Expression of betacyanin biosynthetic genes in response to continuous insect herbivory.

Relative expression levels3 were determined in roots of A. hypochondriacus plants, with contrasting pigmentation patterns, subjected to insect herbivory. Induced or repressed levels of expression (i.e. relative expression ≥1.5 or ≤0.5) are shown in bold text and italics, respectively.1h = time, in hours, when the tissues were sampled after an 18 h period of continuous insect feeding.2The genotypes examined in this study were Ah cv. Nutrisol (AhNut; with predominantly betacyanic leaves), Ah India Red (AhIR; with predominantly betacyanic stems) and Ah India Green (AhIG; with all tissues acyanic).3The fold change in the expression of the target genes was calculated using the 2−ΔΔCt method according to [76].