Comprehensive Metabolomic Profiling of Common Bean (Phaseolus vulgaris L.) Reveals Biomarkers Involved in Viral Disease Detection and Monitoring

Common bean production is vital in Western Kenya for its economic, nutritional, environmental, and cultural significance. It provides a key income source for smallholder farmers, supports regional trade, and contributes to food security with affordable, protein-rich food. However, challenges such as pests, diseases, climate change, poor soil fertility, and limited access to quality seeds hinder production. Among these constraints Bean diseases and especially viral diseases have been documented to account for a higher percentage of crop losses in the field This study was commissioned to conduct a comprehensive analysis of small molecule metabolites in diseased common bean biological systems, aiming to identify potential disease biomarkers and improve the understanding of the related metabolic pathways. To achieve this, virus-free Rosecoco bean cultivars were initially planted and later exposed to viral diseases (BCMV and BCMNV) in designated regions. At the same time, control experiments involved the use of healthy plants. Diseased and healthy leaves were collected for metabolite extraction and analyzed using liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry technology. A total of 354 metabolites were identified across seven pathways, with 51 upregulated metabolites, mainly from fatty acids, terpenoids, and alkaloids. Ten metabolites were identified as differentially expressed, two of which had their molecular structures successfully determined. These metabolites hold potential as biomarkers for viral disease detection, monitoring, and conferring resistance in common bean diseases. These findings emphasize the significance of fatty acids and terpenoids in plant stress responses, suggesting that further research into these pathways is crucial for better understanding plant defence resilience.