Plants do maths to avoid starvation
Plants carry out calculations each night to prevent them starving before dawn, scientists have discovered.
In order to keep themselves going in the absence of sunlight, plants perform division equations at a fundamental biological level to ration their stores of starch until the moment the sun reappears.
By counting their starch and dividing it by the number of hours left until morning they ensure they do not run out until the crack of dawn, and can even adjust their calculations during the night.
Professor Martin Howard, who came up with the equation, said the study, published in eLife, provided "the first concrete example in biology of such a sophisticated arithmetic calculation" at a fundamental biological level.
It plays a crucial role in plants' survival because they are dependent on starch, which is produced from carbon dioxide and sunlight during the day, to provide energy.
"The capacity to perform arithmetic calculation is vital for plant growth," Prof Alison Smith, a biologist who helped make the discovery, explained. "The calculations are precise so that plants make the most efficient use of their food."
It was understood that plants have a mechanism which ensures their starch is not used up in the night, but scientists had no idea how they managed it.
Researchers from the John Innes Centre in Norwich discovered the ability after studying Arabidopsis, a plant in the mustard family. They found that the plants used their starch at a steady rate, so that about 95 per cent of their stock had been used up by dawn. When researchers changed light conditions, the plants altered their rate of starch usage.