Morchella esculenta, a highly valuable edible fungus, is severely threatened by stipe rot disease (SRD). Current limitations in rapid pathogen detection and overreliance on chemical fungicides necessitate integrated and sustainable management strategies. In this study, a total of 42 isolates were obtained by tissue isolation from 96 diseased plants with typical SRD symptoms. Morphological observation and multigene phylogenetic analysis confirmed Fusarium solani as the dominant SRD pathogen in Guizhou (China), with Epicoccum sorghinum identified as a novel pathogen. This was the first documented instance of E. sorghinum causing SRD in M. esculenta. To enable early detection of F. solani, a rapid visual loop-mediated isothermal amplification (LAMP) assay targeting the TEF-1 alpha gene was developed. This method demonstrated high specificity, achieved a detection limit of 5 fg/mu L (10,000 & times; more sensitive than PCR), and successfully identified F. solani infections 28 d before the M. esculenta fruiting body. For sustainable disease control, carvacrol was nanoencapsulated in polydopamine-coated, aminofunctionalized hollow mesoporous silica (CV@AHMS-PDA), achieving 21.68% loading. The CV@AHMS-PDA formulation significantly enhanced antifungal activity (EC50 = 12.03 mu g/mL) by disrupting fungal cell membrane integrity and exhibited temperature-dependent release. Field trials demonstrated that the combination of LAMP-based early warning and CV@AHMS-PDA application achieved a control efficacy of 94.97% against SRD and increased M. esculenta yield by 42.62%. This study provides an effective integrated strategy for sustainable SRD management.

Understanding the insecticide resistance mechanisms and their underlying regulatory pathways is essential for pest management. Previous findings indicated that the overexpression of P450 gene, CYP6ER1, was a key mechanism for sulfoxaflor metabolic resistance in Nilaparvata lugens. However, it remains unclear whether quantitative changes in the target nicotinic acetylcholine receptors (nAChRs) contribute to sulfoxaflor resistance and the underlying regulatory mechanisms involved. Here, qRT-PCR, pairwise correlation analyses and RNAi confirmed that the down-regulation of Nlα4, along with the up-regulation of Nlα10 and Nlβ1, were linked to sulfoxaflor resistance in N. lugens. Four microRNAs, novel-m0262-5p, novel-m0071-3p and novel-m0196-3p, and miR-10471-x were found to target CYP6ER1, Nlα4 and Nlβ1, respectively. Subsequently, the binding activity between these miRNAs and their target genes was verified by dual fluorescence in vitro. Over-supplementation of novel-m0262-5p and miR-10471-x via miRNA agomir injections suppressed the expression of CYP6ER1 and Nlβ1, and decreased nymph resistance to sulfoxaflor. Conversely, novel-m0262-5p and miR-10471-x antagomirs treatment induced the expression of CYP6ER1 and Nlβ1, thereby enhancing sulfoxaflor resistance. Additionally, overexpression of novel-m0071-3p and novel-m0196-3p inhibited Nlα4 expression and increased sulfoxaflor resistance. These findings indicate that miRNAs regulate the differential expression of P450s and nAChRs, mediating both metabolic and target resistance to sulfoxaflor in N. lugens.

Rice false smut, caused by the fungal pathogen Ustilaginoidea virens, poses a significant threat to rice production worldwide. This study aimed to identify the specific target proteins and binding sites of anisaldehyde in U. virens and to elucidate the molecular mechanisms underlying its antifungal activity. In this study, a combination of electron microscopy techniques, integrated transcriptomic and metabolomic analyses, and molecular docking simulations was employed to investigate the effects of anisaldehyde on U. virens. Anisaldehyde significantly inhibited the mycelial growth of U. virens, with a median effective inhibitory concentration (EC₅₀) of 11.18 μg/mL. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations revealed that anisaldehyde treatment led to morphological abnormalities in the mycelia of U. virens, including wrinkles, twisting, and a rough surface, along with an increased number of lipid droplets and enhanced cell membrane permeability. Integrated transcriptomic and metabolomic analyses demonstrated that anisaldehyde significantly affected the glycerophospholipid metabolism pathway. Molecular docking results indicated that anisaldehyde could stably bind to the UV8b_03588 protein. Molecular dynamics simulations further confirmed that anisaldehyde bound to the UV8b_03588 protein with high affinity, and the protein conformation remained stable after binding without any significant conformational changes. The UV8b_03588 protein of U. virens, as a potential target, and the inhibition of its function may be key mechanism underlying the antifungal activity of anisaldehyde. This study provides a theoretical basis for the development of novel plant-derived antifungal agents and offers new insights into the control of rice false smut.

