Figure 1.

The tocopherol biosynthetic pathway in Arabidopsis and its P. syringae-triggered induction in leaves. Tyr, l-Tyr. In Arabidopsis, TAT1 and HPPD are localized in the cytosol, while other tocopherol pathway enzymes are in the chloroplast (Mène-Saffrané, 2017). The coloring of the tocopherol biosynthetic genes represents their degree of regulation in response to P. syringae inoculation (red, strongly up-regulated; orange, moderately up-regulated; black, no significant change; green, down-regulated). The coloring of the frames surrounding the metabolites indicates the degree of pathogen-induced metabolite accumulation (red, strong; orange, moderate; gray, no significant change), and the frame line widths illustrate the absolute levels of the metabolites in inoculated leaves of wild-type plants.