Attenuation of salt stress on the physiology and production of bell peppers by treatment with salicylic acid

Abstract

The use of saline water for irrigation in semi-arid regions has become a reality due to the water scarcity that occurs in most of the year. In this scenario, exogenous application of salicylic acid may be a strategy to mitigate the deleterious effects of salt stress on plants and ensure the production of socioeconomically important crops in the semiarid region of Northeast Brazil, such as bell pepper. Thus, this study examines the osmoprotective effect of salicylic acid on gas exchanges, chloroplast pigments and production components of ‘All Big’ bell pepper plants irrigated with water with different saline levels. The experiment was carried out in greenhouse conditions in Campina Grande - PB, Brazil. Treatments consisted of four levels of electrical conductivity on the irrigation water (0.8, 1.6, 2.4 and 3.2 dS m-1) and four concentrations of salicylic acid (0, 1.2, 2.4 and 3.6 mM), which were distributed in a 4 × 4 factorial arrangement in a randomized block design with three replicates. Increases in irrigation water salinity from 0.8 dS m-1 resulted in changes in gas exchange and total chlorophyll levels of ‘All Big’ bell pepper plants. The estimated salicylic acid concentration of 1.7 mM reduced the effects of salinity on stomatal conductance, transpiration, CO2 assimilation rate, instantaneous carboxylation efficiency, total chlorophyll and fruit diameters. Irrigation with water of 1.8, 0.8 and 1.6 dS m-1 salinity associated with the estimated salicylic acid concentration of 1.6 mM increased the biosynthesis of chlorophylls a and b and the number of fruits, respectively, in bell pepper plants.

Exogenous application of salicylic acid on the mitigation of salt stress in Capsicum annuum L.

“…The high concentration of salts in irrigation water can result in osmotic and ionic imbalance, due to the excess of Na + and Clions, affecting the availability and absorption of water and nutrients by plants (YAISH et al, 2016;SAMADDAR et al, 2019). Symptoms observed in plants under salt stress include delay in leaf production, necrosis of shoots and roots, and reduction of leaf area and photosynthetic activity, thus affecting their growth (VELOSO et al, 2021).…”

Salicylic Acid Foliar Application Increases Crop Yield and Quality Parameters of Green Pepper Fruit during Postharvest Storage

“…Preharvest applications of SA have stimulated the disease resistance against fungal infection of pepper fruits [19][20][21][22]; accordingly, it also reduced the decay incidence and postharvest losses during storage. In the scientific literature, studies focusing on the action of SA preharvest application on salinity stress oxidative damage of sweet pepper plants are also incipient [2,23,24]. Nevertheless, few studies have investigated the effect of SA preharvest treatment on increasing crop yield and quality of pepper fruit [25,26].…”

Salicylic acid does not mitigate salt stress on the morphophysiology and production of hydroponic melon

“…close their stomata as a defense mechanism, aiming at reducing the loss of water to the atmosphere and reducing the absorption of toxic ions (Lima et al, 2019). Veloso et al (2021), evaluating the osmoprotective capacity of salicylic acid on 'All Big' bell pepper plants irrigated with waters of different salinity levels, found that the highest value of gs (0.27 mol H 2 O m -2 s -1 ) was obtained in plants subjected to SA concentration of 1.5 mM, with reductions from this concentration. 'Gaúcho' melon plants (Figure 2B) subjected to nutrient solution electrical conductivity of 2.1 dS m -1 and without application of salicylic acid (0 mM) obtained the highest leaf transpiration (5.52 mmol H 2 O m -2 s -1 ).…”