Huanglongbing (HLB) is the most devastating disease in the citrus tree. The disease is classified as a vector borne disease and results from the interaction between three organisms, namely citrus plants (host), Diaphorina citri psyllids (vector), and Candidatus Liberibacter (pathogen). HLB (a.k.a. citrus greening disease) is caused by fastidious, non-cultivable gram-negative Liberibacter bacteria that multiply inside tree phloem tissue thus blocking nutrient distribution through the plant. HLB disease management is difficult due to the nonspecific symptoms and late diagnosis of disease in citrus trees. Our aim is to develop novel antimicrobial encapsulated nanoparticles that enter the plant vascular system (phloem) where bacteria reside, inhibit bacterial growth, and induce bactericidal effects. Iron nanoparticles were synthesized in a seeded growth scheme with differing surface functionalization, including positive charge conferred with cetyltrimethylammonium bromide, negative charge conferred with ascorbic acid, and neutral charge conferred with polyvinylpyrrolidone ligands. Characterization of synthesized particle-types were performed via dynamic light scattering, transmission electron microscopy (TEM), and atomic force microscopy. Citrus tree uptake was assessed via inductively coupled plasma mass spectrometry and TEM. Antimicrobial sensitivity against a set of gram-positive and gram-negative bacteria was evaluated using the disk diffusion assay. Our findings show that engineered iron nanoparticles can be used as potential therapeutic delivery systems to combat citrus greening disease progression.

Novel iron based nanoformulation for HLB management

ACS Fall 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.