Effect of ABA seed pre-treatment on the response of wheat (Tritium aesitivum L.) to salinity, with special reference to plant growth, ion relations and protein patterns

Abscisic acid (ABA) is an important plant growth hormone. Seeds of wheat varieties differing in salinity resistance were treated with ABA during imbibition and the response to this seed pre-treatment, both under control and saline conditions was evaluated later in the plant life cycle. ABA seed pre-treatment significantly increased the plant growth of salinity sensitive wheat variety; Punjab-85, under NaCl salinity. Further, it reduced the Na+ in third leaf and the fluxes of Na+ (38%) and Cl- (40%) and increased those of K+ (12%) in the plants of same wheat variety. Further, S-K,S-Na calculated in the xylem sap was also enhancement with ABA pre-treatment in Punjab-85 under saline conditions. Comparison of proteins, separated by two-dimensional gel electrophoresis, demonstrated the presence of three new proteins in the extract from ABA pre-treated plants. These ABA-induced proteins, were of molecular weights 15, 18 and 23 kDa. This study has established that ABA seed pre-treatment increased the salinity resistance of the sensitive wheat variety, Punjab-85. The increase in salinity resistance correlated with a reduction in sodium uptake. Further, pre-treatment caused new proteins to be synthesized.