bHLH Transcription Factors involved on the regulation of anthocyanin genes during fruit development in wild strawberry (Fragaria vesca) and red raspberry (Rubus ideaus)

Red coloration on berry fruits is caused due the presence of anthocyanin pigments mainly produced during the late stages of the fruit maturation process. In the past years the interest on anthocyanins and other phenylpropanoids compounds has increased due the proof antioxidant effect both in vitro and in vivo systems, making consider plant breeders around the world consider this plant metabolites as an important trait to follow up. Anthocyanin and proanthocyanidin synthesis is regulated through the interaction of the MYB-bHLH-WD40 complex, which has been characterized in several crops from diverse families, including some Rosaceae species such as strawberry and apple.To date it is not clear which bHLH proteins are involved in this pathway in strawberries and raspberry species, including their correct identification and expression levels during the physiological changes that occur during fruit development and ripening. Here we show the activity of some “key” genes of the anthocyanin pathway like CHS, DFR, UFGT. Using genome wide phylogenetic analysis and the public genome available, we identified three possible bHLH candidates from F vesca and two from R. idaeus based on sequence homology with previously reported bHLH proteins from Malus, Arabidopsis and Fragaria. In order to quantify the activity of the candidate genes involved in this study, we analyze the RNA expression levels trough quantitative Real Time PCR (qRT-PCR) of 6 different fruit stages for Fragaria and 3 for Rubus, young leaves were used as a control tissue