Botrytis Cinerea Research Articles

Biopesticide Compounds from an Endolichenic Fungus Xylaria sp. Isolated from the Lichen Hypogymnia tubulosa

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.

Search for morphological, biochemical, and microbiological markers of resistance of raspberry cultivars to Botrytis cinerea Pers.

Search for morphological, biochemical, and microbiological markers of resistance of raspberry cultivars to Botrytis cinerea Pers.

Development of Pectin-Based Films with Encapsulated Lemon Essential Oil for Active Food Packaging: Improved Antioxidant Activity and Biodegradation

This study evaluated the physicochemical, morphological, and functional properties of pectin-based films incorporated with lemon essential oil (EO) to assess their potential as biodegradable food packaging materials. The results showed that EO incorporation significantly influenced the film’s characteristics. The control film exhibited a smooth surface, while the EO-containing film had a rougher texture with globular structures and interconnected channels, likely representing dispersed EO droplets and matrix alterations. The mechanical analysis revealed increased elongation at break (20.05 ± 0.784%) for EO-incorporated films, indicating improved flexibility, while tensile strength and Young’s modulus decreased, suggesting reduced stiffness. Film thickness increased slightly with EO (0.097 ± 0.008 mm) compared to the control (0.089 ± 0.001 mm), though the difference was not statistically significant (p > 0.05). Moisture content decreased in EO-containing films (28.894%) compared to the control (35.236%), enhancing water resistance. Water solubility increased slightly (16.046 ± 0.003% vs. 15.315 ± 0.040%), while the swelling rate decreased significantly (0.189 ± 0.003 vs. 0.228 ± 0.040; p < 0.05), indicating greater structural stability in aqueous environments due to the hydrophobic nature of EO. Transparency tests showed that EO slightly increased film opacity (0.350 ± 0.02 vs. 0.290 ± 0.012), aligning with trends in UV-protective materials. The EO-incorporated films also exhibited moderate antibacterial activity against Staphylococcus aureus and Escherichia coli. Antifungal tests revealed strong inhibition of Botrytis cinerea (100%) and moderate inhibition of Alternaria alternata (50%) in EO-containing films. These results demonstrate that EO incorporation improves the functional properties of pectin films, enhancing their flexibility, antimicrobial activity, and environmental stability, making them promising candidates for sustainable food packaging applications. These novel active food packaging materials exhibit strong physical properties and significant potential in maintaining food quality and prolonging shelf life.

Sunflower Head Rot Diseases: Botrytis Head Rot and Bacterial Head Rot

Sunflower is the fourth most produced vegetable oil worldwide and is ranked fifth of the 13 cultivated crops of major importance to global food security (FAO 2022; Hajjar and Hodgkin 2007; Seiler et al. 2018). Sunflower is affected by many economically-important and yield-limiting diseases, and this article is the first of an anticipated series of Plant Health Progress - Diagnostic Guides on significant heads diseases of sunflower. This follows a similar series of Plant Health Progress - Diagnostic Guides on sunflower stem diseases (Harveson et al. 2018, Ryley et al. 2021). Here we present information on Botrytis head rot and Bacterial rots, while information on Rhizopus head rot, Sclerotinia head rot, and the Phomopsis/Diaporthe head rots is anticipated in the near future. Botrytis head rot caused by Botrytis cinerea Pers. can be a common and significant disease in favorable environments while bacterial rots usually occur opportunistically and sporadically resulting in limited yield loss. In this paper, we concentrate on providing information to identify and distinguish these diseases, a comprehensive review of methods and techniques for working with the causal pathogens, and emphasizing the importance of disease cycles for identification and management.

Synthesis and antifungal activity of aldehydes-thiourea derivatives as promising antifungal agents against postharvest gray mold disease.

