{"doi":"10.3389/fmicb.2025.1582372","title":"2-Nonanol produced by Bacillus velezensis EM-1: a new biocontrol agent against tobacco brown spot","abstract":"<jats:p>Tobacco brown spot disease, caused by <jats:italic>Alternaria alternata</jats:italic>, poses a significant threat to crop production. Traditional control methods, particularly chemical fungicides, have raised concerns about environmental impact and resistance. Although our previous research has shown that volatile compounds produced by <jats:italic>Bacillus velezensis</jats:italic> EM-1 can effectively suppress <jats:italic>A. alternata</jats:italic>, the specific antifungal compounds and their mechanisms remain unclear. In this study, exposure to the volatiles from strain EM-1 significantly inhibited the mycelial growth and spore germination of <jats:italic>A. alternata</jats:italic>, with 2-nonanol identified as the most potent antifungal compound. Fumigation experiments revealed that 2-nonanol exhibited strong dose-dependent toxicity, with an EC<jats:sub>50</jats:sub> of 0.1055 μL/cm<jats:sup>3</jats:sup> and a minimum inhibitory concentration of 0.2166 μL/cm<jats:sup>3</jats:sup>. <jats:italic>In vivo</jats:italic> experiments on tobacco leaves confirmed that 2-nonanol effectively reduced tobacco brown spot disease incidence and slowed lesion expansion. Transcriptome analysis indicated that 2-nonanol downregulated the expression of genes encoding D-glucose synthesis in carbon metabolism, which limited energy acquisition by <jats:italic>A. alternata</jats:italic>. Moreover, the expression of antioxidant enzymes, including superoxide dismutase (SOD) and catalase (CAT), was markedly suppressed by 2-nonanol, thereby exacerbating cellular damage induced by oxidative stress. These findings suggest that 2-nonanol holds potential as a biocontrol agent for managing tobacco brown spot disease, underscoring the promising role of volatile organic compounds (VOCs) in the development of environmentally friendly biocontrol products.</jats:p>","journal":"Frontiers in Microbiology","year":2025,"id":625530,"datarank":0.16479184330021646,"base_score":1.0986122886681096,"endowment":1.0986122886681096,"self_citation_contribution":0.16479184330021646,"citation_network_contribution":0.0,"self_endowment_contribution":0.16479184330021646,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":2,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":null,"is_data_producer":false,"deposit_databanks":null,"is_oa":false,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":null,"fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":335643,"name":"Xiaobin Han","orcid":null,"position":1,"is_corresponding":false},{"id":1617787,"name":"Xianbo Wang","orcid":null,"position":2,"is_corresponding":false},{"id":1445567,"name":"Jun Wan","orcid":"0000-0002-8273-8839","position":3,"is_corresponding":false},{"id":1617789,"name":"Mingxia Wen","orcid":null,"position":4,"is_corresponding":false},{"id":1617791,"name":"Donglin Zhao","orcid":null,"position":5,"is_corresponding":false},{"id":1617793,"name":"Yanfen Zheng","orcid":null,"position":6,"is_corresponding":false},{"id":61987,"name":"Chengsheng Zhang","orcid":"0000-0002-5238-083X","position":7,"is_corresponding":false},{"id":1617794,"name":"Chuantao Xu","orcid":null,"position":8,"is_corresponding":false},{"id":1617795,"name":"Youqiang Wang","orcid":null,"position":9,"is_corresponding":false},{"id":1617786,"name":"Xiaona Sui","orcid":null,"position":0,"is_corresponding":false}],"reference_count":0,"raw_metadata":{"has_enrichment":true,"resolved":true,"title":"2-Nonanol produced by Bacillus velezensis EM-1: a new biocontrol agent against tobacco brown spot","abstract":"<jats:p>Tobacco brown spot disease, caused by <jats:italic>Alternaria alternata</jats:italic>, poses