Effect of Salicylic Acid, Benzoic Acid, and p-Coumaric Acid on Growth, Chlorophyll, Proline, and Vitamin C of Salinity-Stressed Tobacco (Nicotiana tabacum)

Salinity is an important growth-limiting abiotic stress factor. Salicylic acid (S.A), Benzoic Acid (B.A) and p-coumaric acid (p-CA) are substances generally thought to play a crucial role in the enhancement of salt tolerance and regulation of growth and development in plants. This research was carried out to study the influence of Salicylic Acid (SA), Benzoic Acid (BA), and p-Coumaric acid (p-CA) on growth, contents of chlorophyll, proline and vitamin C in salinity-stressed tobacco plant (Nicotiana tabacum) grown In vitro. The results showed that Salinity (NaCl) stress impairs plant growth and inflicts severe physiological disorders. While supplementation of SA, BA and p-CA resulted in remarkable increases of all investigated biochemical components. Compared to the control, the high concentration of NaCl (150 mM) significantly reduced total fresh weight of tobacco. Total chlorophyll contents were remarkably increased by SA and BA treatments under 100 mM NaCl condition. The highest leaf and stem proline contents were recorded from the treatment of SA supplemented with 150 mM NaCl, while the lowest value was observed in p-CA + 0 mM NaCl treatment. Vitamin C contents were significantly increased by SA and BA treatments under 100 mM and 150 mM NaCl concentrations. SA and BA recovered the damage caused by high concentrations of salinity and enhanced salt tolerance in tobacco. Application of p-CA did not show significant differences compared to the control. This study suggests that SA and its derivatives could be used to overcome damages generated by salinity stress, enhance salt-tolerance and regulate plant growth and development.