Salt Stress Mitigation via the Foliar Application of Chitosan-Functionalized Selenium and Anatase Titanium Dioxide Nanoparticles in Stevia (Stevia rebaudiana Bertoni)

Abstract

High salt levels are one of the significant and major limiting factors on crop yield and productivity. Out of the available attempts made against high salt levels, engineered nanoparticles (NPs) have been widely employed and considered as effective strategies in this regard. Of these NPs, titanium dioxide nanoparticles (TiO2 NPs) and selenium functionalized using chitosan nanoparticles (Cs–Se NPs) were applied for a quite number of plants, but their potential roles for alleviating the adverse effects of salinity on stevia remains unclear. Stevia (Stevia rebaudiana Bertoni) is one of the reputed medicinal plants due to their diterpenoid steviol glycosides (stevioside and rebaudioside A). For this reason, the current study was designed to investigate the potential of TiO2 NPs (0, 100 and 200 mg L−1) and Cs–Se NPs (0, 10 and 20 mg L−1) to alleviate salt stress (0, 50 and 100 mM NaCl) in stevia. The findings of the study revealed that salinity decreased the growth and photosynthetic traits but resulted in substantial cell damage through increasing H2O2 and MDA content, as well as electrolyte leakage (EL). However, the application of TiO2 NPs (100 mg L−1) and Cs–Se NPs (20 mg L−1) increased the growth, photosynthetic performance and activity of antioxidant enzymes, and decreased the contents of H2O2, MDA and EL under the saline conditions. In addition to the enhanced growth and physiological performance of the plant, the essential oil content was also increased with the treatments of TiO2 (100 mg L−1) and Cs–Se NPs (20 mg L−1). In addition, the tested NPs treatments increased the concentration of stevioside (in the non-saline condition and under salinity stress) and rebaudioside A (under the salinity conditions) in stevia plants. Overall, the current findings suggest that especially 100 mg L−1 TiO2 NPs and 20 mg L−1 Cs–Se could be considered as promising agents in combating high levels of salinity in the case of stevia.

Modulating response of Zea mays to induced salinity stress through application of nitrate mediated silver nanoparticles and indole acetic acid

“…Significant increase in shoot length was observed at 80 mM concentration which shows the tolerance of selected verity against salinity stress. The maximum surge in fresh weight of shoot was documented at maximum concentration of (80 mM), agrees with study of (Hafez et al, 2021; Sheikhalipour et al, 2021). The minimum concentration, 40 mM was used to achieve the maximum increase in fresh and dry root weight.…”

Alleviating the adverse effects of salinity on Roselle plants by green synthesized nanoparticles

“…Kumar et al 44 reported that Au-NPs strengthen the antioxidant system in Arabidopsis thaliana while improving the expression of micro-RNAs. Increasing the activities of CAT, SOD, POD, and APX enzymes showed that the line of a defense mechanism by antioxidants was one of the most important mechanisms of Roselle that contributed to the maintenance of its proper, sustainable development, which might explain enhancements in growth parameters 45 .…”

Effect of TiO2 Nanoparticles on the Yield and Photophysiological Responses of Cherry Tomatoes during the Rainy Season

“…Based on the results of studies that confirmed the effect of TiO 2 treatment at a concentration of 0-200 ppm in various crops, in this experiment, the plants were treated with a similar TiO 2 concentration [9,10,12]. TiO 2 foliar spray materials were prepared by mixing 100 mg (T1) or 200 mg (T2) of TiO 2 nanoparticles in 1 L of distilled water containing 1% glycine and stirring for 2 h. TiO 2 solution (T1 or T2) was applied to the foliage at 200 mL per plant on June 26.…”

“…Zahra et al (2017) reported that TiO 2 promotes rice growth, and there is no risk of TiO 2 intake following soil application of TiO 2 [9]. It has been reported that the application of TiO 2 nanoparticles is effective in protecting stevia plants under salt stress conditions by increasing their growth, photosynthetic rate, and antioxidant activity and reducing hydrogen peroxide, malondialdehyde, and electrolytes [10]. In the case of red beans, it is reported that TiO 2 is beneficial for growth by promoting physiological activity [11].…”