Integrating the Nano–Phyto–Micro Triad for Climate-Resilient and Sustainable Agriculture

The convergence of nanotechnology, plant hormones, and plant-associated microbiomes offers a transformative approach for climate-resilient and sustainable agriculture. This perspective examines how nanocarriers can improve the delivery and stability of natural hormones and microbiome-compatible compounds, addressing challenges such as low bioavailability, environmental degradation, and nontargeted effects. Plant hormones, such as auxins, gibberellins, and salicylic acid, play essential roles in stress responses and growth regulation, while beneficial microorganisms contribute to nutrient cycling, pathogen resistance, and resilience against abiotic stresses. However, their practical application remains limited due to their instability and inconsistent performance under field conditions. Recent advancements have demonstrated that innovative nanomaterials, such as polymeric, lipid-based, or silica nanoparticles, can enable the controlled release, targeted delivery, and environmental protection of these compounds. For example, chitosan-based nanoparticles increase root colonization by beneficial microbes and enhance systemic resistance in tomatoes and maize. This review synthesizes the current knowledge and emerging technologies at the nano-phyto-micro interface, highlighting synergistic mechanisms and gaps in regulation, formulation, and large-scale applications. We advocate integrated research strategies that combine omics approaches, advanced formulations, and real-world validations to unlock the full potential of this triad. Aligning nanotechnology with nature-based solutions may pave the way for low-input, high-efficiency farming systems tailored to changing climates.