Detection and quantitation of a rapidly accumulating and predominant 104 kDa heat shock polypeptide in rice

Abstract

When 5-day-old rice seedlings were subjected to a high temperature stress (45°C), the shoots as well as roots synthesized and accumulated a 104kDa polypeptide within 1-2 h of the imposition of the stress. The higher levelsof this polypeptide persisted for nearly 16 h when the 45°C temperature stress was continued for 24 h or up to 4 h when seedlings were brought to recovery at 28°C after 4 h of 45°C temperature stress. The leaves obtained from mature plants also accumulated the same polypeptide in response to temperature stress. Exposure of seedlings to salinity, desiccation, cold, wounding or exogenous abscisic acid application had no effect on the accumulation of this polypeptide. Importanly, this polypeptide made nearly 0.4% of the total soluble protein fraction. High temperature induced accumulation of this polypeptide was noted to be conserved in three indica and three japonica cultivars Oryza sativa tested in this study.