Single nucleotide mutation in FvMYB10 may lead to the yellow fruit in Fragaria vesca

The color of strawberry mainly results from the accumulation of anthocyanins. However, the regulatory mechanism of anthocyanins accumulation in strawberry is not fully understood. To identify the key gene responsible for anthocyanins synthesis, we firstly did complementation test in yellow strawberry (Fragaria vesca accession ‘Yellow Wonder’) with FvF3H from red strawberry (F. vesca accession ‘Ruegen’) which was considered co-segregation with c (yellow fruit color) locus. However, overexpression of FvF3H from red strawberry did not restore the red fruit phenotype and the transgenic lines still showed yellow color. Next, we did genetic mapping of c locus by constructing a F2 population and delimited the candidate gene to 718 kb genomic region. Then, comparative genomic analyses between Arabidopsis thaliana and Fragaria vesca on a genome-wide level was conducted for screening the candidate gene involved in anthocyanins biosynthesis. Interestingly, only one anthocyanin-related gene, FvMYB10, was found in the candidate region based on mapping data and comparative genomic analyses. A single nucleotide mutation in the coding region of MYB10 co-segregated with the fruit phenotype in F2 population and different strawberry varieties and lines. Thus, it was the most likely candidate gene for c locus. Moreover, the mutation region was located in MYB transcription factor R2 DNA-binding domain. Gene expression of FvMYB10 was no significant difference between yellow and red fruit strawberry, which indicated point mutation may affect FvMYB10 protein or structural genes expression instead of transcript level of FvMYB10. This information will provide a platform for understanding the regulatory mechanism of anthocyanin biosynthesis in strawberry.