Thesis Defence: Investigating the Effects of Smoke on Grapevine Chemistry and Terroir Using Artemisia tridentata Nutt. Derived Terpenes and Metabolomics as a Hypothesis Generating Tool

Alisha Lasko Greene, supervised by Dr. Susan Murch, will defend their thesis titled “Investigating the Effects of Smoke on Grapevine Chemistry and Terroir Using Artemisia tridentata Nutt. Derived Terpenes and Metabolomics as a Hypothesis Generating Tool” in partial fulfillment of the requirements for the degree of Master of Science in Chemistry .

An abstract for Alisha Lasko Greene’s thesis is included below.

Defences are open to all members of the campus community as well as the general public. Registration is not required for in person defences.

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ABSTRACT

The wine industry in British Columbia is a major economic contributor. Unfortunately, the industry is challenged by the effects of climate change, such as wildfires. It is accepted that compounds released in biomass burning affect wine grapes and consequently, the wine. Artemisia tridentata Nutt. is an indigenous plant that often grows near vineyards in the South Okanagan wine growing region. I hypothesized that volatile compounds from growing and burning A. tridentata accumulated in commercial grapevines (Vitis vinifera L.) and that wildfire smoke influenced the terror of finished wines. To investigate this hypothesis, my specific objectives were: (a) to develop and validate a method for detection and quantification of terpenes in Vitis vinifera L. grapevine leaves and wine; (b) to determine terpenes in Artemisia tridentata in Vitis vinifera leaves after exposure to living plants in a controlled environment, smoke from a controlled burn of dried A. tridentata leaf, smoke captured from a controlled burn of A. tridentata leaf and dissolved in a solvent, and high-pressure solvent extraction of fresh A. tridentata leaves; and (c) to characterize smoky wine and award-winning wines from the South Okanagan wine growing region using metabolomics. My data show that terpenes released in growing and burning A. tridentata accumulated in Vitis vinifera leaves. Both terpenes detected in the A. tridentata extracts and their degradation products were also detected in the treated leaves. After a metabolomic investigation of smoky wines, several hypotheses were generated regarding nitrogen cycling through the arginine and proline metabolism pathways, and quercetin metabolism during grape-development. Together, these data improve our understanding of smoke events on grapevine chemistry and terroir.