Modeling leaf, shoot, and root apoplast proteomics data into regulatory networks and pathways. The pathways include stress factors (drought and pathogen) upstream of proteins and physiological responses (yellow). Proteins are displayed on the background tree relative to the tissue in which they were found, except for two proteins (orange) that were found both in roots and leaves. Proteins displayed in pathways are identified by protein functional name/abbreviation followed by former poplar protein ID in parenthesis. Abbreviations in parenthesis: SCPL20 = serine carboxypeptidase-like 20, PR5 = pathogenesis-related gene 5, KCS10 = 3-ketoacyl-CoA synthase 10, SIZ1 = E3 SUMO-protein ligase, CP1 = cysteine-type peptidase, SOD = superoxide dismutase, PGK = phosphoglycerate kinase, GST = glutathione S-transferase, SAM = S-adenosylmethionine synthetase, CH-IV = class IV chitinase, TPI = triose-phosphate isomerase, DHAR = dehydroascorbate reductase, BGL2 = beta-1,3-glucanase 2, TIM = triosephosphate isomerase, GAD = glutamate decarboxylase, and ICDH = isocitrate dehydrogenase.