Exploring the bio-defence potential of Sargassum extract: Metabolite profiling and pathway elucidation of sesame in response to Sargassum extract and Macrophomina phaseolina treatments

Abstract

Seaweed extracts function as bio-stimulants due to their rich content of physiologically active compounds enhancing the plant's ability to withstand environmental and pathogen attacks. The seaweed extracts enhance nutrient uptake, improve plant growth and yield in various crops. These extracts reduce the need for synthetic chemicals for disease management, making them an eco-friendly alternative that promotes sustainable agriculture. Metabolite profiling of sesame (Sesamum indicum L.) in response to treatments with Sargassum extract (S-extract) and Macrophomina phaseolina, alone and in combination showed highest accumulation of sugars, followed by polyols and carboxylic acids with all treatments. Heat map analyses revealed distinct metabolite accumulation patterns in sesame. Interestingly, with the S-extract + Macrophomina vs Macrophomina comparison, S-extract + Macrophomina treatment resulted in a greater accumulation of metabolites, suggesting a synergistic effect where S-extract mitigates the stress induced by Macrophomina, activating multiple defence and metabolic pathways. The enrichment of galactose metabolism, along with starch and sucrose metabolism with highest impact indicates participation of energy management towards stress and defence mitigation in sesame plants. Characterizing the metabolomic shifts and identifying specific metabolic signatures linked to enhanced Macrophomina resilience in sesame can facilitate increased and sustainable crop yield.