Mechanistic insights into micro and nanosilicon for environmental stress mitigation in plant.

Over the past two decades, the persistent escalation in global temperatures has emerged as a critical driver of ecological instability, exerting profound consequences on agricultural productivity and sustainability. Various environmental stressors, including biomedical contaminants, collectively impair plant growth, development, and yield potential. Numerous adaptive strategies have been explored to mitigate these stresses and enhance plant resilience. Among these, silicon has gained increasing recognition as a quasi-essential element capable of alleviating abiotic and biotic stress through multifaceted mechanisms. Additionally, Si synergistically interacts with micronutrients and plant growth regulators (PGRs) to promote metabolic efficiency and physiological robustness. Recent advancements highlight the pivotal role of silicon nanoparticles (SiNPs) in enhancing plant growth, nutrient uptake, and stress resilience. SiNPs surpass bulk forms by improving biomass and limiting heavy metal translocation. Mechanistically, they regulate antioxidant enzymes (SOD, CAT, POD, APX), modulate transporter genes and signalling pathways, and influence hormonal cross-talk with ABA, auxin, and ethylene, collectively strengthening plant defence systems. This review highlighted the response of micro- and nano-silicon to regulating key metabolic pathways involved in stress resilience. This review uniquely synthesizes emerging evidence comparing micro- and nano-silicon, emphasizing their distinct roles in modulating antioxidant defence, nutrient signalling, and heavy metal detoxification under environmental stress.