An investigation of immunochemical affinity to stress protein CSP 310 proteins among the native cytoplasmic, mitochondrial and nuclear proteins of winter rye (Secale cereale L.) was carried out by PAGE-electrophoresis in control plants and in plants during exposure to cold stress. Western blotting showed that among the native proteins of all cellular fractions of control plants investigated there was immunochemical affinity to CSP 310 proteins with molecular weights about 230 and to a number of proteins of about 140 kD. The protein with molecular weight 310 kD was found only in cytoplasmic and mitochondrial fractions of control plants. Proteins with molecular weights 470 kD and 320-330 kD with immunochemical affinity to CSP 310, were also found in the nuclear fraction of control plants. By ethidium bromide staining, a cytoplasmic protein with molecular weight 310 kD, as well as nuclear proteins with weights 470 kD and 320-330 kD, were shown to be nucleoprotein complexes. It was shown that during exposure to cold stress the amounts of cytoplasmic proteins 310 and 470 kD and nuclear protein 320 kD are arises. In mitochondrial fraction new proteins appear of molecular weight 320 and 470 kD. By ethidium bromide staining, a cytoplasmic protein with molecular weight 310 kD, as well as nuclear proteins with weights 470 kD and 320-330 kD;, were shown not to be nucleoprotein complexes during exposure to cold stress. At the same time cytoplasmic protein with molecular weight 470 kD was shown to be nucleoprotein complex during exposure to cold stress. (C) 2000 Elsevier Science Ltd. All rights reserved.