The enhanced detoxification capacity caused by the induction or constitutive overexpression of metabolic enzyme genes has complicated sustainable and efficient pest control strategies. This study clarified the detoxification effects of two P450 genes, CYP4CE3 and CYP6FJ3, on multiple insecticides in Sogatella furcifera. The chimeric double-stranded RNA (ch-dsRNA) of these two genes was obtained by using the L4440-HT1115 (DE3) RNase III- system, and the RNA interference (RNAi) effectiveness of ch-dsRNA was verified by microinjection. MON-NH2 was subsequently used to deliver dsRNA as a synergist (MON-NH2@ch-dsRNA) to effectively protect dsRNA from nuclease degradation and stably inhibit CYP4CE3 and CYP6FJ3 expression through insect sap-feeding. Compared with the single insecticide application, the addition of MON-NH2@ch-dsRNA led to an increase in the mortality rates of imidacloprid, clothianidin, dinotefuran, and sulfoxaflor by 22.22-38.90%, with the synergistic enhancement of nitenpyram, yielding a ratio of 1.90-fold. Moreover, the field experiment results revealed that the control effect of nitenpyram was significantly improved by 14.53 and 10.30% on days 3 and 7, respectively, following the application of MON-NH2@ch-dsRNA. Therefore, MON-NH2@ch-dsRNA can be used as a nucleic acid nanosynergist with a broad-spectrum synergistic effect on insecticides in controlling S. furcifera.

BACKGROUND:Sulfoximine insecticide sulfoxaflor acts on insect nicotinic acetylcholine receptors (nAChRs). Metabolic resistance arising from increased activity of detoxification enzymes has been extensively documented in insect populations. Prior research by the present authors demonstrated the involvement of cytochrome P450 monooxygenases in mediating metabolic resistance to sulfoxaflor in Nilaparvata lugens. Nevertheless, investigations into the target-site resistance mechanisms of insects to sulfoxaflor remain limited. RESULTS:The coding sequence (CDS) of 13 nAChR subunits in N. lugens of sulfoxaflor-susceptible (SFX-S) and sulfoxaflor-resistant (SFX-R) strains were cloned. A 'TGAC' insertion mutation at position 1428-1431 of the Nlα4 CDS was identified in the SFX-R strain. Genotyping revealed that 60% of individuals in the SFX-R strain carried the homozygous mutation, while 40% were heterozygous. Additionally, a homozygous mutant (Nlα4-M) strain was established for further investigation. Compared with the SFX-S [median lethal concentration (LC50) = 3.32 mg/L] strain, the expression levels of Nlα4 in the SFX-R (LC50 = 505.64 mg/L) and Nlα4-M (LC50 = 352.72 mg/L) strains were significantly down-regulated by 83.02% and 46.38%, respectively. Genetic linkage analysis confirmed a co-segregation of the Nlα4 mutation and its reduced expression with sulfoxaflor resistance in N. lugens. Furthermore, RNA interference (RNAi) targeting Nlα4 expression in both the SFX-S and Nlα4-M strains significantly decreased susceptibility to sulfoxaflor. CONCLUSION:The results indicate that both the insertion mutation and low expression of the Nlα4 subunit are strongly associated with sulfoxaflor resistance in N. lugens. The present study offers valuable theoretical insights for the rational design of novel insecticides and the effective management of insecticide resistance in N. lugens. © 2025 Society of Chemical Industry.

