Plants perform complex mathematical equations throughout the night to prevent starvation until they can feed at sunrise
- Plants ration starch levels so they last until dawn – even if sunrise changes
- Calculations which divide supplies by time done at ‘fundamental level’
By Rosie Taylor
Research: Scientists studied Arabidopsis, a member of the mustard family, and found they can control starch levels
Plants are capable of performing arithmetic calculations to keep them alive, scientists have discovered.
They use formulas to calculate how to ration their supplies of starch throughout the night to keep them going until sunrise, the researchers have found.
Starch is essential to plants’ survival and is produced through photosynthesis during the day. At night, the plants rely on the store of starch built up in daylight hours to keep them alive.
If they ran out of starch they would stop growing and begin to starve – and would struggle to recover even several hours after the sun came up again. While using too little starch means energy would be wasted.
Scientists at the John Innes Centre in Norfolk, Europe’s leading plant science research facility, have discovered plants ‘count’ their starch and divide it by the number of hours of darkness to ensure the right levels are used.
They found the plants can even adjust the calculations as the night goes on.
The arithmetic happens at a fundamental level, rather than in the brain cells like in animals, researchers said.
Scientists already knew plants managed their starch levels but this breakthrough is the first time they have understood how they do it.
Metabolic biologist Professor Alison Smith told the Telegraph: ‘”The capacity to perform arithmetic calculation is vital for plant growth and productivity.
‘The calculations are precise so that plants prevent starvation but also make the most efficient use of their food.’
They found that even when they changed the lighting to lengthen or shorten hours of darkness, the plant was able to speed up or slow down the rate at which it used starch to make it last until light.
Scientists concluded they were two forms of molecules which controlled the process, which they dubbed ‘S’ for starch and ‘T’ for time.
Professor Smith said: ‘We propose there is a molecule called S which tracks the amount of starch in the plant, and a molecule called T which tracks the time until dawn. The closer to dawn you get, the less of T and S you have.’
Writing in the journal eLife, Professor Smith and colleague Professor Martin Howard said the equation could be used to explain other phenomena in nature, for example, how birds manage energy levels in migration.
They said little stints which fly 5,000km to their breeding sites in the Arctic arrive with only enough fat reserves to survive another 14 hours.
While male emperor penguins who sit incubating their eggs for four months reach run out of fat supplies just at the time their partner returns.