Triacontanol-induced changes in growth, yield, leaf water relations, oxidative defense system, minerals, and some key osmoprotectants in Triticum aestivum under saline conditions

To investigate the effect of exogenous application of triacontanol (TRIA) on 2 wheat (Triticum aestivum L.) cultivars (S-24 and MH-97) under salt stress, an experiment was conducted in a greenhouse under natural climatic conditions. Both cultivars were grown in full strength Hoagland's nutrient solution under nonsaline (0 mM NaCl) or saline (150 mM NaCl) conditions in sand culture. Three optimized TRIA levels (0, 10, and 20 mu M) were used as foliar spray at 3 growth stages, i.e. vegetative, boot, and vegetative + boot stages. Ninety-two-day-old plants were subjected to data analysis. Salinity stress adversely affected various growth, physiological, and biochemical attributes in both wheat cultivars at all growth stages. Under salt stress, activities of superoxide dismutase (SOD) and peroxidase (POD) decreased (cv. MH-97), while those of catalase (CAT) and POD (cv. S-24) increased. Contents of hydrogen peroxide (H2O2), malondialdehyde (MDA), Na+, and Cl- increased in both wheat cultivars at all growth stages. A foliar spray of mu M TRIA. was more effective in reducing the adverse effects of salt stress on growth, yield, and leaf water relations of wheat plants when applied at the vegetative or vegetative + boot growth stages.