{"title":"Antagonistic activity and antagonistic mechanism of volatile organic compounds (VOCs) from Bacillus atrophaeus YL84 against Valsa pyri causing Korla fragrant pear Valsa cankers","authors":"Yuxin Tang, Qinyuan Xue, Yiwen Zhang, Zhe Wang, Zhen Zhang, Lan Wang, Hongzu Feng","doi":"10.1186/s40538-026-00921-3","DOIUrl":null,"url":null,"abstract":"<div><h3>Background</h3><p>Valsa canker of the Korla fragrant pear severely reduces yield and fruit quality. Biological control, owing to its environmental friendliness and safety for humans and animals, has become a major focus of recent research on plant disease management. <i>Bacillus</i> species are well known for their antagonistic activity against plant pathogens, and a biocontrol strain previously isolated in our laboratory (<i>Bacillus atrophaeus</i> YL84) exhibited strong inhibitory activity against <i>Valsa pyri</i>. The present study aimed to further evaluate the inhibitory effects of volatile organic compounds (VOCs) produced by YL84 on <i>V. pyri</i> and to elucidate the underlying antagonistic mechanisms.</p><h3>Results</h3><p>A paired double-Petri-dish assay was employed to evaluate VOC effects on hyphal growth, conidial germination, sporulation, hyphal penetrability, and activities of cell wall-degrading enzymes (CWDEs). Extracellular leakage was quantified to assess cell membrane integrity, while intracellular reactive oxygen species (ROS) levels were assessed by fluorescent probe staining and image analysis. SPME–GC–MS was used to characterize the VOC profile. Results showed that YL84 VOCs significantly inhibited <i>V. pyri</i> hyphal growth, with an inhibition rate of 54.94%. VOC treatment reduced sporulation, abolished hyphal penetrability, and significantly decreased the activities of three CWDEs. The peak extracellular conductivity in the treatment group was 6.15-fold that of the control. ROS levels accumulated significantly over time, with fluorescence intensity increasing by 24.66% and 68.01% on days 3 and 7, respectively, relative to day 1. YL84 VOCs also significantly suppressed toxin biosynthesis, including a 28.97% reduction in protocatechuic acid; assays on detached plant material demonstrated that reduced toxin levels correlated with diminished lesion expansion. Additionally, six potential bioactive compounds, including branched-chain aldehydes and dimethyl disulfide, were identified.</p><h3>Conclusions</h3><p>In summary, VOCs from YL84 exhibit notable antagonistic activity against <i>V. pyri</i>, providing a theoretical basis for further elucidation of their biocontrol mechanisms and potential application.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":512,"journal":{"name":"Chemical and Biological Technologies in Agriculture","volume":"13 1","pages":""},"PeriodicalIF":5.2000,"publicationDate":"2026-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1186/s40538-026-00921-3.pdf","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Chemical and Biological Technologies in Agriculture","FirstCategoryId":"97","ListUrlMain":"https://link.springer.com/article/10.1186/s40538-026-00921-3","RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"AGRICULTURE, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
Background
Valsa canker of the Korla fragrant pear severely reduces yield and fruit quality. Biological control, owing to its environmental friendliness and safety for humans and animals, has become a major focus of recent research on plant disease management. Bacillus species are well known for their antagonistic activity against plant pathogens, and a biocontrol strain previously isolated in our laboratory (Bacillus atrophaeus YL84) exhibited strong inhibitory activity against Valsa pyri. The present study aimed to further evaluate the inhibitory effects of volatile organic compounds (VOCs) produced by YL84 on V. pyri and to elucidate the underlying antagonistic mechanisms.
Results
A paired double-Petri-dish assay was employed to evaluate VOC effects on hyphal growth, conidial germination, sporulation, hyphal penetrability, and activities of cell wall-degrading enzymes (CWDEs). Extracellular leakage was quantified to assess cell membrane integrity, while intracellular reactive oxygen species (ROS) levels were assessed by fluorescent probe staining and image analysis. SPME–GC–MS was used to characterize the VOC profile. Results showed that YL84 VOCs significantly inhibited V. pyri hyphal growth, with an inhibition rate of 54.94%. VOC treatment reduced sporulation, abolished hyphal penetrability, and significantly decreased the activities of three CWDEs. The peak extracellular conductivity in the treatment group was 6.15-fold that of the control. ROS levels accumulated significantly over time, with fluorescence intensity increasing by 24.66% and 68.01% on days 3 and 7, respectively, relative to day 1. YL84 VOCs also significantly suppressed toxin biosynthesis, including a 28.97% reduction in protocatechuic acid; assays on detached plant material demonstrated that reduced toxin levels correlated with diminished lesion expansion. Additionally, six potential bioactive compounds, including branched-chain aldehydes and dimethyl disulfide, were identified.
Conclusions
In summary, VOCs from YL84 exhibit notable antagonistic activity against V. pyri, providing a theoretical basis for further elucidation of their biocontrol mechanisms and potential application.
期刊介绍：
Chemical and Biological Technologies in Agriculture is an international, interdisciplinary, peer-reviewed forum for the advancement and application to all fields of agriculture of modern chemical, biochemical and molecular technologies. The scope of this journal includes chemical and biochemical processes aimed to increase sustainable agricultural and food production, the evaluation of quality and origin of raw primary products and their transformation into foods and chemicals, as well as environmental monitoring and remediation. Of special interest are the effects of chemical and biochemical technologies, also at the nano and supramolecular scale, on the relationships between soil, plants, microorganisms and their environment, with the help of modern bioinformatics. Another special focus is the use of modern bioorganic and biological chemistry to develop new technologies for plant nutrition and bio-stimulation, advancement of biorefineries from biomasses, safe and traceable food products, carbon storage in soil and plants and restoration of contaminated soils to agriculture.
This journal presents the first opportunity to bring together researchers from a wide number of disciplines within the agricultural chemical and biological sciences, from both industry and academia. The principle aim of Chemical and Biological Technologies in Agriculture is to allow the exchange of the most advanced chemical and biochemical knowledge to develop technologies which address one of the most pressing challenges of our times - sustaining a growing world population.
Chemical and Biological Technologies in Agriculture publishes original research articles, short letters and invited reviews. Articles from scientists in industry, academia as well as private research institutes, non-governmental and environmental organizations are encouraged.
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