Role of Salicylic Acid in the Alleviation of Salt Stress on Pea Cultivars Using Growth, Biochemical and Physiological Attributes

Abstract

Salinity stress is the crucial abiotic stress that limits crop production worldwide. A plant growth promoter, salicylic acid (SA), was used as a foliar application (FA) to allay the toxic influence of NaCl (salt) on growth of winter vegetable pea. Salt stress with two doses (0 and 100 mM NaCl) was applied through the rooting growth medium, while two levels of SA were used through exogenously. Salt in the growth medium impaired the shoot fresh (13.25%) and dry weight (21.20%) as well as the root fresh (22.12%) and dry weight (6.65%) in the pea cultivars "RSK 510" and "Lena Pak." Foliar SA reduced salt-induced effects while increasing the dry and fresh weights of the shoot as well as of the root. Besides these growth attributes, salt accumulation also limits the rate of photosynthesis (35%) and transpiration (13.21%), sub-stomatal CO₂ concentration (14.78%), and the stomatal conductance (5%) also, and in the pea cultivars "RSK 510" and "Lena Pak." Here, the foliar spray of SA overcomes these gas exchange parameters and enhances their values. The SA treatment showed higher performance in the cultivar "RSK-510" while lower in the "Lena Pak" under salt stress. Photosynthetic pigment values like the chlorophyll a (15.47%) and b (24.10%) decreased in the cultivars "RSK-510" and "Lena Pak," which were improved by foliar SA treatment. The values of MDA contents were also lessened due to salt accumulation in the plant cell, and that lessened effect was controlled by the foliar spray of SA in both pea cultivars. Overall, it was noted that the cultivation of pea cultivars "RSK-510" and "Lena Pak" showed their growth in regard to biomass production, photosynthetic rate, and transpiration rate, and also that the photosynthetic pigments and foliar spray of SA promoted these growth attributes