Which one among the following nutrients is a structural component of the cell wall of plants?

Calcium is a vital macronutrient that serves as a fundamental structural component of the plant cell wall. It is primarily found in the middle lamella, the outermost layer that cements adjacent plant cells together [4]. Chemically, calcium reacts with pectic acid to form calcium pectate, which acts as an intercellular adhesive or 'cementing material' [4]. This cross-linking of pectin molecules with calcium ions provides essential rigidity, strength, and structural integrity to plant tissues, enabling them to withstand mechanical stress [3]. While other nutrients like phosphorus and potassium are essential for energy transfer and osmotic regulation respectively, they do not form the physical scaffolding of the cell wall. Calcium's role extends to stabilizing cell membranes and regulating cell division and enlargement, making it indispensable for the growth of root and shoot tips [1].

Sources

1. [3] Indian Economy, Nitin Singhania .(ed 2nd 2021-22) > Chapter 9: Agriculture > FERTILISERS > p. 302
2. [4] https://www.sciencedirect.com/science/article/abs/pii/S0981942824002705
3. [1] Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 25: Agriculture > Nitrogen (N) > p. 363