Quantitative characterisation of the effect of external electric fields on Phytophthora palmivora behaviour in vitro and during root infection
File(s)
Author(s)
Moratto, Eleonora
Type
Thesis
Abstract
In this thesis, I present a new strategy to tackle the issue of declining crop yields caused by pests and pathogens, specifically targeting the oomycetes pathogens that currently have no effective control measures. My primary focus is on the under-researched response of phytophthora palmivora to external electric fields, with the goal of using this knowledge to prevent root infections. For this purpose, I developed two new tools: the V-slide to observe electrotactic population behaviour of flagellated organisms over time and the V-box for root infection assays in external electric fields.
I characterized how electric fields affect the early stages of the P. palmivora infection cycle. I found that zoospores tend to accumulate at the positive pole due to electrotaxis. Additionally, I observed that electric fields increase zoospore germination and affect germ tube orientation. Although it remains unclear how zoospores detect electric fields, I showed that ionic currents play a crucial role in this process. I also investigated the potential of using electric fields as a crop protection strategy against P. palmivora root infection. To do this, I applied external electric fields around plant roots in
two configurations: the global configuration, where the electric field surrounds the root, and the local configuration, where the electric field is produced by a device located close to the roots but not surrounding them. I showed that both configurations significantly reduced zoospore attachment to Arabidopsis thaliana and Medicago truncatula roots. Moreover, I found that external electric fields also decreased P. palmivora biomass in Medicago truncatula after 24 hours, indicating that the
protective effect extends to later stages of the P. palmivora infection cycle.
In conclusion, my research opens new avenues for environmentally friendly crop protection
strategies against oomycete pathogens, suggesting a promising alternative to conventional chemical-based preventative methods and the breeding of resistant plants.
I characterized how electric fields affect the early stages of the P. palmivora infection cycle. I found that zoospores tend to accumulate at the positive pole due to electrotaxis. Additionally, I observed that electric fields increase zoospore germination and affect germ tube orientation. Although it remains unclear how zoospores detect electric fields, I showed that ionic currents play a crucial role in this process. I also investigated the potential of using electric fields as a crop protection strategy against P. palmivora root infection. To do this, I applied external electric fields around plant roots in
two configurations: the global configuration, where the electric field surrounds the root, and the local configuration, where the electric field is produced by a device located close to the roots but not surrounding them. I showed that both configurations significantly reduced zoospore attachment to Arabidopsis thaliana and Medicago truncatula roots. Moreover, I found that external electric fields also decreased P. palmivora biomass in Medicago truncatula after 24 hours, indicating that the
protective effect extends to later stages of the P. palmivora infection cycle.
In conclusion, my research opens new avenues for environmentally friendly crop protection
strategies against oomycete pathogens, suggesting a promising alternative to conventional chemical-based preventative methods and the breeding of resistant plants.
Version
Open Access
Date Issued
2023-12-15
Date Awarded
01/03/2024
Copyright Statement
Creative Commons Attribution NonCommercial Licence
Advisor
Sena, Giovanni
Bozkurt, Tolga
Sponsor
Biotechnology and Biological Sciences Research Council (Great Britain)
Publisher Department
Life Sciences
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)