Effect of combined salt and heat treatments on germination and heat-shock protein synthesis in lentil seeds

The germination of lentil seeds was gradually reduced when seeds were exposed to temperature of 30 or 40 degreesC, either alone or combined with 0.1, 0.2 or 0.3 M NaCl or 34.1 % (m/v) PEG 8000, during 6 - 12 h imbibition. [S-35]-methionine incorporation in 12 h imbibed lentil axes also decreased with increasing NaCl concentration at 20 and 40 degreesC, whereas at 30 degreesC only 0.3 M NaCl treatment partially inhibited protein synthesis. An analysis of newly synthesized proteins by 1-D SDS PAGE, showed that the expression of most polypeptides decreased following increasing stress. Among these, low molecular mass heat-shock proteins declining, higher in 40 degreesC treated axes than those treated at 30 degreesC, supports the hypothesis that at this temperature maximal level of expression of these proteins was achieved.