Gray mold disease is caused by B. cinerea, which could severely reduce the production yield and quality of tomatoes. To explore more potential fungicides with new scaffolds for controlling the gray mold disease, ten aldehydes-thiourea derivatives were designed, synthesized and assayed for inhibitory activity against three plant pathogenic fungi. The preliminary antifungal assay suggested that the some title derivatives showed moderate to good antifungal activity against Botrytis cinerea. Especially, compound 9 presented excellent in vitro antifungal activity against B. cinerea (EC50 = 0.70 mg/L), which was superior to boscalid (EC50 = 1.41 mg/L). In vivo antifungal assay indicated 9 displayed good protective effects on tomato leaves infected by B. cinerea. Preliminary mechanism study displayed that 9 could damage the surface morphology, increase the cell membrane permeability and lead to the increase of reactive oxygen species (ROS) level. Enzyme inhibition assay illustrated that 9 could be potential laccase inhibitor. The above bioassay results and mechanism investigation demonstrated that aldehydes-thiourea derivatives could be promising fungicide for further controlling postharvest gray mold disease, which would be potential candidate of fungicidal compound.

Pinnatifone A, isolated from Syringa pinnatifolia (Oleaceae), exhibits inhibitory activity against phytopathogenic fungi and can be employed to formulate a soluble concentrate agent.

In the realm of plant diseases, those caused by fungi and oomycetes are particularly challenging to manage, resulting in significant economic losses. There exist diverse active substances in natural products and developing them into fungicides holds great significance. At the initial phase of our research, we discovered that Syringa pinnatifolia extract demonstrates broad-spectrum inhibitory activity against phytopathogenic fungi. S. pinnatifolia extracts showed inhibitory activity against phytopathogenic fungi in vivo and in vitro, especially Valsa mali and Botrytis cinerea. Totals of eight compounds were isolated by bio-guided isolation (SCX-1 to SCX-8). Among these compounds, 3-methoxy-4-hydroxybenzaldehyde (SCX-2) and pinnatifone A (SCX-8) were found to have excellent antifungal activities against phytopathogenic fungi, the half maximal effective concentration (EC50) of SCX-2 against V. mali was 45.34 μg/mL, the EC50 of compound SCX-8 against B. cinerea was 9.25 μg/mL. Here a formulation of a soluble concentrate agent is presented for the prevention and control of tomato gray mold. This formulation included 45% S. pinnatifolia extract (containing 2.1% pinnatifone A), 16% benzyl alcohol, 24% absolute ethanol, 5% ethylene glycol, and 10% pesticide emulsifier No. 602. The preparation exhibited good protective and curative efficacies against tomato gray mold at a concentration of 100 μg/mL, with efficacies of 65.32% and 54.83%. Our findings provide valuable insights for the structural modification of active compounds derived from S. pinnatifolia and lay a foundation for the development of novel botanical fungicide products utilizing S. pinnatifolia as a raw material. © 2025 Society of Chemical Industry.

Botrytis cinerea PMT4 Is Involved in O-Glycosylation, Cell Wall Organization, Membrane Integrity, and Virulence.

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.

Transcriptome, miRNA, and degradome sequencing reveal the leaf stripe (Pyrenophora graminea) resistance genes in Tibetan hulless barley

