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Fungal infections represent a significant global health concern, with a growing prevalence of antifungal drug resistance. Targeting glucosylceramides (GlcCer), which are functionally important glycosphingolipids (GSL) present in fungal membranes, represents a promising strategy for the development of antifungal drugs. GlcCer are associated with the antifungal activity of certain plant and insect defensins. The 44-residue ETD151 peptide, optimized from butterfly defensins, is active against several fungal pathogens. ETD151 has been shown to induce a multifaceted mechanism of action (MOA) in Botrytis cinerea, a multiresistant phytopathogenic fungus. However, the target has yet to be identified. Our findings demonstrate that the presence of GlcCer in membranes determines the susceptibility of Pichiapastoris and Candida albicans toward ETD151. To ascertain whether this is due to direct molecular recognition, we demonstrate that ETD151 selectively recognizes liposomes containing GlcCer from B. cinerea, which reveals a methylated-sphingoid base structure. The dissociation constant was estimated by microscale thermophoresis to be in the µM range. Finally, fluorescence microscopy revealed that ETD151 localizes preferentially at the surface of B. cinerea. Furthermore, the majority of prokaryotic cells do not contain GSL, which explains their resistance to ETD151. We investigated the susceptibility of Novosphingobium capsulatum, one of the rare GSL-containing bacteria, to ETD151. ETD151 demonstrated transient morphological changes and inhibitory growth activity (IC50 ~75 µM) with an affinity for the cell surface, emphasizing the critical importance of GSL as target. Understanding the MOA of ETD151 could pave the way for new perspectives in human health and crop protection. [ABSTRACT FROM AUTHOR]

Background: Tomato yield and quality are influenced by multiple factors, including conditions during cultivation, post-harvest handling and storage. Botrytis cinerea, the fungal pathogen causing gray mold disease, poses a significant threat to tomato production. This disease poses a serious challenge to tomato cultivation on a global scale, leading to significant crop losses and compromising food supply security. The purpose of this study was to assess the efficacy of three different bacterial bioagents, namely Pseudomonas fluorescens, Bacillus amyloliquefaciens and Pseudomonas chlororaphis, against B. cinerea. Results: From the rhizosphere of a tomato field, 22 bacterial isolates were collected. Among them, three isolates, designated as 1, 8 and 11, displayed notable antagonistic effects against Botrytis cinerea during in vitro testing and were selected for further analysis. The bacteria were identified as Pseudomonas fluorescens, Bacillus amyloliquefaciens and P. chlororaphis through 16S rRNA gene sequencing. The experiments demonstrated that these three isolates significantly inhibited the growth of the pathogenic fungus and promoted plant growth, with B. amyloliquefaciens emerging as the most effective inhibitor, displaying the highest antifungal activity. In vitro and greenhouse experiment suggest that the bacterial isolates hold considerable promise as natural antagonists for managing gray mold disease in tomatoes. The study further recommends using all three isolates for controlling the gray mold, with B. amyloliquefaciens showing the most significant potential, evidenced by its consistently lower disease severity scores, achieving the highest % efficacy (85.75) compared to control. Conclusions: The study emphasizes the significant potential of P. fluorescens, B. amyloliquefaciens and P. chlororaphis as effective bioagents to control tomato gray mold disease, B. cinerea. By directly targeting the fungal pathogen, these isolates provide an effective strategy for mitigating the adverse impacts of gray mold, contributing to higher crop yield and quality. Further research needs on open field trials and commercialization strategies for large-scale application of these bacterial bioagents. [ABSTRACT FROM AUTHOR]

In this study, we investigated the interplay between nitrogen nutrition and the pectin degradation dynamics during Arabidopsis and Botrytis interaction. Our findings revealed that infected detached leaves from nitrogen-sufficient plants released more pectin lyase (PNL)-derived oligogalacturonides compared to nitrogen-deficient ones. We then focused on BcPNL1, the most highly expressed Botrytis PNL upon infection. Using mutant strains lacking BcPNL1, we observed reduced pathogenicity, a delay in germination and a lag in triggering the plant defense response. Additionally, in nitrogen-sufficient detached leaves, the elevated expression of jasmonic acid repressor genes observed upon infection with the wild-type strain was abolished with the mutants. These results linked the increased production of BcPNL-derived products to the increased expression of jasmonic acid repressor genes, contributing partially to the higher susceptibility of nitrogen-sufficient detached leaves. These findings could lay the foundation for new strategies aimed at reconciling both crop resistance to pathogens and the improvement of nitrogen nutrition. The Botrytis cinerea pectin lyase BcPNL1 produces oligogalacturonides that activate expression of jasmonic acid repressor genes, contributing partially to the higher susceptibility of nitrogen-sufficient detached leaves. [ABSTRACT FROM AUTHOR]

