Temperature Regulation Of Prions In Crops

Temperature is a key environmental variable influencing plant distribution. Plants have colonised most habitats, from the tropics to the arctic circle.

How plants are able to adapt to climate is of fundamental interest and of particular relevance during a period of rapid climate change, where plants have already been seen to change their phenology and range.

Despite much interest in this area, understanding has been limited by our lack of knowledge of the mechanisms underlying temperature perception in plants.

Recently, the host lab for this proposal has shown that proteins containing prion-domains (PrD) are able to function as thermosensors by undergoing temperature dependent phase-change.

In unpublished work, the group has found that Heat Shock Factors (HSFs), which are essential for the induction of the protective heat shock proteins, are also controlled by PrDs and undergo phase change.

These molecular sensing mechanisms by HSFs provide a unique opportunity to investigate how variation in the PrDs may “tune” the temperature response such that plants may adapt their HSFs to have a response at a threshold appropriate for their climate. E.g. rice grows robustly under temperature conditions that represent a lethal heatshock for Arabidopsis.

In this proposal, I shall combine my expertise in studying rice environmental sensing from my PhD studies with recent developments in the Wigge laboratory in studying phase change of the HSFs in response to heat.

I will use a comparative biology approach to determine the temperature response set-points of HSFs in vitro from a range of plants that grow under very different temperature regimes, and relate the behaviour of the PrD domains of the HSFs to the biological response of the plants to temperature.

Finally, I will directly test my hypothesis by making directed changes to the thermosensory PrDs to increase and decrease thermal responsiveness, and assay these new thermosensors directly in plants and in a yeast system.