Barley leaf stripe, a disease mainly caused by Pyrenophora graminea (P. graminea) infection, severely affects barley yield and quality and is one of the most widespread diseases in barley production. However, little is known about the underlying molecular mechanisms of leaf stripe resistance. In this study, the transcript expression profiles of normal and infected leaves of resistant Tibetan hulless barley (Hordeum vulgare L. var. nudum Hook. f.) variety Kunlun 14 and susceptible variety Z1141 were analyzed by RNA sequencing (RNA-seq). The results showed a total of 7,669 and 5,943 differentially expressed genes (DEGs) were found in resistant and susceptible Kunlun 14 and Z1141, respectively, with 8,916 DEGs found between Kunlun 14 and Z1141. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis of the 8,916 DEGs identified many significantly enriched categories and pathways, of which a plant–pathogen interaction pathway, containing a total of 102 genes (100 known genes and two novel genes), was found, that was very important for the study of the leaf stripe resistance mechanism. Using RNA-seq, small RNA sequencing (miRNA-seq) combined with degradome sequencing (degradome-seq), four pairs associated with leaf-stripe miRNAs and target genes were obtained, namely Hvu-miR168-5p and Argonaute1 (HvAGO1), Hvu-novel-52 and growth-regulating factor 6 (HvGRF6), Hvu-miR6195 and chemocyanin-like protein (CLP), and Hvu-miR159b and gibberellin-dependent MYB (GAMYB). Transformation of the important target gene HvAGO1 into Arabidopsis verified that HvAGO1 could against Botrytis cinerea. Then RNA-seq and miRNA-seq of Arabidopsis transformed with overexpressed of HvAGO1 were performed. Based on the above research results, we constructed a Protein-Protein Interaction (PPI) network of barley leaf stripe resistance. This study lays the foundation for the study of the barley leaf stripe resistance mechanism and provides new targets for the genetic improvement of disease-resistant barley varieties.

Temporal dynamics of airborne fungi in Swedish forest nurseries.

In Sweden, reforestation of managed forests relies predominantly on planting nursery-produced tree seedlings. However, the intense production using containerized cultivation systems (e.g., high seedling density, irrigation from above, regular fertilization) creates favorable conditions for fungal infections. Despite the harmful role of diseases in forest nurseries, the origin and dispersal factors of fungal pathogens remain largely unknown. A better understanding of the airborne spread of pathogens could improve the prediction of fungal infection, ultimately optimizing preventative methods and decreasing the use of fungicides. This study investigated the temporal dynamics of airborne fungi in forest nurseries, with a focus on fungal pathogens. Airborne fungi were monitored in four Swedish forest nurseries over two growing seasons using spore traps and high-throughput sequencing. Fungal pathogens were identified using bioinformatics and quantified with quantitative PCR. Results showed strong temporal shifts of airborne fungal diversity and community composition following the growing seasons. The airborne spread included high abundances of important fungal pathogens (e.g., Cladosporium sp., Botrytis cinerea, Alternaria sp., Sydowia polyspora, and Melampsora populnea) with individual temporal and spatial variations. In general, the deposited spore loads of nursery pathogens correlated positively with increased temperature and negatively with higher precipitation. This was expressed the strongest for Cladosporium sp., Alternaria sp., and M. populnea, which suggests a higher availability of fungal inoculum in warm and dry periods. This study highlights the influence of seasonality on the temporal dynamics of economically important fungal pathogens in Swedish forest nurseries, which should be considered in the development of a local decision support system.IMPORTANCEFungal diseases in forest nurseries have significant environmental and economic impacts on the tree seedling production. This study highlights the role of seasonality in the airborne spread of fungal pathogens in Swedish forest nurseries. By analyzing airborne fungal spores using advanced sequencing and monitoring techniques, key fungal pathogens and their dispersal patterns over two growing seasons were identified. The findings indicate that warmer, drier periods may increase the spread of fungal pathogens, emphasizing the need for targeted preventative measures. Understanding these temporal dynamics can help optimize the use of fungicides in forest nurseries, thereby promoting more sustainable and environmentally friendly management practices. This research provides valuable insights for improving disease management in forest nurseries, ultimately supporting sustainable tree seedling production.

