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Orthology-based comparative transcriptomic analysis reveals conserved osmoadaptive responses in Bacillus velezensis
Cristián Raziel Delgado-González1, Enna Citlalli Vidal-Martínez1, Elizabeth Pérez-Soto2
1Área Académica de Ciencias Agrícolas y Forestales, Instituto de Ciencias Agropecuarias, Universidad Autónoma del Estado de Hidalgo, 43600, Tulancingo, Hidalgo, Mexico.
Archives of Microbiology
|August 13, 2026
Summary
This study reveals conserved salt-stress responses in Bacillus species, identifying shared genes for osmoadaptation and sodium homeostasis. Comparative transcriptomics highlights common mechanisms for microbial survival under salinity challenges.
Area of Science:
- Microbiology
- Genomics
- Molecular Biology
Background:
- Salinity presents significant osmotic and ionic stress to microorganisms.
- Understanding conserved salt-stress responses across bacterial species is crucial but poorly understood.
- Bacillus species are model organisms for studying stress adaptation.
Purpose of the Study:
- To compare salt-stress transcriptional responses between Bacillus velezensis and Bacillus paralicheniformis.
- To identify conserved osmoadaptive genes and pathways in these phylogenetically distinct Bacillus species.
- To evaluate orthology-based comparative transcriptomics for discovering conserved stress mechanisms.
Main Methods:
- Comparative transcriptomic analysis of RNA-seq data from low- and high-salinity conditions.
- Orthology inference using reciprocal best-hit analysis.
- Differential gene expression analysis using Salmon and DESeq2.
- Functional annotation using KEGG Orthology assignments.
Main Results:
- Identified 1,893 and 1,879 differentially expressed genes in B. velezensis and B. paralicheniformis, respectively.
- 725 orthologous gene pairs showed conserved differential expression under salt stress.
- Conserved upregulation of compatible-solute metabolism, transport, and sodium homeostasis genes (e.g., proB, proC, betB, opuAA, nhaC).
- Conserved downregulation of biofilm formation and extracellular matrix genes.
Conclusions:
- Bacillus velezensis and Bacillus paralicheniformis share conserved transcriptional responses to salt stress.
- Osmoadaptation mechanisms, including compatible-solute management and ion homeostasis, are conserved.
- Orthology-guided comparative transcriptomics is effective for identifying conserved microbial stress responses.
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