Chelated Silicon Mitigated the Salinity-induced Drastic Effects by Regulating the Antioxidant Activities and Biochemical Attributes of Two Different Pea Genotypes

Purpose

Salinity stress has become a major threat to crop growth and food security for the increased population of the globe. Thus, silicon (Si) is a non-essential beneficial element for plants but has multifaceted functions regarding tolerance against abiotic stresses.

Methods

Therefore, a pot experiment was performed to examine the comparative impacts of organic and inorganic sources of Si on the vegetative and physiological behavior of two genotypes of pea plants under non-saline and saline (5 dSm⁻¹) conditions. Two pea genotypes [salt-sensitive (Ambasidar) and salt-tolerant (Samerena zard)] were used in the study, and three treatments i) chelated-Si (EDTA-Si) @ 0.5% ii) inorganic-Si (K₂O₃Si) @ 0.5% and iii) without-Si (control) were devised under three factorial completely randomized design.

Results

Data reflected the positive response of both Si sources but EDTA-Si proved more beneficial in aggravating the growth & gas exchange attributes and activity of antioxidant enzymes significantly in salt-sensitive and salt-tolerant pea genotypes under normal and saline growing conditions. Moreover, the increase in ionic contents (K, Ca, Mg, and P) was also observed except for Na⁺, Cl⁻ and Na: K ratio in pea plants when treated with EDTA-Si.

Conclusions

However, both Si sources improved the measuring traits of both salt-tolerant and salt-sensitive pea genotypes but EDTA-Si revealed a significant improvement in measured attributes of the salt-tolerant genotype as compared to the salt-sensitive. Thus, EDTA-Si ameliorated the negative effects of salinity by enhancing the plant's defense mechanisms, mediated through increased activity of antioxidant enzymes and greater uptake of nutrient ions. This improvement was attributed to enhanced vegetative growth, particularly root growth and proliferation, compared to plants treated with the inorganic form of Si.