Nanoparticle classification and synthesis techniques: Implications for enhancing plant drought resistance

Recent advancements in technology have underscored the significance of the progression of nanotechnology and nanoscience. The growing use of nanotechnology in a variety of scientific and technical fields has contributed to improving contemporary living. Over the past decade, there has been a surge in research endeavors focused on the development of novel methodologies for the synthesis of nanomaterials, with the aim of mitigating the chemical and toxic effects on the environment. In lieu of conventional chemical and physical methodologies, biosynthesis offers a sustainable solution by employing extracts from plants and microorganisms as reducing and stabilizing agents. The employment of nanomaterials in agricultural contexts has emerged as a promising avenue for investigating plant defense systems against abiotic stress. Studies published between 1990 and 2026 were identified through Scopus, Web of Science, PubMed, ScienceDirect, and Google Scholar, and 261 publications were included. This review offers a comprehensive overview of the historical development, classification, and synthesis methods of nanoparticles and provides a concise comparison between green and chemical synthesis of nanoparticles. It further summarizes the application of nanotechnology in agriculture and the general mechanisms of nanoparticles, along with proteomic and transcriptomic methods to mitigate abiotic stress such as drought.