Pesticide Biochemistry and Physiology最新文献

{"title":"9-Methylstreptimidone: A novel promising fungicide disrupting material metabolism and energy synthesis in Colletotrichum orbiculare","authors":"Wenshuai Song ,&nbsp;Jingzheng Sun ,&nbsp;Haifeng Zhang ,&nbsp;Han Wang ,&nbsp;Lifeng Guo ,&nbsp;Xiaoya Fan ,&nbsp;Xi Xu ,&nbsp;Kun Zhang ,&nbsp;Hongbo Pang ,&nbsp;Xiangjing Wang ,&nbsp;Junwei Zhao ,&nbsp;Wensheng Xiang","doi":"10.1016/j.pestbp.2025.106683","DOIUrl":"10.1016/j.pestbp.2025.106683","url":null,"abstract":"<div><div>Cucumber anthracnose caused by <em>Colletotrichum orbiculare</em> is one of the most critical diseases affecting cucurbit crops. Traditional chemical controls mitigate the disease but raise environmental and residue concerns, highlighting the need for eco-friendly alternatives. In this study, three glutarimide compounds were isolated from strain NEAU-S77, identified as a member of the genus <em>Streptomyces</em>, including the active compound 9-methylstreptimidone and two known analogs. 9-Methylstreptimidone exhibited strong antifungal activity against <em>C. orbiculare</em>, with an EC₅₀ of 1.09 μg/mL, outperforming the commercial fungicide Duofu (EC₅₀ = 4.12 μg/mL). Microscopic and biochemical analyses revealed that treatment with 9-methylstreptimidone caused abnormalities in mycelial and cellular structures, compromised cell wall integrity, and disrupted cellular redox equilibrium. Pot experiments showed higher control efficacy against cucumber anthracnose at 2 × and 4 × EC₅₀ (76.9 % and 87.6 %) than Duofu (70.2 % and 80.0 %). Transcriptomic analysis revealed that 9-methylstreptimidone predominantly interfered with the citrate cycle, oxidative phosphorylation, and peroxisome biogenesis. These findings elucidate the antifungal mechanism of 9-methylstreptomycin and underscore its potential as a sustainable fungicidal agent for managing cucumber anthracnose.</div></div>","PeriodicalId":19828,"journal":{"name":"Pesticide Biochemistry and Physiology","volume":"215 ","pages":"Article 106683"},"PeriodicalIF":4.0,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145019619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Functional analysis of the regulation of beta-cypermethrin resistance by Deg-CYP-3 in Dermanyssus gallinae","authors":"Jing Liu,&nbsp;Zhengjie Wang,&nbsp;Shuo Yin,&nbsp;Zhonghao Wang,&nbsp;Meng Wu,&nbsp;Jianhua Qin,&nbsp;Junlong Liu,&nbsp;Chuanwen Wang","doi":"10.1016/j.pestbp.2025.106682","DOIUrl":"10.1016/j.pestbp.2025.106682","url":null,"abstract":"<div><div><em>Dermanyssus gallinae</em> is a significant haematophagous ectoparasite of laying hens. Despite the worldwide application of beta-cypermethrin for mite control, resistance to this compound has been developed by <em>D. gallinae</em>. P450s, as key detoxification enzymes involved in the metabolism of exogenous and endogenous chemical substances, have not been functionally characterized in <em>D. gallinae</em>. Here, the role of the P450s gene (Deg-CYP-3) of <em>D. gallinae</em> in acaricide resistance was studied. Firstly, P450s activities of the five beta-cypermethrin resistant strains (RR) against p-nitroanisole were significantly higher than that of the susceptible strain (RS), suggesting enhanced enzymatic activities might contribute to mite beta-cypermethrin resistance. Both mRNA expression level and DNA copy number of Deg-CYP-3 were significantly higher in RR than in RS, except for DK RR strain. Moreover, recombinant Deg-CYP-3 (rCYP-3) expressed in <em>Escherichia coli</em> displayed high enzymatic activity against p-nitroanisole, while Qulaton-100, acetone, isoacetone, avermectin, and ivermectin were found to inhibit this activity. Immunohistochemical analysis revealed the presence of Deg-CYP-3 protein in the digestive tract and Malpighian tubules. Finally, silencing of Deg-CYP-3 via RNAi resulted in decreased