PhAAT1, encoding an anthocyanin acyltransferase, is transcriptionally regulated by PhAN2 in petunia.

ABSTRACT

Anthocyanins widely exist in plants and they are important pigments for color of petals and fruits. They are produced through a multi-step pathway controlled by transcription factor complexes. The anthocyanin skeleton modification is the last reaction in the anthocyanin synthesis pathway, which improves the stability of anthocyanins. Acylation modification is an important modification of anthocyanins. However, the identification and function of anthocyanin acyltransferase genes and their expression regulation are rarely reported. In this study, we identified the petunia anthocyanin acyltransferase gene, PhAAT1. PhAAT1 is located in the cytoplasm and PhAAT1 silencing changed flower color and reduced the stability of anthocyanin. Metabolomics analysis showed that PhAAT1 silencing led to the reduction of p-coumaroylated and caffeoylated anthocyanins. In addition, PhAAT1 was positively regulated by the MYB transcription factor, PhAN2, which directly interacts with the promoter of PhAAT1.