Figure 2. Metabolic processes (A) and sspecialised metabolite biosynthesis (B) modulated Arabidopsis thaliana roots exposed to heat, drought and the combined stress (heat+ drought). The metabolomics dataset produced through UHPLC-ESI/QTOF-MS was subjected to ANOVA and FC analysis (p < 0.05, FC ≥ 2), and differential metabolites were loaded into the PlantCyc Pathway Tool (https://www.plantcyc.org/). The x axis represents each set of metabolic subcategories, while the y axis corresponds to the accumulative log fold change (FC). The large dots represent the average (mean) of all FCs for the different metabolites in the class, while the small dots represent the individual log FC. The abbreviated subcategory names on the x axis correspond to:AA: amino acids; Nucleo: nucleosides and nucleotides; FA/lipids: fatty acids and lipids; Amines: amines and polyamines; Carbohyd: carbohydrates; Secondary met: secondary metabolism; Cofactors: cofactors, prosthetic groups, electron carriers, and vitamins; Cell-struct: plant cell structures; Metab reg: metabolic regulators; FA/lipids: fatty acid derivatives; N-containing: nitrogen-containing specialised metabolism; S-containing: sulfur-containing specialised metabolism; Terpenophenol: terphenophenolic compounds. The metabolomic dataset produced through UHPLC-ESI/QTOF-MS was subjected to volcano plot analysis (p < 0.05, fold-change > 2) and differential metabolites loaded into PlantCyc Pathway tool.