enzyme activity and increased susceptibility of PG RR strain to beta-cypermethrin, confirming that Deg-CYP-3 is crucial for beta-cypermethrin detoxification. RNAi also resulted in enhanced mortality, as well as reduced oviposition and fecundity in the PG RR strain. Collectively, these findings indicate that resistance of <em>D. gallinae</em> to beta-cypermethrin is associated with elevated P450s protein activity and increased Deg-CYP-3 expression levels. The results provide insights into the metabolic resistance mechanisms of <em>D. gallinae</em> and offer scientific guidance for the management and control of mite.</div></div>","PeriodicalId":19828,"journal":{"name":"Pesticide Biochemistry and Physiology","volume":"215 ","pages":"Article 106682"},"PeriodicalIF":4.0,"publicationDate":"2025-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145004782","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Molecular mechanism and risk assessment of Rhizoctonia solani resistance to the SDHI fungicide isopyrazam","authors":"Zelong Peng ,&nbsp;Suyu Du ,&nbsp;Jiqiang Wang ,&nbsp;Xuedong Han ,&nbsp;Furong Chen ,&nbsp;Yiping Hou","doi":"10.1016/j.pestbp.2025.106674","DOIUrl":"10.1016/j.pestbp.2025.106674","url":null,"abstract":"<div><div>Rice sheath blight is one of the three major rice diseases worldwide, and the succinate dehydrogenase inhibitor (SDHI) fungicide isopyrazam has not yet been registered for its control in China. This study investigated the sensitivity of <em>Rhizoctonia solani</em> to isopyrazam and assessed its resistance risk. Specifically, the sensitivity of 113 <em>R. solani</em> isolates to isopyrazam was evaluated, with EC₅₀ values ranging from 0.0018 to 0.0336 μg/mL and an average of 0.0101 ± 0.0064 μg/mL. Ten isopyrazam-resistant mutants were generated by ultraviolet mutagenesis, including 2 highly resistant (RF &gt; 100), 6 moderately resistant (100 &gt; RF &gt; 20), and 2 lowly resistant (20 &gt; RF &gt; 5) mutants. Fitness assays showed that resistant mutants had significantly reduced mycelial growth and pathogenicity. Positive cross-resistance was observed between isopyrazam and thifluzamide, but no cross-resistance was detected with non-SDHI fungicides. Sequence alignment of the SDH protein indicated that the H249L mutation in the SDHB contributed to moderate resistance, while the I78F mutation in the SDHC was associated with moderate to high levels of resistance. Notably, the SDHC-I78F was identified as a novel mutation site. Molecular docking indicated that these mutations reduced the binding affinity between isopyrazam and the SDH protein. Therefore, we assessed the resistance risk of <em>Rhizoctonia solani</em> to isopyrazam as ranging from low to moderate. These findings indicate that isopyrazam has potential for controlling rice sheath blight in the future.</div></div>","PeriodicalId":19828,"journal":{"name":"Pesticide Biochemistry and Physiology","volume":"215 ","pages":"Article 106674"},"PeriodicalIF":4.0,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145026564","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Trans-2-decenal inhibits Phytophthora capsici by inducing ROS accumulation and mitochondrial dysfunction","authors":"Siyuan Xie ,&nbsp;Lanning Wang ,&nbsp;Jingkun Lv ,&nbsp;Xiang Feng ,&nbsp;Siyu Li ,&nbsp;Haojie Tan ,&nbsp;Chao Wang ,&nbsp;Gang Wang ,&nbsp;Hongjun Ge ,&nbsp;Chun Xiao ,&nbsp;Danyu Shen ,&nbsp;Daolong Dou","doi":"10.1016/j.pestbp.2025.106673","DOIUrl":"10.1016/j.pestbp.2025.106673","url":null,"abstract":"<div><div><em>Phytophthora capsici</em> is a highly destructive plant-pathogenic oomycete that poses a severe threat to global agricultural production. <em>Trans</em>-2-decenal is a natural plant-derived unsaturated aliphatic aldehyde, whose antimicrobial properties against plant pathogens remain poorly understood. In this study, its inhibitory efficacy