Fruit Disease Research Articles

Progress in research on the effects of preharvest inducers on postharvest fruit disease resistance and physiological disorders

Progress in research on the effects of preharvest inducers on postharvest fruit disease resistance and physiological disorders

Sensitivity to the Demethylation Inhibitor Difenoconazole Among Baseline Populations of Various Penicillium spp. Causing Blue Mold of Apples and Pears.

Difenoconazole (DIF), a demethylation inhibitor fungicide, was registered in 2016 for the control of postharvest diseases of pome fruits. In this study, 162 isolates from P. expansum (n = 31) and 13 other "non-expansum" Penicillium spp., i.e., P. solitum (n = 52), P. roqueforti (n = 32), P. commune (n = 15), P. paneum (n = 9), P. psychrosexuale (n = 8), P. crustosum (n = 5), P. carneum (n = 3), P. palitans (n = 2), along with one isolate each of P. citrinum, P. griseofulvum, P. raistrickii, P. ribium, and P. viridicatum, were collected from multiple packinghouses in the U.S. Pacific Northwest. In vitro sensitivity assays showed similar sensitivities of spores and mycelia across species with the mean EC50 values ranging from 0.01 for P. psychrosexuale (n = 8) to 1.33 μg mL-1 for P. palitans (n = 2), whereas the mean EC50s were 0.03, 0.12, 0.19, and 0.51 μg mL-1 for P. expansum (n = 31), P. paneum (n = 9), P. solitum (n = 52), and P. crustosum (n = 5), respectively. The recommended rate of DIF controlled P. expansum and P. roqueforti isolates but not all isolates of four other Penicillium spp. on Fuji apples after five months at 1.5 °C. The mixture of DIF + fludioxonil (FDL) (AcademyTM) controlled all the dual-sensitive isolates (DIFSFDLS) and DIF single-resistant (DIFR) isolates among the six species tested but not the FDLR and dual DIFRFDLR isolates. Notable polymorphism was detected in the CYP51 gene of the "non-expansum" species with four mutations located at four residues. Although the isolates analyzed in this study had not previously been exposed to DIF, the findings indicate variable sensitivity levels among the Penicillium spp.

Extracting Fruit Disease Knowledge from Research Papers Based on Large Language Models and Prompt Engineering

In China, fruit tree diseases are a significant threat to the development of the fruit tree industry, and knowledge about fruit tree diseases is the most needed professional knowledge for fruit farmers and other practitioners in the fruit tree industry. Research papers are the primary sources of professional knowledge that represent the cutting-edge progress in fruit disease research. Traditional knowledge engineering methods for knowledge acquisition require extensive and cumbersome preparatory work, and they demand a high level of professional background and information technology skills from the handlers. This paper, from the perspective of fruit tree industry knowledge dissemination, aims at users such as fruit farmers, fruit tree experts, fruit tree knowledge communicators, and information gatherers. It proposes a fast, cost-effective, and low-technical-barrier method for extracting fruit tree disease knowledge from research paper abstracts—K-Extract, based on large language models (LLMs) and prompt engineering. Under zero-shot conditions, K-Extract utilizes conversational LLMs to automate the extraction of fruit tree disease knowledge. The K-Extract method has constructed a comprehensive classification system for fruit tree diseases and, through a series of optimized prompt questions, effectively overcomes the deficiencies of LLM models in providing factual accuracy. This paper tests multiple LLM models available in the Chinese market, and the results show that K-Extract can seamlessly integrate with any conversational LLM model, with the DeepSeek model and the Kimi model performing particularly well. The experimental results indicate that LLM models have a high accuracy rate in handling judgment tasks and simple knowledge Q&A tasks. The K-Extract method is simple, efficient, and accurate, and can serve as a convenient tool for knowledge extraction in the agricultural field.

Enhancing Fruit Resistance against Fungal Pathogens Using a Pathogen-Associated Molecular Pattern PdEIX.

