VHCA AG, Zurich, Switzerland.)

The exploration of potential candidates for fungicides against four fungal proteins that cause some vital plant diseases, namely Phytophthora capsici, Botrytis cinerea, Fusarium oxysporum f. sp. lycopersici, and Puccinia graminis f. sp. tritici, was conducted using in silico, molecular docking simulations, and molecular dynamic (MD) simulation for selecting the nature of binding affinity with actives sites of proteins. First of all, the DFT was employed to optimize the molecular geometry, and get the prepared optimized ligand. From the DFT data, the chemical descriptors were calculated. Next, two docking tools, such as AutoDock by PyRx and Molecular Docking by Glide from the Schrödinger suite, were used to convey the docking score, and ligand protein interactions against four main proteases, for instance 7VEM, 8H6Q, 8EBB, and 7XDS having name of pathogens: Phytophthora capsici, Botrytis cinerea, Fusarium oxysporum f. sp. lycopersici, and Puccinia graminis f. sp. tritici, respectively. In case of auto dock from PyRx, the fungicides L01, L03, L04, L13, L14, L17, L18, and L19 demonstrated significantly higher affinities for binding to the four fungal pathogens. Surprisingly, it is conveyed that the L03 illustrated the highest binding score against three of 7VEM, 8EBB, and 7XDS proteins and L09 is highest for 8H6Q. However, MD was performed to check the validation and calculation the docking procedure and stability of the protein ligand docked complex accounting of RMSD, RMSF, SASA, Radius of gyration (Rg), Protein secondary structure elements (SSE), Ramachandran plot which confirm that the stability of docked complex is so high, and number of calculating the hydrogen bonds is more than good enough, as a result it is concluded the docking procedure is valid. Finally, Difenoconazole (L03) has been considered as the most promising antifungal drug evaluated from the studies., Competing Interests: The authors have declared that no competing interests exist, (Copyright: © 2025 Naimuzzaman et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

To discover novel inhibitors of pyruvate kinase (PK) as fungicidal candidates, a series of 2-thiazol-2-yl-1,3,4-oxadiazole derivatives were designed by a prediction model with Rhizoctonia solani PK (RsPK) as a protein target and YZK-C22 as a ligand. Fungicidal screening indicated that 5b , 5g , 5h , 5j , 5l , 5p , 5q , and 5s exhibited equal or higher activity compared to YZK-C22 against Botrytis cinerea , Cercospora arachidicola , or R. solani . To our surprise, 5s showed comparable activity to flutriafol with an EC 50 of 0.21 μg/mL vs 0.20 μg/mL, but over 14 times more active than the lead compound YZK-C22 against R. solani with its EC 50 of 0.21 μg/mL vs 3.14 μg/mL (mole ratio over 17-fold). Compound 5s also displayed 2.30-fold better inhibition potency against RsPK compared with YZK-C22 . Moreover, this higher potency of 5s against RsPK was also reflected in a steeper dose-response tendency in the fluorescence quenching assay and a lower dissociation constant in the microscale thermophoresis (MST) assay when compared with YZK-C22 . The results in this study not only broadened the structural diversity of PK inhibitors but also supported 5s as a promising PK-based highly active fungicide lead compound, with stronger binding ability to RsPK than YZK-C22 .

Texenomycins are a family of linear lipopeptaibols with a long polyketide side chain at the N-terminus and 21 amino acid residues at the C -terminus, presenting demonstrated potential as antibiotics against plant fungal pathogens. In this study, texenomycins were identified and isolated from the fungus Mariannaea elegans strain TTI-0396 and showed effective antifungal properties against two plant pathogens Colletotrichum lagenarium and Botrytis cinerea . Through analysis of the whole-genome data of M. elegans strain TTI-0396, we discovered a hybrid PKS-NRPS system with the polyketide synthase (PKS: TexQ), thioesterase (TexO), acyl-CoA ligase (TexI), and three nonribosomal peptide synthetases (NRPSs: TexG, TexJ, TexV) in the tex gene cluster that were proposed to be responsible for the biosynthesis of texenomycins and another related lipopeptaibol, lipohexin. The functions of six key genes ( texQ , texO , texI , texG, texJ , and texV ) in the hybrid PKS-NRPS system were verified by gene deletion experiments, and five genes ( texQ , texO , texI , texG , and texV ) were confirmed to be responsible for the biosynthesis of texenomycins, while four genes ( texQ , texO , texI , and texJ ) were involved in the biosynthesis of lipohexin. Furthermore, the function of one transcription factor gene ( texR ), which enhanced the production of texenomycins by regulating the key genes in the tex gene cluster, was also demonstrated through gene deletion and overexpression experiments. Finally, a hypothetical scheme for texenomycins and lipohexin biosynthesis assembly is proposed. The elucidation of this intricate hybrid PKS-NRPS system has significantly deepened our comprehension of the mechanisms underlying the generation and chemical diversity of fungal lipopeptaibol natural products, offering a promising avenue for future research and potential applications in fungicidal disease control in agriculture.

Four series of novel hydrazide/thiazol/oxazol/oxime ester hybrids of chromene derivatives were designed and synthesized to explore natural-product-based fungicide candidates. Preliminary antifungal activity assay results demonstrated that hydrazide-chromene and thiazol-chromene derivatives exhibited excellent and broad-spectrum inhibitory activity against ten phytopathogenic fungi. Among them, six compounds 4b , 4c , 4d , 4e , 4h , and 4l displayed the most remarkable antifungal effects. Notably, compounds 4e and 4l showed comparable protective and curative effects with chlorothalonil against potatoes and cherry tomatoes infected by Fusarium solani and Botrytis cinerea , respectively. Meanwhile, compound 4e also exerted potential protective and curative effects against rice and pepper leaves infected by Pyricularia oryzae and Phytophthora capsici , respectively. Additionally, a preliminary antifungal mechanism study revealed that compound 4e could significantly inhibit the germination of spores and promote increased mycelium permeability and content leakage by disrupting the fungal membrane structure. The in vitro cytotoxicity results indicated that almost all of the hydrazide-chromene derivatives possessed relatively low cytotoxicity. These findings provide the foundation for the application of chromene-based derivatives as novel fungicide candidates.

Background: The threats to the safety of humans and the environment and the resistance of agricultural chemicals to plant pathogenic fungi and bacteria highlight an urgent need to find safe and efficient alternatives to chemical fungicides and bactericides. In this study, a series of Berberine (BBR) derivatives were designed, synthesized and evaluated for in vitro and in vivo antimicrobial activity against plant pathogenic fungi and bacteria., Results: Bioassay results indicated that compounds A11, A14, A20, A21, A22, A25, A26, E1, E2, E3, Z1 and Z2 showed high inhibitory activity against Sclerotinia sclerotiorum and Botrytis cinerea. Especially, A25 showed a broad spectrum and the highest antifungal activity among these compounds. Its EC 50 value against Botrytis cinerea was 1.34 μg mL -1 . Compound E6 possessed high inhibitory activity against Xanthomonas oryzae and Xanthomonas Campestris, with MIC 90 values of 3.12 μg mL -1 and 1.56 μg mL -1 . A Topomer CoMFA model was generated for 3D-QSAR studies based on anti-B. cinerea effects, with high predictive accuracy, showed that the addition of an appropriate substituent group at the para-position of benzyl of BBR derivatives could effectively improve the anti-B. cinerea activity. In addition, compound A25 could significantly inhibit the spore germination of Botrytis cinerea at low concentration, and compound F4 exhibited remarkable curative and protective efficiencies on rice bacterial leaf blight., Conclusion: This study indicates that the BBR derivatives are hopeful for further exploration as the lead compound with novel antimicrobial agents. © 2024 Society of Chemical Industry., (© 2024 Society of Chemical Industry.)

