With hope in my heart I board a train for Yorkshire. West Yorkshire is home to some of the most picturesque walkways in Britain, notably the Pennine Ring. After a scenic journey I find myself in the vibrant city of Leeds. I head straight for the University where Tolkien began his literary pursuits. Peter Meyer, recently dubbed ‘a voice of reason’ by the Yorkshire Post, works in the Centre for Plant Science. “Plants are our ultimate playground for the study of epigenetic effects on stress response”, says Peter.

He tells me all about mobile elements, pieces of DNA that can literally jump between cells with all sorts of consequences. “You have a conglomerate of viruses and mobile elements that are left behind after millions of years of evolution”. A subset of these small repeat sequences called transposable elements (TEs) can hop around in the plant genome switching genes on and off. “Using TEs is an evolutionary advantage”, explains Peter. These sequences are normally methylated and kept quiet, but environmental triggers can stir them into action. This gives plants an opportunity to respond to environmental change.

“It turns out that transgenes, with which we work, act similarly to TEs”. He shows me some beautiful pictures of red and white Petunia flowers and explains that the colour transgenes can switch off during the life of a plant. What’s more, such changes to flower colour are induced by the environment and can be passed on to future generations. In fact, this epigenetic phenomenon underlies an old breeder’s trick to ensure desirable characteristics. Breeders use flowers that develop early before the plant ages and gene activity changes. As a plant gets older the colour transgenes can switch off resulting in white flowers. If you breed from these white flowers the offspring are quite diverse in colour producing red, white, and variegated flowers. Peter’s work has outlined the molecular basis for this heritable colour morphing, in which DNA methylation is heavily implicated.