PEPXYL

A great deal of scientific effort is being put into peptides as novel pesticides because many of them meet the regulatory requirements for low risk plant protection products. A new approach to control Xf would involve the use of membrane-lytic peptides, plant defence elicitor peptides and peptides that specifically target pathogenicity factors of the pathogen.

This project is carried out in collaboration within the UdG with the Laboratory of Innovation in Processes and Products of Organic Synthesis (LIPPSO), who has participated in previous coordinated projects in the last years.

The main purpose of the project is TO OBTAIN PEPTIDES DIRECTED TOWARDS KEY TARGETS AND PROCESSES TO CONTROL Xf.

To attain this purpose, in a first stage of the project key targets and processes will be evaluated in order to select or design peptides interfering in Xf disease. Then, in a second stage, the peptides will be prepared and screened for their activity and, afterwards, the lead candidates will be evaluated in a proof of concept efficacy assay in plants. Finally, the mechanism of action of the selected lead peptides will be studied.

The specific goals are:

To select key pathogenicity/virulence targets of Xylella fastidiosa for the design of tailored peptides. Key targets of pathogenesis of Xf will be evaluated in order to select the most suitable to develop peptide-based therapeutics for disrupting the pathogenicity of Xf.

To obtain candidate peptides from bacterial origin. The study will be focused on selected strains producing bacteriocins and cyclic lipopeptides such as Bacillus amyloliquefaciens, Bacillus subtillis , Lactobacillus plantarum , Leuconostoc mesenteroides , Lactococcus lactis and  Pantoea agglomerans.

To select the best peptides from the libraries designed by LIPPSO based on the following biological activities: Antibacterial/bactericidal, Defence induction, Motility-attachment and biofilm formation and Peptide-target interaction

To assess the efficacy of the selected peptides to control Xf in model plant hosts. The peptides obtained in the previous stages of the project selected to have activity towards key targets and processes of Xf disease will be evaluated in planta in a proof of concept assay.

To study peptide-target interaction at transcriptomic level. Transcriptional profiling of plant response to the peptide treatment and Xf response to the peptide treatment, and the transcriptional profile of previous treated plant to Xf infection will be done using whole transcriptome shotgun sequencing (RNAseq).