Fig. 3
Hierarchical clustering analysis of all 124 known and unknown differentially accumulated metabolites (DAMs) detected in the apoplast wash fluid collected from the lettuce cultivars Green Towers, Lollo Rossa, or Red Tide at 1- or 7-days post inoculation with Escherichia coli O157:H7 or Salmonella enterica ser. Typhimurium 14028s. Raw peak heights were normalized with Log10 transformation and auto-scaling functions and subjected to Student´s t-test pair-wise comparisons (bacterium vs. mock) to identify DAMs through the MetaboAnalyst5.0 software. DAMs were determined as those having a p-value < 0.05 and a Log2 fold change (FC) ≤ − 1 or ≥ 1. White boxes represent not significant net accumulation. Input data are listed in Dataset S6. Heatmaps and clustering were created with the pheatmap R package using default settings