Background: Growing concerns about sustainability have driven the search for eco-friendly pest management solutions. Combining natural and synthetic compounds within controlled release systems is a promising strategy. This study investigated the co-encapsulation of the natural compound citral (Cit) and the synthetic antifungal cyproconazole (CPZ) using two water-based nanocarriers: solid lipid nanoparticles (SLNs) and chitosan nanoparticles (CSNPs)., Results: Both CSNPs and SLNs loaded with Cit + CPZ displayed superior antifungal activity against Botrytis cinerea compared to free compounds. Notably, CSNPs with a 2:1 Cit:CPZ ratio exhibited the highest efficacy, achieving a minimum inhibitory concentration (MIC 100 ) of < 1.56 μg mL -1 , lower than the 12.5 μg mL -1 of non-encapsulated compounds. This formulation significantly reduced the required synthetic CPZ while maintaining efficacy, highlighting its potential for environmentally friendly pest control., Conclusion: The successful co-encapsulation of Cit + CPZ within CSNPs, particularly at a 2:1 ratio, demonstrates a promising approach for developing effective and sustainable antifungal formulations against B. cinerea. © 2024 Society of Chemical Industry., (© 2024 Society of Chemical Industry.)

Hydrophobic Deep Eutectic Solvents (HDES), as a subclass of Natural Deep Eutectic Solvents (NADES), present a green-chemistry alternative to toxic chemicals. As HDES are based on terpenoids, these solvents could potentially be effective antifungal agents against phytopathogens Monilinia fructicola and Botrytis cinerea that frequently cause diseases in sweet cherry fruit. To contribute to the disease prevention and management goals, as a part of this study, 30 different HDES were tested in the vapor phase, at identical concentrations of 25%, 50%, and 100%. In vitro experiments were conducted on Potato Dextrose Agar medium (PDA), while in planta experiments were carried out in hermetically sealed containers with inoculated sweet cherry fruits. All tested HDES demonstrated efficacy in suppressing the growth of M. fructicola colonies (66 - 100%) and B. cinerea colonies (37 - 100%). According to the Area Under the Disease Progress Curve (AUDPC), all HDES exhibited high efficacy in preventing disease occurrence in cherry fruits by the tested phytopathogens. This research provides the first insights into the antifungal potential of HDES in the vapor phase, with promising applications as biofumigants that minimize harmful impacts on the food - human - environment complex., Competing Interests: Declarations. Ethical approval: Not applicable. Consent to participate: Not applicable. Consent to publish: Not applicable. Competing interests: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

To develop further novel environmentally friendly antifungal agents with high efficacy, a series of pyrazole-5-sulfonamide derivatives were designed and synthesized by using the active molecules synthesized in previous works as lead compounds. Their antifungal activities were evaluated in vitro against ten highly destructive plant pathogenic fungi. The bioassay results indicated that more than half of the target compounds displayed potent antifungal activities (inhibition rate ≥85%) against Valsa mali and Sclerotinia sclerotiorum at 20 mg/L. Among them, compound C22 exhibited significant broad-spectrum antifungal activities against V. mali , S. sclerotiorum , Rhizoctonia solani , Botrytis cinerea , and Trichoderma viride , with EC 50 values of 0.45, 0.49, 3.06, 0.57, and 1.43 mg/L, respectively. Moreover, compounds C21 and C22 exhibited remarkable protective effects on apple Valsa canker similar to tebuconazole (89.5%) at 50 mg/L. Preliminary antifungal mechanism investigations demonstrated that compound C22 may have inhibited V. mali mycelial growth by inducing oxidative damage to the mycelium and compromising the integrity of the cell membrane. Meanwhile, compounds C21 and C22 exhibited no obvious toxicity to worker bees ( Apis mellifera ligustica). Taken together, these pyrazole-5-sulfonamide derivatives, particularly compound C22 , possess huge potential to be developed as novel environmentally friendly fungicides with high efficacy.

Based on previous research, this study synthesized 24 compounds by splicing the substructures of the indolyl group and the isothiocyanate group. Alternaria alternata , Phytophthora capsici , Botrytis cinerea, and Valsa mali were used to test the activity of the target compounds. At 100 μg/mL, compounds 8 , 13 , 14 , and 17 exhibited excellent inhibitory effects of more than 80% on P. capsici , B. cinerea, and V. mail . The EC 50 values of compounds 13 and 14 were 0.64 and 2.08 μg/mL, respectively. Potted antifungal activity demonstrated that compounds 13 and 14 had a protective effect of around 80% against B. cinerea at 200 μg/mL. Further physiological and biochemical studies on B. cinerea revealed that compound 13 thickened cell walls and caused mitochondrial vacuolization. Moreover, theoretical calculations indicated that the charge distribution of indolyl isothiocyanate compounds played a crucial role in the observed fungicidal activity. In summary, this study provided fundamental reference data for the derivative synthesis of these indolyl isothiocyanate compounds.

Fungal secondary metabolites play a highly significant role in crop protection, which is related to their antifungal activity against agriculturally important phytopathogens. In fact, plant diseases caused by fungi including species belonging to the genera of Alternaria , Botrytis , and Fusarium have become increasingly serious affecting crop yield and quality. Hence, there is increasing awareness by the scientific community of the importance of exploiting fungal products for finding new compounds able to inhibit phytopathogens. In this study several drimane-type sesquiterpenes have been detected for the first time as products of Aspergillus xerophilus by GC-MS analysis of the organic extracts obtained from the mycelia and culture filtrates of the fungus grown on two different substrates. Seven pure drimane-type sesquiterpenes were also isolated and identified by spectroscopic methods. The inhibitory effects of the pure compounds have been investigated against three phytopathogenic fungi of agrarian crops (i.e., Botrytis cinerea , Alternaria alternata , and Fusarium oxysporum f. sp. pisi ). Among the drimane-type sesquiterpenes isolated in this study, 9,11-dihydroxy-6-oxodrim-7-ene is the most active against the three phytopathogens. Our findings also reveal the high sensitivity of A. alternata to the isolated compounds. These results pave the way for future applications in agriculture of both A. xerophilus and its metabolites.

Plant pathogenic fungi frequently disrupt the normal physiological and biochemical functions of plants, leading to diseases, compromising plant health, and ultimately reducing crop yield. This study aimed to address this challenge by identifying antifungal agents with innovative structures and novel mechanisms of action. We designed and synthesized a series of flavonoid derivatives substituted with 5-sulfonyl-1,3,4-thiadiazole and evaluated their antifungal activity against five phytopathogenic fungi. Most flavonoid derivatives demonstrated excellent antifungal activity against Botrytis cinerea ( B. cinerea ), Alternaria solani ( A. solani ), Rhizoctorzia solani ( R. solani ), Fusarium graminearum ( F. graminearum ), and Colletotrichum orbiculare ( C. orbiculare ). Specifically, the EC 50 values of 38 target compounds against R. solani were below 4 μg/mL, among which the compounds C13 (EC 50 = 0.49 μg/mL), C15 (EC 50 = 0.37 μg/mL), and C19 (EC 50 = 0.37 μg/mL) had the most prominent antifungal activity, superior to that of the control drug carbendazim (EC 50 = 0.52 μg/mL). Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images of the cellular ultrastructures of R. solani mycelia and cells after treatment with the compound C19 revealed sprawling growth of hyphae, a distorted outline of their cell walls, and reduced mitochondrial numbers. Studying the 3D-QSAR between the molecular structure and antifungal activity of 5-sulfonyl-1,3,4-thiadiazole-substituted flavonoid derivatives could significantly improve conventional drug molecular design pathways and facilitate the development of novel antifungal leads.

