title: A comparison of the chilling-stress response in two differentially tolerant cultivars of tomato (Lycopersicon esculentum).
abstract: The chilling responses of two differentially cold tolerant cultivars of tomato were monitored through in vivo labelling of polypeptides with [35S]methionine, both during a gradual temperature decrease (2 degrees C/day) and also during a rapid cold shock (4 degrees C). The polypeptides were separated by one-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis and revealed by fluorography. Both cultivars showed changes in the polypeptide profiles resulting from either chilling treatment. During the gradual temperature decrease, there were few differences exhibited between the two cultivars. However, during cold shock both cultivars showed the altered synthesis of several unique polypeptides. Both cultivars showed the appearance of a 35-kDa polypeptide during the gradual temperature decrease and also during the cold shock. The appearance of three high relative mass polypeptides was found in both cultivars only during the gradual temperature decrease. Treatments with cycloheximide and chloramphenicol suggested that cold-shock polypeptides are both nuclear and organelle encoded. The cold-shock response in roots was different from the response in leaves and between cultivars. A comparison of the two cultivars showed a number of differences in polypeptide synthesis which may be related to increased cold tolerance.
authors.affiliation: J. Tuzo Wilson Research Laboratories, Department of Botany, University of Toronto, Mississauga, Ont., Canada.
authors.forename: R W
authors.initials: RW
authors.lastname: Giroux
authors.forename: W G
authors.initials: WG
authors.lastname: Filion
mesh_terms: D000064:Acclimatization; D002701:Chloramphenicol / Q000494:pharmacology; D003080:Cold Temperature; D003513:Cycloheximide / Q000494:pharmacology; D018521:Plant Physiological Phenomena; D010940:Plant Proteins / Q000096:biosynthesis*
chemical_list: D010940:Plant Proteins; D002701:Chloramphenicol; D003513:Cycloheximide