Differences in Activities Related to Cessation of Synthesis of Inducible Proteins as an Early Response to Cold between Hardy and Less Hardy Cultivars of Winter Wheat.

Abstract

Using two sets of cultivars, two hardy and two less hardy ones, we studied differences in the regulation of the synthesis of cold-inducible proteins at an early stage of cold acclimation. During 11 days of cold treatment, all four cultivars had changes in rates of protein synthesis, which were divided into four phases. The difference in the regulation of synthesis of the protein was evident at the third and fourth phases. In the less hardy cultivars, rates of synthesis of cold-inducible proteins started to decline and the profiles of proteins being synthesized resembled those of control samples (without cold treatment). In hardy cultivars, rates of synthesis of typical cold-inducible proteins remained unchanged, suggesting that some regulatory mechanisms regulate the continued cold-inducible synthesis of proteins in the latter cultivars by acting, presumably, at particular target sites within the crown cells. Analysis of freezing tolerance showed that in stems and crowns of winter wheat, the cold-inducible proteins do not contribute directly to the freezing tolerance, while some may have roles in bringing about increased longevity in cold environments.