Background: Cationic antimicrobial peptides (AMPs) possess broad-spectrum biological activities with less inclination to inducing antibiotic resistance. Herein a battery of amphiphilic amidines were designed by mimicking the characteristics of AMPs. The antifungal activities and the effects to the hyphal morphology and membrane permeability were investigated., Results: The results indicated the inhibitory rates of ten compounds were over 80% to Botrytis cinerea and ten compounds over 90% to Valsa mali Miyabe et Yamada at 50 mg L -1 . The half maximal effective concentration (EC 50 ) values of compound 5g and 6g to V. mali were 1.21 and 1.90 mg L -1 respectively. The protective rate against apple canker of compound 5g reached 93.4% at 100 mg L -1 on twigs, superior to carbendazim (53.3%). When treated with 5g, the cell membrane permeability and leakage of content of V. mali increased, accompanied with the decrease of superoxide dismutase (SOD) and catalase (CAT) level. Concurrently, the mycelial hyphae contracted, wrinkled, and collapsed, providing evidence of membrane perturbation. A three-dimensional quantitative structure-activity relationship (3D-QSAR) between the topic compounds and the EC 50 to V. mali was established showing good predictability (r 2  = 0.971)., Conclusion: Amphiphilic amidines can acquire antifungal activities by acting on the plasmic membrane. Compound 5g could be a promising lead in discovering novel fungicidal candidates. © 2024 Society of Chemical Industry., (© 2024 Society of Chemical Industry.)

This research adopted the Fischer indole synthesis method to continue constructing a novel drug-like chemical entity based on the guidance of isocryptolepine and obtained four series of derivatives: Y , Da , Db , and Dc . The antimicrobial activity of these derivatives against plant pathogens was further evaluated. The results showed that Dc-2 had the best antifungal effect against Botrytis cinerea , and its EC 50 value was up to 1.29 μg/mL. In addition, an in vivo activity test showed that the protective effect of Dc-2 on apples was 82.2% at 200 μg/mL, which was better than that of Pyrimethanil (45.4%). Meanwhile, it was found by scanning electron microscopy and transmission electron microscopy that the compound Dc-2 affected the morphology of mycelia. The compound Dc-2 was found to damage the cell membrane by PI and ROS staining. Through experiments such as leakage of cell contents, it was found that the compound Dc-2 changed the permeability of the cell membrane and caused the leakage of substances in the cell. According to the above studies, compound Dc-2 can be used as a candidate lead compound for further structural optimization and development.

Naturally derived compounds show promise as treatments for microbial infections. Polyphenols, abundantly found in various plants, fruits, and vegetables, are noted for their physiological benefits including antimicrobial effects. This study introduced a new set of acylated phloroglucinol derivatives, synthesized and tested for their antifungal activity in vitro against seven different pathogenic fungi. The standout compound, 3-methyl-1-(2,4,6-trihydroxyphenyl) butan-1-one ( 2b ), exhibited remarkable fungicidal strength, with EC 50 values of 1.39 μg/mL against Botrytis cinerea and 1.18 μg/mL against Monilinia fructicola , outperforming previously screened phenolic compounds. When tested in vivo, 2b demonstrated effective antifungal properties, with cure rates of 76.26% for brown rot and 83.35% for gray mold at a concentration of 200 μg/mL, rivaling the commercial fungicide Pyrimethanil in its efficacy against B. cinerea . Preliminary research suggests that 2b' s antifungal mechanism may involve the disruption of spore germination, damage to the fungal cell membrane, and leakage of cellular contents. These results indicate that compound 2b has excellent fungicidal properties against B. cinerea and holds potential as a treatment for gray mold.

Sophora flavescens , a traditional Chinese herb, produces a wide range of secondary metabolites with a broad spectrum of biological activities. In this study, we isolated six isopentenyl flavonoids (1-6) from the roots of S. flavescens and evaluated their activities against phytopathogenic fungi. In vitro activities showed that kurarinone and sophoraflavanone G displayed broad spectrum and superior activities, among which sophoraflavanone G displayed excellent activity against tested fungi, with EC 50 values ranging from 4.76 to 13.94 μg/mL. Notably, kurarinone was easily purified and showed potential activity against Rhizoctonia solani , Botrytis cinerea , and Fusarium graminearum with EC 50 values of 16.12, 16.55, and 16.99 μg/mL, respectively. Consequently, we initially investigated the mechanism of kurarinone against B. cinerea . It was found that kurarinone disrupted cell wall components, impaired cell membrane integrity, increased cell membrane permeability, and affected cellular energy metabolism, thereby exerting its effect against B. cinerea . Therefore, kurarinone is expected to be a potential candidate for the development of plant fungicides.

Using antifungal agrochemicals as the most economical solution might reduce plant diseases caused by pathogenic fungi, which have a significant negative impact on the quality and yield of food worldwide. In this work, 33 compounds ( G ) containing 1,2,3-triazole and malononitrile structures were synthesized. When the compounds were tested in vitro against six fungal species, they exhibited significant fungicidal activity toward Botrytis cinerea and Rhizoctonia solani . Compounds G17 and G30 displayed promising in vivo efficacy, with an EC 50 of 0.19 and 0.27 mg/L respectively against R. solani . Fungal ergosterol production was suppressed by compounds G17 and G30 , according to a preliminary analysis of their mechanism of action on R. solani using transcriptomics and scanning electron microscopy. It has been shown through experimentation that compounds G17 and G30 prevent R. solani from synthesizing ergosterol. Ultimately, it was anticipated that compounds G17 and G30 would be discovered to be low-toxic.

Botrytis cinerea is the phytopathogenic fungus responsible for the gray mold disease that affects crops worldwide. Essential oils (EOs) have emerged as a sustainable tool to reduce the adverse impact of synthetic fungicides. Nevertheless, the scarce information about the physiological mechanism action and the limitations to applying EOs has restricted its use. This study focused on elucidating the physiological action mechanisms and prospection of lipid nanoparticles to apply EO of Mentha piperita. The results showed that the EO of M. piperita at 500, 700, and 900 μL L -1 inhibited the mycelial growth at 100 %. The inhibition of spore germination of B. cinerea reached 31.43 % at 900 μL L -1 . The EO of M. piperita decreased the dry weight and increased pH, electrical conductivity, and cellular material absorbing OD 260 nm of cultures of B. cinerea. The fluorescence technique revealed that EO reduced hyphae width, mitochondrial activity, and viability, and increased ROS production. The formulation of EO of M. piperita loaded- solid lipid nanoparticles (SLN) at 500, 700, and 900 μL L -1 had particle size ∼ 200 nm, polydispersity index < 0.2, and stability. Also, the thermogravimetric analysis indicated that the EO of M. piperita-loaded SLN has great thermal stability at 50 °C. EO of M. piperita-loaded SLN reduced the mycelial growth of B. cinerea by 70 %, while SLN formulation (without EO) reached 42 % inhibition. These results supported that EO of M. piperita-loaded SLN is a sustainable tool for reducing the disease produced by B. cinerea., Competing Interests: Declaration of Competing Interest None., (Copyright © 2024 Elsevier GmbH. All rights reserved.)

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., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Kim Marie Umberath reports financial support was provided by German Ministry of Economics and Technology. Louis Backmann reports financial support was provided by German Ministry of Economics and Technology. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: Most microorganisms that cause food decay and the lower the shelf life of foods are fungi. Nanotechnologies can combat various diseases and deal with the application of nanomaterial to target cells or tissues. In this study selenium nanoparticles (Se-NPs) were synthesized using ascorbic acid and characterized by ultraviolet-visible spectroscopy, transmission electron microscopy (TEM), X-ray diffraction and zeta potential. The different concentrations of As/Se-NPs were tested against various fungi, including Alternaria linicola, Alternaria padwickii, Botrytis cinerea, Bipolaris sp., Cephalosporium acremonium, Fusarium moniliform and Fusarium semitectum. This study tested the influence of coated As/Se-NPs on healthy strawberry fruits and those infected with Botrytis cinerea during 16 days of storage, with regard to shelf life, decay percentage, weight loss, total titratable acidity percentage, total soluble solids content (TSS) and anthocyanin content., Results: Energy-dispersive X-ray analysis showed only two elements: selenium and oxygen. TEM images showed that the nanoparticles ranged in size between 26 to 39 nm and were rhombohedral in shape. Se-NPs showed antifungal activity against all tested fungi, the most effective being against Botrytis cinerea, Cephalosporium acremonium and Fusarium semitectum. During storage periods of strawberries fruits coated with As/Se-NPs, the shelf life was increased, and the number of decaying fruits was less than in control (uncoated) and coated infected fruits. The decline in weight loss was lower in coated fruits than in control fruits., Conclusion: These findings demonstrated that As/Se-NPs could effectively maintain the postharvest quality of strawberries, even when the fruit was infected with B. cinerea. © 2024 Society of Chemical Industry., (© 2024 Society of Chemical Industry.)

