Project description:To study microbial interaction effect on transcriptomic profile of B. velezensis 83, a comparative gene expression profiling analysis was performed.
Project description:Southern corn leaf blight (SCLB), caused by Bipolaris maydis, poses a serious threat to maize production worldwide. In our previous study, Bacillus velezensis BV3 was isolated and demonstrated strong antagonistic activity against maize leaf spot pathogens and effective disease control in greenhouse experiments.
Project description:The present study aims to evaluate the response of the three Mediterranean local grapevines ‘Garnacha Blanca’, ‘Garnacha Tinta’, and ‘Macabeo’ to treatments with biocontrol products (BPs), a botanical extract (Akivi, Dittrichia viscosa extract) and a beneficial microorganism (Bacillus UdG, Bacillus velezensis). A combination of transcriptomics and metabolomics approaches were chosen in order to study grapevine gene expression and to identify gene marker candidates, as well as, to determine grapevine metabolites differentially concentrated in response to BPs treatments. Grapevine plants were cultivated in greenhouse controlled conditions and submitted to the treatments, and thereafter, leaves were sampled 24h after treatment to conduct gene expression study by RNA-sequencing for ‘Garnacha Blanca’ leaves extract and by RT-qPCR for the three cultivars. Differentially expressed genes (DEGs) were investigated for both treatments and highly influenced DEGs were selected to be tested in the three cultivars as treatment gene markers. In addition, extraction of leaf components was performed to quantify metabolites such as phytohormones, organic acids, and phenols. Considering all the upregulated and downregulated genes and enhanced metabolites concentrations, the treatments had an effect on jasmonic acid, ethylene, and phenylpropanoids defense pathways. In addition, several DEG markers were identified presenting a stable overexpression after the treatments in the three grapevine cultivars. These gene markers could be used to monitor the activity of the products in field treatments in future research. Further research will be necessary to confirm these first results under field conditions.
Project description:Bacillus velezensis strain GH1-13 isolated from a rice paddy soil in Korea has been reported to promote plant growth and inhibit some pathogens. It contains a plasmid pBV71, thought to be of benefit to the strain, but there is no information on its effect. In order to elicit the plasmid effect on gene expression, mRNA and protein levels were analyzed at various stages of bacterial growth. Comparative gene expression profiles between the plasmid-containing and plasmid-free cells revealed that strain GH1-13 activated a transient stress response in the exponential phase. It showed early activation of expression of sigma W operon, liaIHGFSR operon, and transcription regulators for transition state, associated with carbon catabolite repression and secondary metabolite biosynthesis of acetoin, bacillaene, and macrolactin.
Project description:<p>In this study, a strain isolated from the surface of flue-cured tobacco leaves, identified as <em>Bacillus velezensis</em> HJ-16, was applied in the solid-state fermentation of tobacco leaves. This strain, known for producing thermally stable enzymes, including amylase, cellulase, and protease, significantly improved the sensory qualities of tobacco, enhancing aromatic intensity, density, and softness, while reducing irritation. Whole-genome sequencing and functional annotation revealed that <em>B. velezensis</em> HJ-16 possesses a single circular chromosome containing genes associated with enzyme production and metabolic activities, particularly in carbohydrate metabolism and amino acid metabolism. Untargeted metabolomics analysis identified significant changes in non-volatile metabolites induced by fermentation. These metabolites were enriched in pathways related to flavonoid biosynthesis, alkaloid biosynthesis, aromatic amino acid metabolism, lipid metabolism, and carbon metabolism. Metagenomic analysis showed that Bacillus became the dominant genus on the tobacco leaf surface following inoculation with <em>B. velezensis</em> HJ-16, altering the microbial community composition, reducing diversity and evenness, and enhancing microbial metabolic activity. These findings underscore the potential of <em>B. velezensis</em> HJ-16 as a biotechnological tool to improve tobacco leaf quality.</p>