Effects of Preharvest Application of Acibenzolar-S-methyl and Potassium Silicate on Postharvest Diseases and Fruit Quality of Blueberries

Blueberries are highly perishable and susceptible to storage spoilage, especially fruit rot diseases caused by fungal pathogens. Alternaria rot caused by Alternaria alternata and gray mold caused by Botrytis cinerea are the primary postharvest diseases of blueberries grown in California. We conducted a three-year field experiment to evaluate the effects of preharvest application of Acibenzolar-S-methyl (ASM) and potassium silicate (PSi) on Alternaria rot and gray mold in blueberry fruit inoculated with these pathogens after harvest, as well as naturally occurring fruit rots, fruit-to-fruit spread of gray mold during cold storage, and fruit quality. After four weeks of cold storage, all inoculated fruit developed rots regardless of the treatments applied in the field. In non-inoculated fruit, ASM significantly reduced the percentage of naturally occurring decayed fruit compared to the non-treated control in 2023 but not in 2021 and 2022. PSi significantly reduced the percentage of decayed fruit compared to the non-treated control in 2021 and 2023, but not in 2022. A significant increase in soluble solids and reduction in titratable acidity were observed in the fruit treated with ASM and PSi for the second and third years of the experiment, indicating that both treatments may have enhanced fruit maturity. Our results suggested that preharvest use of ASM and PSi had limited efficacy in postharvest disease control, but may have potential as tools for adjusting fruit maturity of blueberries.

Inhibitory and Curative Effects and Mode of Action of Hydroxychloroquine on Botrytis cinerea of Tomato.

Gray mold is an important disease of crops and is widespread, harmful, difficult to control, and prone to developing fungicide resistance. Screening new fungicides is an important step in controlling this disease. Hydroxychloroquine is an anti-inflammatory and anti-malarial agent, which has shown marked inhibitory activity against many fungi in medicine. This study evaluated the inhibitory activity of hydroxychloroquine against several phytopathogenic fungi, finding a half-maximal effective concentration of 113.82 μg/ml against the hyphal growth of Botrytis cinerea, with significant in-vivo curative effects of 92.37% or 78.37% for gray mold on detached tomato leaves or fruits at 10.0 or 200.0 mg/ml, respectively. Ultrastructural studies indicated that hydroxychloroquine induced collapse of hyphae, with a wrinkled surface, unclear organelle boundaries, and organelle disintegration. Transcriptomic assays revealed that hydroxychloroquine could affect the expression of metabolism-related genes. Molecular docking and molecular dynamics analyses indicated that hydroxychloroquine bound to glucose-methanol-choline oxidoreductase, with low free energy value of -11.4 kcal/mol. Cell membrane permeability assays and hyphal staining confirmed that hydroxychloroquine damaged the cell membrane, causing leakage of hyphal contents and disturbing cell function. Biochemical assays indicated that hydroxychloroquine reduced the concentration of soluble proteins and reducing sugars in the hyphae. In total, hydroxychloroquine disturbed amino acid metabolism, therefore inhibiting the production of biomacromolecules, damaging the cell membrane, and restraining the growth of hyphae, and hence inhibiting gray mold on tomato. This study will explore the use of medicine in the development of agricultural fungicides and their application in managing crop diseases, providing valuable background information.

Spray-Induced Gene Silencing (SIGS): Nanocarrier-Mediated dsRNA Delivery Improves RNAi Efficiency in the Management of Lettuce Gray Mold Caused by Botrytis cinerea

The plant pathogenic fungus Botrytis cinerea causes significant losses in agricultural production and it is rather difficult to control due to its broad host range and environmental persistence. The management of gray mold disease is still mainly based on the use of chemicals, which could have harmful effects not only due to impacts on the environment and human health, but also because they favor the development of fungicide-resistant strains. In this scenario, the strategy of RNA interference (RNAi) is being widely considered, and Spray-Induced Gene Silencing (SIGS) is gaining interest as a versatile, sustainable, effective, and environmentally friendly alternative to the use of chemicals in the protection of crops. The SIGS approach was evaluated to control B. cinerea infection on lettuce plants. In vitro-synthesized dsRNA molecules (BcBmp1-, BcBmp3-, and BcPls1-dsRNAs) were used naked, or complexed to small layered double hydroxide (sLDH) clay nanosheets. Therefore, treatments were applied by pressure spraying whole lettuce plants lately inoculated with B. cinerea. All sprayed dsRNAs proved effective in reducing disease symptoms with a notable reduction compared to controls. The effectiveness of SIGS in reducing disease caused by B. cinerea was high overall and increased significantly with the use of sLDH clay nanosheets. The sLDH clay nanosheet–dsRNA complexes showed better plant protection over time compared to the use of naked dsRNA and this was particularly evident at 27 days post-inoculation. RNAi-based biocontrol could be an excellent alternative to chemical fungicides, and several RNAi-based products are expected to be approved soon, although they will face several challenges before reaching the market.

