Salicylic Acid Supplementation Alleviated The Adverse Effects Of Salinity Stress In Spinacia Oleracea By Improved Antioxidative Defence System

Salicylic acid (SA) has an established role in inducing plant tolerance against various environmental stresses including salinity. It initiates a stress signalling cascade that modulates plant physiological processes such as up-regulation of anti-oxidants, osmotic adjustment and nutrient uptake, thus resulting in a better adaptation during stress. In the present study, two-week-old plants of three spinach (Spinacia oleracea) varieties (All green, Desi palak and Lahori palak) were foliar-sprayed with SA (0, 1 and 2 mM) and NaCl (0, 200 and 300 mM). Results show that NaCl application significantly reduced growth parameters, photosynthetic pigment contents, plant water status, while increased lipid peroxidation, reactive oxygen species and Na uptake in a dose-dependent manner. SA treatment significantly counteracted the salinity-induced damaging effects in all spinach varieties by up-regulating the uptake of K ions and the antioxidant machinery. Overall, our data depicted that SA is a vital player in inducing salinity tolerance in spinach.