A new research platform may help scientists identify potential treatments for citrus greening disease faster, potentially speeding up the search for solutions.
Citrus greening, also known as huanglongbing (HLB), is caused by the bacterium Candidatus Liberibacter asiaticus (CLas). The disease disrupts the tree’s ability to transport nutrients, leading to symptoms such as blotchy leaves, small and misshapen fruit, poor juice quality and declining tree productivity. Finding effective treatments has been difficult because CLas cannot be easily grown in laboratory conditions, making traditional screening methods slow and expensive.
Researchers with the Fund for Citrus Protection (Fundecitrus) in Brazil developed a new method that could help overcome this challenge. Their study (“A Citrus medica stem cutting-based platform for rapid screening of therapeutic compounds against Candidatus Liberibacter asiaticus”) was published in the journal Scientific Reports. The research team included Beatriz Cristina Pecoraro Sanches, Talita Alves dos Santos, Eduardo Silva Gorayeb, Nelson Arno Wulff and Franklin Behlau.
The researchers created a screening system using infected citron (Citrus medica) stem cuttings. Instead of relying on mature citrus trees — which can take years to show measurable responses — the stem-cutting system allows scientists to test potential HLB treatments on a much smaller scale and obtain results more quickly.
The team evaluated seven citrus genotypes and found that citron stem cuttings provided strong rooting performance and consistent growth, making them suitable for testing possible therapeutic compounds. Researchers developed four different testing protocols to measure plant growth, bacterial levels and responses to treatments.
As a proof of concept, the researchers tested oxytetracycline (OTC), an antimicrobial compound used in Florida for HLB management. The study found that OTC treatments reduced CLas levels in treated cuttings compared with untreated plants, demonstrating that the new platform could detect differences in treatment effectiveness.
For citrus growers, the importance of this research is not that it delivers a new field treatment today. Instead, it provides researchers with a faster and more efficient tool for evaluating potential HLB therapies before advancing promising candidates into greenhouse and field trials.
Developing HLB solutions requires testing many different compounds while considering effectiveness, tree health, application methods and long-term sustainability. A faster screening process could allow scientists to evaluate more potential treatments in less time, improving the chances of identifying tools that may eventually become part of integrated HLB management programs.
The researchers say this stem-cutting platform could strengthen early-stage testing of antimicrobial compounds and accelerate therapeutic discovery for citrus greening disease.
For growers facing continued HLB pressure, advances like this represent another step toward expanding the toolbox available for managing the disease.
Read the full research article here.
Share this Post