Work

Evaluation of trap discs for root exudate eco-friendly sampling using rhizoboxes: Application to untargeted screening of organic compounds by gas chromatography hyphenated with high resolution mass spectrometry

Year: 2025

Type: article

Abstract: • Poa annua was used as control plant to validate an unusual sampling methodology. • Sorption discs directly placed on roots in soil successfully trapped exudates. • Sample preparation using traps limits the environmental impact (0.59 score). • Cellulose nitrate traps allow to trap 2960 compounds from soil and plant exudates. • GC-HRMS allowed to discriminate 516 specific compounds of root exudates. In the present paper, an unusual sampling method, called EcoRoot, was investigated for sampling directly in soil, root exudates of Poa annua L., belonging to the Poaceae family. Using a rhizobox, sorption filters were placed directly onto roots to serve as traps for root exudates. Various trap compositions, namely, cellulose nitrate, glass microfiber and nylon, were evaluated for their ability to adsorb/desorb a standard mixture of known exuded compounds and for recovery yield. Cellulose nitrate supports exhibited better yields for compounds known to be exudated by plants of the Poaceae family. Then, two crucial parameters were investigated: the contact and extraction times. The most suitable methodology for extracting the target compounds was a cellulose nitrate support with a contact time of 60 min and 30 min in an ultrasonic bath using a mixture H 2 O/MeOH. Soil and root sampling was carried out under the optimized conditions. Then, silylation of extracts was performed, and GC-HRMS was used to demonstrate that this sampling method could be used to efficiently trap compounds from soil and roots. Moreover, among the 6,136 compounds detected in extracts, 516 appeared to be specific to root exudates. This Ecoroot methodology allows root exudates to be collected in conditions as close as possible to natural growth environment, limiting the environmental impact with a 0.59 score (AGREEprep) compared to hydroponic methods. Ecoroot offers interesting perspectives for studying root exudate metabolome and their temporal and spatial dynamics in the rhizosphere, with important issues in both Ecology and Plant biology.

Source: Journal of Chromatography Open

DOI: 10.1016/j.jcoa.2025.100205

Authors: Victoria Bohm, Estelle Forey, Matthieu Chauvat, Pascal Cardinael, Valerie Peulon-Agasse