Aptamer-based targeted delivery platform for plant agro-chemicals and nutrients

Overview

This research program develops aptamer technology tailored for plant systems, enabling targeted delivery of payloads such as nutrients and agro-chemicals across plant leaf surfaces. While aptamers have been widely used in animal systems to cross biological barriers like the blood-brain barrier, analogous tools for plants have been lacking. By adapting existing expertise in delivery aptamers and applying a novel infiltration SELEX (Systematic Evolution of Ligands by Exponential Enrichment) method, this work unlocks new transporter molecules for precision agriculture applications. The platform addresses a critical gap in plant biotechnology by offering a mechanism to deliver treatments more efficiently while minimizing off-target effects on non-target species and surrounding ecosystems.

Technical specifications

Core approach:

• Infiltration SELEX on O. basilicum (basil) to select single-stranded DNA (ssDNA) sequences capable of crossing the leaf cuticle and entering leaf tissue
• A DNA library is introduced via infiltration against the abaxial (lower) leaf surface, incubated overnight, then washed thoroughly to remove surface-bound sequences
• Internalized DNA is extracted, amplified, and re-applied in successive selection rounds with increasing stringency
• After five rounds of enrichment, ssDNA sequences capable of penetrating the leaf surface from topical deposition alone were detected, while control ssDNA could not

Key features:

• Demonstrated passive penetration of plant leaf surfaces by selected aptamer candidates
• Potential for receptor-mediated uptake, to be confirmed via biomarker identification through cross-linking, pulldown, and mass spectrometry
• Planned expansion to counter-selection strategies for species-specific targeting, such as selecting aptamers that penetrate wild mustard but not canola
• Confocal microscopy with Cy3-tagged aptamers for visual confirmation of uptake

Technology readiness level

This technology is currently at early-stage proof of concept. Preliminary data from five rounds of SELEX enrichment on O. basilicum has demonstrated that unique DNA sequences can penetrate the leaf surface, validating the core hypothesis. Next steps include completing aptamer identification, screening top hits via fluorescence microscopy, and determining whether uptake is passive or facilitated by receptor binding. Future work will expand the platform to include counter-selections for targeted delivery applications, such as weed-specific versus crop-specific penetration. The technology is not yet commercially deployed and represents an active research and development opportunity.