Ksl-w analogues, peptide conjugates and tryptophan-containing cyclic peptides with activity against plant pathogens

Résumé

Plant diseases produced by bacteria are responsible for considerable economic losses. These phytopathologies are highly contagious and difficult to control. With this aim, we selected peptides reported as plant defense elicitors, promiscuous, multifunctional or antimicrobial and tested them against plant pathogenic bacteria, being KSL-W the best candidate. This peptide was taken as a lead and analogues were designed and synthesized, including N-terminal deletion sequences, peptides incorporating D-amino acids and lipopeptides. Moreover, we studied the peptide conjugation of an antimicrobial peptide, a plant defense elicitor peptide and/or a cell-penetrating peptide. The last part of this thesis was focused on the synthesis of cyclic peptides designed by replacing a Phe residue with a Trp. The analysis of the biological activity results showed that this replacement improved the biological profile. In summary, this thesis allowed the identification of new lead peptides to control phytopathogenic diseases.