MODULATION IN ACTIVITIES OF ANTIOXIDANT ENZYMES IN SALT STRESSED AND NON-STRESSED WHEAT (TRITICUM AESTIVUM L.) PLANTS RAISED FROM SEED TREARTED WITH TRIACONTANOL

Before sowing, the seeds of two wheat cultivars, S-24 and MH-97, were treated with three levels [(0 (water), 10 and 20 mu M)] of triacontanol (TRIA) for 12 h. TRIA-treated seeds were grown in full strength nutrient solution for 24 days in a greenhouse, after which time, they were supplied with two salt treatments (0 and 150 mM NaCl). After 21 days of salt application, changes in the malondialdehyde (MDA), hydrogen peroxide (H2O2) and total soluble proteins contents as well as activities of some key antioxidant enzymes (CAT, POD and SOD) were measured. Salinity stress of 150 mM NaCl significantly decreased the activity of SOD, while increased that of CAT, and enhanced the levels of MDA and H2O2 contents in both cultivars under salt stress conditions. The outcome of salt stress was non-significant on soluble proteins and activity of POD. The effect of pre-sowing application of TRIA was non-significant on all measured attributes except that it significantly increased the activity of POD under non-saline conditions. The cultivar difference with respect to the different attributes measured in the present investigation was non-significant.