Abstract

Salicylic acid (SA) is believed to play a role in modulating the adverse effects of abiotic stresses in crop plants, by regulating varied molecular and biochemical responses. The present study was aimed at investigating the combined effects of exogenously applied SA and salinity on root length, chlorophyll content, stomatal conductance and gene expression of Cu/Zn superoxide dismutase (SOD) of barley (Hordeum vulgare L., cv. Rum) at seedling stage. The results revealed that salt stress negatively affected total and maximum root length, total chlorophyll content, stomatal conductance and the expression of CuZn-SOD gene. However, the SA-treated plants had longer total and maximum root length (stimulation of about 13% and 51, respectively), higher chlorophyll content, lower stomatal conductance and lower expression of CuZn-SOD gene compared to plants exposed to salt stress. Overall, these data may lead to a conclusion that SA increases cv. Rum barley growth by improving photosynthesis and regulating osmotic potential.