Salicylic acid alleviated the effect of drought stress on photosynthetic characteristics and leaf protein pattern in winter wheat

Masoumeh Khalvandi,Adel Siosemardeh,Ebrahim Roohi,Sara Keramati

doi:10.1016/j.heliyon.2021.e05908

Abstract

Salicylic acid (SA) is a promising compound to increase plant tolerance to drought stress, and it can affect many aspects of physiological and biochemical processes. This study was focused on the changes in proteins, photosynthesis, and antioxidant system of Sardari wheat ecotypes leave in response to the application of SA under drought stress conditions. Treatments included Sardari wheat ecotypes (Baharband, Kalati, Fetrezamin, Gavdareh, Telvar, and Tazehabad), salicylic acid at 0.5 mM (controls were untreated), and drought stress (30% of the field capacity). The results showed that membrane electrolyte leakage, and lipid peroxidation of all six ecotypes, were obviously increased under drought stress conditions. On the other hand, drought stress decreased leaf chlorophyll content, photosynthetic rate, stomatal conductance, carboxylation efficiency, and transpiration rate. The results of SDS-PAGE indicated that the abundance of some protein spots was downregulated when the plants were exposed to drought stress, while other protein spots’ abundance was upregulated in such a situation. Under stress conditions, the highest antioxidant enzymatic activity, photosynthetic performance, cell membrane stability, and numbers of protein bands were observed in Baharband and Telvar, while the lowest was related to Fetrezamin. Salicylic acid treatments effectively ameliorated the negative effects of drought stress on Sardari ecotypes through improving the photosynthetic performance, keeping membrane permeability, induction of stress proteins, and enhancing the activity of antioxidant enzymes. The above findings suggest that ecotype ability to maintain photosynthetic performance was important to cope with drought stress.

Highlights

Drought stress is one of the most devastating environmental stresses, limiting the productivity of crop plants around the world
In plants that were not treated with Salicylic acid (SA), drought stress significantly enhanced the Superoxide dismutase (SOD) activity of leave tissues compared to the control (Table 2)
The increase in SOD activity was consistently accompanied with a significant increase in CAT activity in the leaves of drought-treated ecotypes compared to the control, with Gavdareh cultivar had the lowest value for CAT activity and Baharband cultivar had the highest value

Summary

Introduction

Drought stress is one of the most devastating environmental stresses, limiting the productivity of crop plants around the world. In response to drought stress, plants activate complex mechanisms, such as the antioxidant defense system, specific proteins like chaperones, and variations in gene expression (Hasan et al, 2018; Huseynova et al, 2007). When antioxidant defense mechanisms are not effective in scavenging and quenching ROS formation, damages to photosynthetic apparatus and cell membrane occur, as well as degradation of biomolecules like pigments and protein, lipid peroxidation, DNA fragmentation, which result in cell death (Allakhverdiev et al, 2001; Abid et al, 2018; Dalal and Tripathy 2018; Shao et al, 2016). It has been shown that there is a significant correlation between the stomatal conductance and photosynthesis response under drought stress, which indicates that stomatal conductance plays a major role in the reduction of leaf photosynthetic rates (Abid et al, 2018; Sarabi et al, 2019)

Methods

Results

Discussion

Conclusion