Figure 5.

AT1, DH29, and CV86 contribute to distinct, but interconnected, MYB8-controlled hydroxycinnamoylputrescine and hydroxycinnamoylspermidine pools. A, PCA showing a separation of herbivory-elicited large-scale metabolic profiles in AT1-, DH29-, and CV86-VIGS leaves compared with an EV-treated leaf profile. PCA analysis was performed after preprocessing using the R package XCMS and log₂ transformation of the raw UPLC-TOF-MS files obtained from the measurement of the leaf tissues harvested 24 h after W+OS treatment. B, Hierarchical clustering analysis, using Pearson correlation as a distance metric, and the heat map of MYB8-dependent m/z signals from UPLC-TOF-MS analysis (log₂-scaled intensities are shown in Supplemental Table S2) that were differentially regulated in AT1-, DH29-, and CV86-VIGS plants (fold change versus EV < 0.5 or EV > 2, unpaired t test on log₂-transformed data: * P < 0.05, ** P < 0.001, *** P < 0.0001) compared with EV plants. The hierarchical clustering analysis separated AT1-dependent putrescine-based PA metabolic clusters from DH29- and putatively CV86-dependent spermidine-based PAs.