Improving the Systemic Uptake of Therapeutic Compounds by Trunk Injections
Posted August 2025
Researchers: Amit Levy, Christopher Vincent, Nabil Killiny
Contact: Amit Levy, UF/IFAS CREC amitlevy@ufl.edu
Summary:
Trunk injection is playing a major role in the survival of Florida’s citrus industry until more long-term solutions are developed. However, injection also causes injury to the trunk around the injection sites, which plugs the xylem and the phloem in the area. This injury will not only reduce the efficiency of the substance uptake and systemic movement, but also force to apply another drilling at a different location for subsequent injections. This wound response involves, in part, the plugging of the phloem by callose, which blocks the phloem. Therefore, there is a need to improve the injection process so that the xylem and phloem don’t get plugged and can support a continuous flow of the antimicrobials in addition to water, sugars, and nutrients. We are working on improving the trunk injection process such that it will not lead to a determinantal plugging of the xylem and phloem. We will do this with these objectives by either using callose inhibitors to improve systemic uptake and reduce huanglongbing symptoms or by targeted root delivery using root aeration and watering tubes to encourage root growth and root tip proliferation around the tubes.
Take Home Message:
- Trunk injection of a callose inhibitor reduced phloem plugging by callose.
- Callose inhibitor increased sugar transport.
- Watering tubes increased the development of roots tips near the port, and the overall development of the root system.
