Amino acid transporters mediate autonomous delivery of nanoparticle vehicles into living plants

Abstract

Presence of the cell wall and the lack of streamlined pathways for cellular delivery of external agents into plants is a core challenge of plant biotechnology and crop engineering development. However, both viral and bacterial transmission have their own restrictions and the few non-heavy metal nanodelivery platforms require external forces for tissue penetration. Such dependency limits any high-throughput application considering the large plant numbers to be treated in the field or even laboratory exercises. Herein, we demonstrate Aspartic acid (Asp) decorated poly(ethylene glycol)-block-poly(2-(diisopropylamino)ethyl methacrylate) (Asp-PEG-PDPA) copolymers assembled micelles (Asp/PDPA-NP), a platform that utilises amino acid transporters (AtAAP1 and AtLHT1) as receptors for clathrin-dependent endocytosis, freely translocate to release loaded cargo into various plant tissue/cell types in a species-independent manner within ≤10 minutes through simple spray or co-culture. As proof-of-concept, abscisic acid (ABA)-loaded Asp/PDPA-NP was tested for its efficacy to confer plant drought resistance. Asp/PDPA-NP@ABA reduced the effective ABA dose down to 1 nM (one million-fold) and elicited anti-drought potency in representative eudicot (soybean) and monocot (maize) crop species. Owing to its delivery efficiency, Asp/PDPA-NP holds promise as a potent carrier for diverse chemicals and biomolecules in plant systems.