Background: Eucalyptus, a widely cultivated woody plant, is susceptible to a diverse array of pests and diseases, leading to reduced yields and economic losses. Traditional breeding methods are very time-consuming; therefore, plant genetic engineering has emerged as a promising approach for plant pathogen management. However, the genetic transformation system of eucalyptus is still in its early stages of development, while studies on transgenic eucalyptus and its disease resistance genes are limited. The SWAP70 gene has been shown to play a crucial role in the defense response of Arabidopsis thaliana and rice. In this study, the model plant A. thaliana was selected for genetic transformation. The aim was to enhance the expression of the EuSWAP70 gene derived from Eucalyptus grandis, and other disease resistance genes by utilizing an artificial GWSF promoter. Results: The results showed that the EuSWAP70 gene was successfully transformed into A. thaliana, and the PCR assay confirmed the presence of the EuSWAP70 gene in transgenic Arabidopsis plants. The gray mold resistance of the EuSWAP70 transgenic Arabidopsis plants under GWSF and CaMV35S promoters was evaluated against Botrytis cinerea infection. After gray mold infection, Arabidopsis plants were ranked by leaf pore area percentage: wildtype > CaMV35S-EuSWAP70 > GWSF-EuSWAP70. The transgenic plants showed stronger gray mold resistance, and the GWSF-EuSWAP70 transgenic plants were stronger than the CaMV35S-EuSWAP70 transgenic plants. [ABSTRACT FROM AUTHOR]

In this study, Minimedusa polyspora and Chaetomium globosum and their metabolites were assessed in vitro for their ability to inhibit growth of Alternaria alternata, Berkeleyomyces basicola, and Botrytis cinerea, gaining insights into their biocontrol mechanisms. A dual culture, an assay for volatile antimicrobial compounds effectiveness (performed in two different conditions), and a culture filtrate antifungal assay were designed to discriminate the involved mechanisms. Moreover, the culture filtrates of these strains were assessed for fungistatic and fungicidal activities (determining also the minimum inhibitory concentration and the minimum fungicidal concentration) and for the occurrence of siderophores. The results show that both M. polyspora and C. globosum inhibited, to different extents, growth of all the pathogens in the plate assays. Both culture filtrates showed fungistatic and fungicidal activities, pointing to the release of diffusible compounds as an involved biocontrol mechanism. Based on the results of this study, M. polyspora and C. globosum are promising bioprotection agents of these phytopathogens and species of interest for further studies aimed at validating their potential in in vivo conditions. [ABSTRACT FROM AUTHOR]

NAC (NAM, ATAF1,2, and CUC2) proteins play important roles in plant defense responses and various developmental processes. Here, we isolated NAC12 from Capsicum annuum (CaNAC12) and investigated its role in stress responses. CaNAC12 encodes a 350 amino acid protein derived from a 1053 bp cDNA, which contains five conserved motifs (A, B, C, D, and E), an N-terminal region, and a variable C-terminal region. Phylogenetic analysis showed that CaNAC12 is clustered in the phylogenetic clade of CaNAC, a specific subset of NAC transcription factors from C. annuum in China. CaNAC12 expression was strongly induced by infection with Xanthomonas axonopodis pv. glycines 8ra, as well as by salicylic acid, abscisic acid, and in red fruits of chili pepper plants. CaNAC12-overexpressing plants showed significantly increased resistance to salt, drought, and Botrytis cinerea infection. Under salt stress conditions, the transgenic lines exhibited higher chlorophyll content, better shoot and root growth, and increased lateral root formation compared to control plants. Under water scarcity, the leaves of the control plants wilted severely compared to those of the transgenic lines, suggesting that CaNAC12 plays a positive role in drought tolerance. RT-PCR analysis also showed higher expression of NbDHN1, NbLEA, and NbHSR203 in the transgenic lines compared to the control plants. In addition, CaNAC12 overexpression improved resistance to Botrytis cinerea infection, as evidenced by a decreased disease index and smaller lesion size compared to the control group. Overall, our results indicate that CaNAC12 is a potential candidate gene involved in both abiotic and biotic tolerance mechanisms. [ABSTRACT FROM AUTHOR]

