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 (R0), irrigation with tap water (R1), and irrigation with tap water + 2 foliar applications of SA with a 1-week interval (R2). 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 R1. However, for other measured traits recovery ability with R2 was greater than with R1. 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.