title: Thermogenesis-triggered seed dispersal in dwarf mistletoe.
abstract: Lodgepole pine dwarf mistletoe (DM), Arceuthobium americanum, is a parasitic flowering plant and forest pathogen in North America. Seed dispersal in DM occurs by explosive discharge. Notably, slight warming of ripe DM fruit in the laboratory can trigger explosions. Previously, we showed that alternative oxidase, a protein involved in endogenous heat production (thermogenesis) in plants, is present in DM fruit. These observations have led us to investigate if thermogenesis induces discharge. Here, infrared thermographs reveal that ripe DM fruits display an anomalous increase in surface temperature by an average of 2.1±0.8 °C over an average time of 103±29 s (n=9, 95% confidence interval) before dehiscence. Furthermore, both non-isothermal and isothermal modulated differential scanning calorimetry consistently show an exothermic event (~1 J g(-1)) in the non-reversible heat flow just prior to discharge. These results support thermogenesis-triggered seed discharge, never before observed in any plant.
authors: Department of Biological Sciences, Thompson Rivers University, Kamloops, British Columbia, Canada V2C 0C8.
authors: Rolena A J
authors: RA
authors: deBruyn
authors: Department of Physical Sciences (Physics), Thompson Rivers University, Kamloops, British Columbia, Canada V2C 0C8.
authors: Mark
authors: M
authors: Paetkau
authors: Pacific Agri-Food Research Centre, Agriculture and Agri-Food Canada, 4200 Highway 97, Summerland, British Columbia, Canada V0H 1Z0.
authors: Kelly A
authors: KA
authors: Ross
authors: Pacific Agri-Food Research Centre, Agriculture and Agri-Food Canada, 4200 Highway 97, Summerland, British Columbia, Canada V0H 1Z0.
authors: David V
authors: DV
authors: Godfrey
authors: Department of Biological Sciences, Thompson Rivers University, Kamloops, British Columbia, Canada V2C 0C8.
authors: Cynthia Ross
authors: CR
authors: Friedman
mesh_terms: D002152:Calorimetry, Differential Scanning; D007259:Infrared Rays; D014784:Mistletoe / Q000502:physiology*; D058614:Seed Dispersal / Q000502:physiology*; D022722:Thermogenesis / Q000502:physiology*; D013817:Thermography; D013997:Time Factors