It’s widely understood that humans have a circadian clock. When we travel long distances, things get knocked out of kilter.
Daily fluctuating rhythms were first discovered in plants in 1729 by measuring leaf-movement rhythms in Mimosas. Now research at the Earlham Institute, led by PhD Student Hannah Rees, has ‘shed light’ on how they work in different crop plant species.
Importantly, Hannah has developed a robust method to accurately measure plant clocks in wheat and Brassica using naturally occurring ‘delayed fluorescence’, which will be very useful for research into improving crops for the future.
Delayed fluorescence is light that is emitted by plants after being illuminated, which persists for a long time when placed in the dark. The paper, published in Plant Methods, sheds light on what makes wheat ‘tick’, and how plants show signs of ageing.
The circadian clock in people is well known, and well understood — such as experiencing jet lag and sleep-deprivation after travelling between different time zones.
Plants, too, suffer similar consequences of changing light conditions, which are now easier to investigate thanks to the recent work at EI. Among the findings, the in-built circadian clock keeps ticking along in Brassica plants in 24-hour light, whereas in wheat the clock oscillates better under constant darkness.
More interestingly still, it appears that in both types of plants, the circadian clock oscillates faster as the plant ages — which is true of even older leaves and younger leaves on a single plant.
The research …. into circadian clocks has great potential in breeding better wheat. We already know that circadian clocks are important for biological processes, such as:
- Photosynthesis (making sugar)
- Defending against pests
- Stomatal conductance (water regulation)
- Fixing nitrogen (for protein production)
- Turning carbon into useful products
“….We hope our work will help to improve crop yields by allowing breeders to select crops with circadian clocks matched for optimal growth in certain regions of the world,” [said lead author Hannah Rees.]
Read full, original article: Sleep, wake, repeat: How do plants work on different time zones?