Chitosan–Selenium Nanoparticle (Cs–Se NP) Foliar Spray Alleviates Salt Stress in Bitter Melon

Abstract

Salt stress severely reduces growth and yield of plants. Considering the positive effects of selenium (Se) and chitosan (Cs) separately against abiotic stress, in these experiments, we synthesized chitosan–selenium nanoparticles (Cs–Se NPs) and investigated their ability to reduce the negative effects of salt stress on growth and some biochemical parameters of bitter melon (Momordica charantia). Bitter melon plants were grown at three NaCl salinity levels (0, 50, and 100 mM) and a foliar spray of Cs–Se NPs (0, 10, and 20 mg L−1) was applied. Some key morphological, biochemical, and physiological parameters in leaf samples and essential oil from fruit were measured at harvest. Salinity decreased growth and yield while foliar application of Cs–Se NPs increased these critical parameters. Furthermore, Cs–Se NPs enhanced bitter melon tolerance to salinity by increasing antioxidant enzyme activity, proline concentration, relative water content, and K+, and decreasing MDA and H2O2 oxidants and Na aggregation in plant tissues. Yield was also improved, as the highest amount of essential oils was produced by plants treated with Cs–Se NPs. Generally, the greatest improvement in measured parameters under saline conditions was obtained by treating plants with 20 mg L−1 Cs–Se NPs, which significantly increased salinity tolerance in bitter melon plants.

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

“…In the case of medicinal and aromatic plant species, the application of nanoparticles is one of the novel and wise strategies used to increase growth, yield and especially secondary metabolites in plants under salt stress [ 25 ]. Moreover, selenium functionalized by a chitosan nanocomposite (Cs–Se NPs) and titanium dioxide nanoparticles (TiO 2 NPs) are some of the proven substantial molecules that are used to enhance the abiotic tolerance range of the crop via the activation of defense mechanisms [ 26 , 27 ]. Considering the relevant stress indicators, treatments of TiO 2 NPs and Cs–Se NPs decreased MDA and H 2 O 2 content and increased agronomic parameters, photosynthetic pigments content, chlorophyll fluorescence, soluble sugars, proline content and antioxidant enzymes activity in some plant species under salinity stress [ 25 , 27 , 28 ].…”

“…Moreover, selenium functionalized by a chitosan nanocomposite (Cs–Se NPs) and titanium dioxide nanoparticles (TiO 2 NPs) are some of the proven substantial molecules that are used to enhance the abiotic tolerance range of the crop via the activation of defense mechanisms [ 26 , 27 ]. Considering the relevant stress indicators, treatments of TiO 2 NPs and Cs–Se NPs decreased MDA and H 2 O 2 content and increased agronomic parameters, photosynthetic pigments content, chlorophyll fluorescence, soluble sugars, proline content and antioxidant enzymes activity in some plant species under salinity stress [ 25 , 27 , 28 ]. In addition to the enhanced crop productivity under salinity stress, total phenolic compounds and essential oil yield were also increased with TiO 2 NPs and Cs–Se NPs treatments [ 25 , 27 , 29 ].…”

“…Considering the relevant stress indicators, treatments of TiO 2 NPs and Cs–Se NPs decreased MDA and H 2 O 2 content and increased agronomic parameters, photosynthetic pigments content, chlorophyll fluorescence, soluble sugars, proline content and antioxidant enzymes activity in some plant species under salinity stress [ 25 , 27 , 28 ]. In addition to the enhanced crop productivity under salinity stress, total phenolic compounds and essential oil yield were also increased with TiO 2 NPs and Cs–Se NPs treatments [ 25 , 27 , 29 ]. However, high TiO 2 NP concentration decreased the growth parameters, photosynthetic pigments and antioxidant activity and increased MDA and H 2 O 2 in the plant [ 25 , 28 ].…”

“…Corresponding to the enhancing and stimulating roles of elements and their application as nanoparticles at non-toxic concentrations, we hypothesized that the relevant nanoparticles will improve the antioxidant status, steviol glycosides and other physiological parameters of stevia; furthermore, these improvements will be manifested in the growth and development of stevia. Both nanoparticle types were previously tested [ 25 , 27 ] and produced promising results related to plant growth, the alleviation of salt stress and an increase in plant chemical constituents desired by humans. As deduced from the findings from the studies by Gohari et al [ 25 ] and Sheikhalipour et al [ 27 ], three concentrations of TiO 2 NPs (0, 100 and 200 mg L −1 ) and Cs–Se NPs (0, 10 and 20 mg L −1 ) were assayed for the current study.…”

The Potential of Using Chitosan on Cereal Crops in the Face of Climate Change

“…Worldwide research is increasingly considering the use of chitosan derivatives, besides chitosan alone, as well as nanoparticles. Moreover, the combination of chitosan nanoparticles with other elements such as copper (Cu), zinc (Zn), selenium (Se), as well as silver (Ag) is becoming widely used [21][22][23]. Researchers suggest that chitosan based metallic nanoparticles may be even more effective than bulk chitosan in anti-pathogenic and plant growth-promoting activities [24].…”