Salicylic-acid-induced recovery ability in salt-stressed Hordeum vulgare plants

The recovery ability of barley plants from salt stress conditions was assessed using foliar application of salicylic acid (SA) in a study conducted under controlled conditions. The barley plants (Hordeum vulgare L. 'Reyhan') were subjected to saline water with varying salinity levels (tap water 0.67 dS m (1) as control, 3, 6, 9, and 12 dS m (1)) from 14 to 42 days after sowing (DAS). Then the plants were subjected to recovery treatments for 4 weeks, from 42 to 70 DAS. The recovery treatments included: non-recovery (R-0), irrigation with tap water (R-1), and irrigation with tap water + 2 foliar applications of SA with a 1-week interval (R-2). The results showed that salt stress decreased shoot and root dry weight, leaf K+ concentration, and photosynthesis rate, while it increased leaf Na+ concentration and free proline, soluble protein, and chlorophyll contents. These reductions were related directly to stress intensity. Both recovery treatments increased shoot dry weight, Na+ concentration, free proline, chlorophyll content, and photosynthetic rate. Compensation of root dry weight losses due to salt stress was observed only in R-1. However, for other measured traits recovery ability with R-2 was greater than with R-1. Overall, it appeared that although recovery treatments could not fully eliminate salt-induced damages, the recovery treatment with SA proved to be very effective in alleviating the adverse effects of salt stress on barley plants.