The potential of volatiles from Brassica juncea seeds against grey mould agent Botrytis cinerea and their effect on storage and sensory quality of spinach leaves

The potential of volatiles from Brassica juncea seeds against grey mould agent Botrytis cinerea and their effect on storage and sensory quality of spinach leaves

Incidence, Distribution, and Pathogenicity of Fungi Growing on Sugar Beet Roots on Top of Outdoor Piles in Idaho.

Sugar beet roots in Idaho are held under ambient conditions in outdoor storage piles which can lead to fungal growth and rot and substantial sucrose loss. Thus the incidence, distribution, and pathogenicity of fungi associated with fungal growth on the surface of sugar beet roots on top of outdoor piles was investigated. The surface fungal growth on sugar beet roots held on top of 14 Idaho outdoor piles [tarped ventilated (TV) piles and piles with no tarps or ventilation (NTV) at 7 locations] was assessed in 2018-19 and 2019-20. Cladosporium spp. were the only fungi covering more than 1% of the root surface (2 to 48%) on top of NTV piles both years with the most frequently isolated species being C. cladosporioides, C. macrocarpon, and C. subtilissimum both years. On TV piles Cladosporium spp. (13 to 60%) were also dominant, but Penicillium spp. (0 to 35%), an Athelia-like basidiomycete (0 to 2%), and Botrytis cinerea (0 to 2%) were also frequently present. In the plug assay to test pathogenicity, B. cinerea caused the most rot (P < 0.0001; averaged 31 to 32 mm of rot) followed by Penicillium spp. (P. expansum 14-22 mm, P. polonicum 14-16 mm, and P. cellarum 10 mm). Although Cladosporium spp. caused little or no rot (0 to 2 mm), workers should be cautious on or around sugar beet piles since a number of the Cladosporium spp. are established to be associated with human clinical samples.

Unravelling the transcriptomic dynamics of Hyphopichia pseudoburtonii in co-culture with Botrytis cinerea.

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.

Pre and postharvest application of nano silver improves gray mold disease resistance and longevity of cut roses

Pre and postharvest application of nano silver improves gray mold disease resistance and longevity of cut roses

Comparative Evaluation of AI-Based Multi-Spectral Imaging and PCR-Based Assays for Early Detection of Botrytis cinerea Infection on Pepper Plants

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.

Cross-resistance between Pseudomonas chlororaphis strain AFS009 metabolites (Howler EVO) and fludioxonil in Botrytis cinerea.

