Salicylic Acid Improves Antioxidant Defense System and Photosynthetic Performance in Aristotelia chilensis Plants Subjected to Moderate Drought Stress

Abstract

Salicylic acid (SA) has been shown to ameliorate drought stress. However, physiological and biochemical mechanisms involved in drought stress tolerance induced by SA in plants have not been well understood. Thus, this study aimed to study the role of SA application on enzymatic and non-enzymatic antioxidants, photosynthetic performance, and plant growth in A. chilensis plants subjected to moderate drought stress. One-year-old A. chilensis plants were subjected to 100% and 60% of field capacity. When plants reached moderate drought stress (average of stem water potential of −1.0 MPa, considered as moderate drought stress), a single SA application was performed on plants. Then, physiological and biochemical features were determined at different times during 14 days. Our study showed that SA application increased 13.5% plant growth and recovered 41.9% AN and 40.7% gs in drought-stressed plants on day 3 compared to drought-stressed plants without SA application. Interestingly, SOD and APX activities were increased 85% and 60%, respectively, in drought-stressed SA-treated plants on day 3. Likewise, SA improved 30% total phenolic content and 60% antioxidant capacity in drought-stressed A. chilensis plants. Our study provides insight into the SA mechanism to tolerate moderate drought stress in A. chilensis plants.

Mechanistic Insights on Salicylic Acid Mediated Enhancement of Photosystem II Function in Oregano Seedlings Subjected to Moderate Drought Stress

“…It appears that SA’s mode of action depends considerably on several characteristics, such as the plant species, exposure duration, the concentration used, and the environmental conditions [ 60 , 61 , 106 , 107 ]. Thus, data on the effects of SA on plant physiological processes under stressed or non-stressed conditions remain debatable [ 106 ], but generally it can be recognized that SA has a positive effect on plant responses to many abiotic stresses such as heat, chilling, salinity, drought, and heavy metal toxicity [ 60 , 84 , 108 , 109 , 110 , 111 , 112 , 113 , 114 , 115 , 116 ]. The diverse impact of SA on different plant species may be due to the diversification of the SA signaling and biosynthesis pathways in plants [ 117 ].…”

Harnessing the Role of Foliar Applied Salicylic Acid in Decreasing Chlorophyll Content to Reassess Photosystem II Photoprotection in Crop Plants

“…Experimental evidence showed that SA exerts inhibitory effects on chlorophyll content, stomatal function, photosynthetic parameters, and carboxylating enzymes, playing a regulatory role associated with photosynthetic reactions [52]. SA takes part in plant responses to many abiotic stresses such as drought, salinity, chilling, heat, and heavy metal toxicity [10,11,[53][54][55][56][57][58]. However, since its mode of action depends significantly on numerous aspects, such as the plant species, the environmental conditions, the concentration used, the duration of exposure, and the concentrations of other external agents [4,20,59], data on exogenously applied SA on plant physiological processes under stress or non-stress conditions remain controversial [20].…”

The Role of Stress Modifier Biostimulants on Adaptive Strategy of Oregano Plant for Increasing Productivity under Water Shortage

“…The application of salicylic acid (SAA) at various concentrations through seed soaking, root administration or foliar spraying, has been found to alleviate the negative effects of water deficit on stomatal conductance, tissue water status, plant physiological processes, membrane properties, and chlorophyll content [ 17 ]. Exogenously applied SAA boosts the activity of antioxidant enzymes and the production of antioxidant compounds, increases plant resistance to abiotic stresses [ 13 ], and reduces the lipid peroxidation of the cell tissues and membranes [ 18 ].…”