Antimicrobial Peptides for Fire Blight Control

Effect of antimicrobial peptides and monoterpenes on control of fire blight

Spanish Journal of Agricultural Research ◽

10.5424/sjar/2020182-15629 ◽

2020 ◽

Vol 18 (2) ◽

pp. e1002

Author(s):

Mahdi Akhlaghi ◽

Saeed Tarighi ◽

Parissa Taheri

Keyword(s):

Antimicrobial Peptides ◽

Fire Blight ◽

Erwinia Amylovora ◽

Plant Diseases ◽

Guaiacol Peroxidase ◽

Resistance Level ◽

Defense Enzyme ◽

Colony Number ◽

Blight Disease ◽

Central Composite

Aim of study: Antimicrobial peptides and monoterpenes are safe compounds that have been used for control of many plant diseases. Herein, the effects of two recombinant antibacterial peptides (AMPs) were compared with two monoterpenes for control of Erwinia amylovora directly or via induction of plant defense enzyme guaiacol peroxidase (GPOD).Area of study: The experiments were performed at the Ferdowsi University of Mashhad (Iran).Material and methods: The central composite design (CCD) method was used to study the effect of mixing the compounds and copper compound (Nordox) in controlling the pathogen. The resistance level was studied on shoots of tolerant (‘Dargazi’) and semi-susceptible (‘Spadona’) pear cultivars treated with the antibacterial compounds.Main results: Thanatin and 1,8-cineole showed the highest and lowest antibacterial effects. All treatments reduced E. amylovora pathogenicity on blossom. The CCD analysis revealed that the best reduction in colony number obtained by mixing Lfc, thanatin, thymol, 1,8-cineole and Nordox at concentrations of 32, 16, 24, 250 and 250 μg/mL. Thymol and 1,8-cineole at 500 μg/mL decreased disease severity significantly compared to that of AMPs. The level of GPOD enzyme in ‘Dargazi’ was higher than in ‘Spadona’. All treatments increased the GPOD levels in both cultivars. Furthermore, resistance level and GPOD ratio were negatively correlated.Research highlights: Antimicrobial peptides showed better effect on growth inhibition of E. amylovora than monoterpenes. Mixing of these peptides and monoterpens at special dosage enhanced their antimicrobial efficacy against E. amylovora; that could represent a new method in control of fire blight disease.

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Evaluation of Three Antimicrobial Peptides Mixtures to Control the Phytopathogen Responsible for Fire Blight Disease

Plants ◽

10.3390/plants10122637 ◽

2021 ◽

Vol 10 (12) ◽

pp. 2637

Author(s):

Rafael Mendes ◽

Sara Sario ◽

João Pedro Luz ◽

Natália Tassi ◽

Cátia Teixeira ◽

...

Keyword(s):

Antimicrobial Peptides ◽

Fire Blight ◽

Green Revolution ◽

Fruit Trees ◽

Control Measures ◽

Phytopathogenic Bacterium ◽

Viable Cells ◽

Efficient Control ◽

High Reduction ◽

Blight Disease

Fire blight is a severe bacterial plant disease that affects important chain-of-value fruit trees such as pear and apple trees. This disease is caused by Erwinia amylovora, a quarantine phytopathogenic bacterium, which, although highly distributed worldwide, still lacks efficient control measures. The green revolution paradigm demands sustainable agriculture practices, for which antimicrobial peptides (AMPs) have recently caught much attention. The goal of this work was to disclose the bioactivity of three peptides mixtures (BP100:RW-BP100, BP100:CA-M, and RW-BP100:CA-M), against three strains of E. amylovora representing distinct genotypes and virulence (LMG 2024, Ea 630 and Ea 680). The three AMPs’ mixtures were assayed at eight different equimolar concentrations ranging from 0.25 to 6 μM (1:1). Results showed MIC and MBC values between 2.5 and 4 μM for every AMP mixture and strain. Regarding cell viability, flow cytometry and alamarBlue reduction, showed high reduction (>25%) of viable cells after 30 min of AMP exposure, depending on the peptide mixture and strain assayed. Hypersensitive response in tobacco plants showed that the most efficient AMPs mixtures and concentrations caused low to no reaction of the plant. Altogether, the AMPs mixtures studied are better treatment solutions to control fire blight disease than the same AMPs applied individually.

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