Having grown up in Kenya, a tropical country with stunning biodiversity, I was captivated by the natural world from an early age – enchanted by large mammals, majestic trees, and vibrant insects. I took Biology as an undergraduate degree at the University of Sheffield with hopes of doing something animal-related. However, at the end of my 1st year, I did an internship at the World Agroforestry Centre in Nairobi, where I extracted DNA from the traditional African orphan crop, Shea (Vitellaria paradoxa) (http://africanorphancrops.org/). Since then, my interests switched to agriculture, food security, and plant science. At the end of my 2nd year, I did a computational research project, where I investigated changes in DNA methylation, over 10 generations, in 2 different Arabidopsis thaliana mutants. This landed me my PhD project, which I started at the end of my 3rd year.
DNA methylation is an epigenetic mark that can be maintained over several generations. It can change the expression of genes independently of DNA sequence by changing the biochemical properties of DNA and/or chromatin. Upon exposure to pests and pathogens, plants lose DNA methylation at distinct loci which augments and/or primes plant immunity. This better prepares individuals for future attacks and can be transmitted to subsequent generations, even in the absence of further exposure. This remarkable feat of phenotypic plasticity is dependent on epigenetic mechanisms, like DNA methylation. As part of this PhD project, I will investigate how DNA methylation regulates the expression of genetic elements in response to biotic stress in the model plant species Arabidopsis thaliana. I will explore mechanisms within a generation, across a generation, and over 10 generations. Understanding these pathways will contribute to the growing body of research that links plant immunity to epigenetic mechanisms – a field that will likely provide novel solutions to the pressing issue of food insecurity in the near(ish) future.