Rosa1, a Transposable Element-Like Insertion, Produces Red Petal Coloration in Rose Through Altering RcMYB114 Transcription

Abstract

Rose (<i>Rosa</i> sp.) flowers have a rich diversity of colors resulting from the differential accumulation of anthocyanins, flavonols, and carotenoids. However, the genetic and molecular determinants of the red-petal trait in roses remains poorly understood. Here we report that a transposable element-like insertion (Rosa1) into <i>RcMYB114</i>, a R2R3-MYB transcription factor's promoter region causes its transcription, resulting in red petals. In red-petal varieties, <i>RcMYB114</i> is expressed specifically in flower organs, but is absent from non-red varieties. Sequencing, yeast two-hybrid, transient transformation, and promoter activity assays of <i>RcMYB114</i> independently confirmed the role of Rosa1 in altering <i>RcMYB114</i>'s transcription and downstream effects on flower color. Genetic and molecular evidence confirmed that the Rosa1 transposable element-like insertion, which is a previously unknown DNA transposable element, is different from those in other plants and is a reliable molecular marker to screen red-petal roses.