Microwave Treatment for Citrus Huanglongbing Control: Pathogen Elimination and Metabolomic Analysis

Area of Science:

• Agricultural Science
• Plant Pathology
• Biotechnology

Background:

• Huanglongbing (HLB), caused by Candidatus Liberibacter asiaticus (CLas), devastates global citrus production.
• Current control strategies for HLB are limited and often not economically viable.
• There is an urgent need for novel, sustainable methods to manage HLB.

Purpose of the Study:

• To investigate microwave irradiation as a physical control method against HLB.
• To assess the efficacy of microwave treatment in reducing CLas titers in citrus plants.
• To analyze the metabolomic changes in citrus plants following microwave treatment.

Main Methods:

• HLB-infected citrus plants were subjected to microwave irradiation (2450 MHz, 500 W or 250 W) over 10 cycles.
• CLas titer reduction was quantified using molecular methods.
• Non-targeted metabolomic analysis was performed to identify changes in plant metabolites.

Main Results:

• Microwave treatment achieved up to 99.83% reduction in CLas titer.
• Fifteen significantly altered metabolites were identified, including upregulated beta-caryophyllene and lysophosphatidylinositols.
• Downregulation of 5'-S-methyl-5'-thioadenosine was observed post-treatment.

Conclusions:

• Microwave irradiation is an effective physical method for suppressing CLas, the causal agent of HLB.
• The treatment induces significant physiological and metabolic changes in citrus plants.
• Microwave technology shows potential as a sustainable alternative to chemical HLB control, pending further optimization.