Protein synthesis during cold shock in barley tissues. Comparison of two genotypes with winter and spring growth habit.

In barley (Hordeum vulgare L.) seedlings, a temperature step-down from 24 °C to 6°C (cold shock) determined a reduction in the incorporation of labeled aminoacids and modified the electrophoretic pattern of total proteins. At 6 °C some new proteins appeared and others were intensified (cold shock-induced proteins= CSPs); meantime, few proteins disappeared or were curtailed (cold-repressed proteins=CRPs). The majority of the proteins of the seedlings were labeled at about the same rate both at 6 °C and 24 °C, whereas at 0 °C only the cold shock proteins and a few others were detectable. The cold shock-induced variations of the protein profile differed in roots and in seed remnants which showed only some of the CSPs detected in roots. Total protein synthesis of barley genotypes lsquoOnicersquo and lsquoGeorgiersquo, which have respectively a winter and spring growth habit, were similarly inhibited by a temperature drop. The two genotypes, however, showed some differences in the CSPs and CRPs pattern. Because lsquoOnicersquo and lsquoGeorgiersquo have also a different thermotolerance, the hypothesis can be made that in barley specific CSPs are involved in conferring various degrees of cold resistance.