Production of Phytohormones by Pseudomonas amygdali and their Role in the Hyperplastic Bacterial Canker of Almond

Pseudomonas syringae pv. actinidiae (Psa) causes bacterial canker of kiwifruit, which is an ongoing threat to New Zealand kiwifruit production. Disease control depends on orchard practices such as removal of visibly diseased material, pruning during low-risk periods, and the application of foliar bactericides. Although the use of copper compounds on Actinidia species (kiwifruit) can cause phytotoxicity, copper-based formulations remain a key component of Psa control in New Zealand. The effect of single copper applications on Psa infection of ‘Hort16A’ trap plants was studied over the Spring of 2014 (Sept—Nov). Psa leaf spots were observed at the beginning of October, appearing first on the untreated plants. Although the copper sprays did not achieve complete protection, particularly as the inoculum built up during November, the copper-sprayed plants always had less disease than the untreated plants.

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Bacterial canker of stone-fruit trees in California

Hilgardia ◽

10.3733/hilg.v08n03p083 ◽

1933 ◽

Vol 8 (3) ◽

pp. 83-123 ◽

Cited By ~ 24

Author(s):

Edward E. Wilson

Keyword(s):

Fruit Trees ◽

Stone Fruit ◽

Bacterial Canker

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BIOASSAY TO DETERMINE CHERRY ROOTSTOCK TOLERANCE TO `BACTERIAL CANKER' CAUSED BY PSEUDOMONAS SYRINGAE PV SYRINGAE

HortScience ◽

10.21273/hortsci.25.11.1354 ◽

1990 ◽

Vol 25 (11) ◽

pp. 1354F-1355

Author(s):

Elzbieta Krzesinska ◽

Anita Nina Miller

Keyword(s):

Relative Humidity ◽

Pseudomonas Syringae ◽

Bacterial Suspension ◽

Avirulent Strain ◽

Bacterial Canker ◽

Symptom Development ◽

Virulent Strains ◽

Callus Production ◽

Root Stock ◽

One Year

An excised twig assay was developed to evaluate cherry geno-types for their tolerance to Pseudomonas syringae pv. syringae. One-year-old wood was collected at monthly intervals from October until January of `Royal Ann', `Corum', and a number of cherry rootstock. The rootstock included; F/12–1 and Giessen (GI) and M × M selections. A 2-cm incision (“^”-shaped flap) was made on each twig. A 20-μl droplet of inoculum or water was placed onto each incision. The inoculum was prepared with one avirulent (K4) and three virulent strains (W4N54, AP2, B15) concentrations (105, 106, or 107 cfu). Inoculated twigs were placed in test tubes and incubated at 15C in high relative humidity for 3 weeks. After incubation, twigs were evaluated for gummosis production (0–3, 0 = no gummosis), incision browning (1–4, 1 = yellow pith), and callus production (0–1, 0 = no callus). The concentration of bacterial suspension had no effect on symptom development. No gummosis or browning was observed on twigs inoculated with water or the avirulent strain. Based on the gummosis and browning ratings, rootstock M × M 2, M × M 39, M × M 60, GI 148-1, GI 154-2, and GI 154-4 were found to be resistant to these three strains of P. syringae in this assay. Root-stock F 12-1, GI 169–15, GI 172–9, and GI 173-9 were found to be tolerant.

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Hydrogen peroxide generated by over-expression of cytosolic superoxide dismutase in transgenic plums enhances bacterial canker resistance and modulates plant defence responses

Molecular Biology Reports ◽

10.1007/s11033-020-05660-8 ◽

2020 ◽

Vol 47 (8) ◽

pp. 5889-5901

Author(s):

Mohamed Faize ◽

Lydia Faize ◽

Nuria Alburquerque ◽

Jean Stéphane Venisse ◽

Lorenzo Burgos

Keyword(s):

Hydrogen Peroxide ◽

Superoxide Dismutase ◽

Plant Defence ◽

Bacterial Canker ◽

Over Expression ◽

Defence Responses ◽

Plant Defence Responses

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

Molecules ◽

10.3390/molecules26051461 ◽

2021 ◽

Vol 26 (5) ◽

pp. 1461

Author(s):

Nuno Mariz-Ponte ◽

Laura Regalado ◽

Emil Gimranov ◽

Natália Tassi ◽

Luísa Moura ◽

...

Keyword(s):

Flow Cytometry ◽

Antimicrobial Peptides ◽

Pseudomonas Syringae ◽

Pathogenic Bacteria ◽

High Efficiency ◽

Bacterial Canker ◽

Membrane Permeation ◽

Flow Cytometry Analysis ◽

Pathogenic Agent ◽

Peptide Mixtures

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.

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