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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 #417338
Research Project: Management and Biology of Arthropod Pests and Arthropod-borne Plant Pathogens

Location: Emerging Pests and Pathogens Research

Title: Nanometal reagent therapeutics suppress Candidatus Liberibacter asiaticus, the causal pathogen of Huanglongbing

Author
item DEMIRDEN, NURSENA - Oak Ridge Institute For Science And Education (ORISE)
item Larson, Nicholas
item Heck, Michelle
item Niedz, Randall

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: Huanglongbing (HLB), also known as citrus greening, is one of the most devastating citrus diseases worldwide. HLB symptoms include yellowing of shoots, blotchy mottled leaves, corky veins, malformed and discolored fruits, premature fruit drop, and root loss, resulting eventually in tree death. It is caused by the psyllid-transmitted, phloem-limited bacteria "Candidatus Liberibacter asiaticus" (CLas). However, the detailed molecular mechanisms of CLas have not been fully understood yet. Oxytetracycline (OTC), an injected antibiotic, has now been approved for use in citrus to control CLas. The fact that growers are willing to treat trees individually changes how our team is screening for HLB solutions. Now, molecules are being evaluated by tree injection in the field alone and in combination with OTC. Work in the lab is done only in the context of field observations. To better understand how classes of unknown molecules work in the field, we developed a minimum inhibitory concentration (MIC) assay to assess molecule antimicrobial activities against Agrobacterium tumefaciens, a bacteria phylogenetically related to CLas. OTC standards are useful to benchmark assay performance. One class of molecules being evaluated includes metallic nanometer particles, including zinc oxide, magnesium oxide, and calcium oxide. This presentation will focus on detailing the MIC and other lab assays that are used to develop mechanistic data that may explain or support field observations during trunk injection. There is an urgent need to identify or develop inhibitor molecules to suppress or eradicate CLas from infected citrus plants.