Fruit is an essential part of the human diet, and postharvest fungal diseases are the major cause of fruit postharvest losses worldwide. Pathogen-associated molecular patterns (PAMPs) are important elicitors from microbes, and the recognition between microbial PAMPs and plant receptors leads to PAMP-triggered immunity. Here, we identified a PAMP, PdEIX, that is an important protein elicitor with plant immunity-inducing activity, from the citrus green mold pathogen Penicillium digitatum. PdEIX showed an apoplastic location similar to that of known PAMPs, and plant receptor-like protein NbEIX2, receptor-like kinase BAK1, and other signaling components of plant immunity were required for PdEIX-triggered plant cell death in the model plant Nicotiana benthamiana. Moreover, PdEIX triggered a series of immune responses in citrus fruit and enhanced the resistance of citrus and other fruit against fungal pathogens. Our results indicate that application of a microbial PAMP as the plant immunity inducer is an effective strategy for controlling postharvest fungal diseases of fruit.

Antifungal lipopeptides from the marine Bacillus amyloliquefaciens HY2-1: A potential biocontrol agent exhibiting in vitro and in vivo antagonistic activities against Penicillium digitatum.

This study aimed to clarify the antifungal activity and action mechanism of the lipopeptides from a marine Bacillus amyloliquefaciens HY2-1 against Penicillium digitatum both in vitro and in vivo. Results showed that HY2-1 lipopeptides exerted obvious inhibitions on spore germination and mycelium growth of P. digitatum. Furthermore, HY2-1 lipopeptides caused the aggravated lipid peroxidation, the decreased ergosterol biosynthesis, and the increased nucleic acid and protein leakage in P. digitatum, suggesting the damaged membrane integrity and permeability of P. digitatum. In addition, HY2-1 lipopeptides induced ROS burst and reduced the activities of antioxidant superoxide dismutase and peroxidase in P. digitatum, indicating that the intracellular redox homeostasis of P. digitatum was disturbed. In vivo biocontrol experiments showed that HY2-1 lipopeptides could effectively reduce the occurrence of green mold disease in citrus fruits artificially inoculated with P. digitatum spores. Most significantly, 4.8mg/mL of HY2-1 lipopeptides achieved 100% of biocontrol efficacy after 30days of storage and increased significantly contents of total phenols and flavonoids in citrus peels, demonstrating that HY2-1 lipopeptides inhibited green mold disease by exerting their antifungal activities and triggering fruit defense responses. This study deepens the understanding of marine Bacillus lipopeptides in the biological control of postharvest diseases.

Development of chitosan coating product containing bitter gourd extract to delay anthracnose disease in mango

Mangifera indica cv. ‘Nam Dok Mai’ is the most popular fruit in Asia and worldwide, but it often faces anthracnose disease both in the vegetative stage (on leaves) and the reproductive stage (on fruit). The symptoms of this disease affect low yield and limit export; therefore, the effect of coating to reduce the incidence of anthracnose disease in mango fruits is necessary. This research aimed to develop an edible chitosan coating containing bitter gourd extract. Mango fruits were coated with 0.5, 1.0 and 2.0% chitosan solution (70-75% deacetylation; 310-375 kDa) and appropriate 500 ppm bitter gourd extract. The result showed that chitosan coating with bitter gourd extract could not extend the shelf life of mango fruits and decrease the incidence of disease longer when compared with coatings with chitosan or bitter gourd extract alone. Further, it could also delay ripening. Disease incidence and lesion diameter on mangoes coated with 2% chitosan with bitter gourd extract was the most effective (P < 0.05) within 5, 7 and 10 days after storage. Weight loss in mangoes increases during ripening; however, chitosan coating can help reduce weight loss. Fruits coated with 1% chitosan were the best formula for reducing weight loss. Chitosan coating adding bitter gourd extract is the best choice to replace chemical treatment to obtain better quality before export or transportation.

