Biostimulatory effects of silicon on vegetable crop growth, productivity, and stress resilience: A review

• Si improves root development, photosynthesis, and nutrient uptake, leading to increased biomass and higher crop productivity. • It strengthens cell walls and triggers defense responses, helping plants withstand drought, salinity, and heavy metal toxicity. • Si acts as a physical and biochemical barrier, reducing damage from pests and pathogens, minimizing reliance on chemical pesticides. • It optimizes the absorption and utilization of essential nutrients like nitrogen, phosphorus, and potassium, enhancing overall plant health. • Si contributes to firmer textures, prolonged shelf life, and enhanced resistance to post-harvest decay, reducing food losses. Silicon (Si) has emerged as a beneficial element that enhances plant tolerance against diverse biotic and abiotic stresses; however, its mechanistic integration in vegetable crops remains insufficiently synthesised. This review critically consolidates recent advances in Si uptake, transporter regulation, translocation, and deposition dynamics, with emphasis on their coordination with metabolic and hormonal signalling networks. Evidence from transcriptomic, proteomic, and metabolomic studies demonstrates that Si modulates antioxidant defence systems, osmolyte accumulation, and stress-responsive transcription factors, while influencing salicylic acid, jasmonic acid, and ethylene pathways. Rather than acting solely as a structural barrier, Si functions as a regulatory modulator that integrates physical reinforcement with molecular reprogramming. The review also discusses emerging insights into Si nanoparticles, foliar application efficiency, and synergistic interactions with biofertilizers. Understanding these coordinated mechanisms is crucial for developing Si-based strategies to enhance vegetable productivity and climate resilience under changing environmental conditions.