Seed Pre-treatment with Polyhydroxy Fullerene Nanoparticles Confer Salt Tolerance in Wheat Through Upregulation of H2O2 Neutralizing Enzymes and Phosphorus Uptake

Abstract

Polyhydroxy fullerenes nanoparticles (PHF) are regarded as free radical sponges. Can they mitigate oxidative stress and induce tolerance in plants exposed to salinity? The influence of PHF seed pre-treatment on growth and biochemical attributes of NaClstressed wheat is studied. Wheat seeds (cv. Ujala) were pre-treated with control, hydro-priming, 10, 40, 80, and 120 nM PHF doses for 10 h and grown in sand-filled pots under control (0 mM NaCl) and salinity (150 mM NaCl) provided through nutrient solution. Salinity markedly decreased root and shoot growth attributes consistent with the reduction in the chlorophyll contents, whereas it increased the antioxidant activities of superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), and ascorbate peroxidase (APX) enzymes. Plants exposed to salinity exhibited increase in malondialdehyde (MDA) and hydrogen peroxide (H 2 O 2) contents which indicated oxidative stress. Further, salinity triggered rise in Na + uptake while decreased in K + and Ca 2+ contents both in the root and shoot. By contrast, wheat seedlings grown from PHF-treated seeds exhibited recovery in root and shoot growth under salinity. This recovery was linked with lower levels of MDA and H 2 O 2 contents and higher antioxidant activities of CAT, POD, and APX enzymes under salinity stress. The PHF-treated plants had higher chlorophyll, free amino acids, ascorbic acid, and soluble sugars. Moreover, PHF seed pre-treatment resulted in higher K + and P contents in the root while higher P contents in the shoot. Above all, PHF application mitigated adverse effects of salinity and promoted early seedling growth and establishment in wheat.

Foliar applied fullerol differentially improves salt tolerance in wheat through ion compartmentalization, osmotic adjustments and regulation of enzymatic antioxidants

“…Also, the seedlings exhibited better osmotic ion adjustments (particularly K ? and P ions) and less content of MDA and H 2 O 2 (Shafiq et al 2019). On the basis of these short-term effects of PHF as seed priming agent, we further hypothesized that its foliar spray might also promote salt tolerance in wheat.…”

“…In our previous study, seed pre-treatment with PHF at nano-molar concentrations promoted salt tolerance in 30-day old wheat seedlings through improvements in chlorophyll contents, free amino acids, total sugars and enhancing the activities of H 2 O 2 scavenging enzymes viz. CAT, POD and APX (Shafiq et al 2019). Also, the seedlings exhibited better osmotic ion adjustments (particularly K ?…”

Sodium Exclusion Affects Seed Yield and Physiological Traits of Wheat Genotypes Grown Under Salt Stress

“…3a-c). The salt-induced reduction in chlorophyll pigments has been reported earlier in a number of crops including wheat (Acosta-Motos et al 2017;Shafiq et al 2019). The extent of saltinduced reduction in chlorophyll a and b contents depends on the salt tolerance potential of plants (Hamada and El-Enany 1994).…”

“…It is now well evident that high concentrations of soluble salts cause both osmotic stress and ionic stress, which can effectively damage the photosynthetic apparatus and hamper a myriad of physio-biochemical processes (Acosta-Motos et al 2017;Shafiq et al 2019). For example, Ashraf and Harris (2005) reported that salinity-induced stomatal closure and reduced rate of leaf expansions lead to consequently restrict plant growth and yield.…”

“…For example, Ashraf and Harris (2005) reported that salinity-induced stomatal closure and reduced rate of leaf expansions lead to consequently restrict plant growth and yield. Over time, salinity is believed to cause Na + toxicity in the leaves which may impair a number of physiological processes (Munns 2002;Acosta-Motos et al 2017;Shafiq et al 2019).…”