2026-10-09T17:12:28Z https://api.figshare.com/v2/oai

oai:figshare.com:article/34014605 2026-09-28T14:20:03Z category_8 category_13 category_272 category_39 category_734 category_133 portal_87 item_type_3 month_year_09_2026

<i>Bacillus aerophilus</i> A5 suppresses tobacco root rot and gene expressions involved in fungal chitin metabolism Xinrui Li (443177) Fei Xiong (294384) Ning Jiang (118848) Tianfu Zhao (24645942) Yanxia Hu (18827053) Yongzhan Cai (11130579) Yuanhu Xuan (4898059) Xiaotong Gai (5575355) Microbiology Genetics Environmental Sciences not elsewhere classified Ecology Biological Sciences not elsewhere classified Plant Biology Tobacco root rot Bacillus aerophilus Fusarium biological control UDP-N-acetylglucosamine cell wall precursor metabolism <p>Tobacco root rot is a destructive soil-borne disease that constrains sustainable tobacco production in Yunnan. <i>Fusarium oxysporum</i> and <i>Fusarium solani</i> species complex are currently considered the principal pathogens associated with this disease. Therefore, effective biocontrol agents are needed, and understanding their pathogen-side modes of action is essential for improving biological management strategies. This study screened 100 bacterial strains isolated from the tobacco rhizosphere using plate confrontation assays and identified A5 as a broad-spectrum antagonistic strain. A5 consistently inhibited four tobacco root rot-associated <i>Fusarium</i> species, with hyphal growth inhibition rates of 63.31%, 59.42%, 69.64%, and 68.82%, respectively. Phylogenetic analyses of 16S rRNA and <i>gyrB</i> sequences placed A5 close to <i>Bacillus aerophilus</i>, supporting its classification as a <i>B. aerophilus</i>-related biocontrol candidate. To investigate the fungal response to A5, <i>F. solani</i> was exposed to 10% sterile A5 fermentation supernatant and analyzed using transcriptomic sequencing. GO and KEGG enrichment analyses showed differentially expressed genes (DEGs) involved in UDP-<i>N</i>-acetylglucosamine biosynthesis and associated cell wall precursor metabolic processes. Because <i>F. oxysporum</i> has a more established genetic manipulation system in tobacco root rot research, this species was used for downstream functional validation. RT-qPCR confirmed the significant expression responses of FOXG_19023, FOXG_10443, and FOXG_12345 after the treatment with A5 supernatant. Subsequent construction of knockout mutants demonstrated that deletion of FOXG_19023 significantly restricted colony growth, suggesting that FOXG_19023 may contribute to vegetative growth of <i>F. oxysporum</i>, although its specific role in UDP-<i>N</i>-acetylglucosamine-related cell wall metabolism remains to be explored. Overall, A5 was identified as a tobacco root rot biocontrol bacterium with activity against <i>Fusarium</i> pathogens. These results further suggest that A5 may affect expression of genes involved in pathogen UDP-<i>N</i>-acetylglucosamine-related metabolism, and this response may be associated with impaired <i>Fusarium</i> hyphal growth. This study provides a potential biocontrol resource for sustainable tobacco root rot management and offers candidate pathogen-side targets for future studies on the molecular mechanisms underlying <i>Bacillus</i>-mediated suppression of <i>Fusarium</i>.</p> 2026-09-28T14:20:03Z Dataset Dataset 10.6084/m9.figshare.34014605.v1 https://figshare.com/articles/dataset/_i_Bacillus_aerophilus_i_A5_suppresses_tobacco_root_rot_and_gene_expressions_involved_in_fungal_chitin_metabolism/34014605 CC BY 4.0