Botrytis cinerea ( B. cinerea ) and Colletotrichum gloeosporioides ( C. gloeosporioides ) were isolated from the decaying strawberry tissue. The antifungal properties of Monarda didyma essential oil (MEO) and its nanoemulsion were confirmed, demonstrating complete inhibition of the pathogens at concentrations of 0.45 μL/mL (0.37 mg/mL) and 10 μL/mL, respectively. Thymol, a primary component of MEO, was determined as an antimicrobial agent with IC 50 values of 34.51 ( B. cinerea ) and 53.40 ( C. gloeosporioides ) μg/mL. Hippophae rhamnoides oil (HEO) was confirmed as a potent antioxidant, leading to the development of a thymol-HEO-chitosan film designed to act as an antistaling agent. The disease index and weight loss rate can be reduced by 90 and 60%, respectively, with nutrients also being well-preserved, offering an innovative approach to preservative development. Studies on the antifungal mechanism revealed that thymol could bind to FKS1 to disrupt the cell wall, causing the collapse of mitochondrial membrane potential and a burst of reactive oxygen species.

Botrytis cinerea is an important fungal pathogen that causes gray mold disease in plants. Previously, Bacillus velezensis TCS001 live culture presented broad-spectrum antifungal activity against various plant pathogenic fungi and oomycetes, particularly B. cinerea . Here, the bioactivity of lipopeptides produced by TCS001 against B. cinerea was investigated. The IC 50 values of the crude lipopeptide extract (CLE) from TCS001 to suppress mycelial growth and conidial germination were 14.20 and 49.39 mg/L, respectively. SEM and TEM imaging revealed that CLE caused morphological deformities and ultrastructural changes in the mycelium. Transcriptomic analyses combined with Δ Bcpsd mutant construction demonstrated that the CLE could confer antifungal activity via suppressing Bcpsd expression in the pathogen. In addition, the CLE activated the plant immune system by increasing the content of defense-related enzymes and the expression of marker genes in immunity signaling pathways in cucumber plants. Therefore, TCS001 CLE could be potentially developed into biopesticides for the biocontrol of gray mold disease.

In this study, a series of novel hydrazide-containing flavonol derivatives was designed, synthesized, and evaluated for antifungal activity. In the in vitro antifungal assay, most of the target compounds exhibited potent antifungal activity against seven tested phytopathogenic fungi. In particular, compound C32 showed the best antifungal activity against Rhizoctonia solani (EC 50 = 0.170 μg/mL), outperforming carbendazim (EC 50 = 0.360 μg/mL) and boscalid (EC 50 = 1.36 μg/mL). Compound C24 exhibited excellent antifungal activity against Valsa mali , Botrytis cinerea , and Alternaria alternata with EC 50 values of 0.590, 0.870, and 1.71 μg/mL, respectively. The in vivo experiments revealed that compounds C32 and C24 were potential novel agricultural antifungals. 3D quantitative structure-activity relationship (3D-QSAR) models were used to analyze the structure-activity relationships of these compounds. The analysis results indicated that introducing appropriate electronegative groups at position 4 of a benzene ring could effectively improve the anti- R. solani activity. In the antifungal mechanism study, scanning electron microscopy and transmission electron microscopy analyses revealed that C32 disrupted the normal growth of hyphae by affecting the structural integrity of the cell membrane and cellular respiration. Furthermore, compound C32 exhibited potent succinate dehydrogenase (SDH) inhibitory activity (IC 50 = 8.42 μM), surpassing that of the SDH fungicide boscalid (IC 50 = 15.6 μM). The molecular dynamics simulations and docking experiments suggested that compound C32 can occupy the active site and form strong interactions with the key residues of SDH. Our findings have great potential for aiding future research on plant disease control in agriculture.

The discovery of readily available and easily modifiable new models is a crucial and practical solution for agrochemical innovation. Antifungal function-oriented fusion of triazole with the prevalidated lead ( R )- LE001 affords a novel framework with a broad and enhanced antifungal spectrum. Characterized by the easy accessibility and adjustability of [1,2,4]triazolo[4,3- a ]pyridine, modular fine-tuning provided a set of unprecedented leads (e.g., Z23 , Z25 , Z26 , etc.) with superior antifungal potentials than the positive control boscalid. Candidate Z23 exhibited a more promising antifungal activity against Sclerotinia sclerotiorum , Botrytis cinerea , and Phytophthora capsici with EC 50 values of 0.7, 0.6, and 0.5 μM, respectively. This candidate could effectively control boscalid-resistant B. cinerea strains and also exhibit good vivo efficacy in controlling gray mold. Noteworthily, both the SDH-inhibition and the efficiency against Oomycete P. capsici are quite distinct from that of the positive control boscalid. A molecular docking simulation also differentiates Z23 from boscalid. These findings highlight the potential of [1,2,4]triazolo[4,3- a ]pyridine amide as a novel antifungal model.

An intelligent delivery nanoformulation could enhance the utilization efficacy, uptake, and translocation of pesticides in plants. Herein, a redox/pH-triggered and fluorescent smart delivery nanoformulation was designed and constructed by using hollow mesoporous organosilica nanoparticles (HMONs) and ZnO quantum dots as the nanocarrier and capping agent, respectively. Boscalid was further loaded to generate Boscalid@HMONs@ZnO with a loading rate of 9.8% for controlling Botrytis cinerea ( B. cinerea ). The quantity of boscalid released by Boscalid@HMONs@ZnO in a glutathione environment or at pH 3.0 was 1.3-fold and 1.9-fold higher than that in a neutral condition. Boscalid@HMONs@ZnO has 1.7-fold the toxicity index of boscalid technical against B. cinerea in antifungal experiments. Pot experiments revealed that the efficacy of Boscalid@HMONs@ZnO was significantly enhanced more than 1.27-fold compared to commercially available water-dispersible granules of boscalid. Due to the fluorescence properties of Boscalid@HMONs@ZnO, pesticide transport's real-time monitoring of pesticide translocation in tomato plants could be observed by confocal laser scanning microscopy. Fluorescence images revealed that HMONs@ZnO had been effectively transported via treated leaves or roots in tomato plants. This research showed the successful application of HMONs@ZnO as a nanocarrier for controlling disease and offered an effective avenue to explore the real-time tracking of pesticide translocation in plants.

Lignin, renowned for its renewable, biocompatible, and environmentally benign characteristics, holds immense potential as a sustainable feedstock for agrochemical formulations. In this study, raw dealkaline lignin (DAL) underwent a purification process involving two sequential solvent extractions. Subsequently, an enzyme-responsive nanodelivery system (Pyr@DAL-NPs), was fabricated through the solvent self-assembly method, with pyraclostrobin (Pyr) loaded into lignin nanoparticles. The Pyr@DAL-NPs shown an average particle size of 250.4 nm, demonstrating a remarkable loading capacity of up to 54.70 % and an encapsulation efficiency of 86.15 %. Notably, in the presence of cellulase and pectinase at a concentration of 2 mg/mL, the release of Pyr from the Pyr@DAL-NPs reached 92.66 % within 120 h. Furthermore, the photostability of Pyr@DAL-NPs was significantly improved, revealing a 2.92-fold enhancement compared to the commercially available fungicide suspension (Pyr SC). Bioassay results exhibited that the Pyr@DAL-NPs revealed superior fungicidal activity against Botrytis cinerea over Pyr SC, with an EC 50 value of 0.951 mg/L. Additionally, biosafety assessments indicated that the Pyr@DAL-NPs effectively declined the acute toxicity of Pyr towards zebrafish and posed no negative effects on the healthy growth of strawberry plants. In conclusion, this study presents a viable and promising strategy for developing environmentally friendly controlled-release systems for pesticides, offering the unique properties of lignin., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

