Mass spectrometry-based metabolomics oriented by correlation analysis for wound-induced molecule discovery: identification of a novel jasmonate glucoside

Introduction − Jasmonates are members of the oxylipin family involved in various plant regulatory processes, particularly in the response to biotic and abiotic stresses. They are present in very low amounts in wounded plants, which complicates their detection within complex plant extracts. Therefore, advanced analytical methods are needed for the profi ling and characterisation of novel jasmonate derivatives. Objective – To use metabolomics to search for original wound-induced metabolites belonging to the jasmonate family. Methodology – Numerous Arabidopsis specimens harvested at various time points after wounding were analysed by ultra-high pressure liquid chromatography coupled to time-of-fl ight mass spectrometry (UHPLC/TOFMS). A correlation analysis based on kinetic profi le similarities with known jasmonates was applied to fi nd wound-induced molecules having a potential role in defence signalling. Their characterisation was performed by tandem mass spectrometry and capillary nuclear magnetic resonance spectroscopy. Results – The statistical data treatment highlighted several previously reported jasmonates as well as a new glucoside derivative of the jasmonate 3-oxo-2-(2Z-pentenyl) cyclopentane-1-butyric acid (OPC-4). The monitoring of its kinetics in response to wounding revealed a delayed accumulation compared to the profi le of OPC-4. This suggests an inactivation or elimination of OPC-4 through the formation of a polar glucosylated metabolite. Conclusion – The metabolomic approach developed has proved useful in the discovery of original jasmonates synthesised in response to plant wounding