Fig. 5. Profiles in triterpenes ‘Rugiada’ and ‘Golden Delicious’ at the three developmental stages selected for RNA-sequencing analysis.

a A shift in triterpene pattern in ‘Rugiada’ is noticeable from 76 Days after Full Bloom (DAFB), where lupane-type triterpenes and caffeate conjugate proportion increase. *Significant differences (p ≤ 0.01) between ‘Rugiada’ and ‘Golden Delicious’ concentrations, as determined by Student t-tests. b Heat map representing the correlation coefficients between triterpene concentrations (classified per type) and the expression of genes in the MYB family (RPKM values). The heat map was calculated using normalised log10-transformed metabolite/gene expression levels, mean-centered, and standardised data. Cluster I represents a subset of MYB genes that were highly correlated with both the ursane-type and oleanane-type triterpenes, while cluster II represents a subset of MYB genes that were highly related to the lupane series of triterpenes, as well as to the triterpene-caffeates. See Table 1 for gene descriptions. c Differential expression analysis of genes identified in cluster II over the developmental series. Data represent means and SE of three biological replicates each per sample (generated from a pool of skin tissues from four different fruits). Significance was calculated according to one-way ANOVA for each time point (p < 0.05), where lowercase letters above bars result from the comparison of groups using Tukey’s. Groups connected by the same letter are not significantly different