The resistance risk and mechanisms of propiconazole in Rhizoctonia solani remain unclear. In this study, the sensitivity of 159 R. solani isolates to propiconazole was determined, and the EC50 value was 0.2286 μg/mL. Nineteen propiconazole-resistant mutants of R. solani were obtained through fungicide adaptation, and the compound fitness indexes of these propiconazole-resistant mutants were lower than those of their parental isolates. Cross-resistance analysis revealed that there was no cross-resistance between propiconazole and other fungicides, apart from prochloraz. Although no point mutations occurred in the RsCYP51 gene or its promoter regions, the expression levels of RsCYP51 and efflux transporter genes increased substantially in the propiconazole-resistant mutants. Furthermore, a 1:1 synergistic combination of propiconazole and kresoxim-methyl (SCpk(1:1)) could simultaneously cause more severe damage to both cell membrane integrity and mitochondrial function. Field trials demonstrated that SCpk(1:1) achieved over 86% control efficacy against rice sheath blight applied at 120 g a.i./ha.

Citral (C10H16O), an acyclic monoterpene compound widely present in the essential oils of plants such as Litsea cubeba and Cymbopogon citratus, exhibits excellent potential as a green pesticide alternative in the field of sustainable crop protection due to its broad-spectrum biological activities (insecticidal, antimicrobial, and herbicidal) and prominent environmental safety (no genotoxicity, low ecological accumulation risk). This review systematically summarizes the plant resource distribution, extraction processes, biosynthetic synthesis pathway, and chemical preparation of citral; elaborates on the innovative findings in agricultural pest control as well as postharvest preservation, and summarizes the mechanisms of action against agricultural pests; and discusses the research progress in overcoming application bottlenecks such as high volatility and instability through structural modification and functional optimization strategies. The purpose of this review is to provide a solid scientific foundation and important reference for the research and development of citral-based green pesticides.

Citral, an organic compound found in lemongrass (Cymbopogon citratus) oil and Litsea cubeba essential oil, has been reported to exhibit notable antifungal activity against Magnaporthe oryzae (M. oryzae), the pathogen of rice blast, which causes significant economic losses in rice production. However, the role of citral in inducing oxidative stress related to antifungal ability and its underlying regulatory networks in M. oryzae remain unclear. In this study, we investigated the oxidative effects of citral on M. oryzae and conducted transcriptomic and widely targeted metabolomic (WTM) analyses on the mycelia. The results showed that citral induced superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) activities but reduced glutathione S-transferase (GST) activity with 25% maximal effective concentration (EC25) and 75% maximal effective concentration (EC75). Importantly, citral at EC75 reduced the activities of mitochondrial respiratory chain complex I, complex III and ATP content, while increasing the activity of mitochondrial respiratory chain complex II. In addition, citral triggered a burst of reactive oxygen species (ROS) and a loss of mitochondrial membrane potential (MMP) through the observation of fluorescence. Furthermore, RNA-seq analysis and metabolomics analysis identified a total of 466 differentially expression genes (DEGs) and 32 differential metabolites (DAMs) after the mycelia were treated with citral. The following multi-omics analysis revealed that the metabolic pathways centered on AsA, GSH and melatonin were obviously suppressed by citral, indicating a disrupted redox equilibrium in the cell. These findings provide further evidences supporting the antifungal activity of citral and offer new insights into the response of M. oryzae under oxidative stress induced by citral.

