Meeting Abstract
Anthocyanins are the main class of pigments found in flowers, and are largely responsible for determining floral hue and color intensity. Even over relatively short evolutionary timescales, radical changes in flower pigmentation have occurred in many plant genera. However, the genetic mechanisms underlying these changes at the species level are generally unknown. It is thought that because of pleiotropic effects, the core genes of the pathway are unlikely to suffer deleterious mutations, preserving the vital roles of the pathway products in other tissues. This suggests an important role for regulatory changes in the evolution of floral pigmentation. We use HPLC to identify and quantify floral products of the anthocyanin pathway, and qPCR to measure gene expression of 7 core genes of the pathway, in 28 species (3 individuals per species) of the Iochrominae clade (Solanaceae). We found that complete losses of floral anthocyanins are convergently due to down-expression of three late genes of the pathway. We are currently using transcriptomics to identify the regulatory elements responsible for these changes in a subset of species. Additionally, we aim to further our understanding of the control of metabolic flux through the pathway, i.e. which genes are reducing or increasing the total amount of pathway products, and the ratio of products, for example anthocyanins vs. flavonols.
