James Forsythe

How does the circadian clock regulate disease resistance?

About me

I am a plant scientist with an interest in responses to stress.
My first degree was in Plant and Microbial Sciences (Natural Sciences) at St Johns College, Cambridge; with a research project combining plant pathology and development.
I then completed a two year Master’s degree at Kyoto University (Japan) studying stress-induced flowering, thanks to a MEXT scholarship, before coming to York for a PhD combining plant pathology and mathematical modelling.
I have also spent some time as a research intern at the Okinawa Institute of Science and Technology, looking into plant epigenetics, and between my degrees I was at the University of Nottingham working on abiotic stress tolerance in barley.

My project

How do plants measure and respond to the time of day?

Plants, like other organisms, have an internal timekeeping mechanism.
This mechanism, the circadian clock, allows them to change their behaviour to respond to predictable, regular changes in light and temperature as the sun rises and sets.
The circadian clock is a network of genes which regulate each other, producing daily oscillations in gene activity.
With around one third of the genes of the model plant Arabidopsis regulated by the circadian clock, the oscillations of the clock genes enable selective, time-specific regulation of genes involved in many physiological processes, like photosynthesis, so they can act at certain times of day.

How does the circadian clock relate to disease?

One of the processes regulated by the circadian clock is disease resistance.
For a variety of fungal and bacterial pathogens, including Botrytis cinerea and Pseudomonas syringae, disease progresses differently after inoculation in the day to the night, which may be termed circadian susceptibility.
However, disabling key genes in the circadian clock mechanism results in no difference in disease progression after inoculation in the day to the night.
The proteins of these clock genes act as transcription factors, regulating the activation of defence genes by binding to their DNA.

How does JAZ6 link the circadian clock and pathogen defence?

JAZ6 is a gene which regulates the plant hormone response to wounding and disease, but also has a role in mediating circadian susceptibility.
The jaz6 mutant shows no difference in disease progression after inoculation in the day to the night, just like key clock gene mutants.
JAZ6 is likely regulated by the circadian clock in some way, distinctly from the 11 other JAZ genes.
JAZ6 may also be able to impact disease in a distinct manner from the other JAZ genes.
My two main aims are to determine:
i) How does the time-of-day impact on JAZ6 activity?
ii) How does JAZ6 impact on disease susceptibility?
I will be using a variety of experimental techniques to look for genes and proteins which specifically regulate or interact with JAZ6, as opposed to the other JAZs.
While also modelling how JAZ6 may be regulated by the circadian clock, by building on previous models of the timekeeping mechanism.


Twitter: @JamesMAForsythe

LinkedIn: https://www.linkedin.com/in/james-forsythe-a72412190/