<p>Artificial intelligence (AI), nanotechnology, and biosensing are converging to create a new era of data-driven, responsive, and climate-resilient agriculture, which we term as Plant-Nanotechnology 4.0. Plant-Nanotechnology 4.0 integrates nanoscale biosensors and smart responsive nanomaterials directly into plants and soil to form independent, closed-loop systems that can sense in real-time, predictive analytics and targeted interventions on demand to the molecular level, unlike traditional smart agriculture methods, which mainly use IoT (Internet of Things) sensors, drones, and AI to monitor and make decisions. This framework integrates high-resolution nano-biosensors to detect biotic and abiotic stresses early, AI-based predictive models, and smart nanomaterials controlled-release nano-fertilizers, nano-pesticides, and CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) nanocarriers, to perform very specific, stimuli-responsive functions. The resulting system facilitates proactive over reactive crop management, which is more efficient in the use of resources, acts as a more effective way of minimizing chemical inputs, and providing better resiliency to climate stressors without the necessity of transgenic modification. Although evidence-based research shows yield improvements and reduced ecological footprint, biosafety, long-term ecological effects, and fair access to smallholder farmers continue to be major challenges. This review summarizes recent developments, outlines the main gaps in the research, and gives a roadmap of the safe, scalable, and inclusive deployment of Plant-Nanotechnology 4.0, a transformative approach to sustainable global food security.</p> Graphical Abstract <p></p>