MOLECULAR PHYSIOLOGICAL STUDIES ON HEAT SHOCK PROTEIN EXPRESSION IN A STRESSED PLANT

Abstract

The experiments described in the present investigation were designed to compare the effect of pre-emergence treatment with different salinity levels on growth and the photosynthetic pigments of selected Zea mays cvs. Giza 628, single cross hybrid 122 and Giza 2 to determine the highest tolerant line or the highest sensitive one for different salinity levels. The effects of abiotic stresses (salinity, drought and high temperature) on growth characteristics, endogenous phytohormones, photosynthetic pigments, cell ultrastructure, carbohydrate contents, certain mineral ion contents, total amino nitrogen and proline contents, total soluble protein and protein profile were also studied. In addition, the effects of heat and drought stresses on heat shock protein expression in both tolerant and sensitive Zea mays Lines were examined. Moreover, trials to isolate a fragment of heat shock gene encode for HSP 18 from the tolerant line were carried out. Finally, applying the osmoprotectant glycine betaine to improve the stress tolerance in Zea mays Line was done. The results cleared that Zea mays cv. Giza 2 has been shown to be the most tolerant line, while single cross 122 was found to be the most sensitive one.