The soil microbiome plays an important role in wetland ecosystem services and functions. However, the impact of soil hydrological conditions on wetland microorganisms is not well understood. This study investigated the effects of wetted state (WS); wetting–drying state (WDS); and dried state (DS) on the diversity of soil bacteria, fungi, and archaea. The Shannon index of bacterial diversity was not significantly different in various flooding conditions (p > 0.05), however, fungal diversity and archaeal communities were significantly different in different flooding conditions (p < 0.05). Significant differences were found in the beta diversity of bacterial, fungal, and archaeal communities (p < 0.05). Additionally, the composition of bacteria, fungi, and archaea varied. Bacteria were predominantly composed of Proteobacteria and Actinobacteria, fungi mainly consisted of Ascomycota and Mucoromycota, and archaea were primarily represented by Crenarchaeota and Euryarchaeota. Bacteria exhibited correlations with vegetation coverage, fungi with plant diversity, and archaea with aboveground vegetation biomass. The pH influenced bacterial and archaeal communities, while soil bulk density, moisture, soil carbon, soil nitrogen, and plant community diversity impacted fungal communities. This study provides a scientific basis for understanding the effects of different hydrological conditions on microbial communities in the Huihe Nature Reserve; highlighting their relationship with vegetation and soil properties, and offers insights for the ecological protection of the Huihe wetland.

The soft rot disease caused by Fusarium oxysporum leads to a significant reduction in the yield of Dendrobium officinale. However, research into the synergistic inhibitory effect of essential oils in D. officinale is extremely limited. In this study, we systematically investigated the direct and indirect inhibitory activity of carvacrol, citral and their combination against F. oxysporum, and their synergistic inhibitory mechanism. Carvacrol and citral exhibited significant direct and indirect inhibitory activity against F. oxysporum with EC50 values of 54.37 mg/L and 119.32 mg/L (direct), 18.01 μL/(L•air) and 48.70 μL/(L•air) (indirect). Synergistic analysis revealed that the optimal synergistic toxicity of carvacrol and citral combination (Ca•Ci) against F. oxysporum was 10:1, with co-toxicity coefficient (CTC) of 131.57 and EC50 value of 44.24 mg/L. Microscopy confirmed that the Ca•Ci led to more significant tip constriction, uneven surfaces and serious rupture of F. oxysporum mycelia than single compound. Transmission electron microscopy (TEM) showed that Ca•Ci also caused significant ultrastructural alterations to F. oxysporum, manifesting as cytoplasmic disorganization and partial organellar disintegration. Moreover, Ca•Ci dramatically increased the sensitivity of F. oxysporum to calcofluor white compared with a single compound. Ca•Ci also considerably upregulated the expression of chitinase-related gene (FOXG_12882) and β-1,3-glucanase-related gene (FOXG_10637) in F. oxysporum, resulting in higher chitinase and β-1,3-glucanase activity. However, it should be noted that carvacrol exerted a greater contribution than citral. In conclusion, the combination of carvacrol and citral greatly disrupted the cell wall integrity of F. oxysporum, thereby exhibiting a synergistic effect.

Dendrobium officinale soft rot is a widespread and destructive disease caused by Fusarium oxysporum that can seriously affect yield and quality. To better understand the fungal infection and colonization, we successfully created an F. oxysporum labeled with green fluorescent protein using the Agrobacterium tumefaciens-mediated transformation method. Transformants had varying fluorescence intensities, but their pathogenicity did not differ from that of the wild type. Fluorescence microscopy revealed that F. oxysporum primarily entered the aboveground portion of D. officinale through the leaf margin, stomata, or by direct penetration of the leaf surface. It then colonized the mesophyll and spread along its vascular bundles. D. officinale exhibited typical symptoms of decay and wilting at 14 days postinoculation, accompanied by a pronounced fluorescence signal in the affected area. The initial colonization of F. oxysporum in the subterranean region primarily involved attachment to the root hair and epidermis, which progressed to the medullary vascular bundle. At 14 days postinoculation, the root vascular bundles of D. officinale exhibited significant colonization by F. oxysporum. Macroconidia were also observed in black rot D. officinale tissue. In particular, the entire root was surrounded by a significant number of chlamydospore-producing F. oxysporum mycelia at 28 days postinoculation. This approach allowed for the visualization of the complete infection process of F. oxysporum and provided a theoretical foundation for the development of field control strategies.

