Mapping mechanistic pathways of seed priming in maize (Zea mays L.): A systematic review

Seed priming is recognised as an effective approach to enhance stress resilience and crop performance in maize (Zea mays L.), however, the underlying mechanistic relationships remain insufficiently integrated.This review systematically synthesises the literature from 2020 to 2025, analysing how various priming agents, stress types, and maize genotypes are linked on the core biochemical and physiological pathways.The results reveal that all effective seed priming strategies converge on the rapid induction of antioxidant enzymes, superoxide dismutase, catalase, and peroxidases, which form the primary defence against oxidative stress during early development.The specific priming agent determines the recruitment of auxiliary pathways, including hormone crosstalk, osmoregulation, ion homeostasis, and reserve mobilisation, which are engaged according to the prevailing stress condition.The genotype background modulates the extent, but not the direction, of physiological benefits, with tolerant lines consistently displaying superior outcomes.To encapsulate these multidimensional relationships, a Sankey diagram is presented, mapping the flow from the priming type through activated mechanisms to physiological responses and genotype outcomes.This integrative visual framework clarifies the hierarchical and contextdependent nature of seed priming in maize, serving as a practical tool for designing targeted, genotype-tailored interventions.K e y w o r d s: mechanistic pathways, physiological responses, genotype-stress interactions, Maize (Zea mays L.) Stress, Biotic Stress, Heavy-Metal Toxicity, Chemical Stress, Abiotic Stress, etc.• Example: "PEG-6000 induced stress" becomes "Drought/Water Deficit"; "NaCl" becomes "Salinity/ Alkalinity." • Activated Mechanism: Mechanistic descriptors (often diverse and idiosyncratic in the literature) were harmonised to a smaller set of canonical mechanisms.The rules captured both direct mentions (e.g., "CAT activity ↑") and indirect indicators (e.g., "reduced MDA" mapped to redox, "shoot length ↑" to growth activation):• Antioxidant/Redox Defence (e.g., SOD, CAT, POD, APX induction, ROS scavenging) • Hormone Crosstalk (e.g.