Abstract

Flavonoids synthesis and anthocyanin accumulation depends on the control exerted by transcription factors of the MYB R2R3 subfamily. In Rosaceae studies have focused primarily on the identification and characterization of MYB 10 and MYB 1 factors, both involved in regulating the synthesis of flavonoids, but studies of the other factors involved are scarse. Using BLAT and BLAST tools in strawberrygenome and phytozome databases we find putative R2R3 MYB subfamily genes for each Rosaceae species with sequenced genome.111, 115 and 116 gene models for apple, peach and strawberry have been found, respectively. These were analyzed together with 126 R2R3 MYB genes described for Arabidopsis thaliana. Clades associated with the regulation of flavonoid synthesis were identified. To clarify the role of gene models found, the construction of a new phylogenetic tree was performed. This tree incorporated the R2R3 MYB transcription factors previously described for Rosaceae, Arabidopsis and grapevine allowing the association of potencial orthologous genes to each gene model. Some of the identified gene models were tested in Japanese plum (Prunus salicina). Some of the candidate genes were isolated and their expression patterns in skin and pulp, at different stages of fruit development, were determined. Events of expansion, loss, or retention of genes in Rosaceae are discussed.