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

The grey mould fungus Botrytis cinerea is a dangerous plant pathogen responsible for substantial agricultural losses worldwide. The pathogenic mechanisms still have many unclear aspects, and numerous new pathogenic genes remain to be identified. Here, we show that the sterol regulatory element-binding protein Sre1 plays an important role in the development and pathogenicity of B. cinerea. We identified a homologue of gene SRE1 in the B. cinerea genome and utilized a reverse genetics approach to create the knockout mutant Δsre1. Our results demonstrate that SRE1 is essential for conidiation, as Δsre1 produced only 3% of the conidia compared to the wild-type strain. Conversely, Δsre1 exhibited increased sclerotium production, indicating a negative regulatory role of SRE1 in sclerotium formation. Furthermore, ergosterol biosynthesis was significantly reduced in the Δsre1 mutant, correlating with increased sensitivity to low-oxygen conditions. Pathogenicity assays revealed that Δsre1 had significantly reduced virulence, although it maintained normal infection cushion formation and penetration capabilities. Additionally, SRE1 was found to be crucial for hypoxia adaptation, as Δsre1 showed abnormal germination and reduced growth under low-oxygen conditions. These findings suggest that SRE1 mediates the development and pathogenicity of B. cinerea by regulating lipid homeostasis and facilitating adaptation to host tissue environments. [ABSTRACT FROM AUTHOR]

Strawberry is a perishable fruit and gray mold is one of the main reasons which reducing its shelf life. Due to the limitations of using chemical poisons, it seems necessary to use safe methods such as the use of essential oils (EOs) and edible coatings to control this fungus maintain the quality, and increase the storage period. However, the high volatility of EOs and organoleptic effects on agricultural products have hindered the direct application of EOs. This study is designed to enhance the shelf life of strawberries by designing nanoemulsion systems of EO with chitosan as follows: in the first experiment, the effect of nanoemulsion of the thymol, one of the main components of thyme, with a concentration of 5 g/L, alone and in combination with chitosan (CH) biopolymer was investigated on Botrytis cinerea. All treatments significantly reduced fungal growth compared to the control sample. Also, combined treatment showed the highest level of inhibition of B. cinerea. The second experiment was performed to evaluate the quality changes and post -harvest wastes of strawberries during storage. In this section, the fruits were coated with thymol 0.5%, thymol nanoemulsion 0.5%, and thymol nanoemulsion 0.5% + CH 0.5% and kept at 4 °C. Results presented that the application of the applied treatments had a positive effect on the physicochemical and biochemical indicators of strawberry fruit during the post-harvest period and caused better preservation of firmness, prevented weight loss and reduced microbial load. Also, the lowest rate of weight loss, the highest rate of firmness, and the lowest rate of growth of microorganisms were observed in covered fruits with treatment of thymol nanoemulsion 0.5% + CH 0.5%. Finally, this treatment can be suggested as a suitable cover to maintain the quality and reduce post-harvest waste of strawberries. [ABSTRACT FROM AUTHOR]

