ASSESSING THE IMPACT OF LATITUDE AND ELEVATION ON THE REGULATION OF BERRY SECONDARY METABOLITES IN THINLEAF HUCKLEBERRY

The overarching goal of the projectis to leverage cutting edge transcriptomic, metabolomic, phylogeographic, and bioinformatic techniques to understand how latitude, elevation, and evolutionary history affect dietary secondary metabolite production in economically important thinleaf huckleberry.The berry ofVaccinium membranaceumDouglas ex Torr., thinleaf huckleberry, is well-known for its flavor profile and has been economically important since its establishment as a forestry industry in the United States in the 1930s.Domestication efforts have not yet succeeded and harvesting pressure on natural populations remains high. Results of this project may impact ecological, economic, and social aspects of forest management of thinleaf huckleberry.Developmental and environmental regulation of desirable compounds in the berries is not well understood, but examples in closely related species ofVacciniumshow that light quality and elevation contribute to secondary metabolite production and regulation. This project will test questions in both controlled environments and the field and will uniquely incorporate phylogenetic history into the assessment of patterns of expression of these metabolites. In addition, this plant is geographically widespread west of the Rocky Mountains with disjunct populations in the Great Lakes Region (GLR) and the GLR populations will provide a replicate latitudinal data point to more thoroughly isolate the impact of latitude on regulation of secondary metabolites. Details of the three objectives of the proposed research are:Objective 1: Determine the expected response of secondary metabolite production in thinleaf huckleberry fruits in controlled treatments of UV intensity.H1:CHS,DFR,ANS, andUFGTwill be upregulated at higher UV exposure.H2:Quantity of anthocyanins, flavonols, and hydroxycinnamic acids will be greater in berries matured at higher UV exposure.Objective 2: Compare expression of genes in secondary metabolic pathways and secondary metabolite content of berries between low and high elevation populations across a latitudinal gradient.H1:Higher expression ofCHS,DFR,ANS, andUFGTwill be correlated with higher latitude and higher elevation.H2:Higher quantities of anthocyanins, flavonols, and hydroxycinnamic acids will be correlated higher latitude and higher elevation.Objective 3: Examine the phylogeographic history of thinleaf huckleberry and the impact of evolutionary history on patterns of secondary metabolite production in berries across the geographic range.H1:Expression levels ofCHS,DFR,ANS, andUFGTand quantities of anthocyanins, flavonols, and hydroxycinnamic acids have phylogenetic structure.H2:Any relationships found between latitude and elevation and secondary metabolite production hold (Aim 2: H1, H2) after accounting for phylogeny.