Salt stress is considered as one of the critical factors threatening the growth and development of plants worldwide. The present study was aimed to evaluate the effect of potassium silicate (K2SiO3) on some physio-chemical characteristics of daisies under different levels of salinity stress. For this purpose, daisies (Bellis perennis ʻRob Royʼ) plants were treated with K2SiO3 (0, 2, and 4 Mm) and grown under salt stress (0, 30 and 60 mM NaCl). The results showed that salt stress stimulated mineral uptake, while application of 4 mM K2SiO3 reduced leaf Na+ and Cl− content (54 and 164%) at 60 mM salinity compared to unsprayed plants. Leaf osmotic potential was more negative in 60 mM salinity treatment than in the other treatments. Increasing salt stress level reduced the photosynthetic parameters (chlorophyll, A, E, gs, and WUE) in leaves, while K2SiO3 treatment improved the parameters. Application of 4 mM K2SiO3 increased plant’s tolerance to stress by increasing carbohydrate, proline, phenolics and flavonoids. Application of K2SiO3 reduced malondialdehyde levels at 30 and 60 mM salt stress by 23.4 and 23%, respectively, by increasing membrane stability. However, application of K2SiO3 significantly increased the ability of plants to withstand salt stress by enhancing the accumulation of silicon (Si) and potassium (K) in plants compared to the unsprayed plants, which was due to the significant exclusion of Na+. The activity of peroxidase, ascorbate peroxidase, catalase, and superoxide dismutase exhibited positive increase as a result of K2SiO3 application under salt stress. In general, our results indicated that use of K2SiO3 can be considered as a common strategy to maintain the growth of plants under salt stress.

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