title: Temperature-triggered periodical thermogenic oscillations in skunk cabbage (Symplocarpus foetidus).
abstract: The natural occurrence of temperature-triggered and light-independent thermogenic oscillation in the spadix of skunk cabbage, Symplocarpus foetidus, was discovered. The identified thermogenic oscillator had an accurate periodical cycle (ca. 60 min per cycle) that apparently responded to an increase or decrease in the spadix temperature with a threshold of less than 0.9 degrees C. Neither a constant ambient air temperature nor transient changes in the ambient air temperature within 10 min (19 degrees C --> 15 degrees C --> 19 degrees C) induced the temperature oscillation in the spadix. Moreover, the periodical cycles were independent of the weight of the spadix (2.5-9.2 g) and the amplitudes of the temperature oscillations were correlated with the magnitude of the changes in the spadix temperatures. These results imply that periodical temperature oscillations in the spadix of S. foetidus possess a quantitative regulatory process that involves a temperature sensation and subsequent heat production. Based on these results, we propose a time-dependent thermogenic oscillatory model that acts as a precise thermal regulator under dynamic environmental temperature changes.
authors.affiliation: Cryobiosystem Research Center, Faculty of Agriculture, Iwate University, Ueda 3-18-8, Morioka, Iwate, 020-8550 Japan. kikuito@iwate-u.ac.jp
authors.forename: Kikukatsu
authors.initials: K
authors.lastname: Ito
authors.forename: Takanori
authors.initials: T
authors.lastname: Ito
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Onda
authors.forename: Matsuo
authors.initials: M
authors.lastname: Uemura
mesh_terms: D029064:Araceae / Q000502:physiology*; D010507:Periodicity; D018514:Plant Structures / Q000502:physiology*; D013696:Temperature; D022722:Thermogenesis; D013997:Time Factors