In this work, liposomes loaded with the fungicide, Fludioxonil (FLUD), for the containment of fungal diseases in agriculture were developed. Three types of vesicles with different compositions were compared: (I) plain vesicles, composed of soy phosphatidylcholine and cholesterol; (II) PEG-coated vesicles, with an additional polyethylene glycol coating; and (III) cationic vesicles, containing didodecyldimethylammonium bromide. Nanometric-sized vesicles were obtained both by the micelle-to-vesicle transition method and by the extrusion technique, and encapsulation efficiency, drug loading content, and Zeta potential were determined for all the samples. The extruded and PEGylated liposomes were the most stable over time and together with the cationic ones showed a significant prolonged FLUD release capacity. The liposomes' biological activity was evaluated on conidial germination, germ tube elongation and colony radial growth of the ascomycete Botrytis cinerea , a phytopathogenic fungus affecting worldwide many important agricultural crops in the field as well as in the postharvest phase. The extruded and PEGylated liposomes showed greater effectiveness in inhibiting germ tube elongation and colony radial growth of the fungal pathogen, even at 0.01 µg·mL -1 , the lowest concentration assessed.

Currently, allosteric inhibitors have emerged as an effective strategy in the development of preservatives against the drug-resistant Botrytis cinerea ( B. cinerea ). However, their passively driven development efficiency has proven challenging to meet the practical demands. Here, leveraging the deep learning Neural Relational Inference (NRI) framework, we actively identified an allosteric inhibitor targeting B. cinerea Chitinase, namely, 2-acetonaphthone. 2-Acetonaphthone binds to the crucial domain of Chitinase, forming the strong interaction with the allosteric sites. Throughout the interaction process, 2-acetonaphthone diminished the overall connectivity of the protein, inducing conformational changes. These findings align with the results obtained from Chitinase activity experiments, revealing an IC 50 value of 67.6 μg/mL. Moreover, 2-acetonaphthone exhibited outstanding anti- B. cinerea activity by inhibiting Chitinase. In the gray mold infection model, 2-acetonaphthone significantly extended the preservation time of cherry tomatoes, positioning it as a promising preservative for fruit storage.

The active splicing strategy has witnessed improvement in bioactivity and antifungal spectra in pesticide discovery. Herein, a series of simple-structured molecules ( Y1 - Y53 ) containing chloro-substituted benzyl esters were designed using the above strategy. The structure-activity relationship (SAR) analysis demonstrated that the fatty acid fragment-structured esters were more effective than those containing an aromatic acid moiety or naphthenic acid part. Compounds Y36 and Y41 , which featured a thiazole-4-acid moiety and trifluoromethyl aliphatic acid part, respectively, exhibited excellent in vivo curative activity (89.4%, 100 mg/L Y36 ) and in vitro fungicidal activity (EC 50 = 0.708 mg/L, Y41 ) against Botrytis cinerea . Determination of antifungal spectra and analysis of scanning electron microscopy (SEM), membrane permeability, cell peroxidation, ergosterol content, oxalic acid pathways, and enzymatic assays were performed separately here. Compound Y41 is cost effective due to its simple structure and shows promise as a disease control candidate. In addition, Y41 might act on a novel target through a new pathway that disrupts the cell membrane integrity by inducing cell peroxidation.

Scaffold hopping and structural fine-tuning are important strategies for agrochemical innovation. Multidimensional optimization of the prevalidated antifungal lead R -LE001 was conducted via the design, synthesis, and bioevaluation of 53 new compounds differing in either scaffold or substituent. The antifungal structure-activity relationship (SAR) revealed that a number of amides containing 2-(2-oxazolinyl) aniline (NHPhOx) or 2-(2-thiazolinyl) aniline (NHPhthiOx) demonstrated a more promising antifungal effect than both R -LE001 and the positive control boscalid. Specifically, compound 10 (encoded LEX-K01 ) shows an excellent antifungal effect against Botrytis cinerea with an EC 50 value lower than 0.11 μM. This small change leads to a significant improvement (over 1 order of magnitude) in bioactivity compared to that of either R -LE001 (EC 50 = 1.41 μM) or boscalid (EC 50 = 2.01 μM) and fluxapyroxad (EC 50 = 4.35 μM). With much lower resistance factors, LEX-K01 ( 10 ) was more efficacious against the two boscalid-resistant strains of B. cinerea TZ01 and NJBH2017. A combination of LEX-K01 ( 10 ) and boscalid in a ratio of 1:3 showed synergistic effects against resistant B. cinerea TZ01 and NJBH2017, with SR values of 3.01 and 2.55, respectively. LEX-K01 ( 10 ) has a curative efficacy (70.3%) more prominent than that of boscalid (51.2%) in controlling disease caused by B. cinerea . The molecular docking simulation of LEX-K01 ( 10 ) with the SDH protein of B. cinerea displayed four hydrogen bonds with amino acid residues TYR144, ARG88, TRP81, and SER84, rationalizing a stronger affinity than boscalid. The scanning electron microscopy (SEM) characteristic revealed that it could cause an obvious collapse of B. cinerea mycelium. This work indicates that LEX-K01 ( 10 ) has the potential to be further explored as a new antifungal agent.

Botrytis cinerea is a severe threat in agriculture, as it can infect over 200 different crop species with gray mold affecting food yields and quality. The conventional treatment using fungicides lead to emerging resistance over the past decades. Here, we introduce Photodynamic Inactivation (PDI) as a strategy to combat B. cinerea infections, independent of fungicide resistance. PDI uses photoactive compounds, which upon illumination create reactive oxygen species toxic for killing target organisms. This study focuses on different formulations of sodium-magnesium-chlorophyllin (Chl, food additive E140) as photoactive compound in combination with EDTA disodium salt dihydrate (Na 2 EDTA) as cell-wall permeabilizer and a surfactant. In an in vitro experiment, three different photosensitizers (PS) with varying Chl and Na 2 EDTA concentrations were tested against five B. cinerea strains with different resistance mechanisms. We showed that all B. cinerea mycelial spheres of all tested strains were eradicated with concentrations as low as 224 µM Chl and 3.076 mM Na 2 EDTA (LED illumination with main wavelength of 395 nm, radiant exposure 106 J cm -2 ). To further test PDI as a Botrytis treatment strategy in agriculture a greenhouse trial was performed on B. cinerea infected bell pepper plants (Capsicum annum L). Two different rates (560 or 1120 g Ha -1 ) of PS formulation (0.204 M Chl and 1.279 M Na 2 EDTA) and a combination of PS formulation with 0.05% of the surfactant BRIJ L4 (560 g Ha -1 ) were applied weekly for 4 weeks by spray application. Foliar lesions, percentage of leaves affected, percentage of leaf area diseased and AUDPC were significantly reduced, while percentage of marketable plants were increased by all treatments compared to a water treated control, however, did not statistically differ from each other. No phytotoxicity was observed in any treatment. These results add to the proposition of employing PDI with the naturally sourced PS Chl in agricultural settings aimed at controlling B. cinerea disease. This approach seems to be effective regardless of the evolving resistance mechanisms observed in response to conventional antifungal treatments., (© 2024. The Author(s).)

