Figure 1

Visual representation of the polyphenolic pathway in apple. The main polyphenolic classes (adjusted form Henry-Kirk et al. [[55]]) are highlighted in grey boxes. For each step the committed enzyme is indicated with the corresponding MDP gene ID, whose expression was experimentally assessed. Outside the main frame anthocyanins are also indicated, although they were not investigated, since this class (leading to the red coloration) is negligible in the “Granny Smith” apple cultivar.