Gray mold disease (GMD), caused by Botrytis cinerea (B. cinerea) infection on rose petals, is an important disease of greenhouse rose flowers, that significantly decreases the ornamental value of cut flowers. This study investigated the potential of preharvest and postharvest treatment with nano silver (PrNS and PoNS, respectively) as a novel control strategy against GMD and to improve the vase life of rose flowers. PrNS treatment in the greenhouse (rose flowers were sprayed with NS) notably reduced the GMD infection rate and disease symptom severity in rose flowers than in the non-treated (NT) flowers. PoNS (cut roses were placed and sprayed with NS) and the combination of PrNS and PoNS treatments (Pr-PoNS) were more effective in suppressing B. cinerea growth in petals and prolonging the vase life of cut flowers than the NT and PrNS flowers. PoNS and Pr-PoNS also improved flower opening and water relations in cut roses during the vase period. The lower maximum quantum yield of PSII (Fv/Fm) values, higher non-photochemical quenching (NPQ) values, and elevated leaf and petal temperatures in NT flowers suggested that these parameters can be used to detect water stress and GMD infections in rose flowers. PoNS and Pr-PoNS effectively reduced ethylene damage and disease infection by downregulating the mRNA levels of ethylene biosynthesis and pathogenesis-related genes in rose petals. Furthermore, PoNS and Pr-PoNS reduced the mRNA levels of senescence-inducible and cytokinin degradation-related genes, while promoting the levels of cytokinin biosynthesis genes in petals, thus retarding flower senescence. Therefore, NS is effective in decreasing GMD infection and improving the postharvest life of rose flowers. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Plants are exposed to pathogens at specific, yet predictable times of the day–night cycle. In Arabidopsis, the circadian clock influences temporal differences in susceptibility to the necrotrophic pathogen Botrytis cinerea. The jasmonic acid (JA) pathway regulates immune responses against B. cinerea. The paralogous basic helix–loop–helix transcription factors MYC2, MYC3 and MYC4 are primary regulators of the JA pathway, but their role in regulating temporal variation in immunity is untested. This study aimed to investigate the roles of the MYC transcription factors in the temporal defence response to B. cinerea. We inoculated leaves from wild-type, myc single-, double- and triple-knockout mutants, and lines overexpressing MYC2, MYC3 or MYC4, with B. cinerea at two times of day in constant light, and compared lesion sizes. The presence of MYC2, MYC3 or MYC4 alone was sufficient to maintain temporal variation in susceptibility, but this was abolished in the myc234 triple-knockout mutant. Constitutive expression of MYC2, MYC3 or MYC4 abolished time-of-day differences in susceptibility. The data suggest that MYC2, MYC3 and MYC4 function redundantly in regulating temporal defence responses against B. cinerea and are a point of convergence between the JA pathway and the circadian clock in Arabidopsis. This article is part of the Theo Murphy meeting issue 'Circadian rhythms in infection and immunity'. [ABSTRACT FROM AUTHOR]

Hyphopichia pseudoburtonii, is emerging as a potential biocontrol agent against various phytopathogens. These traits have been attributed to the production of various antifungal compounds in the presence of target pathogens. However, the broad molecular mechanisms involved in the antifungal activity are not yet understood. This study employed RNA sequencing to assess the temporal changes in H. pseudoburtonii Y963 gene expression patterns when co-cultivated with Botrytis cinerea. Genes differentially expressed in H. pseudoburtonii in co-culture with B. cinerea, compared to the monoculture were evaluated after 24, 48, and 120 h of growth. Up-regulation of genes encoding major core histones (H2A, H3, H4) and ribosomes in the first 24 h suggested an abundance of cells in the S phase of the cell cycle. At 48 h, the genes up-regulated highlight mitotic cell cycle activity and induction of filamentous growth, while in later stages, up-regulation of genes encoding high affinity transporters of sugars, copper and iron, as well as those involved in the retention and utilization of siderophore-iron was evident. Altogether, the data allude to competition for space and nutrients as key mechanisms activated in H. pseudoburtonii in the presence of B. cinerea. This research offers new insights into H. pseudoburtonii transcriptomic response to B. cinerea and illuminates the adaptive strategies and molecular mechanisms behind its antifungal activity. [ABSTRACT FROM AUTHOR]

To investigate the chemical composition of Pelargonium roseum essential oil (EO) and its antifungal activities against Botrytis cinerea of cherry tomato as a potential alternative to synthetic chemical fungicides for postharvest preservation of fruits and vegetables. In this study, the EO of P. roseum was extracted by water vapor distillation, and the chemical components were determined by gas chromatography-mass spectrometry (GC-MS). The inhibitory effects of different concentrations of the EO and its compounds on the growth of mycelium and the germination of spores were determined by the poison food technique and dual culture method, respectively. Results showed that the extraction rate of P. roseum EO was 0.43%, and 19 compounds were identified in the EO. The major constituent was citronellol (52.16%) followed by nerol (21.93%), citronellyl formate (9.87%), and isomenthol (5.18%). And the EO and its compounds had a significant inhibitory effect (P<0.05) on growth of mycelium and germination of spores against B. cinerea. The inhibitory activity of the dual culture method was much better than that of the poison food technique. There was a dosage-effect relationship between the dosage of the EO and inhibitory activity. In vivo vapor contact test results showed that the EO of P. roseum and its compounds had good inhibitory activity against the postharvest grey mould of cherry tomatoes, and the disease control rate was as high as 98.45% when the dosage of EO was 250.00 mg/L. Thus, the results obtained in this study demonstrate the potential of the EO from P. roseum as an eco-friendly natural fungicide using for postharvest disease control, but its mechanism of action needs to be further investigated. [ABSTRACT FROM AUTHOR]

