Antimicrobial Peptide Evaluation for Huanglongbing, Canker and Psyllid Resistance
Subtropical Insects and Horticulture Research
2009 Annual Report
1a.Objectives (from AD-416)
Huanglongbing (HLB) is a citrus disease of great economic importance in Florida. The disease is considered to be the most severe disease of citrus where it occurs and has the potential to devastate the Florida industry. The control measures that are currently available are commercially unacceptable over the long term, unproven and ultimately not sustainable. Additionally, there are no known sources of genetic resistance. Therefore, the near term prospects of developing resistant cultivars through conventional breeding are not promising. Test possible antimicrobial peptides in in-vitro assays against the Asian citrus psyllid (ACP) and against surrogate alphaproteobacter species closely related to the causal organism of HLB, and against the causal agent of citrus canker to determine the potential of the peptides against the tests organisms and ultimately to produce resistance plants.
1b.Approach (from AD-416)
Cooperator will pretest for purity and supply to ARS twenty different peptides that through its consultant accompany AgroMed has reason to believe may be effective against HLB, the ACP and citrus canker. Trials will be conducted and assays against HLB and causal organism of citrus canker.
This project is related to Objective 1: Create new genetic combinations of citrus, Objective 2: Screen germplasm for important traits and select superior individuals, and Objective 3: Evaluate selections for field performance and other traits.
The twenty antimicrobial peptides provided by Southern Gardens Citrus were assessed for effectiveness against the canker pathogen and two relatives of the HLB-associated micro-organism, and several have been identified which were extremely active at low levels and had no disruptive effect on red blood cells.
Progress in assessing antimicrobial peptides in vitro was provided to the cooperator by email and through conference calls.