BACKGROUND: Owing to their surface modifiability, smart mesoporous silica nanoparticles (MSNs) can be designed to respond to plant disease-microenvironmental stimuli, thereby achieving on-demand release of active ingredients to control disease by effectively improving citral (CT) stability. RESULTS: A pH/chitinase dual stimuli-responsive essential oil-delivery system (CT@HMS@CH/TA) was successfully fabricated by encapsulating CT in hollow mesoporous silica (HMS), and coating with tannic acid (TA) and chitosan (CH) within HMS by using the layer-by-layer assembly technique (LbL). CT@HMS@CH/TA with an average particle size of 125.12 +/- 0.12 nm and a hollow mesoporous nanostructure showed high CT-loading efficiency (16.58% +/- 0.17%). The photodegradation rate of CT@HMS@CH/TA under UV irradiation (48 h) was only 15.31%, indicating a 3.34-fold UV stability improvement. CT@HMS@CH/TA exhibited a higher CT release rate in response to acidic pH and the presence of chitinase, simulating the prevailing conditions as Magnaporthe oryzae infection. Furthermore, CT@HMS@CH/TA exhibited better adhesion without affecting normal rice growth, significantly upregulating chitinase gene expression and enhancing chitinase activity on M. oryzae, thus enhancing CT antifungal activity. CONCLUSION: CT@HMS@CH/TA improved CT stability and showed intelligent, controlled release-performance and higher antifungal efficacy, thus providing a new strategy for efficient application of essential oils for green control of rice blast disease. (c) 2024 Society of Chemical Industry.

BACKGROUNDHexaconazole, thifluzamide, difenoconazole and azoxystrobin are widely used fungicides for the control of Rhizoctonia solani in China. However, few studies have assessed the sensitivity and resistance risk of R. solani to these four fungicides. RESULTSThe sensitivities of 126 R. solani isolates to hexaconazole, thifluzamide, difenoconazole and azoxystrobin were determined, with average half maximal effective concentration (EC50) values of 0.0386, 0.0659, 0.663 and 1.508 mu g mL-1, respectively. Field resistance monitoring of the four fungicides showed that the three isolates had moderate resistance to difenoconazole. Resistant mutants to the four fungicides were obtained by fungicide adaptation, and resistance could be stably inherited by most mutants. Compared with those of the parent isolates, the biological characteristics of hexaconazole-resistant mutants exhibited enhanced or similar compound fitness index (CFI), whereas most of the other mutants displayed reduced or comparable CFI. There was evidence of positive cross-resistance between hexaconazole and difenoconazole. In the presence of fungicides, the expression of the CYP51 genes in hexaconazole- and difenoconazole-resistant mutants significantly increased, the expression of SDH genes in thifluzamide-resistant mutants significantly decreased, and the expression of the Cyt b gene in azoxystrobin-resistant mutants did not significantly change. CONCLUSIONBased on these data, we speculated that R. solani had a low-to-medium resistance risk to four fungicides. The change of target gene expression may be one of the reasons for fungicide resistance in R. solani. This study provides a theoretical basis for monitoring resistance emergence and developing resistance management strategies to control R. solani. (c) 2024 Society of Chemical Industry.

This study aims to determine the effects of the natural product aloesin against Magnaporthe oryzae. The results exposed that aloesin had a high inhibitory effect on appressorium formation (the EC50 value was 175.26 μg/mL). Microscopic examination revealed that 92.30 ± 4.26% of M. oryzae spores could be broken down by 625.00 μg/mL of aloesin, and the formation rate of appressoria was 4.74 ± 1.00% after 12 h. M. oryzae mycelial growth was weaker than that on the control. The enzyme activity analysis results indicated that aloesin inhibited the activities of polyketolase (PKS), laccase (LAC), and chain-shortening catalytic enzyme (Aayg1), which are key enzymes in melanin synthesis. The inhibition rate by aloesin of PKS, LAC, and Aayg1 activity was 32.51%, 33.04%, and 43.38%, respectively. The proteomic analysis showed that actin expression was downregulated at 175.62 μg/mL of aloesin, which could reduce actin bundle formation and prevent the polar growth of hyphae in M. oryzae. This is the first report showing that aloesin effectively inhibits conidia morphology and appressorium formation in M. oryzae.

