Fig. 2
Analysis of the Nicotiana defensive metabolome under NO2. Foliar metabolite profiles of Nicotiana plants exposed to 40 ppb NO2 (blue bars) and 0 ppb NO2 (white bars) under low and high concentrations of root-available NO3, based on three classes of defence-related secondary metabolites (alkaloids, phenolics and diterpene glycosides). a Nicotine; b anatabine; c alkaloid 3; d chlorogenic acid; e caffeic acid 2; f caffeic acid 3; g terpenoid glycoside 1; h terpenoid glycoside 2; i terpenoid glycoside 3; j terpenoid glycoside 4. Alkaloid (a–c) and phenolic (d–f) quantities are given as µg gFW−1; terpenoid glycosides (g–j) are given as peak-area gFW−1. An asterisk (*) denotes a significant main or interactive effect of NO2 treatment; a dagger (†) denotes a significant main or interactive effect of NO3 treatment and ns indicates not significant (GLMM). Data represent N = 3 chamber averages with N = 4 plants per chamber, and error bars are +1 SE, with full statistical results provided in Supplementary Table 2
