Nitric Oxide Enhances Salt Tolerance through Regulating Antioxidant Enzyme Activity and Nutrient Uptake in Pea

Abstract

Background: Salinity is one of the environmental stress factors that restrict the crop production by endangering agricultural areas. Nitric oxide (NO) protects plants from damage caused by oxidative stress conditions in various biological ways. Methods: In this greenhouse investigation during 2018, pea plants were irrigated with three levels of NaCl (0, 50 and 100 mM) solutions. NO solutions were prepared with three different doses (0, 75 and 100 µM SNP). These solutions were applied to the seeds before sowing and then to the leaves of the pea cultivars. The study was conducted to analyze the impact of NO on growth, malondialdehyde (MDA), hydrogen peroxide (H2O2), antioxidant enzyme activity and nutrient uptake in two pea cultivars under salinity conditions. Result: Salinity reduced fresh-dry weight, relative water content (RWC), and chlorophyll a and b content of pea. However, NO enhanced these parameters under salt stress. Salinity increased tissue electrical conductance (TEC), H2O2 and MDA content, which were decreased by combined application of NaCl and NO. Salinity caused an increase in antioxidant enzyme activity in pea and NO made a significant improvement in their activities under salinity conditions. Salinity treatments decreased the ratio of K+/Na+ and Ca2+/Na+ in both cultivars, and application of NO elevated them as compared to the control under salt stress. In conclude, exogenous NO treatment could help pea to tolerate salinity stress by increasing the chlorophyll content and regulating antioxidant enzyme activity and nutrient uptake.

Protective Effects of Sodium Nitroprusside on Photosynthetic Performance of Sorghum bicolor L. under Salt Stress

“…The obtained results are in harmony with earlier investigations on maize, sorghum, tomato, mustard, barley, and pea plants under salt stress [15,[65][66][67][68][69][70][71]. Our data (Figure 1) are also in accordance with previous studies on soy bean and pea plants under salt stress [72,73], which have shown that treatment with SNP prevents a salt-induced reduction of the leaf pigment content. SNP application alleviated the salt-induced decrease in chlorophyll synthesis, and enhanced the accumulation of the light-harvesting chlorophyll a/b complex of PSII (LHCII) and PSIA/B in barley seedlings [74].…”

The Role of Nitric Oxide in Plant Responses to Salt Stress

“…However, exogenous NO alleviated this effect [ 40 ]. Similarly, NO application increased the chlorophyll content in salt-stressed pea, bermudagrass, and soybean plants [ 41 , 42 , 43 ]. Moreover, although the chloroplast thylakoid system is distorted in salinized plants, combined SNP and S supplementation positively affected the chloroplast structure in salinized mustard plants, restoring them to a normal shape, and the thylakoid system was appropriately rearranged [ 44 ].…”

“…NO is a powerful inhibitor of ROS, which can cause lipid peroxidation. SNP application has been shown to decrease the contents of H 2 O 2 , superoxide anion, and MDA in NaCl-stressed pak choi, pepper, mustard, pea, eggplant, tomato, spinach, and barley plants, thereby preventing oxidative damage [ 21 , 34 , 39 , 40 , 41 , 53 , 58 , 59 ].…”

Effect of Different Bacterial Strains on the Germination Forage Pea (Pisum sativum ssp. arvense L.) under Salt Stress

“…It was found that there was no germination at 200 mM salt concentration in peas and a decrease in the germination characteristics of both species with increasing salt concentration (Dadasoglu et al 2020). Studies conducted with peas indicate that salt stress negatively affects plant growth (Kaya, 2021;Dadasoglu et al 2021; Effect of Different Bacterial Strains on the Germination Forage Pea (Pisum sativum ssp. arvense L.) under Salt Stress Prakash et al 2021).…”