Soil derived metabolic profiling and their impact on the root growth in peanuts (Arachis hypogaea L.)

Plant growth is intricately regulated by soil ecosystems, where dynamic interactions between plants and soil metabolites shape root development. As critical mediators of these interactions, soil metabolites not only reflect biogeochemical cycling but also directly modulate root morphogenesis by eliciting stimulatory or inhibitory responses. To decode the mechanisms driving peanut ( Arachis hypogaea L.) root system development, utilizing UPLC-HRMS we profiled 702 soil specific metabolites across diverse soil samples and further identified 118 differentially expressed metabolites, which were then associated with peanut root length phenotypes. Through systematic screening, four root-promoting metabolites (nicotinamide, carbendazim, vanillic acid, and raffinose) and four phytotoxic compounds (phthalic acid, myristic acid, formononetin, and syringic acid) were identified. Our results showed that the seedlings treated with nicotinamide, carbendazim, vanillic acid, and raffinose promotes root elongation by up to 28.3% as compared to untreated seeds. Whereas, seedlings treated with phthalic acid, myristic acid, formononetin, and syringic acid, suppressed root growth by 56.6%, demonstrating a bimodal inhibition pattern. Dose-response assays revealed hierarchical efficacy among these metabolites, with carbendazim and formononetin representing the most potent enhancer and suppressor, respectively. Current findings reveal a causal link between soil metabolite composition and peanut root development, providing a biochemical basis for harnessing soil-specific metabolites in precision agriculture.