Post-harvest conservation of orange (Citrus sinensis L.) using bacterial biocontrol agents isolated from the rhizosphere of the cashew tree (Anacardium occidentale L.) in Côte D’ivoire

Post-harvest fruit diseases, mainly due to fungi microscopic, constitute one of the main factors of fruit deterioration during their conservation. Unlike chemical control, biological control is more beneficial given its ecological and health nature for the consumer. However, this fight could have impacts on biochemical parameters and organoleptic of preserved fruits. The objective of this study is to highlight the inhibitory activity of bacterial biocontrol agents isolated from the rhizosphere of the cashew tree on the germs responsible for post-harvest spoilage of the orange. To do this, 300 oranges were collected from the fruit market in Côte d’Ivoire. The flora fungal spoilage of these oranges was isolated on PDA medium and conservation tests of the oranges with the supernatant of bacterial biocontrol agents were carried out. The results obtained made it possible to identify three (3) genera of fungi on spoiled oranges including Colletotrichum, Alternaria and Lasiodiplodia with respective isolation frequencies of 11%, 33% and 56%. Also, preserving the oranges with the supernatant of the bacterial biocontrol agents made it possible, over 14 days, to note an absence of growth of fungi and no sign of spoilage unlike the control oranges.

Morphological and molecular identification of Alternaria dumosa causing post-harvest black spot disease in persimmon (Diospyros Kaki l.) in Pakistan

A survey was conducted from October to January 2021 in local fruit markets in Lahore and surrounding areas to collect persimmon fruit (Diospyros kaki) displaying small black spots, ranging from 3-5 mm in size. To isolate the pathogen, tissue segments (3-5 mm) from the symptomatic fruit were placed on Malt Extract Agar and incubated at 28°C. After 7 days, light brown mycelia appeared. Based on morphological characteristics, the preliminary pathogen was tentatively identified as Alternaria dumosa. To confirm the identification, genomic DNA was extracted and amplified using primer pairs for ITS, GAPDH, Calmodulin, Actin, and TEF. The resulting sequences were compared to those in GenBank using BLAST searches in NCBI, confirming a close match to A. dumosa. The sequences were deposited in GenBank under accession numbers OK447926, OL754642, OL804135, OL830275, and OL962418. For pathogenicity testing, surface-sterilized, uninfected persimmon fruits were inoculated with a conidial suspension (106 spores/ml) of the isolate from this study, while sterile distilled water was used for the control treatment. The fruits were then incubated at 28°C for 7 days. The experiment was repeated twice for validation. Pathogenicity tests showed that 85% of the inoculated persimmon fruits developed characteristic black spots within 7 days, indicating the high virulence of A. dumosa under controlled conditions. The inoculated fruits displayed symptoms similar to those observed in naturally infected fruits, while the control fruits remained symptom-free. Based on these results, we concluded that A. dumosa is the causative agent of leaf spot disease in persimmon fruit.

Antifungal Activity of Ethanolic Extracts from Aeroponically Grown Cape Gooseberry (Physalis peruviana L.) with LED Lights and In Vitro Habituated Roots.