a significant threat to crop production. Traditional control methods, particularly chemical fungicides, have raised concerns about environmental impact and resistance. Although our previous research has shown that volatile compounds produced by <jats:italic>Bacillus velezensis</jats:italic> EM-1 can effectively suppress <jats:italic>A. alternata</jats:italic>, the specific antifungal compounds and their mechanisms remain unclear. In this study, exposure to the volatiles from strain EM-1 significantly inhibited the mycelial growth and spore germination of <jats:italic>A. alternata</jats:italic>, with 2-nonanol identified as the most potent antifungal compound. Fumigation experiments revealed that 2-nonanol exhibited strong dose-dependent toxicity, with an EC<jats:sub>50</jats:sub> of 0.1055 μL/cm<jats:sup>3</jats:sup> and a minimum inhibitory concentration of 0.2166 μL/cm<jats:sup>3</jats:sup>. <jats:italic>In vivo</jats:italic> experiments on tobacco leaves confirmed that 2-nonanol effectively reduced tobacco brown spot disease incidence and slowed lesion expansion. Transcriptome analysis indicated that 2-nonanol downregulated the expression of genes encoding D-glucose synthesis in carbon metabolism, which limited energy acquisition by <jats:italic>A. alternata</jats:italic>. Moreover, the expression of antioxidant enzymes, including superoxide dismutase (SOD) and catalase (CAT), was markedly suppressed by 2-nonanol, thereby exacerbating cellular damage induced by oxidative stress. These findings suggest that 2-nonanol holds potential as a biocontrol agent for managing tobacco brown spot disease, underscoring the promising role of volatile organic compounds (VOCs) in the development of environmentally friendly biocontrol products.</jats:p>","is_dataset_classified":null,"base_score":1.0986122886681096,"endowment":1.0986122886681096,"datacite_reuse_total":0,"file_count":0,"downloads":0,"views":0,"has_version_chain":false,"is_dataset":false,"is_oa":false,"pmid":"40371117","pmcid":"PMC12075116","openalex_id":"https://openalex.org/W4409975035","authors":[],"funders":[],"total_grants":0,"fwci":1.9011,"citation_percentile":0.85172262,"influential_citations":0,"citation_trend":[{"year":2025,"count":1},{"year":2026,"count":1}],"oa_status":"gold","license":"cc-by","oa_locations":[{"url":"https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2025.1582372/pdf","host_type":"journal"},{"url":"https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2025.1582372/pdf","host_type":"publisher"},{"url":"https://www.frontiersin.org/articles/10.3389/fmicb.2025.1582372/full","host_type":"publisher"},{"url":"https://doi.org/10.3389/fmicb.2025.1582372","host_type":"journal"},{"url":"https://pubmed.ncbi.nlm.nih.gov/40371117","host_type":"repository"},{"url":"https://doaj.org/article/aab24954aa984f84a885922a6be2ee60","host_type":"repository"},{"url":"https://www.ncbi.nlm.nih.gov/pmc/articles/12075116","host_type":"repository"},{"url":"https://europepmc.org/articles/PMC12075116","host_type":"Europe_PMC"},{"url":"https://europepmc.org/articles/PMC12075116?pdf=render","host_type":"Europe_PMC"}],"fields_of_study":["Plant-Microbe Interactions and Immunity","Essential Oils and Antimicrobial Activity","Plant tissue culture and regeneration"],"mesh_terms":[],"keywords":["Sweet spot","Biological pest control","Biology","Microbiology","Botany","Alternaria alternata","Carbon metabolism","Tobacco brown spot disease","volatile organic compounds","Transcriptomics","Bacillus Velezensis","2-Nonanol"],"sdg_mappings":[],"linked_datasets":[],"clinical_trials":[],"software_tools":[],"database_accessions":[{"name":"gca"}],"source":"live","citation_network_status":"fetched"},"created_at":"2026-08-04T07:02:14.217158Z","pmid":null,"pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}