Synthetic Nanomaterials for Nucleic Acid Delivery in Plants: Design Principles, Delivery Mechanisms, and Nano–Plant Interactions

Advances in plant genetic engineering hold significant promise for addressing urgent global food security needs. Nevertheless, conventional biomolecule delivery techniques, such as Agrobacterium-mediated transformation and biolistics, are hindered by inherent limitations, including narrow host compatibility, inconsistent efficiency, and unintended tissue damage. Nanotechnology has arisen as a transformative approach that exploits the tunable physicochemical properties of nanomaterials to bypass biological barriers, facilitating efficient, non-invasive, and species-independent nucleic acid delivery in plants. While prior reviews have acknowledged nanomaterials as promising delivery vehicles, key mechanistic and functional dimensions remain insufficiently explored. This review summarizes recent breakthroughs in nanomaterial-based delivery systems, emphasizing innovative uptake mechanisms, intracellular trafficking, and systemic transport processes. Additionally, this review explores the dual functionality of nanomaterials, which serve not only as efficient nucleic acid carriers but also as active biostimulants that enhance nutrient assimilation, stress tolerance, and innate immunity in plants. These multifaceted roles underscore the importance of incorporating such dual capabilities into the rational design of plant-specific nanocarriers. By integrating these insights, this work offers a comprehensive framework to support the development of efficient and sustainable nano-delivery platforms for next-generation plant genetic engineering.