Salicylic acid induced physiological and biochemical changes in wheat seedlings under water stress

Salicylic acid ( SA) is an important signal molecule modulating plant responses to stress. It is recently reported to induce multiple stress tolerance in plants including drought. An experiment was, therefore, conducted to ascertain the effect of salicylic acid on the growth and metabolic profile of wheat seedlings under water stress. Irrespective of the SA concentration (1-3 mM) and water stress, SA treated plants showed, in general, a higher moisture content, dry mass, carboxylase activity of Rubisco, superoxide dismutase ( SOD) activity and total chlorophyll compared to those of untreated seedlings. SA treatment, under water stress, protected nitrate reductase (NR) activity and maintained, especially at 3 mM SA concentration, the protein and nitrogen content of leaves compared to water sufficient seedlings. Results signify the role of SA in regulating the drought response of plants and suggest that SA could be used as a potential growth regulator, for improving plant growth under water stress.