“…The ability of plants to adapt to low temperatures has been attributed to changes in specific biochemical processes (Caldwell, 1990), including the synthesis of temperature-shock proteins (Guy et al, 1985), alterations in structure and function of enzymes involved in key metabolic reactions (Berry and Bjorkman, 1980 Pierce, 1988), and the development and repair of the photosynthetic apparatus (Goldberg et al, 1989; Nie and Baker, 1991). Changes in cell plasma membrane structure (Steponkus, 1984; Steponkus and Lynch, 1989; Raison and Orr, 1990) or in the insoluble cell wall proteins may also be involved in plant cell acclimation to temperature extremes (Lamport, 1977(Lamport, ,1980Cassab andVarner, 1987, 1988). The work of Lamport (1977of Lamport ( ,1980 demonstrated that the extracellular matrices of the primary cell walls of angiosperms comprise 4-hydroxyproline-rich glycoproteins, i.e., extensins, arabinogalactan proteins, salt-extractable glycoproteins, lectins, and agglutinins, in which a number of proline residues are posttranslationally modified to 4-trans-hydroxyproline (Lamport, 1980;Fincher et al, 1983;McNeil et al, 1984;Cassab et al, 1985; Cooper et al, 1987;Corbin et al, 1987;Averyart-Fullard et al, 1988; Showalter et al, 1990; Marcus et al, 1991;Kielszewskietal., 1992).…”