Abstract Detail

Comparative Genomics/Transcriptomics

Drummond, Chloe [1], Yin, Shuhan [2], Renner, Tanya [3].

Flavonoid expression in Vaccinium membranaceum Douglas ex Torr. leaves across gradients of latitude and elevation.

Vaccinium membranaceum Douglas ex Torr. (thinleaf huckleberry, Ericaceae) commonly occurs as a dominant understory species in the Pacific Northwest and the Rocky Mountain Region. Its leaves, stems, and berries are an important food source for grizzly bears and American black bears, as well as ungulates and birds. The flavonoid content of Vaccinium leaves, including anthocyanins, catechins, and proanthocyanidins, has been shown to change in response to light intensity and along latitudinal gradients. At higher light intensities, an increase in leaf flavonoid content might be attributed to the need for photoprotection against light that exceeds photosynthetic capacity. At higher latitudes, although light intensity may decrease as it passes through more atmosphere, lower temperatures that can reduce photosynthetic capacity, combined with longer growing season daylight length, may induce flavonoid photoprotective response. Higher elevations may also increase flavonoid content due to lower temperatures and higher light intensity, particularly of ultraviolet (UV) radiation. Even though V. membranaceum leaves are an important nutritional source for animals and are harvested for medicinal purposes, its leaf flavonoid response to latitude and elevation has not yet been studied using transcriptomic tools. Illuminating the patterns of flavonoid response over these gradients may inform our evolutionary understanding of how V. membranaceum adapts to abiotic stress and our ecological understanding of correlation between geography and digestibility of leaves by animals. In addition, it may inform any attempts to commercially grow this species, an effort that may reduce stress of over harvesting on natural populations. We tested the effects of latitude and elevation on flavonoid gene expression and biosynthesis by analyzing leaves collected from seven populations along a latitudinal gradient and at varying elevations within a three-week period in August 2022. Environmental data such as soil constituency and canopy cover were collected, alongside genotyping-by-sequencing data, to account for covarying effects of environment and genetic background. RNA-Seq transcriptomic data were analyzed using weighted gene correlation network analysis (WGCNA), differential gene expression (DGE) analysis, and gene ontology (GO) term enrichment. Our results help to evaluate abiotic stress response in thinleaf huckleberry, a species with an important ecological role, and serve as a foundation for understanding how this species may endure greater UV exposure or movement to higher latitudes in the future due to climate change.

1 - The Pennsylvania State University, Entomology, 512 ASI Building, University Park, PA, 16802, United States
2 - The Pennsylvania State University, Entomology, 138 ASI Building, University Park, Pennsylvania, 16802, United States
3 - The Pennsylvania State University, Department of Entomology, 512 ASI Building, University Park, PA, 16802, USA

Keywords:
Flavonoid Biosynthesis
Huckleberry
Transcriptomics
Latitude
Elevation
Landscape Transcriptomics.

Presentation Type: Oral Paper
Number: CGT5006
Abstract ID:850
Candidate for Awards:None