Genome-Wide Metatranscriptomics Crosswalk of Diseased Common Beans (Phaseolus Vulgaris L) Unravels Critical Metabolic Pathways Involved in Plant Defense Mechanisms

The common bean (Phaseolus vulgaris L.) is a vital food crop worldwide, especially in Latin America, Asia, and Sub-Saharan Africa, due to its high levels of protein, fiber, and essential nutrients. However, it is vulnerable to viral infections, particularly from the Bean Common Mosaic Virus and Bean Common Mosaic Necrosis Virus. While previous research has largely focused on specific resistance genes, a broader understanding of the plant’s complete immune response remains limited. To investigate this, a study was conducted involving 51 infected leaf samples. RNA was extracted, and deep metatranscriptomic sequencing was performed using the Illumina MiSeq platform. The results indicated that several genes related to stress response, nitrogen metabolism, and biosynthesis pathways were activated during infection. Significant defense mechanisms included pathogen recognition, production of antimicrobial peptides, and alterations in metabolic activity. The Mitogen-Activated Protein Kinase (MAPK) signaling pathway and enzymes like glycosyl transferases, which help build protective structures, played a critical role. These findings suggest that the bean’s defense system is complex and involves not only direct attacks on pathogens but also metabolic shifts and microbial interactions. Understanding these processes provides valuable insights for breeding stronger, disease-resistant, and climate-resilient bean varieties.