Howler EVO is a biological fungicide based on metabolites of the bacterium Pseudomonas chlororaphis strain AFS009. One of the metabolites, pyrrolnitrin (PRN), is a chemical analogue of the phenylpyrrole fludioxonil used to manage gray mold of fruit crops caused by Botrytis cinerea. Resistance to fludioxonil in B. cinerea is well documented and linked to mutations in the transcription factor mrr1, leading to overexpression of the ATP-Binding Cassette (ABC) transporter gene BcatrB. Moderately resistant isolates are designated MDR1 and MRD1h based on the specific variation of mutations in mrr1 and the level of BcatrB expression. This study investigated EC50 values of 54 B. cinerea isolates sensitive and with moderate resistance to fludioxonil for sensitivity to fludioxonil and Howler EVO. The Pearson correlation coefficient indicated a strong correlation between EC50 values of fludioxonil and Howler EVO. Isolates that were moderately resistant to fludioxonil and classified as MDR strains were also moderately resistant to Howler EVO. The effect of Howler EVO and fludioxonil on BcatrB gene expression was studied by qPCR. Both fungicides induced the BcatrB gene expression significantly up to 100-fold in sensitive B. cinerea isolates. Howler EVO significantly induced the BcatrB gene expression in all MDR1 isolate but not in the MDR1h isolate. In detached fruit assays on cherry, sensitive B. cinerea isolates were completely inhibited by formulated fludioxonil (Scholar) and significantly suppressed in growth by Howler EVO. However, MDR1 and MDR1h isolates produced disease in Scholar and Howler EVO treatments. Our results indicate cross-resistance between the synthetic fungicide fludioxonil and the biofungicide Howler EVO, indicating that, at least for some biofungicides, resistance management is necessary.

Nano-Formulated Pyraclostrobin With Iron Bismuthide Enhances Efficient Utilization of Active Ingredient and Improves Biosafety.

The widespread application of pyraclostrobin (PYR), an important strobilurin fungicide with low utilization efficiency, urgently requires optimization for sustainable agriculture. In this study, nanoformulated PYR with nano-iron bismuthide (FeBi) was successfully prepared via flash nanoprecipitation, yielding spherical PYR/FeBi nanoparticles (NPs, Φ120nm) with stable drug loading capacity (67.9%) and controlled release. These NPs exhibited enhanced anti-Botrytis activity in vitro and superior in vivo performance. On tomato leaves, PYR/FeBi NPs at 80µg/mL achieved greater than 90% curative and protective efficacy against Botrytis cinerea infection and significantly mitigated lesion expansion, surpassing commercial PYR suspension concentrate (SC) at equivalent concentrations. On tomato seedlings, PYR/FeBi NPs significantly reduced gray mold disease by 89%, compared to 67% with PYR SC at the same concentration. The mechanism underlying this enhanced activity involved stronger disruption of mitochondrial metabolism, including acetylation process, oxalate production, and damage to mycelia and conidia. Further, PYR/FeBi NPs displayed reduced cytotoxicity on human Hek293 and Chinese hamster V79 cells compared to PYR SC. The results highlighted the biocompatibility and potential of PYR/FeBi NPs for efficient utilization of active ingredients in sustainable agriculture.

Evaluating the Role of Viable Cells, Heat-Killed Cells or Cell-Free Supernatants in Bacterial Biocontrol of Fungi: A Comparison Between Lactic Acid Bacteria and Pseudomonas.

This study investigated whether viable cells, dead cells or cell-free supernatants (CFS) were responsible for the biocontrol effect of strains from two important bacterial genera, Pseudomonas and Lactobacillus, known for their antifungal properties against plant pathogens and food spoilage microorganisms. Specifically, the capability of these strains to produce extracellular hydrolytic enzymes on specified media was assessed, along with their effectiveness in inhibiting the mycelial growth of several phytopathogenic fungi (Fusarium oxysporum, Botrytis cinerea, Pythium ultimum and Rhizoctonia solani) using dual culture plate assays. Results from these inhibition assays revealed that P. fluorescens PF05 and L. plantarum LMG 23520 strains were the most effective in suppressing fungal growth, especially F. oxysporum. Therefore, further experiments were carried out to investigate the antifungal potential of the viable cells, heat-killed cells (HKC) and CFS from these strains against the germination of F. oxysporum spores. The viable cell trial proved successful, whereas HKC from the two bacterial isolates were ineffective against fungal spore germination. Conversely, the CFS of L. plantarum LMG 23520 was able to prevent fungal spore development for up to six days. The CFS of P. fluorescens PF05, instead, did not yield positive results. Additional studies are required to evaluate the potential inhibitory effects of the CFS from P. fluorescens PF05 and the HKC from both strains.