Regulation of Cold Acclimation

Exposure to low, non-freezing temperatures induces molecular, morphological, and physiological changes in plants which result in the acquisition of freezing tolerance (Va-sil’yev, 1961; Guy, 1990; Thomashow, 1993; Hughes and Dunn, 1996). Light, through the process of photosynthesis, provides the energy required for the complex metabolic changes of cold acclimation (Dexter, 1933; Tysdall, 1933; Steponkus and Lanphear, 1968; Gusta et al., 1982; Griffith and Mclntyre, 1993). Huner and co-workers have demonstrated that the freezing tolerance of cereals is not only correlated to the capacity to keep QA, the stable quinone electron acceptor of photosystem II (PSII), in the oxidized state, but also to an increased photosynthetic capacity (PSmax) (Huner et al., 1993; Oquist et al., 1993).