Researchers at the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) are using RNA interference (RNAi) to alter field populations of the Asian citrus psyllid (ACP).
Nabil Killiny, UF/IFAS associate professor, shared the latest findings from his team’s RNAi research in a recent All In For Citrus podcast episode. He says the team is using RNAi to attack the ACP and limit HLB transmission from plant to plant. The research takes a three-pronged approach, aimed at disrupting how the disease’s bacteria attaches to the insect, how well the insect flies and how well it can tolerate insecticides.
The first approach to avoid HLB transmission from plant to plant is disrupting how HLB’s bacteria attaches to ACP. Essentially, the RNAi silences the way the insect interacts with the bacteria, turning the ACP from a vector to a non-vector.
“If we use the RNAi to reduce the expression of these protein receptors, then the bacteria cannot bind to this protein, so the bacteria will not recognize the insect, and then we will not have transmission,” Killiny explained.
The second approach deals with targeting the psyllid’s ability to fly. By altering the genes involved in wing development, RNAi can impact the psyllid’s ability to fly and prevent transmission of HLB from tree to tree.
The third and final approach of the research is to look at using RNAi to break insecticide resistance. Insecticides are one of the principal tools used to manage ACP. Their overuse has led to the evolution of insecticide resistance in some ACP populations, rendering them less susceptible to insecticide treatment.
According to Killiny, RNAi can be used to precisely target and shut down important genes in ACP to manage the insect’s response to insecticides. The result is simultaneously reducing resistance and increasing susceptibility to insecticides.
Researchers are still looking at the most effective delivery system for RNAi. Several delivery methods are being evaluated, including trunk injection, foliar sprays and utilizing laser rays to remove the thick cuticle on the citrus leaf in order to increase penetration.
Listen to the full interview with Killiny in the March episode of the All In For Citrus podcast, a joint project of UF/IFAS and AgNet Media.