A Synergic Potential of Antimicrobial Peptides against Pseudomonas syringae pv. actinidiae.

Nuno Mariz-Ponte,Conceição Santos,Fernando Tavares,Luísa Moura,Natália Tassi,Paula Gomes,Cátia Teixeira,Laura Regalado,Emil Gimranov

doi:10.3390/molecules26051461

Abstract

Pseudomonas syringae pv. actinidiae (Psa) is the pathogenic agent responsible for the bacterial canker of kiwifruit (BCK) leading to major losses in kiwifruit productions. No effective treatments and measures have yet been found to control this disease. Despite antimicrobial peptides (AMPs) having been successfully used for the control of several pathogenic bacteria, few studies have focused on the use of AMPs against Psa. In this study, the potential of six AMPs (BP100, RW-BP100, CA-M, 3.1, D4E1, and Dhvar-5) to control Psa was investigated. The minimal inhibitory and bactericidal concentrations (MIC and MBC) were determined and membrane damaging capacity was evaluated by flow cytometry analysis. Among the tested AMPs, the higher inhibitory and bactericidal capacity was observed for BP100 and CA-M with MIC of 3.4 and 3.4–6.2 µM, respectively and MBC 3.4–10 µM for both. Flow cytometry assays suggested a faster membrane permeation for peptide 3.1, in comparison with the other AMPs studied. Peptide mixtures were also tested, disclosing the high efficiency of BP100:3.1 at low concentration to reduce Psa viability. These results highlight the potential interest of AMP mixtures against Psa, and 3.1 as an antimicrobial molecule that can improve other treatments in synergic action.

Highlights

Bacterial canker of kiwifruit (BCK) is globally destroying many orchards of Actinidia deliciosa and A. chinensis, generating dramatic economic losses to producers [1,2]
The peptides were isolated with high purity (≥98%), according to reverse-phase high performance liquid chromatography (RP-HPLC) analysis, and their expected molecular weights (MW) were confirmed by electrospray ionization-ion trap mass spectrometry (ESI-IT MS) (Figures S1–S12 in Supplementary Materials)
hypersensitivity response (HR) in N. tabacum leaves 48 h post-inoculation of para gestão sustentável do cancro bacteriano (Psa) CFBP7286 treated with individual vidual peptides, namely BP100, CA-M and 3.1 in three different concentrations (1, 2, and 6.2 μM)

Summary

Introduction

Bacterial canker of kiwifruit (BCK) is globally destroying many orchards of Actinidia deliciosa and A. chinensis, generating dramatic economic losses to producers [1,2]. Actinidiae (Psa) being the etiologic agent of this disease [1,3,4]. BCK is considered the most important disease of kiwifruit orchards, Pseudomonas syringae pv. The taxonomy of this gram-negative bacteria is complex due to its physiological and genetic diversity, and because of successive reclassifications, it currently aggregates the biovars 1, 2, 3, 5, and 6 based on molecular and biochemical differences [5,6,7,8].

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Conclusion