Effect of salicylic acid foliar application on growth, glandular hairs and essential oil yield in Salvia officinalis L. grown under zinc stress

Abstract

Background Generally, zinc (Zn) is an essential element and acts as a plant nutrient, but at higher concentrations, it is toxic. Higher uptake and translocation of Zn into plant tissues can cause serious physiological and biochemical alterations. However, salicylic acid (SA) is an endogenous regulator of growth and signaling molecule responsible for inducing environmental stress tolerance in plants. Therefore, spray application of SA could provide protection against several types of stresses such as Zn toxicity. In this context, the ameliorative effect of SA (0.5 and 1 mM) on Salvia officinalis L. under Zn stress (40 mM) was studied. Results Zn stress decreased growth, chlorophyll content, essential oil yield and peltate glandular trichome density. This toxicity can be linked to a strong accumulation of Zn in the various parts of the plant. In addition, Zn stress disturbed nutrients assimilation (K, P and Ca). However, spray of SA, particularly at 0.5 mM improved all parameters studied under both Zn and normal conditions. The positive effects of SA under Zn stress condition may be due to the decrease of Zn accumulation in different parts of the plant. This decrease was accompanied by an increase in K, P and Ca content. In addition, the histological study of S. officinalis leaves showed the presence of two types of glandular hairs, the peltate and capitate glands. In the leaves of stressed plants, we noticed the presence of glands with deformations in the form of pockets in the number of one or more as well as the glands with an oval form. On the other hand, all these abnormalities glands were not detected in stressed plants that were sprayed with SA. Therefore, the absence of these anomalies under the effect of SA showed the remedial effect of this growth regulator. Conclusion The findings of the present work suggest that spraying SA maybe useful for improving the plant growth in Zn-contaminated areas.

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

“…In our case an excess of salt could be at the origin of these deformations. The same structures have been observed by Es-sbihi et al [19] in S. officinalis cultivated under excess zinc. Treatment of plants with SA under this metallic stress does not showed the presence of these deformities.…”

Salicylic Acid Foliar Spray Enhanced Silybum marianum Growth and Yield, as Well as Its Chemical Constituents and Chalcone Synthase Gene Activity

“…Our results indicated that 10 −4 M salicylic acid has higher enhancement effects on the plant growth parameters (plant height, number of leaves and branches, and the DW of root and aerial parts) and yield (capitula number and fruit DW) even though both concentrations (10 −4 and 10 −3 M) of salicylic acid have increased S. marianum plant growth and yield as compared with the control. Increased growth and yield of medicinal plants resulting from exogenously applied salicylic acid were previously reported by numerous research groups [11,15,17,27,35]. Salicylic acid is a phenolic plant hormone, which induces both cell division and elongation, resulting in greater plant growth [36].…”

“…Indeed, salicylic acid-induced flavonoid accumulation has been reported in a variety of plant species, including tea, cucumber, and satsuma [26,43,44]. Besides flavonoid compounds, the induction of various other secondary metabolites by salicylic acid has also been reported in a variety of plants such as coriander, fennel, achillea, marigold, fenugreek, onion, and Salvia officinalis [11,15,25,27,35,45,46]. Exogenous salicylic acid treatment has been shown to affect flavonoid biosynthesis in plants through increased expression of flavonoid biosynthesis-related genes, such as CHS genes [13,23,24,44,47].…”

“…The successful induction of various secondary metabolites by salicylic acid in different medicinal plant species has prompted us to conduct the present study. We have selected 10 −4 and 10 −3 molar (M) salicylic acid concentrations to apply as foliar spray to the S. marianum plants as these two concentrations have been tested in several plant species [17,[25][26][27].…”

Effect of zinc imbalance and salicylic acid co‐supply on Arabidopsis response to fungal pathogens with different lifestyles

“…Under Zn stress, application of the phytohormone salicylic acid (SA) may improve plant growth and alleviate damage due to Zn toxicity (Es-sbihi et al 2020). Exogenous SA has also been reported to play an important role in ion uptake and transport (Shi & Zhu 2008;Sharma et al 2020) and in nutrient fortification (Smole n et al 2016).…”