Improving the Systemic Uptake of Therapeutic Compounds by Trunk Injections

Improving the Systemic Uptake of Therapeutic Compounds by Trunk Injections

Report Date: 02/12/2023
Project: 22-017   Year: 2023
Category: Horticultural & Management
Author: Amit Levy
Sponsor: Citrus Research and Development Foundation

1. Please state project objectives and what work was done this quarter to address them:Objective 1: Using callose inhibitors to improve systemic uptake and reduce HLB symptoms.A study was implemented incorporating 12 replicates of all proposed treatments.  We continued our field experiment on sweet orange ~8 years old (Citrus x sinensis) trees: (1) injected control (water), (2) Oxytetracycline (2 g per tree), (3) DDG (0.1 mM), (4) DDG (0.1mM) + Oxytetracycline (2 g per tree), (5) DDG (1mM), (6) 3AB (0.1mM), (7) 3AB (0.1mM) + Oxytetracycline (2 g per tree), (8) 3AB (1mM). Then we designed the appropriate map for the experiment. We measured baseline stomatal conductance, trunk diameter, canopy volume and canopy density. Injection treatments were accompanied with measurements of canopy dimensions and density, and followed by measurements of stomatal conductance.  No treatment reduced stomatal conductance, and we conclude that the treatments do not negatively impact tree physiology in the short term. Canopy growth will be measured at 6 months post-treatment. Furthermore, six mature leaf samples per tree were collected to measure the CLas titer and quantify calloselevel of each tree. Leaf samples were collected to measure the CLas titre and quantify the callose level of trees 1 and 2 weeks after treatments. Lastly, we measured the Oxytetractcline on the trees. Suprisingly we saw that there was no difference between the different samples, and they were all the same. We went back and evaluated all our procedures. Unfortunatly, we found that we made a mistake in the Oxytetracycline measurements. and injected only a small amount, a small percentange of what we had planned. We decided to repeat the injections.Objective 2: Maintaining water-saturated injection site: Sealed trunk injection ports that stay functional by avoiding woundresponses.Experments planned.Objective 3: Targeted root delivery.No progress. 2. Please state what work is anticipated for next quarter:We will reinject trees and evaluate the trees for callose level and Clas titre monthly. We will also measure the canopy volume and density. We will begin experiments for objectives 2 and 3. 3. Please state budget status (underspend or overspend, and why):Underspend- since it took some time to initiate the work 4. Please show all potential commercialization products resulting from this research, and the status of each:We are still evaluating the effect of the callose inhibitor in the field trials  


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