AtMYB11 regulates caffeoylquinic acid and flavonol synthesis in tomato and tobacco

Interest in so-called functional foods, i.e., foods that promote health and disease prevention, is increasing. Consumption of plant polyphenols has been implicated in the prevention of age-related diseases, cardiovascular disease and cancer. AtMYB12 and AtMYB111, which were originally identified as flavonol-specific transcriptional activator in Arabidopsis thaliana, induces the accumulation of high levels of polyphenols in tobacco and tomato plants. In this study, we determined that the transcription factor AtMYB11 as its close homologs, AtMYB12 and AtMYB111, regulate flavonoid and caffeoylquinic acid biosynthesis in tomato and tobacco plants. Constitutive expression of AtMYB11 enhanced the expression of genes in the phenylpropanoid biosynthesis pathway, resulting in the accumulation of flavonoids and chlorogenic acid in tobacco and tomato plants. Increases in dicaffeoylquinic acid and tricaffeoylquinic acid content were only detected in AtMYB11-expressing tomato fruits. These results suggest the potential of transgenic tomatoes with improved antioxidant properties as functional foods.