Synergistic Effects of Bioactive Compounds and Nano-Enabled Fertilization on Growth and Physio-Biochemical Responses of Maize Under Drought Stress

Abstract

Maize (Zea mays L.) is a major cereal crop of global significance, contributing substantially to food security and agricultural sustainability. Enhancing its physiological performance through innovative nutrient management and bioactive compounds is essential for improving productivity under changing environmental conditions. This study investigated the combined effects of γ-aminobutyric acid (GABA), kaempferol (KP), and nanoparticle (NP)–coated urea on maize growth and physiological responses. The experimental treatments were designed to evaluate how these inputs interact to influence nutrient utilization, stress-related physiological processes, and plant morphology. Growth attributes, including shoot and root development and biomass accumulation, were assessed under varying concentrations of GABA and KP in combination with NP-coated urea. The results demonstrated a pronounced concentration-dependent response. Under non-GABA conditions, shoot length increased by 4.5% and 9% with 5 µM and 10 µM KP, respectively. In the presence of 0.1 mM GABA, root length exhibited substantial enhancement, increasing by 20.29% with 5 µM KP and by 39.72% with 10 µM KP. Leaf dry weight also increased markedly, showing gains of 21.35% and 53.26% at 5 µM and 10 µM KP, respectively. These findings reveal a synergistic interaction between GABA, kaempferol, and NP-coated urea, suggesting that their integrated application can effectively promote maize growth and improve physiological efficiency. The study provides a promising framework for developing advanced nutrient and stress-management strategies to enhance maize performance