The main challenge in the development of agrochemicals is the lack of new leads and/or targets. It is critical to discover new molecular targets and their corresponding ligands. YZK-C22 , which contains a 1,2,3-thiadiazol-[1,2,4]triazolo[3,4- b ][1,3,4]thiadiazole skeleton, is a fungicide lead compound with broad-spectrum fungicidal activity. Previous studies suggested that the [1,2,4]triazolo[3,4- b ][1,3,4]thiadiazole scaffold exhibited good antifungal activity. Inspired by this, a series of pyrrolo[2,3- d ]thiazole derivatives were designed and synthesized through a bioisosteric strategy. Compounds C1 , C9 , and C20 were found to be more active against Rhizoctonia solani than the positive control YZK-C22. More than half of the target compounds provided favorable activity against Botrytis cinerea , where the EC 50 values of compounds C4 , C6 , C8 , C10 , and C20 varied from 1.17 to 1.77 μg/mL. Surface plasmon resonance and molecular docking suggested that in vitro potent compounds C9 and C20 have a new mode of action instead of acting as pyruvate kinase inhibitors. Transcriptome analysis revealed that compound C20 can impact the tryptophan metabolic pathway, cutin, suberin, and wax biosynthesis of B. cinerea . Overall, pyrrolo[2,3- d ]thiazole is discovered as a new fungicidal lead structure with a potential new mode of action for further exploration.

In this study, 24 indole derivatives containing 1,3,4-thiadiazole were discovered and synthesized. The target compounds' antifungal efficacy against 14 plant pathogenic fungal pathogens was then determined in vitro . With an EC 50 value of 2.7 μg/mL, Z2 demonstrated the highest level of bioactivity among them against Botrytis cinerea ( B.c .), exceeding the concentrations of the control prescription drugs azoxystrobin (Az) (EC 50 = 14.5 μg/mL) and fluopyram (Fl) (EC 50 = 10.1 μg/mL). Z2 underwent in vivo testing on blueberry leaves in order to evaluate its usefulness in real-world settings. A reasonable protective effect was obtained with a control effectiveness of 93.0% at 200 μg/mL, which was superior to those of Az (83.0%) and Fl (52.0%). At 200 μg/mL, this chemical had an efficacy of 84.0% in terms of curative efficacy. These figures outperformed those of Az (69.0%) and Fl (48.0%). Scanning electron microscopy (SEM) experiments and light microscopy experiments showed that Z2 altered the integrity of the cell wall and cell membrane of the pathogenic fungus B.c ., which led to an increase in the content of malondialdehyde (MDA), cellular leakage, and cellular permeability. Enzyme activity assays and molecular docking studies indicated that Z2 could act as a potential succinate dehydrogenase inhibitor (SDHI). It was hypothesized that Z2 could cause disruption of mycelial cell membranes, which in turn leads to mycelial death. According to the research, indole derivatives containing 1,3,4-thiadiazole were expected to evolve into new fungicides due to their significant antifungal effects on plant fungi.

In the search for novel succinate dehydrogenase inhibitor (SDHI) fungicides to control Rhizoctonia solani , thirty-five novel pyrazole-4-carboxamides bearing either an oxime ether or an oxime ester group were designed and prepared based on the strategy of molecular hybridization, and their antifungal activities against five plant pathogenic fungi were also investigated. The results indicated that the majority of the compounds containing oxime ether demonstrated outstanding in vitro antifungal activity against R. solani, and some compounds also displayed pronounced antifungal activities against Sclerotinia sclerotiorum and Botrytis cinerea . Particularly, compound 5e exhibited the most promising antifungal activity against R. solani with an EC 50 value of 0.039 μg/mL, which was about 20-fold better than that of boscalid (EC 50 = 0.799 μg/mL) and 4-fold more potent than fluxapyroxad (EC 50 = 0.131 μg/mL). Moreover, the results of the detached leaf assay showed that compound 5e could suppress the growth of R. solani in rice leaves with significant protective efficacies (86.8%) at 100 μg/mL, superior to boscalid (68.1%) and fluxapyroxad (80.6%), indicating promising application prospects. In addition, the succinate dehydrogenase (SDH) enzymatic inhibition assay revealed that compound 5e generated remarkable SDH inhibition (IC 50 = 2.04 μM), which was obviously more potent than those of boscalid (IC 50 = 7.92 μM) and fluxapyroxad (IC 50 = 6.15 μM). Furthermore, SEM analysis showed that compound 5e caused a remarkable disruption to the characteristic structure and morphology of R. solani hyphae, resulting in significant damage. The molecular docking analysis demonstrated that compound 5e could fit into the identical binding pocket of SDH through hydrogen bond interactions as well as fluxapyroxad, indicating that they had a similar antifungal mechanism. The density functional theory and electrostatic potential calculations provided useful information regarding electron distribution and electron transfer, which contributed to understanding the structural features and antifungal mechanism of the lead compound. These findings suggested that compound 5e could be a promising candidate for SDHI fungicides to control R. solani , warranting further investigation.

A strain of marine actinomycetes was isolated from an intertidal zone and identified as Streptomyces cinereoruber . Through the fermentation of this strain, a compound with fungicidal activity was extracted and purified. Using mass spectrometry (MS) and nuclear magnetic resonance (NMR) data, the metabolite was determined to be an aurone. The toxicity of the aurone toward four kinds of tumor cells-SH-SY5Y, HepG2, A549, and HeLa cells-was verified by the MTT method, delivering IC 50 values of 41.81, 47.19, 63.95, and 51.92 μg/mL, respectively. Greenhouse bioassay showed that the aurone exhibited a high fungicidal activity against powder mildew ( Botrytis cinerea ), cucurbits powder mildew ( Sphaerotheca fuliginea (Schlecht ex Ff.) Poll), and rice blast ( Pyricularia oryzae ).

Botrytis cinerea is a ubiquitous fungus that affects hundreds of plants, resulting in economic losses to the horticulture and fruit industry. The search for new antifungal agents is a matter of current interest. Thus, in this work a series of geranylated phenols in which the side alkyl chain has been hydrated have been synthesized, and their activity against B. cinerea has been evaluated. The coupling of phenol and geraniol has been accomplished under microwave irradiation obtaining the highest reaction yields in the shortest reaction times. Hydration of the side chain was carried out in dioxane with p -toluenesulfonic acid polymer-bound as the catalyst. All synthesized compounds were tested against B. cinerea using the growth inhibition assay and EC 50 values were determined. The results show that activity depends on the number and nature of functional groups in the phenol ring and hydration degree of the geranyl chain. The most active compound is 1,4-dihydroquinone with one hydroxyl group attached at the end of the alkyl chain. Results from a molecular docking study suggest that hydroxyl groups in the phenol ring and alkyl chain are important in the binding of compounds to the active site, and that the experimental antifungal activity correlates with the number of H-bond that can be formed in the binding site.

Botrytis cinerea, the causal agent of gray mold is one of the major devastating fungal pathogens that occurs in strawberry cultivation and leads to massive losses. Due to the rapid emergence of resistant strains in recent years, an ecofriendly disease management strategy needs to be developed to control this aggressive pathogen. Bacillus velezensis CE 100 exhibited strong antagonistic activity with 53.05% against B. cinerea by dual culture method. In the present study, 50% of culture filtrate supplemented into PDA medium absolutely inhibited mycelial growth of B. cinerea whereas the highest concentration (960 mg/L) of different crude extracts including ethyl acetate, chloroform, and n-butanol crude extracts of B. velezensis CE 100, strongly inhibited mycelial growth of B. cinerea with the highest inhibition of 79.26%, 70.21% and 69.59% respectively, resulting in severe damage to hyphal structures with bulging and swellings. Hence, the antifungal compound responsible was progressively separated from ethyl acetate crude extract using medium pressure liquid chromatography. The purified compound was identified as methyl hippurate by nuclear magnetic resonance and mass spectrometry. The inhibitory effect of methyl hippurate on both spore germination and mycelial growth of B. cinerea was revealed by its dose-dependent pattern. The spore germination rate was completely restricted at a concentration of 3 mg/mL of methyl hippurate whereas no mycelial growth was observed in agar medium supplemented with 4 mg/mL and 6 mg/mL of methyl hippurate by poisoned food method. Microscopic imaging revealed that the morphologies of spores were severely altered by long-time exposure to methyl hippurate at concentrations of 1 mg/mL, 2 mg/mL and 3 mg/mL and hyphae of B. cinerea were severely deformed by exposure to methyl hippurate at concentrations of 2 mg/mL, 4 mg/mL and 6 mg/mL. No significant inhibition on tomato seed germination was observed in treatments with methyl hippurate (2 mg/mL) for both 6 h and 12 h soaking period as compared to the controls. Based on these results, B. velezensis CE 100 could be considered a potential agent for development of environmentally friendly disease control strategies as a consequence of the synergetic interactions of diverse crude metabolites and methyl hippurate., (© 2021. The Author(s), under exclusive licence to Springer Nature B.V.)

