High aspect ratio graphene oxide: a highly efficient plasmid DNA deliverer for plant seed

Plant genetic engineering plays a central role in crop improvement and the biosynthesis of natural products. However, the plant cell wall serves as a natural barrier that restricts the efficient delivery of exogenous biomolecules, particularly the direct transfer of plasmid DNA into plant seeds. Here, we introduce a novel form of graphene oxide characterized by a high aspect ratio, synthesized through low-voltage, low-current, and prolonged electrochemical oxidation in a 0.5 mol/L NaOH aqueous solution. The high aspect ratio graphene oxide (HARGO) can effectively deliver plasmid DNA to Poa crymophila Keng seeds, achieving a 90% success rate. Furthermore, it is effective for both wheat and rice seeds. The underlying mechanism of this efficient delivery is that HARGO can physically absorb plasmid DNA and transport the adsorbed plasmid DNA into plant cells and deeper tissues through passive transport, eliminating the need for chemical modification of polyethylene glycol (PEG) and polyethyleneimine (PEI). These findings offer a dependable non-integrating plasmid DNA delivery tool for plant genetic engineering, which will significantly impact the advancement of plant biotechnology.