Thiamine: A Shield Against Plant Stress

Thiamine (vitamin B1) is an essential micronutrient required for cellular metabolism and energy production in all living organisms. Its biologically active form, thiamine pyrophosphate (TPP), serves as a critical cofactor for several key enzymatic processes, including those involved in glycolysis, the oxidative pentose phosphate pathway, and the tricarboxylic acid (TCA) cycle. Through these pathways, TPP facilitates the conversion of carbohydrates, lipids, and proteins into usable energy. Beyond its metabolic importance, recent research has highlighted thiamine’s role in enhancing plant immunity by activating systemic acquired resistance (SAR) and strengthening defence responses against both biotic and abiotic stressors. Multiple studies have shown that the expression of genes involved in thiamine biosynthesis increases in plants exposed to various stresses. Investigations of gene expression, thiamine and intermediate metabolite accumulation, and enzyme activity complementation have all supported the protective role of thiamine in plants. This chapter will examine thiamine’s function as a stress-responsive signalling molecule, outline its biosynthetic pathway, and discuss its regulatory mechanisms. Additionally, the chapter will briefly address the practical implications of these findings, reinforcing thiamine’s proposed role in plant stress resilience.