A class of molecules named stable antimicrobial peptides (SAMPs) can treat and prevent citrus greening, a study finds. A highly destructive citrus disease, citrus greening, or Huanglongbing (HLB), is caused by the bacterium Candidatus Liberibacter asiaticus (CLas). The disease is a major threat to the global citrus industry, costing billions of dollars in losses each year, and there are no effective strategies to prevent infection or treat infected trees. To identify plant immune system molecules that could potentially address this problem, Hailing Jin and colleagues compared small RNA and mRNA profiles of HLB-sensitive cultivars and HLB-tolerant citrus hybrids and relatives. The analysis revealed that HLB tolerance is associated with SAMPs. Multiple SAMP injections into three HLB-positive citrus varieties reduced CLas levels, increased tree growth and leaf production, and prevented tree death and disease symptoms, such as yellow striping on leaves, when compared with injections of a mock solution. Next, the authors sprayed a SAMP solution or buffer as mock treatment onto healthy trees and exposed the trees to CLas. SAMP application reduced infection rates and CLas levels, increased tree growth, and prevented tree death. According to the authors, SAMP treatments may represent a practical, eco-friendly, nontoxic, long-lasting, and effective strategy to prevent and treat citrus greening.
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Article #20-19628: "A stable antimicrobial peptide with dual functions of treating and preventing citrus Huanglongbing," by Chien-Yu Huang et al.
MEDIA CONTACT: Hailing Jin, University of California, Riverside, CA; tel: 951-329-1632; email: <hailingj@ucr.edu>
Journal
Proceedings of the National Academy of Sciences