Loss-of-function mutation of anthocyanidin synthase results in yellow pigmented fruits in Rubus idaeus L.

Yellow raspberry fruits have reduced anthocyanin content and offer an unique possibility to study the genetics of anthocyanin biosynthesis in this important soft fruit. A key step in the biosynthesis of coloured pigments is catalyzed by anthocyanidin synthase (ANS) by the conversion of leucoanthocyanidin to anthocyanidin. Here, we describe the cloning and characterisation of an ANS gene from raspberry and identification of one mutated ANS allele in the yellow variety “Anne”. A 5-bp insertion in the coding region was identified. This insertion creates a premature stop codon and is predicted to result in a truncated protein of 264 amino acids (AA), compared to 414 AA for the wild type (WT) ANS found in red variety “Tulameen”. The level of ANS mRNA in turning stage of yellow fruits is reduced leading to loss of visible anthocyanin pigments. Taken together, our data shows that the mutation in raspberry ANS gene is responsible for yellow phenotypes at least in the variety studied here