(143d) Morphology-Based Transport of Gold Nanoparticles in Mature Plant Leaves

Plant genetic engineering has the potential to mitigate the effects of climate change and rising populations via the creation of high-yield crop varieties and climate-resilient plants. To this end, we require a plant genetic engineering toolset that is (i) plant-species independent, (ii) able to bypass physical barriers present in mature plant tissues, and (iii) capable of controlled localization and cargo release. A principal challenge in this field remains the efficient delivery of biological cargo across a plant’s cell wall and cell membrane. Existing tools for plant genetic engineering suffer limitations in species range, cargo diversity, tissue damage, efficiency, and transgene integration resulting in regulatory oversight. Recently, nanoparticles (NPs) have emerged as promising materials for use as cargo carriers into plant cells. Owing to their highly tunable chemical and physical properties, NPs can be synthesized and surface functionalized to achieve targeted localization and cargo release.

Current techniques either use pathogens or biolistic force to deliver biomolecules to plants. There is interest in unassisted (non-biolistic, force-independent) delivery of genetic cargoes into plant cells, in which nanocarriers may need to remain below the cell wall size exclusion limit. However, there lacks a set of heuristics for NP design for unassisted DNA, RNA, and protein delivery in plants.

Herein, we utilize a library of NA-coated gold nanoparticles as model materials to elucidate the effect of NP morphology on transport in plant tissues and on cargo protection against nuclease degradation. Our study suggests that nanoparticle morphology impacts both the uptake pathway, timescale, and extent of nanoparticle internalization into plant cells. The workflow presented in this work can be utilized to probe the effect of other nanoparticle-based design parameters such as size and surface chemistry on biomolecule delivery efficacy, which can enable the creation of NP design heuristics for force-independent internalization. This work serves as an initial platform that can be built on to understand how design parameters affect delivery in plants for more targeted applications of bionanotechnologies in plant genetic engineering and more broadly in environmental and agricultural science.