and underlying mechanisms against <em>P. capsici</em> were systematically investigated. <em>Trans</em>-2-decenal exhibited potent inhibitory activity against <em>P. capsici</em> via biofumigation, with an EC₅₀ value of 12.37 μg/mL. It not only impacted normal hyphal morphology and ultrastructure, but also inhibited sporangia formation, zoospore release, and germination in a dose-dependent manner. Calcofluor white staining showed that <em>trans</em>-2-decenal disrupted cell wall integrity. <em>Trans</em>-2-decenal treatment compromised cell membrane integrity and permeability, accompanied by DNA and soluble protein leakage. Additionally, <em>trans</em>-2-decenal triggered intracellular ROS accumulation, reduced glutathione levels, and disrupted mitochondrial membrane potential, ultimately leading to cellular dysfunction and death. <em>In planta</em> assays validated its robust control efficacy against <em>P. capsici</em> infection. Transcriptomic analysis further identified 2557 differentially expressed genes, with significant downregulation in critical metabolic pathways such as nitrogen metabolism, tyrosine metabolism and phenylalanine metabolism. Taken together, these results elucidate a multitarget inhibitory mechanism of <em>trans</em>-2-decenal against <em>P. capsici</em>, and highlight its potential as an eco-friendly agent for the sustainable management of <em>Phytophthora</em>-induced plant diseases.</div></div>","PeriodicalId":19828,"journal":{"name":"Pesticide Biochemistry and Physiology","volume":"215 ","pages":"Article 106673"},"PeriodicalIF":4.0,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144997503","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The discovery of marine natural product Streptochlorin and its inhibition of Banana fusarium wilt by targeting the GPI pathway","authors":"Xian Xiao ,&nbsp;Renwei Xu ,&nbsp;Wenjie Wu ,&nbsp;Xiaojia Zhang ,&nbsp;Yunfei Zhang ,&nbsp;Lanying Wang ,&nbsp;Yanping Luo","doi":"10.1016/j.pestbp.2025.106675","DOIUrl":"10.1016/j.pestbp.2025.106675","url":null,"abstract":"<div><div>Marine actinomycetes represent a crucial reservoir of bioactive natural products, offering significant potential for developing green strategies in plant disease control. This study took Streptomyces CH06 isolated from corals in the South China Sea as the research object and systematically analyzed the antifungal mechanism of its metabolite <strong>Streptochlorin</strong> against <em>Fusarium oxysporum</em> f. sp. <em>cubense</em> Race4 (FOC4), the causative agent of banana <em>Fusarium</em> wilt. CH06 was identified via polyphasic taxonomy. Fermentation on Gao's No. 1 medium and LC-MS/NMR analysis yielded 10 metabolites, including novel nucleoside H7 and <strong>Streptochlorin</strong> (H5). <strong>Streptochlorin</strong> inhibited 10 phytopathogens by over 70 % at 13 μg/mL, and the EC₅₀ for FOC4 is 7 μg/mL. In the pot, <strong>Streptochlorin</strong> (20 μg/mL) achieved 95.5 % control of banana Fusarium wilt, surpassing carbendazim (89.9 %). Multi-omics analysis revealed that <strong>Streptochlorin</strong> disrupts fungal cell wall integrity by specifically inhibiting the glycosylphosphatidylinositol (GPI) targeting the GPI anchorprotein biosynthesis pathway (GPI11 protein abundance decreased to 38 % of the control). Phenotypic analyses confirmed increased membrane permeability (elevated extracellular conductivity), cell wall glucan exposure (Congo red staining), and hyphal surface blurring (TEM observations). This study for the first time elucidated the molecular mechanism by which <strong>Streptochlorin</strong> suppresses phytopathogenic fungi through targeting the GPI anchor protein biosynthesis pathway, providing novel insights for developing green fungicides derived from marine microorganisms.