Pepper production is a critical component of the global agricultural economy, with exports reaching a remarkable $6.9B in 2023. This underscores the crop's importance as a major economic driver of export revenue for producing nations. Botrytis cinerea, the causative agent of gray mold, significantly impacts crops like fruits and vegetables, including peppers. Early detection of this pathogen is crucial for a reduction in fungicide reliance and economic loss prevention. Traditionally, visual inspection has been a primary method for detection. However, symptoms often appear after the pathogen has begun to spread. This study employs the Deep Learning algorithm YOLO for single-class segmentation on plant images to extract spatial details of pepper leaves. The dataset included hyperspectral images at discrete wavelengths (460 nm, 540 nm, 640 nm, 775 nm, and 875 nm) from derived vegetation indices (CVI, GNDVI, NDVI, NPCI, and PSRI) and from RGB. At an Intersection over Union with a 0.5 threshold, the Mean Average Precision (mAP50) achieved by the leaf-segmentation solution YOLOv11-Small was 86.4%. The extracted leaf segments were processed by multiple Transformer models, each yielding a descriptor. These descriptors were combined in ensemble and classified into three distinct classes using a K-nearest neighbor, a Long Short-Term Memory (LSTM), and a ResNet solution. The Transformer models that comprised the best ensemble classifier were as follows: the Swin-L (P:4 × 4–W:12 × 12), the ViT-L (P:16 × 16), the VOLO (D:5), and the XCIT-L (L:24–P:16 × 16), with the LSTM-based classification solution on the RGB, CVI, GNDVI, NDVI, and PSRI image sets. The classifier achieved an overall accuracy of 87.42% with an F1-Score of 81.13%. The per-class F1-Scores for the three classes were 85.25%, 66.67%, and 78.26%, respectively. Moreover, for B. cinerea detection during the initial as well as quiescent stages of infection prior to symptom development, qPCR-based methods (RT-qPCR) were used for quantification of in planta fungal biomass and integrated with the findings from the AI approach to offer a comprehensive strategy. The study demonstrates early and accurate detection of B. cinerea on pepper plants by combining segmentation techniques with Transformer model descriptors, ensembled for classification. This approach marks a significant step forward in the detection and management of crop diseases, highlighting the potential to integrate such methods into in situ systems like mobile apps or robots. [ABSTRACT FROM AUTHOR]

The synthesis, crystal structure, Hirshfeld analysis, and antifungal assessment of a new monohydrated Schiff base with a triazole moiety are reported. The structural study revealed the presence of three significant hydrogen bonds (N--H···N, O--H···N, and O--H···O), which contribute to the cohesion of the crystal. These bonds generate two-dimensional layers parallel to the bc plane, built on the basis of rings with the graph-set motifs R4 4(8) and R4 4(24). The crystal structure is further consolidated by interactions between similar rings. The antifungal activity of the Schiff base was evaluated against three fungi: Fusarium oxysporum, Botrytis cinerea, and Alternaria alternata, showing significant antifungal activity, particularly against Alternaria alternata. [ABSTRACT FROM AUTHOR]

Verticillium wilt caused by the soil‐borne fungus Verticillium dahliae Kleb., is a destructive plant disease that instigates severe losses in many crops. Improving plant resistance to Verticillium wilt has been a challenge in most crops. In this study, a V. dahliae secreted protein VdSP8 was identified and shown to activate hyper‐sensitive response (HR) and systemic acquired resistance (SAR) to Pseudomonas syringae pv. tomato DC3000 (Pst DC3000) and Botrytis cinerea in tobacco plants. We identified a β‐glucosidase named GhBGLU46 as a cotton plant target of VdSP8. VdSP8 interacts with GhBGLU46 both in vivo and in vitro and promotes the β‐glucosidase activity of GhBGLU46. Silencing of GhBGLU46 reduced the expression of genes involved in lignin biosynthesis, such as GhCCR4, GhCCoAOMT2, GhCAD3 and GhCAD6, thus decreasing lignin deposition and increasing Verticillium wilt susceptibility. We have shown that GhBGLU46 is indispensable for the function of VdSP8 in plant resistance. These results suggest that plants have also evolved a strategy to exploit the invading effector protein VdSP8 to enhance plant resistance. Summary statement: The Verticillium dahliae effector protein VdSP8 triggers plant defence response, and interacts with the cotton β‐glucosidase GhBGLU46 to promote lignin biosynthesis and enhance plant resistance to Verticillium wilt. [ABSTRACT FROM AUTHOR]

