Expression of a boiling-stable protein (BsCyp) in response to heat shock, drought and ABA treatments in Sorghum bicolor

The effect of heat stress, drought and abscisic acid (ABA) on the induction of boiling-stable proteins were studied in 12 h germinated sorghum embryos and endosperm. SDS-PAGE revealed the heat shock induction of one major 97 kDa boiling-stable protein both in embryos and endosperm. Western blotting analysis, using polyclonal antibodies raised against a 20 kDa Arabidopsis thaliana cyclophilin, revealed the induction of a cross-reacting band (97 kDa, BsCyp) in both embryos and endosperm in a time dependent manner. The BsCyp boiling-stable polypeptide was also regulated by exogenous application of ABA, indicating its role in water stress adaptation. Drought stress also resulted in a significant induction of boiling-stable protein (BsCyp) in both embryos and endosperm. Based upon these observations the possible role of BsCyp in water stress tolerance is discussed.