I thought that only humans can do arithmetic, but plants do division as well. I guess a brain with a neocortex is not required. New research shows that arabidopsis plants perform an arithmetic feat to know how to distribute stored energy during the night when there is no light, preventing starvation.

Plants get their energy from light through a process called photosynthesis. This involves breaking down carbon dioxide compounds into sugars. And we all know what awesome byproduct that gives us; oxygen! So during the day they store sugars, and during the night plants do division in order to distribute the sugars at a steady rate. This insight comes from new research done by the scientists at the John Innes Centre and found through the open access journal eLife.

It is vital that plants do division in order to be able to grow properly. Learning more about this process has some implications, such as possible plant hacking in order to achieve higher crop yields. This is already being done with GMOs.

Plants do division during night time. There are certain “mechanisms” in the leaves that measure how much of the starch is stored and how much time will pass until the sun rises. Plants also have a sort of an internal “biological clock” which allows them to guess when dawn will come. There are three clock genes that work together like a seesaw. When dawn comes, these genes instruct the plant to make two proteins, CCA1 and LHY. These proteins tell the plant that it is daytime. During the day these are destroyed, which allows for the third protein, TOC1, to be made. This tells the plant that it is night time. That last protein also tells the plant that it’s time to make the first two, so the whole process cycles again.

According to Professor Alison Smith,

the calculations are so precise so that plants prevent starvation but also make most efficient use of their food.

Using up the starch too fast will induce starvation, while using it up too slow will waste the unused starch. Scientists predict that there are two molecules that encode the information about how much starch is stored at a given time and time until dawn breaks. Let’s call these molecules S and T for the time being. The rate at which starch is consumed is set by the ratio of S molecules to T molecules. Because a ratio is actually a fancy way to say division, scientists are confident in the claim that plants are division experts.

Sources:

http://elife.elifesciences.org/content/2/e00669

http://news.jic.ac.uk/2013/06/plants-do-sums-to-get-through-the-night/

http://arabidopsis.info/InfoPages?template=arabidopsis;web_section=arabidopsis

http://www.plantsci.cam.ac.uk/research/webb/plantTime/clock.html