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ARS Home » Northeast Area » Ithaca, New York » Robert W. Holley Center for Agriculture & Health » Emerging Pests and Pathogens Research » Research » Publications at this Location » Publication #417327
Research Project: Management and Biology of Arthropod Pests and Arthropod-borne Plant Pathogens

Location: Emerging Pests and Pathogens Research

Title: Symbiont Technology: development and optimization of a novel delivery approach for therapeutics to control Candidatus Liberibacter asiaticus

Author
item Pitino, Marco
item FLEITES, LAURA - Perpetual Peptides, Inc
item Coradetti, Samuel
item Deblasio, Stacy
item Rhodes, Brian
item SULLIVAN, SAMANTHA - Perpetual Peptides, Inc
item HARPER, DOUGLAS - Perpetual Peptides, Inc
item FITZGERALD, JOHN - Perpetual Peptides, Inc
item TRIMMER, MARK - Perpetual Peptides, Inc
item Thomson, James - Jim
item Niedz, Randall
item Heck, Michelle
item Shatters, Robert - Bob

Submitted to: International Research Conference on Huanglongbing
Publication Type: Abstract Only
Publication Acceptance Date: 3/1/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Citrus Huanglongbing (HLB) presents a significant challenge in disease management due to the systemic, vector-transmitted, and phloem-limited lifestyle of the causative agent Candidatus Liberibacter asiaticus (CLas). Effective therapies for HLB will require scalable manufacturing and reliable, affordable, low-maintenance delivery into the phloem of trees in the field. We describe the development of Symbiont technology that coopts Agrobacterium tumefaciens ability to insert DNA into plant genomes (the transferred DNA is called T-DNA). By modifying the T-DNA to express only plant growth regulator (PGR) genes and a gene of interest, we created a cluster of dividing plant cells that produce therapeutic biomolecules. We call the structure a Symbiont because of its benefit to the plant. The Symbiont has vascular connections to the plant and continually produces therapeutic peptides. No opine genes are encoded in Symbiont plasmids, and thus, disarmed Agrobacteria do not persist in Symbionts. Optimization of light exposure, temperature and humidity greatly enhanced growth and homogeneity of marker gene expression for Symbionts grown on citrus trees in controlled conditions. Certain plasmids led to more rapid development of Symbionts with increased longevity. Ongoing work is focused on using Symbionts to screen antimicrobial peptides that reduce CLas titer and improve tree health and to enhance peptide export from the Symbiont. Symbiont technology is also a promising platform for plant cell based in vitro production of biomolecules, which can be purified and injected into diseased plants. Seven binary vectors were constructed that contain, within the T-DNA, various iterations of the PGR genes, a cloning site for candidate antimicrobials and/or other therapeutics, a fluorescent/visual reporter, and an antibiotic resistance gene for transformed cell selection. Each vector has a unique phenotype in Symbionts and in Symbiont cells in in vitro culture. While early-stage technology, Symbionts may one day provide a biological approach to deploying plant therapeutics.