Green mold caused by Penicillium digitatum is a major post-harvest disease in citrus fruits. Therefore, the search for sustainable and low-environmental-impact alternatives for the management of these fungi is of utmost importance. Physalis peruviana L. is a native fruit of the Peruvian Andes with rich bioactive components present throughout the plant. Its antifungal activity stands out, attributed to its high content of phenols, coupled with its antioxidant capacity and antimicrobial activity. Plants were cultivated aeroponically under a combination of red, mixed (50% red, 50% blue), and green LED lights. Additionally, in vitro-habituated roots free of plant growth regulators were also cultivated. An ethanol extraction assisted by ultrasound for 30 min followed by maceration for 72 h was performed, and the extract was filtrated and evaporated in an extraction hood. Antioxidant activity was assessed using the DPPH method, total polyphenols were measured using the Folin-Ciocâlteu method, and an antifungal test in vitro by the poisoned food method was conducted against P. digitatum. In vitro assays revealed that extracts from leaves, roots, and fruits exerted a significant inhibitory effect on the growth of P. digitatum, as evidenced by a reduction in colony radius when cultured employing the poisoned food method, with IC50 values of 62.17, 53.15, and 286.34 µg·mL-1, respectively, compared to 2297 µg·mL-1 for the commercial fungicide Captan 50WP. Although leaves had higher total polyphenol content, no direct correlation with antifungal activity was found. Colored LEDs enhanced phenol accumulation, antioxidant capacity, and antifungal properties in plant parts compared to white LEDs and in vitro roots. These findings suggest P. peruviana as a new alternative biological production system to provide natural compounds for post-harvest disease management.

DINOV2-FCS: a model for fruit leaf disease classification and severity prediction.

The assessment of the severity of fruit disease is crucial for the optimization of fruit production. By quantifying the percentage of leaf disease, an effective approach to determining the severity of the disease is available. However, the current prediction of disease degree by machine learning methods still faces challenges, including suboptimal accuracy and limited generalizability. In light of the growing application of large model technology across a range of fields, this study draws upon the DINOV2 visual large vision model backbone network to construct the DINOV2-Fruit Leaf Classification and Segmentation Model (DINOV2-FCS), a model designed for the classification and severity prediction of diverse fruit leaf diseases. DINOV2-FCS employs the DINOv2-B (distilled) backbone feature extraction network to enhance the extraction of features from fruit disease leaf images. In fruit leaf disease classification, for the problem that leaf spots of different diseases have great similarity, we have proposed Class-Patch Feature Fusion Module (C-PFFM), which integrates the local detailed feature information of the spots and the global feature information of the class markers. For the problem that the model ignores the fine spots in the segmentation process, we propose Explicit Feature Fusion Architecture (EFFA) and Alterable Kernel Atrous Spatial Pyramid Pooling (AKASPP), which improve the segmentation effect of the model. To verify the accuracy and generalizability of the model, two sets of experiments were conducted. First, the labeled leaf disease dataset of five fruits was randomly divided. The trained model exhibited an accuracy of 99.67% in disease classification, an mIoU of 90.29%, and an accuracy of 95.68% in disease severity classification. In the generalizability experiment, four disease data sets were used for training and one for testing. The mIoU of the trained model reached 83.95%, and the accuracy of disease severity grading was 95.24%. The results demonstrate that the model exhibits superior performance compared to other state-of-the-art models and that the model has strong generalization capabilities. This study provides a new method for leaf disease classification and leaf disease severity prediction for a variety of fruits. Code is available at https://github.com/BaiChunhui2001/DINOV2-FCS.

Plum pox virus: An overview of the potyvirus behind sharka, a harmful stone fruit disease

Plum pox virus: An overview of the potyvirus behind sharka, a harmful stone fruit disease

Biocontrol yeast Kurtzmaniella quercitrusa BS-AY-S1 controls postharvest green mold of citrus fruit by producing metabolites with antifungal activity