ROP small GTPases function as signaling hubs that mediate various physiological processes, including plant defense. Their specific roles in strawberry resistance against gray mold remain uncharacterized. In this study, we identified 53 ROP genes across the genomes of six Rosaceae species. Based on sequence homology, they were classified into three distinct phylogenetic clades. Detailed analysis of FveROP proteins revealed the presence of highly conserved catalytic G-domains, which are essential for their GTPase activity. By conducting transient overexpression experiments in strawberry fruits challenged with the gray mold pathogen Botrytis cinerea, we investigated the impact of the FveROP4 gene on disease resistance. The overexpression of both wild-type and constitutively active forms of FveROP4 enhanced resistance against B. cinerea infection. Subsequent analysis revealed that overexpression of FveROP4 and FveCAROP4 genes led to increased accumulation of reactive oxygen species. Moreover, FveROP4 was localized on the plasma membrane, where it interacted directly with FveRBOHF1, corroborating the results obtained through yeast two-hybrid and luciferase complementation imaging assays. The study findings may provide valuable insights for investigating the mechanisms of ROP signaling in regulating the immune response in strawberries and could significantly contribute to strawberry breeding programs aimed at developing new cultivars with enhanced fruit shelf life. [ABSTRACT FROM AUTHOR]

Objective: To search new antifungal compounds for effectively controling vital plant diseases, we designed and synthesized series of N -acyl and acylthiourea of substituted 2-amino-1,3-benzothiazole. Methods: The in vitro antifungal activities of the target compounds were screened against the mycelium growth rate of Valsa mali and Botrytis cinerea. The in vivo antifungal activities were evaluated on grape fruit against B. cinerea. Microscopic inspection and electrical conductivity detection were used to explore the effects of screened compound on the mycelium growth of B. cinerea. Results: The results showed that the most active compounds against V. mali were A12 and B9, while the most active compounds against B. cinerea were B9 and B10. Structure activity relationship (SAR) indicates that 6-NO2 on benzothiazole ring and electron withdrawing substitutes (-NO2, -CF3) on the aryl ring of acyl group are benefical to the activity of benzothiazole acylthiourea. Meanwhile, compounds B9 and B10 exhibited 80%–95% control effects on grape fruit against B. cinerea at 200 μg/mL. Compound B9 could destroy the structure of mycelium by increasing the permeability of cell membrane to inhibit the growth of B. cinerea. Conclusions: The structure activity relationship and the action mechanism of the title compounds are helpful to design new fungicide. [ABSTRACT FROM AUTHOR]

The present investigation focused on exploring the potential of fungal endophytes as a valuable source of bioactive compounds with diverse applications. The phenolic compound 5-methylmellein was isolated for the first time from Alternaria burnsii, an endophytic fungus associated with Morus alba Linn. The compounds were structurally characterized using comprehensive spectral analysis, including 1H-, 13C, and 2D-NMR, as well as HRESI–MS. The study investigated the antifungal activity of 5-methylmellein against several plant pathogenic fungi, including Botrytis cinerea, Colletotrichum gloeosporioides, Cercospora beticola, and Rhizoctonia solani. In vitro assays showed significant inhibition of various plant pathogenic fungi, and the IC50 values ranging from 34.59 ± 1.03a µg/mL to 44.76 ± 1.03b µg/mL against the tested fungi. In vivo experiments on apples and grapes revealed that 5-Methylmellein significantly reduced fruit decay caused by Botrytis cinerea. The wound incidence in the control group reached 95.78%, while the treated groups exhibited a reduction of 37.54% after 15 days. These findings underscore the potential of 5-methylmellein as a potent antifungal agent, suggesting its eco-friendly application in agriculture for managing fruit decay. [ABSTRACT FROM AUTHOR]