Plant fungal diseases can lead to yield reduction and quality degradation in crops, which usually cause serious economic losses. Additionally, chemical fungicides used in the prevention and control of plant diseases are increasingly restricted due to resistance development and high toxicity. Therefore, biogenic fungicides such as chitosan with low toxicity and good biocompatibility are receiving increasing attention. This study found that the acid swelling chitosan pretreatment method can accelerate the rate of the specific oxidation of chitosan catalyzed by the TEMPO-NaBr-NaOCl system. This study proved that OCTS induces plant disease resistance, and the control efficiencies achieved in protection and treatment experiments against Botrytis cinerea were 80.6 % and 83.4 %, respectively, at 400 μg/mL OCTS. In addition, OCTS can promote plant growth and enhance plant defense enzyme activities. This research has realized a forward-looking exploration of the application of OCTS in the agricultural field., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Plant pathogenic fungi decrease the quality and productivity of plant production. The botanical fungicides have better biocompatibility and rapid biodegradation, little or no cross resistance, and the structural diversity, and thus are beneficial to deal with plant fungal diseases. Osthole has been widely used as the commercial botanical fungicide against powdery mildew in China. In this article, a series of osthole derivatives were synthesized, which respectively contain different substituents on the benzene ring, at the C8-position and pyrone ring. All the target compounds were evaluated in vitro for their antifungal activity against resistant phytopathogenic fungi. Colletotrichum fragariae, Strawberry Botrytis Cinerea, Kiwifruit Botrytis Cinerea, Kiwifruit brown Rots, which are common in fruit fungal diseases. The compound C 4 was identified as the most promising candidate with the EC 50 values at 38.7 µg/mL against Colletotrichum Fragariae, 14.5 µg/mL against Strawberry Botrytis Cinerea and 24.3 µg/mL against Kiwifruit Botrytis Cinerea, respectively, whereas the antifungal activity against resistant phytopathogenic fungi. of osthole is too low to be used (EC 50  > 400 ppm). The results of mycelial relative conductivity determination, PI uptake and fluorescence spectroscopy indicated that the cell membrane of fungi is the key action site of C 4 . Besides, C 4 has the potent inhibitory activity against both of plant and human pathogenic bacteria. Our studies showed that C 4 was worthy for further attention as a promising botanical fungicide candidate in crop protection., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Rotting caused by grey mould (Botrytis cinerea) is a concerning disease for numerous crops both pre- and postharvest stages. Application of antagonistic yeasts is a promising strategy for controlling grey mould incidence which could mitigate undesirable consequences of using synthetic fungicides. In this work, a screening for detection of yeasts isolated from figs producers of antifungal volatile organic compounds (VOCs) were performed by confrontation in double dishes systems. Eleven out of 34 yeasts confronted reduced B. cinerea growth parameter in vitro. This reduction was correlated (p ≤ 0.050) with the production of 10 volatile compounds: two acids (acetic acid and octanoic acid), 7 esters (Ethyl propionate, n-Propyl acetate, Isobutyl acetate, 2-methylbutyl acetate, furfuryl acetate, phenylmethyl acetate, 2-phenylethyl acetate) and one ketone (Heptan-2-one). In bases on in vitro assay, Hanseniaspora uvarum 793 was applied to in vivo assays with strawberries and cherries. The reduction of incidence of B. cinerea in strawberries at 7 °C and 25 °C was 54.9 and 72.1% after 6 and 3 days, respectively. The reduction of incidence of B. cinerea in cherries at 7 °C and 25 °C was 48.9 and 45.6% after 5 and 4 days, respectively. These results showed that VOCs produced by Hanseniaspora uvarum 793 are effective in the control of incidence of Botrytis cinerea in fruits, being a potential alternative to chemical fungicide., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Botrytis cinerea is a necrotic plant fungus that causes gray mold disease in over 200 crops, including grapevine. Due to its genetic plasticity, this fungus presents strong resistance to many fungicides. Thus, new strategies against B. cinerea are urgently needed. In this context, antimicrobial photodynamic treatment (APDT) was considered. APDT involves the use of a photosensitizer that generates reactive oxygen species upon illumination with white light. Tetra-4-sulfonatophenyl porphyrin tetra-ammonium (TPPS) was tested on B. cinerea using light. 1.5 µM TPPS completely inhibited mycelial growth. TPPS (12.5 µM) was tested on three grapevine clones from Chardonnay, Merlot and Sauvignon, grown in vitro for 2 months. Treated root apparatus of the three backgrounds increased thiol production as a molecular protection against photoactivated TPPS, leading to a normal phenotype as compared with control plantlets. Finally, 2-month-old grapevine leaves were infected with 4-day-old mycelium of B. cinerea pre-incubated or not with TPPS. The pre-treated mycelium was unable to infect the detached leaves of any of the three grapevine varieties after 72 h growth when subjected to a 16 h photoperiod, contrary to untreated mycelium. These results suggest a strong potential of photo-treatment against B. cinerea mycelium for future agricultural practices in vineyard or other cultures.

Pyraclostrobin (PYR) is a commonly used strobilurin fungicide, which inhibits mitochondrial respiration at the ubiquinol oxidation center site of the cytochrome bc1 complex. Little information is available regarding the crystal structure of PYR on its fungicidal effect. In this study, the crystal structures of eight PYRs (PYR-A to H) from different sources are determined by using high-resolution X-ray powder diffraction (XRPD) and model construction with the Pawley refinement module. The effects of PYRs on mycelium growth, the kinetics of mycelial growth, conidial germination, and tube elongation of conidia of Botrytis cinerea from tomato are compared. The level of organic acids in the mitochondrial tricarboxylic acid cycle of PYR-treated B. cinerea is analyzed. The results show that PYR-A to PYR-H have their own unique character of XRPD patterns, but the crystal morphology of eight PYRs presents in the triclinic crystal system and space group P 1̅. PYR-D with the eclipsed conformation and rational edge angles α (72.599°) and β (98.612°) in the crystal cell shows the highest inhibitory effect against mycelium growth with EC 50 as 3.383 μg mL -1 , the best time-dependent effects on the mycelium growth kinetics, and the strongest inhibition on tube elongation of conidia, whereas PYR-E with anticonformation is the worst. Moreover, a significant accumulation of fumarate, malate, and oxalate in the PYR-D-treated mycelium is observed. These findings reinforce the need for a definite crystal structure of PYR to limit usage and mitigate future selection pressure for gray mold management.

Botrytis cinerea , gray mold, is one of the most notorious phytopathgens, causing serious economic loss in the agricultural industry. The phytotoxic effects are mainly derived from secreted virulence proteins and terpenoid-type secondary metabolites. Azole fungicides are commonly used to manage the disease. However, their biochemical effects other than sterol biosynthesis were not documented, especially toxic secreted metabolites. In this study, six azole fungicides were treated with in vitro and in vivo conditions. Comprehensive profiles of primary and secondary metabolites in culture media were evaluated to assess the fungal metabolomes under pesticide-stressed conditions. The results indicated that extensive metabolic differentiation was induced by azole fungicides. Epoxiconazole clearly reduced the extracellular phytotoxin concentrations, while the level of indole-3-acetic acid was increased. In addition, significant differentiation of primary metabolism could be deduced from secreted metabolite profiles, including the tricarboxylic acid cycle and aromatic amino acid catabolism. Cellular lipid profiles, including fatty acids and sterol, have been altered drastically by azoles, which indicate extensive changes of cellular lipid metabolism. These system-wide metabolic alterations resulted in reduced plant damages, proven by the in vivo assay with tomato. Overall, azole fungicides induced significant changes of endo- and exometabolomes and could reduce the fungal infection. The experimental results will provide a more detailed understanding of physiological changes of phytopathogens under pesticide treatment and information for new pesticide development.

