DISSERTATION RESEARCH: Selective constraints, genetic correlations, and divergence of the flavonoid pathway in Silene vulgaris

University Of Virginia Main Campus, Charlottesville VA

Investigators

Abstract

The plant flavonoid pathway forms distinct groups of chemicals responsible for several important roles, including pigmentation, plant defense, antioxidants, and sunscreen. An interconnected network of genes is responsible for the production of each flavonoid subgroup. Changes in gene regulation and subsequent flavonoid expression will be controlled by genes and enzymes that are shared among different branches of the pathway, suggesting that there may be trade-offs between flavonoid groups and therefore the related ecological functions. Next-generation sequencing in the form of multiple transcriptomes will be made of Silene vulgaris individuals taken from a reciprocal transplant experiment of high and low elevation plants (high and low UV-B environments) to test for adaptation to specific environments and flavonoid gene expression, which will be compared to chemical analyses of flavonoids. This will allow the consideration the entire flavonoid pathway simultaneously, in particular how increased expression of a specific branch affects the overall expression phenotype. Studying the correlated traits of a metabolic pathway will shed light on the evolution of secondary metabolism in plants, illuminating how different points in gene networks can be subject to adaptive evolution and influence overall pathway development. Since flavonoids are ubiquitous, this research will be applicable to most plants. In particular, the proposed research will also expand on knowledge of plant adaptive divergence along UV-B gradients, shifts in which have been associated with human-mediated global change. This proposal also details using next-generation sequencing techniques in a natural setting and non-model organism, which may encourage further studies along those lines.