</div></div>","PeriodicalId":19828,"journal":{"name":"Pesticide Biochemistry and Physiology","volume":"215 ","pages":"Article 106675"},"PeriodicalIF":4.0,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144997504","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Clothianidin exposure enhances fecundity in Bactrocera dorsalis via metabolic activation and endocrine modulation: implications for pest resurgence","authors":"Zhen Li ,&nbsp;Zhenya Li ,&nbsp;Yuqiang Xi ,&nbsp;Xiaolong Wang ,&nbsp;Hong Peng ,&nbsp;Shiheng An ,&nbsp;Xinming Yin","doi":"10.1016/j.pestbp.2025.106672","DOIUrl":"10.1016/j.pestbp.2025.106672","url":null,"abstract":"<div><div>Chemical insecticides have been fundamental in managing agricultural pests, yet prolonged use can cause sublethal effects that promote pest resurgence. This study investigated the effects of the neonicotinoid insecticide clothianidin on the reproduction, physiological metabolism, and population dynamics of <em>Bactrocera dorsalis</em>. Exposure to sublethal and lethal concentrations (LC₂₀ and LC₅₀) of clothianidin led to an increase in the reproductive capacity of F₀ females. Furthermore, this reproductive enhancement was transferred to the F₁ generation, especially in the LC₅₀ treatment group. Further analysis revealed that clothianidin exposure led to significant alterations in lipid and carbohydrate metabolism, with increases in glycogen and glucose levels contributing to enhanced reproductive success in the F₀ generation. This enhancement correlates with elevated levels of juvenile hormone (JH) and 20-hydroxyecdysone (20E), both of which are crucial for reproductive regulation, along with increased expression of <em>vitellogenin</em> (<em>Vg</em>) and its receptor (<em>VgR</em>). Consequently, the life parameters of the F₁ population, including fecundity (<em>f</em>_<em>x</em>), survival rate (<em>v</em>_<em>xj</em>), intrinsic growth rate (<em>r</em>), finite growth rate (<em>λ</em>), and net reproductive rate (<em>R</em>₀), exhibited significant increases. Concurrently, the average generation time (<em>T</em>) decreased, leading to an overall acceleration in population growth. These findings provide important insights into the physiological adaptations of <em>B. dorsalis</em> to clothianidin, suggesting that its use, while effective against pest populations, may lead to unintended consequences on pest resurgence, thus contributing to our understanding of the complexities involved in pest management strategies and highlights the need for careful application of insecticides to mitigate risks associated with pest resurgence.</div></div>","PeriodicalId":19828,"journal":{"name":"Pesticide Biochemistry and Physiology","volume":"215 ","pages":"Article 106672"},"PeriodicalIF":4.0,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144997501","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unveiling the functional contribution of Malpighian tubule specific glucose transporters to xenobiotics tolerance in Spodoptera litura","authors":"Long Jin ,&nbsp;Zixin Zhang ,&nbsp;Haoran Kong ,&nbsp;Chengcheng Fan ,&nbsp;Furong Mao ,&nbsp;Yiou Pan ,&nbsp;Qingli Shang","doi":"10.1016/j.pestbp.2025.106663","DOIUrl":"10.1016/j.pestbp.2025.106663","url":null,"abstract":"<div><div>Glucose transporters (GLUTs) are members of the solute carrier (SLC) family 2, which play crucial roles in various physiological processes. In this study, 108 SLC genes were identified from the transcriptomic and <em>Spodoptera litura</em> genome database (ASM270686v3), of which the GLUT genes were the focus. Transcriptome analysis and quantitative Real-time PCR (qPCR) revealed that <em>SlGLUT2</em> and <em>SlGLUT6</em> were specifically expressed in Malpighian tubules, and that their expression significantly increased after treatment with various xenobiotics. The structural features of the SlGLUT2 and SlGLUT6 proteins, as well as their glucose transport characteristics, were analyzed using homology modeling and molecular docking. Moreover, the ectopic expression of <em>SlGLUT2</em> and <em>SlGLUT6</em> in <em>Drosophila</em> led to a significant increase in the tolerance of the flies to diamide insecticides. Moreover, the knockdown of <em>SlGLUT2</em> and <em>SlGLUT6</em> expression through RNA interference (RNAi) decreased the tolerance of <em>S. litura</em> to cyantraniliprole and chlorantraniliprole. Therefore, <em>SlGLUT2</em> and <em>SlGLUT6</em> may play important roles in xenobiotic tolerance in <em>S. litura.