Metabolite Profiling of Urban and Forest Tree Rhizosphere Soil using Analytical Instruments

Abstract

The rhizosphere is the area of the soil affected by plant roots and plays an important role in plant health, nutrient cycling, and soil structure. This study investigated differences in rhizosphere soil metabolites between trees in urban and forest environments using LC/MS-Q-TOF and GC/MS. Urban environments can cause soil pollution and ecosystem disturbance due to the accumulation of heavy metals and petrochemicals, while forest environments are rich in organic matter and fallen leaves, maintaining a nutrient-rich environment in which various microorganisms coexist. Rhizosphere soil samples were collected from Dankook University (city) and Taejo Mountain (forest) in Cheonan, South Korea, extracted using methanol and chloroform using the Soxhlet extraction method, and then analyzed by LC/MS-Q-TOF and GC/MS. N-Nitrosopyrrolidine, a possible carcinogen from automobile exhaust and industrial activities, has been found in the rhizosphere soil of urban trees. Forest rhizosphere samples showed high concentrations of momilactone A, which is important for plant defense mechanisms. 140 significant metabolites were identified through MPP analysis. Furthermore, GC/MS analysis confirmed that siloxanes and oleamides were predominantly detected in urban and forest samples, respectively. Overall, this study highlights the impact of environmental conditions on rhizosphere soil chemistry and microbial ecosystems and provides insights for urban greening and forest conservation strategies. Comprehensive profiling of rhizosphere metabolites will improve our understanding of plant-soil interactions and contribute to maintaining soil health and plant diversity in diverse ecosystems.