Proteins found within the fungal cell wall usually contain both N- and O-oligosaccharides. N-glycosylation is the process where these oligosaccharides (hereinafter: glycans) are attached to asparagine residues, while in O-glycosylation the glycans are covalently bound to serine or threonine residues. The PMT family is grouped into PMT1, PMT2, and PMT4 subfamilies. Using bioinformatics analysis within the Botrytis cinerea genome database, an ortholog to Saccharomyces cerevisiae Pmt4 and other fungal species was identified. The aim of this study was to assess the relevance of the bcpmt4 gene in B. cinerea glycosylation. For this purpose, the bcpmt4 gene was disrupted by homologous recombination in the B05.10 strain using a hygromycin B resistance cassette. Expression of bcpmt4 in S. cerevisiae ΔScpmt4 or ΔScpmt3 null mutants restored glycan levels like those observed in the parental strain. The phenotypic analysis showed that Δbcpmt4 null mutants exhibited significant changes in hyphal cell wall composition, including reduced mannan levels and increased amounts of chitin and glucan. Furthermore, the loss of bcpmt4 led to decreased glycosylation of glycoproteins in the B. cinerea cell wall. The null mutant lacking PMT4 was hypersensitive to a range of cell wall perturbing agents, antifungal drugs, and high hydrostatic pressure. Thus, in addition to their role in glycosylation, the PMT4 is required to virulence, biofilm formation, and membrane integrity. This study adds to our knowledge of the role of the B. cinerea bcpmt4 gene, which is involved in glycosylation and cell biology, cell wall formation, and antifungal response. [ABSTRACT FROM AUTHOR]

The best known Microdochium spp. are important pathogens of small-grain cereals and/or endophytes of diverse monocot hosts. This study is the first report of M. majus isolated from asymptomatic grapevine tissues. It was hypothesised that this M. majus strain, CBS 152328, was an endophyte and an antagonist of some fungal pathogens of grapevine. Microscopic examinations revealed that this strain was a necrotrophic mycoparasite of Botrytis cinerea. This was demonstrated in the confrontation zones of dual cultures of M. majus and B. cinerea, and also on the surface of co-inoculated grape leaf discs and germinated wheat grains. Pathogenicity tests indicated that M. majus can colonise both grape leaf discs and germinated wheat, but it only damaged wheat. When co-inoculated with B. cinerea onto grape leaf discs, the M. majus strain CBS 152328 suppressed its mycohost on grape tissues and prevented leaf necrosis caused by B. cinerea. In addition to the parasitism, M. majus also showed mild antibiosis against B. cinerea, as well as a defence elicitor effect on grape leaf discs. This work is the first report of the mycoparasitic behaviour of M. majus, in addition to its first isolation from a dicot host. [ABSTRACT FROM AUTHOR]

Apples and strawberries hold significant commercial and nutritional value but face pre- and post-harvest spoilage due to infections by Botrytis cinerea. While spoilage is conventionally managed using synthetic chemicals, there is a growing interest in utilising yeasts as biological control agents. This study aimed to assess the antifungal potential of non-Saccharomyces yeasts Suhomyces pyralidae, Meyerozyma guilliermondii, Pichia kluyveri, Zygoascus hellenicus, and Aureobasidium melanogenum against three B. cinerea strains (B05.10, IWBT-FF1, and PPRI 30807) on agar plates and in post-harvest trials on apples and strawberries. Aureobasidium melanogenum exhibited a broad range of extracellular enzyme production and inhibition rates of 55%, 52%, and 40% against the strains. In volatile organic compound (VOC) assays, P. kluyveri and S. pyralidae achieved 79% and 56% inhibition, respectively, with VOCs like isobutanol, isoamyl alcohol, 2-phenylethanol, isoamyl acetate, and 2-phenethyl acetate identified. In post-harvest trials, S. pyralidae was most effective on apples, with inhibition rates up to of 64%. The commercial fungicide Captan and S. pyralidae and P. kluyveri achieved 100% inhibition against the B. cinerea strains B05.10 and IWBT-FF1 on strawberries. These findings highlight the potential of the selected yeast species as biological control agents against B. cinerea, warranting further research into their application in commercial fruit protection. [ABSTRACT FROM AUTHOR]