</em></div></div>","PeriodicalId":19828,"journal":{"name":"Pesticide Biochemistry and Physiology","volume":"215 ","pages":"Article 106663"},"PeriodicalIF":4.0,"publicationDate":"2025-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144921607","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"BbCFEM7 contributes to the virulence of entomopathogenic fungi by competing for iron with Enterococcus mundtii","authors":"Yuejin Peng ,&nbsp;Xu Zhang ,&nbsp;Guang Wang ,&nbsp;Qingqing Liu ,&nbsp;Tianjiao Zhan ,&nbsp;Sicai Xu ,&nbsp;Guanli Xiao ,&nbsp;Guangzu Du ,&nbsp;Wenqian Wang ,&nbsp;Bin Chen","doi":"10.1016/j.pestbp.2025.106666","DOIUrl":"10.1016/j.pestbp.2025.106666","url":null,"abstract":"<div><div>Common in fungal extracellular membrane (CFEM) domain proteins are a unique family of extracellular membrane proteins in fungi. <em>Beauveria bassiana</em>, as a entomopathogenic fungus, plays a critical role in the biological control of agricultural and forestry pests. However, the mechanism of interaction between entomopathogenic fungi and host gut microbes is rarely reported. The contribution of the <em>BbCFEM7</em> gene to fungal growth virulence and immune defense was evaluated. According to the gut microbial diversity results, the absence of <em>BbCFEM7</em> had a considerable influence on the insect gut bacterial communities, especially enterococcus. The infection with Δ<em>BbCFEM7</em> strains significantly affected the contents of fatty acids (including short-chain fatty acids), organic acids, and indole metabolites in insect gut and hemolymph when compared to wild type strain (WT). <em>Enterococcus mundtii</em> was isolated in a fungus-infected insect hemolymph. According to in vitro and in vivo experiments, fungi and bacteria exerted an inhibitory effect on the growth of each other through rapid iron acquisition. Our study demonstrated that when <em>B. bassiana</em> infected insects, <em>BbCFEM7</em> competed for iron ions with the <em>E. mundtii</em> escaping from the gut to the hemolymph, inducing metabolic dysregulation in the gut and hemolymph, thereby evading host immunity and augmenting fungal virulence. Enriching the host infection mechanism of fungal CFEM domain proteins, the results of this study provide a new reference for supplementing the Anna Karenina Principle (AKP) and further revealing the interaction between insect gut bacteria and pathogenic fungi.</div></div>","PeriodicalId":19828,"journal":{"name":"Pesticide Biochemistry and Physiology","volume":"215 ","pages":"Article 106666"},"PeriodicalIF":4.0,"publicationDate":"2025-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144997502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bioactivity of the defensive chemicals of six millipede species in the superorder Juliformia against Solenopsis invicta Buren (Hymenoptera: Formicidae)","authors":"Delong Kong ,&nbsp;Siquan Ling ,&nbsp;Wanru Guo ,&nbsp;Eduardo G.P. Fox ,&nbsp;Jinzhu Xu ,&nbsp;Jiamei Zhong ,&nbsp;Desen Wang ,&nbsp;Hualong Qiu ,&nbsp;Weixin Liu","doi":"10.1016/j.pestbp.2025.106670","DOIUrl":"10.1016/j.pestbp.2025.106670","url":null,"abstract":"<div><div>Millipedes are known to produce a diverse array of chemical defenses against natural predators, notably ants, positioning them as a promising source of natural products useful for pest