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Sustainable agricultural production is critically antagonistic by fluctuating unfavorable environmental conditions. The introduction of mineral elements emerged as the most exciting and magical aspect, apart from the novel intervention of traditional and applied strategies to defend the abiotic stress conditions. The silicon (Si) has ameliorating impacts by regulating diverse functionalities on enhancing the growth and development of crop plants. Si is categorized as a non-essential element since crop plants accumulate less during normal environmental conditions. Studies on the application of Si in plants highlight the beneficial role of Si during extreme stressful conditions through modulation of several metabolites during abiotic stress conditions. Phytohormones are primary plant metabolites positively regulated by Si during abiotic stress conditions. Phytohormones play a pivotal role in crop plants’ broad-spectrum biochemical and physiological aspects during normal and extreme environmental conditions. Frontline phytohormones include auxin, cytokinin, ethylene, gibberellin, salicylic acid, abscisic acid, brassinosteroids, and jasmonic acid. These phytohormones are internally correlated with Si in regulating abiotic stress tolerance mechanisms. This review explores insights into the role of Si in enhancing the phytohormone metabolism and its role in maintaining the physiological and biochemical well-being of crop plants during diverse abiotic stresses. Moreover, in-depth information about Si’s pivotal role in inducing abiotic stress tolerance in crop plants through metabolic and molecular modulations is elaborated. Furthermore, the potential of various high throughput technologies has also been discussed in improving Si-induced multiple stress tolerance. In addition, a special emphasis is engrossed in the role of Si in achieving sustainable agricultural growth and global food security.

When a mixture of two or more reducing agents is titrated, a curve with multiple inflection points results provided the reduction potentials of the species are sufficiently different (1). This is comparable to the titration of two acids with different dissociation constants or of two ions forming precipitates of different solubilities with same reagent (2). The effect of complexation on redox potentials is well documented (3-19) and some articles to this effect are published in this Journal (3, 4). Our experiment is a simple potentiometric titration aimed to invoke the underlying concept of the complexation effect on redox potential of a redox couple. Potentiometric titrations have been widely discussed in this Journal (20-24); however, no method is reported for potentiometric titration of metal ions on the basis of the ligand effect. We choose iron(III)-iron(II) couple because it occurs in many natural redox systems. In this experiment, three iron(II) octahedral complexes, iron(II) aqua, [Fe(OH 2 ) 6 ] 2þ ; iron(II) EDTA, [Fe EDTA] 2-; and iron(II) phenanthroline [Fe(o-phen) 3 ] 2þ , are combined into mixtures of reducing agents and are oxidized to the corresponding iron(III) complexes. Multiple inflections in the titration curve depict the different redox potential of iron(III)-iron(II) couple in these complexes that can be attributed to the complexation effect. This experiment illustrates the effect of the stabilities of iron(III)-iron(II) complexes with EDTA, water, and 1-10 phenanthroline ligands on redox potential.