Fig 8. PCA analysis carried on the metabolite identified and quantified after rosmarinic acid treatment.

Principal Component Analysis model scores A) and loading B) plot of metabolite profile of control plants (CR-RA1– CR-RA4, replicates of control samples) and plants exposed to RA (TR-RA1– TR-RA4, replicates of the treated samples). Both score and loading plots were generated using the PCs, PC1 vs PC2, with the explained variances reported in brackets; C) Overlay heat map of metabolite profiles in Arabidopsis roots exposed to RA in comparison with control roots. Heatmap is commonly used for unsupervised clustering. Agglomerative hierarchical clustering begins with each sample as separate cluster and then proceeds to combine them until all samples belong to one cluster. Each square represents the effect of RA on the amount of every metabolite using a false-color scale. Red or green regions indicate increase or decrease metabolite content, respectively.