Botrytis cinerea, the grey mould fungus affecting over 1400 plant species, employs infection cushion (IC), a branched and claw-like structure formed by mycelia, as a critical strategy to breach host surface barriers. However, the molecular mechanisms underlying IC formation remain largely unexplored. In this study, we utilized a forward genetics approach to establish a large T-DNA tagged population of B. cinerea, which contained 14,000 transformants. Through phenotype screening, we identified 161 mutants with defects in IC development. Detailed analyses revealed that these mutants exhibited various degrees of impairment in IC formation, ranging from complete failure to form ICs to a reduction in the number and maturity of ICs. Further genetic analysis of one of the mutants led to the identification of EXO70, a gene encoding a component of the exocyst complex, as a key regulatory factor in IC development. Mutants with deletion of EXO70 failed to form ICs, confirming its crucial role in the process. The mutant library reported here provides a rich resource for further large-scale identification of genes involved in IC development. Our findings provide valuable insights into the genetic and molecular basis of IC formation and offer new targets for controlling B. cinerea pathogenicity. [ABSTRACT FROM AUTHOR]

The potential use of volatile compounds released from milled seeds of mustard (Brassica juncea cv. Malopolska) obtained from three different companies was tested in in vitro and in vivo experiments for their inhibitory effect on Botrytis cinerea growth on agar media and its infection on vegetable leaves of cucumber, bean and spinach. In the experiments with spinach, the effect of volatiles from mustards on the storage and sensory quality of fumigated leaves was evaluated. The antifungal effect of the volatiles depended on the source and dosage of mustard seeds and biofumigation time. The most efficient inhibition of B. cinerea mycelium growth on agar media and vegetable leaves was mustard S from SHR company. The development of grey mould on spinach leaves was inhibited in the treatment with 4 h biofumigation with the volatiles from mustard S seeds in experiments conducted at 10 °C and also at 18 °C. In the sensory and storage quality analysis, the spinach leaves treated with volatiles from mustard seeds showed acceptable parameters that predisposed the product to consumption. The results show that it is possible to reduce the incidence of vegetable grey mould with the treatment of milled mustard seeds, opening a potential application of biofumigation in the control of B. cinerea in vegetables. [ABSTRACT FROM AUTHOR]

Background: Hazelnut (Corylus), a significant woody oil tree species in economic forests, faces production constraints due to biotic stresses, with Hazelnut Husk Brown Rot, caused by the pathogenic necrotrophic fungus Botrytis cinerea (B. cinerea), being the most severe. To date, limited information is available regarding the resistance of hazelnuts to B. cinerea. To better understand the mechanisms of resistance to B. cinerea. in hazelnut, we conducted metabolomics and WGCNA analyses of a B. cinerea-resistant Ping'ou hybrid hazelnut variety (Dawei; DW) and a susceptible variety (Qiuxiang; QX). Methods: In this study, metabolomics and weighted gene co-expression network analysis (WGCNA, weighted correlation network analysis) were applied to elucidate the resistance mechanisms underlying different hazelnut varieties to B. cinerea. Our study focused on the metabolome profiles of DW and QX plants after 72 h of B. cinerea infection. Results: Venn analysis of QX_0 vs. DW_0 and QX_72 vs. DW_72 revealed 120 differential accumulation metabolites (DAMs) that were upregulated. Among these metabolites, the concentrations of flavonoids and phenolic acids in DW were significantly higher than those in QX, respectively, suggesting that the elevated levels of these compounds contribute substantially to the resistance of hazelnut against B. cinerea. 3,4-hydroxyphenyllactic acid and phloretin were significantly more abundant in accumulation in DW than in QX after infection by B. cinerea. Conclusions: This study provides that the elevated levels of these compounds (flavonoids and phenolic acids) contribute substantially to the resistance of hazelnut against B. cinerea. Furthermore, 3,4-hydroxyphenyllactic acid and phloretin were identified as pivotal metabolites in modulating the resistance of hazelnut to B. cinerea. Through WGCNA analyses, we identified four transcription factors (WRKY19, HSFC1, ERF071, and RAP2-1) that are most likely to regulate the synthesis of 3,4-dihydroxyphenyllactic acid and phloretin. This study provides crucial insights for further investigation into the regulatory network of metabolites associated with hazelnut resistance to B. cinerea. [ABSTRACT FROM AUTHOR]