Green mold caused by Penicillium digitatum is the leading postharvest disease in citrus fruit. While chemical fungicides are commonly used for management, yeast-based biological control strategy offers a promising and eco-friendly alternative. In this study, yeast strains were isolated from citrus orchards and the strain with the best biocontrol efficacy was screened to investigate its mechanisms for controlling postharvest green mold in citrus fruit. In total, 30 yeast strains were isolated from fruits, leaves and soil of two citrus orchards. Subsequently, 8 yeast strains tested in vivo effectively inhibited green mold in citrus fruit, with Kurtzmaniella quercitrusa BS-AY-S1 achieving the best biocontrol efficacy by reducing the disease incidence (DI) by 58.33 % and lesion diameter (LD) by 73.36 % compared to the control on the 6th day. BS-AY-S1 exhibited excellent colonization ability, laying the foundation for its biocontrol efficacy. Furthermore, the antifungal properties of BS-AY-S1 metabolites were evaluated. The fermentation supernatant of BS-AY-S1 effectively inhibited the growth of P. digitatum and controlled green mold in citrus fruit. Additionally, the volatile organic compounds (VOCs) from BS-AY-S1 markedly reduced the spore germination, spore production and mycelial growth of P. digitatum, and slowing down the progression of green mold in citrus fruit. In total, 20 VOCs, including alcohols, aldehydes, esters, ethers and ketones produced by BS-AY-S1, were identified by gas chromatography-ion mobility spectrometry (GC-IMS). In conclusion, BS-AY-S1 demonstrated potential for controlling postharvest green mold in citrus fruit, with its mechanisms of action including the ability to colonize citrus fruit wounds and produce antifungal metabolites and VOCs.

Chickpea NCR13 disulfide cross-linking variants exhibit profound differences in antifungal activity and modes of action.

Small cysteine-rich antifungal peptides with multi-site modes of action (MoA) have potential for development as biofungicides. In particular, legumes of the inverted repeat-lacking clade express a large family of nodule-specific cysteine-rich (NCR) peptides that orchestrate differentiation of nitrogen-fixing bacteria into bacteroids. These NCRs can form two or three intramolecular disulfide bonds and a subset of these peptides with high cationicity exhibits antifungal activity. However, the importance of intramolecular disulfide pairing and MoA against fungal pathogens for most of these plant peptides remains to be elucidated. Our study focused on a highly cationic chickpea NCR13, which has a net charge of +8 and contains six cysteines capable of forming three disulfide bonds. NCR13 expression in Pichia pastoris resulted in formation of two peptide folding variants, NCR13_PFV1 and NCR13_PFV2, that differed in the pairing of two out of three disulfide bonds despite having an identical amino acid sequence. The NMR structure of each PFV revealed a unique three-dimensional fold with the PFV1 structure being more compact but less dynamic. Surprisingly, PFV1 and PFV2 differed profoundly in the potency of antifungal activity against several fungal plant pathogens and their multi-faceted MoA. PFV1 showed significantly faster fungal cell-permeabilizing and cell entry capabilities as well as greater stability once inside the fungal cells. Additionally, PFV1 was more effective in binding fungal ribosomal RNA and inhibiting protein translation in vitro. Furthermore, when sprayed on pepper and tomato plants, PFV1 was more effective in reducing disease symptoms caused by Botrytis cinerea, causal agent of gray mold disease in fruits, vegetables, and flowers. In conclusion, our work highlights the significant impact of disulfide pairing on the antifungal activity and MoA of NCR13 and provides a structural framework for design of novel, potent antifungal peptides for agricultural use.

VOZ-dependent priming of salicylic acid-dependent defense against Rhizopus stolonifer by β-aminobutyric acid requires the TCP protein TCP2 in peach fruit.

