Enhanced Salt Tolerance of Tomatoes by Exogenous Salicylic Acid Applied Through Rooting Medium

Abstract

In Tunisia, like in the other countries of the Mediterranean, tomato is ranked among the important vegetables in the economic sphere. Tunisia ranks as the first consumer of this vegetable in the world. However, tomatoes are exposed to multiple environmental stresses. In particular, salinity is the most stressful limiting factor to productivity. Salt tolerance of the tomato is susceptible to be ameliorated by genetic and physiologic ways. Salicylic acid (SA), a plant phenolic, is now considered as a hormone-like endogenous regulator, and its role in the defense mechanisms against biotic and abiotic stressors has been well documented. So, the aim of this study was to investigate the impact of exogenous application of SA (0.01 mM) on growth, nutritional behavior, and some metabolic parameters (total chlorophyll, soluble sugars, proline, and proteins) of tomato plants cv. Moneymaker exposed to NaCl (100 mM). Our results showed that the application of 0.01 mM SA to tomato plants via root drenching attenuate the depressive effect of salinity on plants. This amelioration results in stimulation of growth and development of plant. Under stress conditions, SA-treated plants exhibited more accumulation of photosynthetic pigments and K(+) contents. Thus, SA induces an increase in soluble sugars in roots and leaves; also, we noted the increase of proteins only in roots. Overall, the adverse effects of salt stress tomato plants were alleviated by the exogenous application of SA at vegetative stage, which upregulated nutrition and the accumulation of some organic solutes and osmoprotectors such sugars, proline, and proteins. So salicylic acid can be greatly used to enhance salt tolerance of tomato plants.

Time‐course analysis of salicylic acid effects on ROS regulation and antioxidant defense in roots of hulled and hulless barley under combined stress of drought, heat and salinity

“…The SA‐triggered free proline accumulation in the barley roots might be an SA‐induced feature adaptive to the PEG + heat + salt. These findings are consistent with those of exogenous application of SA in barley (EI‐Tayeb ), lentil (Misra and Saxena ) and tomato (Wasti et al ) under salt, maize (Shan and Wang ) under drought and wheat (Khan et al ) under heat stress alone. The SA‐induced protective effect of proline accumulation on hulled/hulless barley may be the response of the osmotolerance of the roots under the combined stress of drought, heat and salinity.…”

Regulation of water, salinity, and cold stress responses by salicylic acid

“…Strawberry plants treated with SA exhibited greater growth, as did higher chlorophyll concentrations under salt stress (Karlidag et al, 2009). Tomato plants treated with 0.01 mM SA via root drenching improved the plants’ growth and increased the accumulation of photosynthetic pigments, the K + concentration, and the soluble sugar concentration (Wasti et al, 2012). Pretreatment of tomato with SA in hydroponic culture triggered the accumulation of ABA, leading to an improved acclimation to salt stress (Szepesi et al, 2009).…”

Salicylic Acid and Calcium Treatments Improves Wheat Vigor, Lipids and Phenolics Under High Salinity

“…Especially, SA was found to improve plant tolerance mechanisms to salinity stress. 27,28 Another strategy that partially alleviates the deleterious effects of saline stress on plants is the nutrient supply (as Se, N, Ca) in order to reduce Na + and Cl -injures in plants. 29,30 …”