Thellungiella: an Arabidopsis-related model plant adapted to cold temperatures.
Thellungiella salsuginea, a wild crucifer that grows in subarctic Canada and is closely related to Arabidopsis thaliana, was examined for its suitability as a model plant for studies of tolerance to cold and freezing temperatures. Thellungiella completed its life cycle at 5 degrees C, demonstrating that temperature-sensitive processes such as seed germination and the production of pollen and seeds were resistant to cold temperatures. Moreover, the plant exhibited dramatically different vegetative and flowering phenotypes in response to growth at cold temperature and shifts to cold temperature. Northern analyses showed that genes induced by cold in Arabidopsis, including CBF1, the transcriptional activator for the cold-regulated (COR) genes COR15a and COR47, were also expressed in Thellungiella. Freezing tolerance, assayed by the regrowth of intact plants, increased from -13.0 to -18.5 degrees C after cold treatment. The plants lacked endogenous ice nucleation or anti-freeze activity, indicating a potential for supercooling. As a close relative to Arabidopsis, Thellungiella exhibits extreme cold tolerance and should be an important model system in the elucidation of stress tolerance mechanisms.
Griffith
Marilyn
M
Department of Biology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada.
Timonin
Mary
M
Wong
Annie C E
AC
Gray
Gordon R
GR
Akhter
Sajjad R
SR
Saldanha
Marsha
M
Rogers
Michael A
MA
Weretilnyk
Elizabeth A
EA
Moffatt
Barbara
B
D000064:Acclimatization / Q000502:physiology*; D019607:Brassicaceae / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D003080:Cold Temperature; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D018525:Germination / Q000502:physiology; D012639:Seeds / Q000502:physiology