ant control. A top invasive ant species of international scale is the red imported fire ant, <em>Solenopsis invicta</em>, for which there are numerous studies surveying alternative chemicals, as traditional insecticides have not been able to stop their spread. In this study, we characterized the composition of the defensive secretions from six quinone millipedes and evaluated the fumigant, contact, and repellent activities of some main components against <em>S. invicta</em> workers. In total, 27 components were detected in the defensive secretions of the six millipede species, with 2-methoxy-3-methyl-1,4-benzoquinone being the predominant compound overall. Nine compounds (1,4-benzoquinone, <em>α</em>-pinene, dimethyl trisulfide, <em>β</em>-pinene, 2-methyl-1,4-benzoquinone, 2-methoxy-3-methyl-1,4-benzoquinone, orcinol, 3,4-dimethoxyphenol, and 1-hydroxycyclohexyl phenyl ketone) were selected for bioassays. Among them, the three benzoquinones displayed significant fumigant and contact toxicity, as well as repellent effects against <em>S. invicta</em>. Dimethyl trisulfide exhibited fumigant and repellent activity, while 1-hydroxycyclohexyl phenyl ketone demonstrated just contact toxicity. These findings highlight the potential of millipede-derived compounds as natural agents for <em>S. invicta</em> control, possibly to direct a mixture of chemicals for use against fire ants' infestation in transported goods.</div></div>","PeriodicalId":19828,"journal":{"name":"Pesticide Biochemistry and Physiology","volume":"215 ","pages":"Article 106670"},"PeriodicalIF":4.0,"publicationDate":"2025-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144996844","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synergistic antifungal activity and mechanism of carvacrol/citral combination against fusarium oxysporum in Dendrobium officinale","authors":"Xuemei Lu ,&nbsp;Ke Hu ,&nbsp;Minggui Ou ,&nbsp;Min Li ,&nbsp;Xinchun Zhang ,&nbsp;Xingyu Zhan ,&nbsp;Xun Liao ,&nbsp;Ming Li ,&nbsp;Rongyu Li","doi":"10.1016/j.pestbp.2025.106671","DOIUrl":"10.1016/j.pestbp.2025.106671","url":null,"abstract":"<div><div>The soft rot disease caused by <em>Fusarium oxysporum</em> leads to a significant reduction in the yield of <em>Dendrobium officinale</em>. However, research into the synergistic inhibitory effect of essential oils in <em>D. officinale</em> is extremely limited. In this study, we systematically investigated the direct and indirect inhibitory activity of carvacrol, citral and their combination against <em>F. oxysporum</em>, and their synergistic inhibitory mechanism. Carvacrol and citral exhibited significant direct and indirect inhibitory activity against <em>F. oxysporum</em> 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 <em>F. oxysporum</em> 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 <em>F. oxysporum</em> mycelia than single compound. Transmission electron microscopy (TEM) showed that Ca•Ci also caused significant ultrastructural alterations to <em>F. oxysporum</em>, manifesting as cytoplasmic disorganization and partial organellar disintegration. Moreover, Ca•Ci dramatically increased the sensitivity of <em>F. oxysporum</em> to calcofluor white compared with a single compound. Ca•Ci also considerably upregulated the expression of chitinase-related gene (<em>FOXG</em>_12882) and <em>β</em>-1,3-glucanase-related gene (<em>FOXG</em>_10637) in <em>F. oxysporum</em>, resulting in higher chitinase and <em>β</em>-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 <em>F. oxysporum</em>, thereby exhibiting a synergistic effect.</div></div>","PeriodicalId":19828,"journal":{"name":"Pesticide Biochemistry and Physiology","volume":"215 ","pages":"Article 106671"},"PeriodicalIF":4.0,"publicationDate":"2025-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144926304","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}