To find a precise, efficient, and safe method to control rice sheath blight disease (caused by Rhizoctonia solani), this study used the natural product magnolol as the fungicide. Based on the characteristics of cell wall-degrading enzymes (CWDEs) released by R. solani during the early stages of infection, a Mag@CMCS@CPSG (magnolol@carboxymethyl chitosan@carboxymethyl cellulose, pectin, sodium alginate, and glycerol) film was constructed to control the release of magnolol in response to CWDEs. The Mag@CMCS@CPSG film increased magnolol toxicity against R. solani, decreased EC50 from 7.33 μg/mL to 4.37 μg/mL, and effectively blocked the invasion of mycelia. Under the stimulation of CWDEs released during R. solani infection, the cumulative release of magnolol by the Mag@CMCS@CPSG film reached 75.62% after 96 h, and the disease index of rice treated with Mag@CMCS@CPSG film significantly decreased. The maximum field control effect of Mag@CMCS@CPSG film on rice sheath blight disease was 72.47%, which was not significantly different from that of the commercial preparation jinggangmycin; however, the holding period was better. The Mag@CMCS@CPSG film reduced the loss of rice yield and quality caused by infection with R. solani and did not cause phytotoxicity or residue. In conclusion, the Mag@CMCS@CPSG film can achieve accurate and green control of rice sheath blight.

Smart metal-organic framework nanocarriers that respond to microenvironmental stimuli related to plant diseases can achieve the on-demand release of active ingredients to control diseases. The plant essential oil citral (CT) has significant biological activity against most pathogens but its poor stability limits its application in the field. To improve the applicability of plant essential oils, we aimed to construct a pH responsive essential oil delivery system (CT@ZIF-8) based on the zeolitic imidazolate framework-8 in this study. The high specific surface area of ZIF-8 enables CT@ZIF-8 remarkable loading capacity, and the metal-organic framework effectively delays the volatilization of CT. The results showed that CT@ZIF-8 was approximately 177 nm in size, had a stable nanostructure, and displayed a high pesticide loading efficiency (15.22%). The photodegradation rate of CT loaded in ZIF-8 under UV irradiation (48 h) was only 17.99%, much lower than that of CT alone (51.18%). The CT@ZIF-8 had a pH-responsive controlled release property, releasing CT from CT@ZIF-8 in a pH-dependent manner. The bioactivity results showed that CT@ZIF-8 had a lower EC50 than CT against three fungi (Magnaporthe oryzae, Botryosphaeria dothidea, and Fusarium oxysporum), enhancing the antifungal activity of CT. After 3 d of reagent treatment, only CT@ZIF-8 maintained good control against rice blast (75.76%) and soft rot (63.69%) infection. We have constructed a smart delivery system for essential oils, which provides a new pathway for the efficient application of plant-derived essential oils in the green control of plant diseases.

采用菌丝生长速率法测定了 3种中药乙醇提取物对猕猴桃葡萄座腔菌(Botryosphaeria dothidea)的毒力以及联合作用.结果表明:苦参、丹参以及黄岑片3种乙醇提取物对B.dothidea菌丝生长均有一定的抑制作用,其EC50分别为60.44、60.78和97.86 μg/mL.苦参和丹参提取物以有效质量比为1∶1、1∶3、1∶6时对猕猴桃B.dothidea均表现为增效作用,其CTC分别为133.16、126.16和129.56;而黄岑片·苦参、黄岑片·丹参的提取物复配则均表现为相加作用,其CTC为80.71～117.62.该研究结果可为防治猕猴桃软腐病的药剂组合提供参考.

