title: Spatiotemporal Floral Scent Variation of Penstemon digitalis.
abstract: Variability in floral volatile emissions can occur temporally through floral development, during diel cycles, as well as spatially within a flower. These spatiotemporal patterns are hypothesized to provide additional information to floral visitors, but they are rarely measured, and their attendant hypotheses are even more rarely tested. In Penstemon digitalis, a plant whose floral scent has been shown to be under strong phenotypic selection for seed fitness, we investigated spatiotemporal variation in floral scent by using dynamic headspace collection, respectively solid-phase microextraction, and analyzed the volatile samples by combined gas chromatography-mass spectrometry. Total volatile emission was greatest during flowering and peak pollinator activity hours, suggesting its importance in mediating ecological interactions. We also detected tissue and reward-specific compounds, consistent with the hypothesis that complexity in floral scent composition reflects several ecological functions. In particular, we found tissue-specific scents for the stigma, stamens, and staminode (a modified sterile stamen common to all Penstemons). Our findings emphasize the dynamic nature of floral scents and highlight a need for greater understanding of ecological and physiological mechanisms driving spatiotemporal patterns in scent production.
authors.affiliation: Plant Ecology and Evolution, Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Uppsala, 75236, Sweden, rosalieburdon@gmail.com.
authors.forename: Rosalie C F
authors.initials: RC
authors.lastname: Burdon
authors.forename: Robert A
authors.initials: RA
authors.lastname: Raguso
authors.forename: André
authors.initials: A
authors.lastname: Kessler
authors.forename: Amy L
authors.initials: AL
authors.lastname: Parachnowitsch
mesh_terms: D000080462:Acyclic Monoterpenes; D035264:Flowers / Q000737:chemistry / Q000502:physiology*; D008401:Gas Chromatography-Mass Spectrometry; D039821:Monoterpenes / Q000032:analysis; D009812:Odorants / Q000032:analysis*; D032263:Penstemon / Q000737:chemistry / Q000502:physiology*; D054817:Pollination; D055549:Volatile Organic Compounds / Q000032:analysis*
chemical_list: D000080462:Acyclic Monoterpenes; D039821:Monoterpenes; D055549:Volatile Organic Compounds; C018584:linalool