Including recent news about a peptide derived from finger limes, researchers have found many compounds over the last several years that could help growers manage or even fend off huanglongbing (HLB) disease.
University of Florida Institute of Food and Agricultural Sciences Research Assistant Scientist Choaa El-Mohtar and his team have developed a new way to see how compounds can possibly impact trees in their current generation and express new traits relatively quickly. The system uses the citrus tristeza virus (CTV) to vector the compounds. Researchers refer to the technique as CTV expression.
El-Mohtar said that many compounds have been identified, and researchers have been introducing them to trees for several years. “One aspect of our collaboration is expressing antimicrobial peptides through the CTV vector,” he said. “We express them in citrus seedlings and then infect them with the HLB bacteria through the Asian citrus psyllid vector. Then we wait one to two years to see which one has an effect and which ones do not.”
Many antimicrobial peptides have been screened over the years. A few of those peptides have been very promising by inducing tolerance to HLB. “For example, the HLB bacteria will be present in the plant, but the seedling will continue to grow, versus if you don’t put the antimicrobial peptide in the seedling, it will collapse,” El-Mohtar said.
The University of Florida holds the patent to the CTV technology and licenses it to Southern Gardens Citrus Nursery. El-Mohtar said the next step is getting the technology in the field for growers. A permit has been issued by USDA to allow large-scale field experiments in all counties and geographical locations.
After what he believes will be successful field testing, El-Mohtar said when the technology roll outs to growers it will be included in the seedlings and introduced to mother trees that are then grafted.
The CTV system has allowed researchers to skip major regulatory slowdowns that face genetically engineered plants and the process of waiting for the tree to mature. El-Mohtar said it is exciting to see the technology so close to being a tool for growers, which he said is the whole point of doing the research in the first place.
Listen to El-Mohtar’s full interview in the September episode of the All In For Citrus podcast.