title: Photoperiodic regulation of a 24-kD dehydrin-like protein in red-osier dogwood (Cornus sericea L.) in relation to freeze-tolerance.
abstract: A predominant 24-kD dehydrin-like protein was previously found to fluctuate seasonally within red-osier dogwood (Cornus sericea L.) stems. The current study attempted to determine what environmental cues triggered the accumulation of the 24-kD protein and to assess its potential role in winter survival. Controlled photoperiod and field studies confirmed that photoperiod regulates a reduction of stem water content (SWC), freeze-tolerance enhancement and accumulation of the 24-kD protein. Diverse climatic ecotypes, which are known to respond to different critical photoperiods, displayed differential reduction of SWC and accumulation of the 24-kD protein. A time-course study confirmed that prolonged exposure to short days is essential for SWC reduction, 24-kD protein accumulation, and freeze-tolerance enhancement. Water deficit induced 24-kD protein accumulation and enhanced freeze-tolerance under long-day conditions. In all instances, freeze-tolerance enhancement and 24-kD protein accumulation was preceded by a reduction of SWC. These results are consistent with the hypothesis that C. sericea responds to decreasing photoperiod, which triggers a reduction in SWC. Reduced SWC in turn may trigger the accumulation of the 24-kD protein and a parallel increase in freeze-tolerance.
authors.affiliation: Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47907-1165, USA.
authors.forename: Dale T
authors.initials: DT
authors.lastname: Karlson
authors.forename: Yan
authors.initials: Y
authors.lastname: Zeng
authors.forename: Vicki E
authors.initials: VE
authors.lastname: Stirm
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Joly
authors.forename: Edward N
authors.initials: EN
authors.lastname: Ashworth
mesh_terms: D000064:Acclimatization / Q000502:physiology*; D029768:Cornus / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D005615:Freezing; D017440:Photoperiod; D010940:Plant Proteins / Q000378:metabolism*; D018517:Plant Roots / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D012621:Seasons; D014867:Water / Q000494:pharmacology
chemical_list: D010940:Plant Proteins; D014867:Water; C070556:dehydrin proteins, plant