Development of a root exudate collection protocol to monitor changes in exudation in response to stress by NMR metabolomics analysis
Résumé
Root exudates are composed of a wide range of compounds including primary and secondary metabolites. They are involved in plant growth and responses to environmental stresses. Although root exudates are important in root-microorganisms interactions, few data exist on the metabolite’s composition of this highly sophisticated molecular mixture and most of them are still unknown. In addition, the impact of biotic or abiotic stresses on their precise composition remains to be clarified.
Here, using pea (Pisum sativum) as a plant model, we have developed an easy and reproducible protocol to follow modifications of root exudation in response to both biotic (elicitors, pathogens) and abiotic stresses (drought, salinity, extreme temperatures…) using an NMR untargeted approach. Pea seedlings were hydroponically grown, and root exudates were collected in distilled water or calcium chloride solution for 15 or 120 minutes. NMR analysis showed that root immersion during 15 minutes in calcium chloride limits seedling stress without modifying exudate diversity. Using these “basal” collection conditions, the protocol was applied to faba bean (Vicia faba), a closed related member of the Fabaceae family. NMR metabolic profiles revealed that the two species could be discriminated according to their exudate composition (Fortier et al., 2023).
Using this protocol, we are currently investigating the impact of elicitors on pea root exudate composition.
Fortier et al. (2023) Plant Science. 331 : 111694.