Discriminating upland and lowland rice genotypes through proteomic approach

Most of the crop plants respond to growth limiting heat shock or other stresses by inducing or enhancing the expression of a number of specific stress proteins called heat shock proteins. These proteins act as important constituents of molecular mechanisms for tolerance. Rice is one of such crops that grow during very hot season, and any deficiency of water can subject rice plant (especially the lowland cultivars) to heat stress. The present study was therefore, conducted to discriminate upland and lowland rice genotypes on the basis of their tolerance to environmental stresses such as heat (high temperature). The objectives were to see differences i) in heat tolerance level of upland and lowland rice genotypes to water deficiency ii) in quality and quantity of heat shock proteins in tolerant and sensitive genotypes and iii) possible role of heat shock proteins in the tolerance of lowland rice genotypes. For this purpose, one weak old seedlings comprising 5 upland and lowland rice genotypes and their inter-generic hybrids were exposed to heat stress of 45-55 °C for 16-18 h. Proteins were extracted from leaf sheaths. Variations in heat shock proteins, thus detected, are being discussed with special reference to tolerance for heat and water deficiency in rice.