PROTEIN PROFILES IN WHEAT SEEDLINGS SUBJECTED TO DEHYDRATION STRESS

Changes in the soluble protein content, electrophoretic profiles of total and thermostable proteins and polypeptides in endosperms and roots of wheat seedlings germinated under optimal and stress conditions were investigated. Low and high temperature, 0.2 M NaCl, 0.5 M sucrose, 30 mu M ABA and 10 mM H2O2 were applied as stress factors and seeds germinated for 72 hours. The results obtained show that the time course of soluble protein mobilization at early germination depended on the nature of stress factors applied. The response to stress conditions was tissue specific. Low temperature stress elicited the greatest number and most intense total polypeptides in the roots of treated seedlings. High temperature most strongly influenced the thermostable polypeptide profile in endosperms. Content of a 25-kDa polypeptide related to cold tolerance increased in the roots of stressed seedlings. A thermostable polypeptide with a molecular weight of 42 kDa was found in H2O2 stressed samples that was highly intensive and probably constitutes a stress specific response.