New research affirms a unique stable antimicrobial peptide (SAMP) found in an Australian plant can destroy HLB and help prevent infection.
Hailing Jin, University of California Riverisde geneticist who led the research, shared the exciting discovery during the 2021 Florida Citrus Show.
The naturally occurring peptide is found in HLB-tolerant citrus relatives, such as the Australian finger lime. The peptide has dual functions of inhibiting Candidatus Liberibacter asiaticus (CLas) growth in HLB-positive trees and activating host immunity to prevent new infections. Jin said it is rare for a treatment to achieve both of these functions.
According to Jin, the peptide’s corkscrew-like helix structure is able to quickly puncture the CLas bacterium, causing it to die typically within half an hour. She said it’s a much faster process than using traditional antibiotics.
When the research team injected the peptides into trees already infected with HLB, the trees survived and grew healthy new shoots. Jin said the experiment confirmed that the peptide can rescue trees already infected with the disease.
The team also tested the peptide’s efficacy using a spray application. Researchers infected healthy sweet orange trees with HLB-positive psyllids. After spraying at regular intervals, only three of the 10 trees tested HLB-positive, and none of the trees died. In the control, nine of 10 untreated trees became HLB-positive and four trees died.
This peptide is also stable in high temperatures. Most of the antibiotics that growers are spraying in the field are temperature sensitive, so when they’re applied in warm climates, like Florida and California, their effects are largely reduced. According to Jin, this peptide remains active in 130-degree heat.
The peptide has also proven to be safer for the environment compared to other synthetic treatments.
Field trials of the peptides are underway in Florida.
Invaio Science has licensed the SAMP technology. The company’s proprietary injection technology will further enhance the treatment.
Learn more about the peptide.