Biology subjects

Ketehouli, T.

Publications and source records attributed to Ketehouli, T..

4 recordsLinked to original sources

bioRxiv2026

Seed Microbiome Transfer Mitigates Intergenerational Dysbiosis, Modulates Plant Defenses and Suppresses Foliar Disease

Antibiotic-induced disruption of plant-associated microbiomes has the potential to alter host health beyond the directly exposed generation, yet whether the effects of dysbiosis are transmitted through the seed microbiome remains unknown. Here, we investigated the intergenerational impacts of streptomycin-induced dysbiosis in tomato (Solanum lycopersicum), demonstrated that seed microbiome transfer (SMT) restores progeny microbiome function and disease resistance, and characterized the underlying physiological and genetic mechanisms. Parental streptomycin exposure altered the composition of progeny rhizosphere bacterial communities, reduced expression of defense-associated genes, and increased susceptibility to Xanthomonas perforans. Suppression of immune gene expression was strongly associated with increased disease severity, indicating that parental dysbiosis impaired progeny plants ability to mount effective immune responses. Transfer of the seed microbiome from healthy plant donors partially restored rhizosphere community composition, reduced disease severity and recovered defense gene expression of three genes. Together, our findings demonstrated that antibiotic exposure microbiome disturbance generates intergenerational legacy effects that influence plant immunity and disease susceptibility and seed microbiome transfer can counteract this dysbiosis across generations.

plant biology↗

bioRxiv2026

Antibiotics and copper drive compartment-specific dysbiosis and functional reprogramming in tomato microbiomes

Plant-associated microbiomes help sustain plant immunity and productivity, yet the degree to which agricultural antimicrobials reshape these microbial networks and alter disease outcomes remains poorly characterized. Here, we quantified how chemical inputs such as copper and streptomycin trigger distinct, compartment-specific dysbiosis in tomato (Solanum lycopersicum), fundamentally decoupling microbiome-mediated immunity from pathogen defense. We demonstrated that chemical disturbance correlates with increased susceptibility to bacterial spot caused by Xanthomonas perforans. Notably, streptomycin-induced dysbiosis increased epidemic intensity, characterized by physiological and growth trade-offs, including reduced fruit number, mass, and seed weight, alongside a decline in photosynthetic gas exchange; while copper-induced dysbiosis had intermediate effects. Chemical perturbation restructured microbiomes in a niche-dependent manner based on amplicon profiling: seeds and the phyllosphere showed the greatest instability, including higher dispersion, taxon turnover, and network reorganization under streptomycin, whereas rhizosphere communities remained more deterministic but were structurally reshaped by copper. Rhizosphere metagenomics further revealed enrichment of antibiotic-resistance functions under streptomycin treatment and of metal-tolerance and oxidative-stress functions under copper treatment, along with shifts in genes linked to cell-envelope remodeling and redox metabolism. These findings identify microbiome dysbiosis as a mechanistic bridge between chemical stress and plant disease, and support crop protection strategies that preserve microbiome integrity.

plant biology↗

bioRxiv2026

Patching the Leak or Rebuilding the Boat? Evaluating Targeted Probiotic Cyanobacteria and Microbiome Transplants to Counteract Rhizosphere Dysbiosis

Antibiotic use in agricultural systems can unintentionally disrupt beneficial rhizosphere microorganisms, yet the consequences of this dysbiosis for plant fitness remain insufficiently understood. Building on previous findings that application of streptomycin to the roots decreases cyanobacteria and increases tomato plant susceptibility to foliar Xanthomonas infection, this study aimed to determine whether this relationship reflects causation or correlation. We evaluated whether targeted inoculation with the filamentous nitrogen-fixing cyanobacterium Cylindrospermum sp. (CI) or a complex rhizosphere microbiome transplant (RMT) could mitigate antibiotic-induced dysbiosis. As expected, streptomycin treatment significantly increased bacterial spot disease severity and reduced microbial richness in the rhizosphere, marked by a pronounced decline in cyanobacterial and Cylindrospermum operational taxonomic units. Co-occurrence network analysis revealed that this dysbiotic state was defined by reduced community connectivity and increased negative associations, indicating a breakdown in cooperative microbial relationships. Notably, both CI and RMT reduced plant disease severity, though they caused distinct rhizosphere community reassembly outcomes. While RMT relied on microbial functional redundancy, the targeted CI approach achieved more robust colonization and effectively "patched" the functional gap left by dysbiosis. Microbiome restoration directly influenced host physiology, significantly reducing the overactivation of ethylene-mediated defense genes, such as ERF1, and partially reinstating auxin-responsive signaling pathways (IAA21) that were disrupted under dysbiosis. These findings suggest that targeted microbial inoculation could reverse dysbiosis and enhance plant resilience under pathogen pressure as effectively as complex microbial transplants. This work highlights a shift in microbiome management: from the complex rebuilding of communities to the strategic repair of specific functional gaps.

microbiology↗

bioRxiv2024

The Underground World of Plant Disease: How Does Rhizosphere Dysbiosis Affect Plant Health Above-ground?

Similar to the human gut microbiome, diverse microbes colonize the plant rhizosphere, and an imbalance of this microbial community, known as dysbiosis, may negatively impact plant health. This study aimed to investigate the influence of rhizosphere dysbiosis on above-ground plant health using tomato plants (Solanum lycopersicum L.) and the foliar bacterial spot pathogen Xanthomonas perforans as model organisms. Four-week-old tomato plants rhizospheres were treated with streptomycin (0.6 g x L-1), or water (negative control) and spray-inoculated with X. perforans (105 cells x mL-1) after 24 h. Half of the plants treated with streptomycin and X. perforans received soil microbiome transplants (SMT) from uninfected plant donors 48 h after streptomycin application. Streptomycin-treated plants showed a 26% increase in disease severity compared to plants that received no antibiotic, while plants that received the SMT had an intermediate level of disease severity. Antibiotic-treated plants showed a reduced abundance of rhizobacterial taxa like Cyanobacteria from the genus Cylindrospermum as well as down-regulation of genes related to plant primary and secondary metabolism and up-regulation of plant defense genes associated with induced systemic resistance (ISR). This study highlights the crucial role of beneficial rhizosphere microbes in disease resistance, even to foliar pathogens.

plant biology↗