Rice false smut, caused by the fungus Ustilaginoidea virens, is a destructive grain disease in rice-producing areas worldwide. To reveal the action mechanism of osthole against U. virens, the mycelial morphology, differential genes and metabolites of osthole-treated U. virens were determined using electron microscopy and multi-omics, respectively. The hyphae of osthole-treated U. virens were severely wrinkled and distorted with rough cell walls, uneven thickness, and protoplast aggregation. Calcium fluorescent white staining showed that osthole affected chitin synthesis in U. virens. The differential genes and metabolites in U. virens were significantly enriched in amino sugar and nucleotide sugar metabolism pathway. The expression of the acetylglucosamine phosphate mutase (AGM) gene (UvAGM1) and UDP-N-acetylglucosamine was significantly down regulated. The AGM of osthole-treated U. virens was 133.43 ng/mL, which was significantly lower than that of the control group (205.67 ng/mL). Osthole combined with the amino acid residue THR334 of AGM via hydrogen bonding. These results indicate that UvAGM1 may be a key candidate gene of osthole against U. virens. Overall, the results provide valuable information for the application of osthole to control rice false smut.

Dendrobium officinale Kimura et Migo is a traditional Chinese herbal medicinal plant. However, the frequent occurrence of soft rot disease (SRD) is one of the most harmful diseases in D. officinale production in recent years, which can seriously affect its yield and quality. In this study, the major pathogenic fungus (SR-1) was isolated from D. officinale with typical symptoms of SRD, and was identified as Fusarium oxysporum through morphological and molecular identification. The biological activities of five natural products were determined against F. oxysporum using a mycelial growth inhibition assay. The results showed that osthole had the highest antifungal activity against F. oxysporum, with an EC50 value of 6.40 mg/L. Scanning electron microscopy (SEM) showed that osthole caused F. oxysporum mycelia to shrink and deform. Transmission electron microscopy (TEM) showed that the organelles were blurred and the cell wall was thickened in the presence of osthole. The sensitivity of F. oxysporum to calcofluor white (CFW) staining was significantly enhanced by osthole. Relative conductivity measurements and propidium iodide (PI) observation revealed that osthole had no significant effect on the cell membrane. Further experiments showed that the activity of chitinase and β-1,3-glucanase were decreased, and expression levels of chitinase and β-1,3-glucanase related genes were significantly down-regulated after treatment with osthole. In conclusion, osthole disrupted the cell wall integrity and dynamic balance of F. oxysporum, thereby inhibiting normal mycelial growth.

Magnolol is a natural compound extracted from the traditional Chinese medicine Magnolia officinalis, which exhibits antimicrobial properties. However, magnolol is insoluble in water and consists of a phenolic hydroxyl group, which is volatile; these factors hinder its application. In this study, a safe and environmentally friendly method to improve the microbial resistance and storability of harvested fruits is developed using the water-soluble carrier carboxymethyl chitosan (CMCS) and magnolol. Magnolol was loaded on CMCS particles to form Magnolol@CMCS antimicrobial particles, a preservation coating agent. Magnolol@CMCS particles effectively solved the problems of water insolubility and agglomeration of magnolol and reduced the size distribution D50 value of magnolol from 0.749 to 0.213 μm. Magnolol@CMCS particles showed greater toxicity against Staphylococcus aureus, Escherichia coli, and Botryosphaeria dothidea than that of magnolol alone, with effective medium concentration (EC50) values of 0.9408, 142.4144, and 8.8028 μg/mL, respectively. Kiwifruit treated with the Magnolol@CMCS solution showed delayed changes in fruit hardness and soluble solid and dry matter contents and significantly higher ascorbic acid (vitamin C) and soluble total sugar contents and sugar:acid ratios compared with that of the control fruit. In addition, no disease spots were observed on fruit treated with the Magnolol@CMCS solution within 7 days after inoculation with B. dothidea. In conclusion, Magnolol@CMCS particles showed antimicrobial activity on harvested fruits, effectively delayed the hardness and nutritional changes of fruits during storage, and improved the storability of kiwifruit.