Vascular plant one-zinc finger (VOZ) transcription factors (TFs) play crucial roles in plant immunity. Nevertheless, how VOZs modulate defense signaling in response to elicitor-induced resistance is not fully understood. Here, the defense elicitor β-aminobutyric acid (BABA) resulted in the visible suppression of Rhizopus rot disease of peach fruit caused by Rhizopus stolonifer. Defense priming by BABA was notably associated with increased levels of salicylic acid (SA) and SA-dependent gene expression. Data-independent acquisition proteomic analysis revealed that two VOZ proteins (PpVOZ1 and PpVOZ2) were substantially upregulated in BABA-induced resistance (BABA-IR). Furthermore, the interaction of PpVOZ1 and PpVOZ2 and their potential target of the TEOSINTE-BRANCHED1/CYCLOIDEA/PCF (TCP)-family protein PpTCP2 screened from protein-protein interaction networks was confirmed by yeast two-hybrid (Y2H), luciferase complementation imaging and glutathione S-transferase pull-down assays. Furthermore, subcellular localization, yeast one-hybrid, electrophoretic mobility shift assay and dual-luciferase reporter assays demonstrated that nuclear localization of both PpVOZ1 and PpVOZ2 was critical for their contribution to BABA-IR, as these proteins potentiated the PpTCP2-mediated transcriptional activation of isochorismate synthase genes (ICS1/2). The overexpression of both PpVOZ1 and PpVOZ2 could activate the transcription of SA-dependent genes and provide disease resistance in transgenic Arabidopsis. In contrast, the ppvoz1cas9 and ppvoz2cas9 loss-of-function mutations and the voz1cas9 voz2cas9 double mutation attenuated BABA-IR against R. stolonifer. Therefore, the three identified positive TFs, PpVOZ1, PpVOZ2, and PpTCP2, synergistically contribute to the BABA-activated priming of systemic acquired resistance in postharvest peach fruit by a VOZ-TCP-ICS regulatory module.

Simple and rapid capillarity-assisted ultra-trace detection of thiram on apple surface with a silver nanoparticles/filter paper SERS substrate.

Thiram is a readily synthesized, cost-effective antimicrobial agent widely used to control diseases in fruits and vegetables. Given the potential health hazards associated with thiram residues and advancements in detection methods, it is crucial to develop a rapid and sensitive technique for detecting these residues on fruit surfaces. Here, we prepared the Ag@filter paper (Ag@FP) surface-enhanced Raman scattering (SERS) substrate in a controlled manner and innovatively developed a capillarity-assisted SERS (CA-SERS) detection method. Sampling can be completed in less than 1 min by either wiping or using the CA-SERS method. Utilizing a portable Raman device, the detection limit for thiram residues on apple surfaces can reach as low as 0.005 ng/cm2 with the CA-SERS detection method. Furthermore, the substrate is cost-effective, can be prepared in just 7 min, and remains stable at room temperature for up to 40 days. Additionally, we developed a cost-effective, centimeter-scale auxiliary detection device to facilitate efficient on-site detection.

Postharvest Immersion in Slightly Acidic Electrolyzed Water Improves Guava Storability by Regulating Phenylpropane Metabolism.

Postharvest guava fruit are at high risk of decay and spoilage, which extremely restrains the further advancement of guava industry in China. Currently, slightly acidic electrolyzed water (SAEW) has been shown to be potent in maintaining the storability of fruits and vegetables. Accordingly, this work was designed to figure out the effectiveness of SAEW on storability maintenance in postharvest guavas via regulating the phenylpropane metabolism. On the harvest day, fresh guavas were immersed in distilled water or SAEW (available chlorine concentration: 30 mg L-1) for 10 min, followed by storage for 15 d (25 °C, 80% RH). Results showed that, in comparation with the control guavas, SAEW-treated guavas exhibited lower levels of fruit disease index, malondialdehyde, and cell membrane permeability, while showing higher levels of fruit firmness and commercially acceptable fruit rate, as evidenced by enhanced contents of titratable acid, total soluble solids, vitamin C, total soluble sugar, and reducing sugar. Moreover, SAEW treatment improved the activities of disease-resistance enzymes and the contents of sinapic acid, p-coumaric acid, ferulic acid, caffeic acid, and lignin. The above data revealed that SAEW treatment-enhanced storability of guavas was attributed to the increased disease-resistance enzyme activities and disease-resistance substance contents, which improved the fruit disease resistance and slowed down the disease occurrence.

Impact of GRAS compounds applied by ultrasonic nebulization on decay control and quality parameters in Persian lime.

