CAREER: Testing The Predictability of Flower Color Evolution at a Phylogenetic Scale in the Petunieae Clade (Solanaceae)

University Of Colorado At Boulder, Boulder CO

Investigators

Abstract

Evolutionary biologists have long recognized that species can evolve many different forms (phenotypes) using the same sets of genes. One explanation for this pattern is that new forms can arise by changes in gene regulation, that is, shifts in when and where those genes are active. Although regulatory differences are known to underlie changes in features as complex as eyes and wings, it remains unclear how broadly this regulatory hypothesis applies and whether, in some cases, changes in the genes themselves are more important. This project will address this question by tracing the evolutionary changes involved in flower color transitions across Petunieae, a group of 140 species that includes the ornamental petunias. The genes that produce floral pigments are well studied, making it possible to characterize the genetic changes associated with flower color evolution even at this broad scale. As a part of this work, the researchers will create and present color-themed activities to diverse groups of K-12 students and undergraduates in order to enhance teaching and learning about the connections between genes, pathways, and phenotypes across the tree of life. This project will test the role of regulatory evolution in the color diversification of Petunieae through three specific aims. The first aim will infer the history of flower color shifts in the clade using a new phylogeny constructed from transcriptomic data. Building on this phylogenetic framework, the second aim will use comparative methods and biochemical profiling to quantify the evolutionary relationship between changes in the expression of pigment pathway genes and color variation. Given the modular nature of the regulation of these genes, the third aim will test for correlated evolution of gene expression across the phylogeny. These aims will be carried out through collaborations with botanists from Brazil and Argentina, who will participate in research exchanges to foster the sharing of knowledge and techniques. At a local scale, the research activities will be integrated into outreach events as well as inquiry-based course modules for undergraduates and upward-bound high school students. These innovative teaching approaches will be coupled with new tools to assess learning gains and guide improvement.