Heat stable proteins and desiccation tolerance in recalcitrant and orthodox seeds

During development of peanut seeds, a set of low molecular weight polypeptides was identified most of which were heat-stable. For wampee seeds, only one band of heat-stable proteins could be checked out by SDS-PAGE. It had a molecular weight of 20 kDa and constituted 1% of the total proteins. By Western blot analysis, wampee seed axes can express dehydrin-like proteins (at 67-88 days (d) after anthesis) but the level was very low. Stachyose and sucrose increased and maltose declined with the acquisition of desiccation tolerance during embryogenesis of peanut seed. Following the development of wampee seed, glucose and maltose decreased gradually, while fructose, sucrose and stachyose increased markedly. It may be assumed that the heat-stable and low molecular weight polypeptides synergize with soluble sugars in the acquisition of desiccation tolerance in peanut seed though not in wampee seed.