Xanthatin, a natural sesquiterpene lactone, occurs as one of the major constituents of Xanthium plants (Compositae) and exhibits many important biological properties. To discover natural products-based pesticides, forty-nine Michael-type thiol/amino adducts of xanthatin were synthesized and characterized, while their pesticidal activities were investigated. Among them, compounds 2c, 2h, 2i, and 2t exhibited more potent antifungal activity against Botrytis cinerea (IC 50  = 0.96, 0.38, 6.33, and 7.21 µg/mL, respectively) than xanthatin and the two commercial fungicides. Compounds 2t and 2u displayed broad-spectrum and excellent antifungal effects against all tested phytopathogenic fungi, while their IC 50 values ranged from 7.21 to 75.88 µg/mL. Compounds 2a, 2f, 2l, 2m, 2v, 7c, 7e, 7h, 7i, and 7j showed moderate larvicidal activity against Plutella xylostella Linnaeus. Furthermore, compounds 2b, 7g, and 7h demonstrated significant ovicidal activity against P. xylostella with the LC 50 values of 14.04, 10.00, and 11.95 mg/L, respectively. These findings suggest that thiol/amino appended in the C-13 position of xanthatin may improve antifungal and ovicidal activities for the derivatives. It was also noticed that the exocyclic double bond of xanthatin is crucial for its larvicidal activity. This work also provides some important hints for further design, synthesis, and structural modification of the xanthanolides sesquiterpene lactones toward development of the new environmentally friendly pesticides for sustainable agricultural production., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Thirty-four novel compounds were synthesized using chesulfamide (N-(2-trifluoromethyl-4-chlorophenyl)-2-oxocyclohexyl sulfonamide), a high-profile fungicide, as the lead compound, and their structures were characterized by 1 H NMR, 13 C NMR, MS and elemental analysis. Additionally, the structure of (1S,2R)-2-((3-bromophenethyl)amino)-N-(4-chloro-2-trifluoromethylphenyl)cyclohexane-1-sulfonamide (IV-9) was confirmed by X-ray single crystal diffraction. The mycelium inhibition tests, spore germination inhibition tests, tomato pot tests and field trials were performed against strains of B. cinerea. Bioassay results showed that most of target compounds had good fungicidal activity against B. cinerea, in particular, IV-9 exhibited similar or superior effects to procymidone, boscalid and pyrisoxazole in all in vitro and in vivo tests. Moreover, there was no positive cross-resistance found between the compound IV-9 and eight commercial fungicides (azoxystrobin, boscalid, chlorothalonil, diethofencarb, fludioxonil, procymidone, pyrimethanil and pyrisoxazole) in the cross-resistance validation test performed by an innovative method., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

In order to explore more efficient sulfonamides against Botrytis cinereal , 36 novel cyclohexylsulfonamides were synthesized by N -(3-dimethylaminopropyl)- N '-ethylcarbodiimide (EDCI) and 1-hydroxybenzotriazole (HOBt) condensation reaction using chesulfamide as a lead compound, introducing thiazole and pyrazole active groups. Their structures were characterized by 1 H-NMR, 13 C-NMR, mass spectrum (MS), and elemental analysis. Compound III -31 was further confirmed by X-ray single crystal diffraction. The in vitro and in vivo fungicidal activities against B . cinerea were evaluated by three bioassay methods. The results of mycelial growth demonstrated that median effective concentration (EC 50 ) values of nine compounds were close to boscalid (EC 50 = 1.72 µg/mL) and procymidone (EC 50 = 1.79 µg/mL) against B . cinerea (KZ-9). In the spore germination experiment, it was found that compounds III-19 and III-31 inhibited germination 93.89 and 98.00%, respectively; at 10 µg/mL, they approached boscalid (95.97%). In the tomato pot experiment, the control effects of two compounds (III-21 and III-27) were 89.80 and 87.90%, respectively, at 200 µg/mL which were significantly higher than boscalid (81.99%). The structure-activity relationship (SAR) was also discussed, which provided a valuable idea for developing new fungicides., Competing Interests: The authors declare no conflict of interest.

A 11 kDa antifungal protein FEAP was purified from buckwheat ( Fagopyrum esculentum) seed extract with a procedure involving (NH 4 ) 2 SO 4 precipitation and chromatography on SP-Sepharose, Affi-gel blue gel, Mono S, and Superdex peptide. Its N-terminal sequence was AQXGAQGGGAT, resembling those of buckwheat peptides Fα-AMP1 and Fα-AMP2. FEAP exhibited thermostability (20-100 °C) and acid resistance (pH 1-5). Its antifungal activity was retained in the presence of 10-150 mmol/L of K + , Mn 2+ , or Fe 3+ ions, 10-50 mmol/L of Ca 2+ or Mg 2+ ions, and 50% methanol, 50% ethanol, 50% isopropanol, or 50% chloroform. Its half-maximal inhibitory concentrations toward spore germination and mycelial growth in Botrytis cinerea were 79.9 and 236.7 μg/mL, respectively. Its antifungal activity was superior to the fungicide cymoxanil mancozeb (248.1 μg/mL). FEAP prevented B. cinerea from infecting excised leaves, intact leaves, and isolated fruits of cherry tomato. Its mechanism involved induction of an increase in cell membrane permeability and a decrease in mitochondrial membrane potential.

To develop more valuable and effective fungicide candidates, a novel series of 3,4-dichloroisothioxazole-based cycloalkylsulfonamides were synthesized and their structures were identified by 1 H NMR, 13 C NMR, MS and elemental analysis. Compound 3k was further confirmed by X-ray single crystal diffraction. The in vitro bioassay results demonstrated that the target compounds showed significant fungicidal activity on mycelial growth and spore germination of Botrytis cinerea. Especially, compound 3j, with prominent inhibition effect on mycelial with EC 50 and EC 80 values of 1.4 and 23.7 μg/mL respectively, was comparable to the selected commercial fungicide. Moreover, at 50 μg/mL, the inhibition rate of compound 3j on spore germination was recorded up to 89.7%. The further in vivo bioassay results indicated compound 3j continued to show high control effect on tomato leaves, flowers and fruit at 200 μg/mL, with control efficiencies of 94.3%, 89.3% and 91.9%, respectively. The structure-activity relationship showed that the compound with a five-membered ring possessed the best activity after the introduction of the active fragment of the 3,4-dichloroisothioxazole, provided a valuable idea for further creation of new fungicides., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Botrytis cinerea is an economically important fungal pathogen with a host range of over 200 plant species. Unfortunately, gray mold disease caused by B. cinerea has not been effectively controlled because of its high risk for fungicide resistance development. As a part of our ongoing efforts to develop novel sulfonamides as agricultural fungicides against Botrytis cinerea, we introduced 2-aminoethanesulfonic acid (taurine) substructure, designed and synthesized a series of novel 2-substituted acylaminoethylsulfonamides. The newly synthesized sulfonamides were evaluated in vitro and in vivo for their fungicidal activity against Botrytis cinerea, of which the 2-ethoxyacetylamide derivative (V-A-12, EC 50  = 0.66 mg·L -1 ) exhibited the highest potency in vitro and superior fungicidal activity compared with procymidone (EC 50  = 1.06 mg·L -1 ). In vivo bioassay indicated that compound V-A-12 could be effective for the control of tomato gray mold. Moreover, the structure-activity relationship of these sulfonamides was analyzed by establishing a three-dimensional quantitative structure-activity relationship (3D-QSAR) model, which can provide guidance for the development of sulfonamides as fungicides. Finally, the effeicacy of sulfonamide derivatives was again verified in the activity evaluation against resistant Botrytis cinerea strains. These results further enhance the development value of 2-substituted acylaminoethylsulfonamides to control the tomato gray mold., (Copyright © 2019 Elsevier Inc. All rights reserved.)