Salicylic Acid Improves the Salt Tolerance Capacity of Saponaria officinalis by Modulating Its Photosynthetic Rate, Osmoprotectants, Antioxidant Levels, and Ion Homeostasis

Abstract

Salicylic acid (SA) plays an important role in regulating salt stress tolerance in plants. However, there are no studies on the effect of exogenous SA on Saponaria officinalis under salt stress. To study the effectiveness of SA on mitigating salt stress, S. officinalis were used in a pot experiment of salt stress simulated with an NaCl solution (100, 200, and 300 mmol L−1), while an SA solution (0, 0.2, 0.4, 0.6, 0.8, 1.0 mmol L−1) was sprayed on leaves. Under salt stress, spraying SA caused an increase in the salt damage index, electrolyte leakage, and a reduction in malondialdehyde and Na+ content, but an increase in the rate of photosynthesis, chlorophyll, soluble sugar, soluble protein, free proline, K+, Mg2+, Ca2+ content, the K+/Na+ ratio, superoxide dismutase, peroxidase, catalase, ascorbate peroxidase activity, and the comprehensive score. The results show that SA improves the salt tolerance capacity of S. officinalis by modulating its photosynthetic rate, osmoprotectants, antioxidant levels, and ion homeostasis. However, the effectiveness of SA was not linearly related to its concentration. In summary, our findings reveal the protective roles of SA against salinity in S. officinalis and suggest that the use of 0.6 mmol L−1 of SA in salt stress conditions could be an effective approach to reduce the damage caused by saline soil in S. officinalis.

Morpho-Biochemical Modification of Petunia to Saline Water and Salicylic Acid Applications

“…Current outcomes revealed that irrigation with saline water considerably decreased the chlorophyll index relative to irrigation with tap water. A decline in chlorophyll has been stated previously in several plants [8,11,12,58]. The deterioration of chlorophyll caused by saline water might be related to boosted chlorophyllase activity [59,60], decreased assimilation of the key chlorophyll pigment complexes encoded by the cab gene family [61], and/or a drop in chlorophyll biosynthesis intermediation concentrations [62].…”

“…Current results revealed that the spraying of SA boosted chlorophyll accumulation in salt-affected plants. Plants treated with SA had higher levels of chlorophyll than control or salt-affected plants [8,11,58,68,69]. Variations in chlorophyll with SA spraying are advocated to be concentration dependent and species specific [11,12].…”

Phytohormones Promote the Growth, Pigment Biosynthesis and Productivity of Green Gram [Vigna radiata (L.) R. Wilczek]

“…Similar findings were previously reported by Gacnik et al [123], who opined that exogenously applied SA accelerated plant growth and development along with enhancing the quality of the traits of Mentha piperita. Xu et al [124] reported that foliar-applied SA in a 0.6 mmol L −1 dose increased the growth of crop plants by preventing electrolyte leakage, and increased the photosynthesis rate in addition to promoting the biosynthesis of chlorophyll, soluble sugar and soluble protein. Additionally, it increased the accumulation of K + , Mg 2+ and Ca 2+ content and the K + /Na + ratio, and maintained ionic homeostasis.…”

The role of γ-aminobutyric acid and salicylic acid in heat stress tolerance under salinity conditions in Origanum vulgare L.

“…SA application caused an additional enhancement in photosynthetic rate, osmoprotectants, and antioxidant levels in salinity stress. It also modulates ion homeostasis and ameliorates salinity tolerance in Saponaria officinalis [45].…”