Transcriptomic and metabolomic profiling reveals early responses of tomato plants elicited by compost-derived bacteria

Solanum lycopersicum seedlings exposed in vitro to compost-derived Bacillus sonorensis show the broadest early response, including reduced primary root length and lateral root number.

• Why it matters: Predicting how compost microbiota and specific bacterial strains affect plant physiology is difficult, and their early plant responses remain poorly characterized beyond standard bacterial traits.
• What they did: Tomato seedlings were inoculated with isolated strains (Bacillus sonorensis, Glutamicibacter arilaitensis, Kocuria rhizophila) and assessed via root phenotyping, root and shoot transcriptomics, and mass spectrometry metabolite profiling in tissues, exudates, and culture filtrates.
• The result: B. sonorensis triggered broad transcriptional changes in metabolism, redox balance, hormone signalling, and defence-associated pathways; G. arilaitensis was more selective and tissue-dependent, while K. rhizophila had limited effects, with all isolates reshaping primary metabolism and exudate composition.