Smarty Plants: Can a Plant Tell Time?

Humans have it easy when it comes to telling time. We simply whip out our smartphones or glance at a somewhat antiquated watch. Plants, however, cannot make use of a time-telling accessory, but they are still able to tell time. How does this work?

Plants may not need to catch a train or make it to a meeting, they actually need to know the time even more than humans as they base their survival off of it. All plants require sunlight to produce their food through photosynthesis. New research has proven that at least one important plant uses a protein like a stopwatch to help keep time for improved food production.

Scientists at Southern Methodist University have been studying plants and their circadian rhythm by focusing on specific proteins in the thale cress weed. This plant is special, as it may grow differently depending on the amount of light it is exposed to (which would help researchers see results). It was found that a protein called Zeitlupe (ZTL for short) actually changes its shape when it is exposed to blue light. After one to two hours, the protein then returns to its original shape like an organic stopwatch. Following this initial research, the scientists joined forces with other researchers from Japan as well as those from Ohio State and the University of Washington to further study the specific chemical events that cause this ZTL protein’s change in shape and how it works.

After more extensive research by the new super team, it was found that a chemical bond forms when light activates ZTL; the length of the bond plays an important role in plants’ ability to maintain a 24-hour circadian rhythm. The chemical bond then controls the shape changes to guide the activities of the protein. Basically, the time between the creation of the bond after exposure to blue light and its shape breaking acts like a countdown. It is then used to keep a plant’s internal “clock” in sync with its environment.

So, what does this actually mean and why do we care? This study could help humans of the future “hack” photosynthesis and allow researchers to actually manipulate a plant’s response to its environment. In turn, these findings could then be applied to agricultural crops to increase yields.

These findings show just how little humans really know about the complex workings of plants. The PLANTZ team is always amazed at how intricate and smart our green friends really are… but we think we’ll stick to telling time the old-fashioned way for now. Check out the full study here.