Improving salinity tolerance in Salvia officinalis L. by foliar application of salicylic acid

Abstract

Background Higher absorption and translocation of sodium (Na) and chlorine (Cl) ions in plant tissue can lead to serious physiological and biochemical changes. However, salicylic acid (SA) is a natural signaling molecule responsible for the induction of environmental stress tolerance in plants. Spraying SA could provide protection against several types of stress such as salinity. This study aimed to show the influence of SA spraying (0.5 and 1 mM) on the damaging effects of NaCl toxicity (150 mM) in Salvia officinalis L. plants. Results The results showed that salinity strongly inhibited the growth of aerial and root parts and this inhibition was accompanied by a significant decrease in the production of chlorophyll pigments (by 63%). There was also a significant accumulation of Na, mainly in the roots. This accumulation of Na+ ions was accompanied by a decrease of calcium (Ca), potassium (K) and phosphorus (P) concentrations. However, SA mainly at 0.5 mM, greatly improved plant growth, essential oils and chlorophyll pigments synthesis. Besides, SA led to a decrease in Na content and an improvement in Ca, K and P content in the leaves and roots. Salt stress decreased the essential oil yield from 1.2% (control) to 0.4% (NaCl). Furthermore, gas chromatography–mass spectrometry analysis of essential oils exhibited that the 1,8-cineol, α-thujone, and camphor were identified as the main components of essential oils under all treatments. However, we noted in stressed plant treated or not with SA the appearance of the new majority compound thujanone. Salt stress decreased the major compounds content. SA spray under stress condition increased the content of major compounds compared to stressed plants untreated with SA. The histological study in scanning electron microscopy showed the peltate glands density decreased strongly under NaCl toxicity. However, SA application on stressed plants increased peltate glands density. On the other hand, the glands of stressed plants often show certain anomalies in the morphology: the first anomaly observed was the presence of glandular structures characterized by deformations in the form of small protuberances located on the head of the gland. The second, a less common abnormality is the morphological change in certain glands that change from a spherical to an ovoid shape. On another hand, all these anomalies were not detected in stressed plants sprayed with SA. Therefore, the absence of these anomalies under the effect of SA showed the repairing effect of this growth regulator. Conclusion The findings of the present work suggest that spraying of SA may be useful for improving the plant growth in NaCl-contaminated areas.

Synergistic Effects of Salicylic Acid and Melatonin on Modulating Ion Homeostasis in Salt-Stressed Wheat (Triticum aestivum L.) Plants by Enhancing Root H+-Pump Activity

“…Salt stress is an important environmental constraint that can affect the growth and productivity of wheat [ 3 , 6 ]. Previous studies have shown that the exogenous application of SA or MT enhances plant salt tolerance [ 7 , 9 , 10 , 16 ]. However, our knowledge regarding the mechanisms involved in their combined treatment-mediated salt tolerance still remains fragmentary.…”

“…Salicylic acid (SA, 2-hydroxybenzoic acid), as a plant growth regulator, can stimulate several biochemical events, resulting in a new metabolic state [ 7 , 16 ]. It has been shown that SA regulates plant salt tolerance by involving in redox homeostasis, suggesting that SA can interact with ROS signal pathways [ 17 , 18 ].…”

“…It has been shown that SA regulates plant salt tolerance by involving in redox homeostasis, suggesting that SA can interact with ROS signal pathways [ 17 , 18 ]. Several studies have shown that SA-regulated plant salt tolerance could contribute to maintaining cellular detoxification through the regulation of antioxidant enzyme activity, antioxidant molecules synthesis, organic solute accumulation, nutrient uptake, protein metabolism, and photosynthetic activity [ 7 , 16 , 19 , 20 , 21 , 22 , 23 ]. However, there is still a lack of information available regarding the core pathways precisely regulated by SA.…”

Protective Effects of Salicylic Acid and Calcium Chloride on Sage Plants (Salvia officinalis L. and Salviaelegans Vahl) under High-Temperature Stress

“…Yadegari [26] showed that at low concentrations, while SA had a stimulating effect at higher concentrations, it reduced essential oil content in S. officinalis. Furthermore, Es-sbihi et al [27] also reported that a low (0.5 mM) SA application to S. officinalis reduced plant Na + content, improved growth, and increased nutrient (calcium, potassium, and phosphorus) levels, chlorophyll, essential oil content, and peltate gland density. SO plants are clearly highly tuned to the absolute levels of SA because a small amount of change can result in drastically different responses.…”

Influence of Climate-Related Environmental Stresses on Economically Important Essential Oils of Mediterranean Salvia sp.

“…The accumulation of manool, labdane type diterpene, at high salinity levels can be exploited as a precursor of ambergris fragrant products ( Taarit et al, 2010 ), but the severity of salt stress affects the physiological traits and yield, thus this can be considered more as a marker of severe salt stress in S. offciinalis . Alleviation of salt stress in sage has been confirmed after foliar application of SA with a variety of changes in the chemical composition of essential oils ( Zohra Es-Sbihi et al, 2021 ). Sage essential oil from aerial plant parts is mainly composed of 1,8-cineole, α/β-thujone, and camphor, and salt stress can induce a significant increase in these compounds with some new compounds recorded, such as viridiflorol, β-caryophyllene, myrentol, and pulegone.…”