Polyacrylamide gel electrophoresis of total soluble proteins extracted from the seeds of cotton and esterase isoenzymes from pearl millet cultivars aged under ambient and high humidity (75% RH)-high temperature (35°C) conditions was conducted. In cotton, the banding pattern of total soluble protein was not affected by natural ageing in spite of considerable viability loss. However, under accelerated ageing, prominent differences in the protein profiles wsre observed even when there was only a decline in seed vigour and not in viability. In pearl millet, the banding pattern of esterase isoenzymes changed both under natural and accelerated ageing conditions. In both crops, some of the lower mobility bands present in the freshly harvested seeds were not detectable after ageing, instead, some additional bands having higher mobility were detected. It is suggested that additional bands which appear after ageing may be a result of breakdown of the lower mobility bands (high molecular weight proteins) or may have been synthesized in response to the shock caused by accelerated ageing.
