Table 2. Up- and down-regulated metabolites tentatively assigned in leaves and roots of Geranium pratense ,Leucanthemum vulgare , and Ranunculus acris . We assigned the molecular formula and the putative compound name based on the high-resolution mass-to-charge values generated by liquid chromatography quadrupole time-of-flight mass spectrometry. Abbreviations: Rt = Retention time in liquid chromatography in seconds; eV = Fragmentation energy in electron volt; MS = mass spectrometry; PPI = plant-plant interaction; PSI = plant-soil interaction.