Carbon nanotubes (CNTs) have been explored as a promising approach to improve plant drought resilience by regulating various morphological, physiological, and biochemical processes. Morphologically, CNTs can infiltrate root tissues, creating nano-channels that may improve water and nutrient uptake. On the physiological level, these nanomaterials can affect plant hormone signaling by modifying the concentrations of essential hormones such as abscisic acid (ABA), auxins, cytokinins, and gibberellins, thereby stimulating cell and root development, and stress resilience. CNTs improve the efficiency of photosynthesis by enhancing chlorophyll fluorescence, chlorophyll content, promoting electron flow, and crucial enzyme activity such as Rubisco and phosphoenolpyruvate carboxylase (PEPC), which are essential for effective CO₂ fixation and photosynthesis assimilation. Biochemically, CNTs mitigate drought-induced oxidative stress by upregulating antioxidant enzymes, regulating reactive oxygen species (ROS) levels, and modulating osmoprotectants such as proline and sugars. However, research on CNTs and their impact remains limited, , underscoring the necessity for more thorough exploration of their mechanisms, safety, and long-term effects. This review explores the morphological, physiological, and biochemical mechanisms underlying CNT-induced stress tolerance in plants, with a particular focus on their ability to enhance drought resistance. Furthermore, the phytotoxicity effects linked to CNT exposure were discussed. In addition, the limitations and future opportunities for employing CNTs in sustainable agriculture were outlined, covering safety aspects, cost-effectiveness, and environmental sustainability.
