Stacey Smith Awarded NSF CAREER Grant
CAREER: Testing The Predictability of Flower Color Evolution at a Phylogenetic Scale in the Petunieae Clade (Solanaceae)
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.This research in Petunieae may lead to new approaches for the genetic engineering of crop plants, where pigments are valued as antioxidants. In addition, the scope of this project, looking at entire genetic pathways across a large radiation of species, may provide the foundation for developing model-based methods for predicting how genetic changes are likely to alter phenotype. 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 includes three major research 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. This work 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.