The application of generally recognized as safe (GRAS) substances for postharvest fungal control of fruit is an alternative to the conventional use of synthetic fungicides. In this study, two GRAS compounds were applied by ultrasonic nebulization (USN) to lime fruit for the control of Penicillium italicum, the cause of blue mold. Lime fruits were treated with sodium bicarbonate (1, 2, 3% w/v), acetic acid (0.5, 1, 1.5% w/v) and sterile distilled water by USN for 5, 10-15min. The effect of the USN treatments was evaluated in vitro, selecting the agent with the best effect. In vivo, the incidence and severity of blue mold disease and lime fruit quality parameters were evaluated. Although sodium bicarbonate inhibited P. italicum in vitro tests, USN treatments with acetic acid significantly inhibited 75.4% of mycelial growth and 100% of P. italicum germination. USN treatments (1% and 1.5% acetic acid) reduced disease incidence and severity (preventive and curative tests) on fruit stored at 25°C; however, at 15°C there was no significant difference with respect to USN of sterile distilled water. Lime quality parameters were not adversely affected by USN treatments with acetic acid. The application of 1 or 1.5% acetic acid by USN appears to be a promising option for the control of blue mold disease in Persian lime fruits.

Functionalized chalcogenide thin films for early detection of plant diseases via spore detection

This study investigates the functionalization of Ge-Se-Te chalcogenide thin films using various organosilane precursors, including TEOS, OTES, APTES, ImPTES and MPTMS, to render them more hydrophilic or hydrophobic, or impart surface charges. The integrity of the deposited hybrid layers was confirmed by proton Nuclear Magnetic Resonance spectroscopy after alkaline depolymerization of test samples. The modified surfaces were characterized by Water Contact Angle measurements, Scanning Electron Microscopy and Atomic Force Microscopy. The ability of these functionalized surfaces to immobilize individual or mixed spores of two different varieties, Venturia inaequalis and Penicillium expansum, both responsible for fruit tree diseases, was evaluated. The two spore varieties behaved similarly, whether alone or mixed. Neither spore variety adhered to very hydrophilic surfaces. While the percentage of immobilized Venturia inaequalis spores increased with the surface hydrophobicity, Penicillium expansum spores were not immobilized on highly hydrophobic surfaces. Venturia inaequalis spores, characterized by a very negative zeta potential, were very well immobilized on positively charged surfaces. Consequently, the best immobilization percentage for this spore variety was obtained for the surface functionalized with ImPTES, a precursor characterized by a stable positive charge of imidazolium group. Penicillium expansum spores were less sensitive to positive charges due to their less negative zeta potential. The highest immobilization percentage for this spore variety was obtained with the precursor TEOS. One explanation could be the formation of hydrogen bonds.

Antifungal efficacy and biofumigation potential of hydrophobic deep eutectic solvents: Postharvest treatment against Monilinia fructicola and Botrytis Cinerea.

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.

Effects of Perillaldehyde and Polyamines on Defense Mechanisms of Sweet Potatoes against Ceratocystis fimbriata.

Sweet potato (Ipomoea batatas) serves as a significant food and economic crop worldwide. However, its production and safety are jeopardized by black rot, a disease caused by Ceratocystis fimbriata. Although polyamines (PAs) are common biological growth factors, their function in the storage of fruits and vegetables remains poorly understood. This study examines the physiological roles of both exogenous and endogenous PAs in C. fimbriata, particularly their metabolism via gene knockout techniques. Additionally, we assessed how exogenous PAs affect sweet potato storage resistance. Our findings reveal that PAs are crucial in managing oxidative and cell wall stress in C. fimbriata. At high concentrations, PAs displayed cytotoxic effects through the upregulation of nitric oxide synthase (TAH18). Furthermore, exogenous PAs significantly enhanced the defense mechanisms of sweet potatoes during storage. The concurrent use of perillaldehyde (PAE), a natural antibacterial compound, additionally decreased the incidence of black rot in sweet potatoes. This study provides a novel strategy and theoretical basis for the prevention and control of fungal diseases in stored fruits and vegetables.