Cell wall softening drives Venus flytrap snap

Scientists have identified the long-sought mechanism that allows the Venus flytrap to snap shut with remarkable speed, solving a biological puzzle that has intrigued researchers since the time of Charles Darwin. According to a new study published in the journal Science, the plant's rapid closure is driven by an almost instantaneous softening of the cell walls on the outer surface of its specialized leaf, rather than by a rapid movement of water as previously hypothesized.

The Venus flytrap, a carnivorous plant native to parts of North and South Carolina, captures insects by rapidly closing its hinged, jaw-like leaves when trigger hairs inside are touched twice in quick succession. For over a century, the leading explanation for this movement was that water rapidly redistributed between cells, causing one side of the leaf to swell. However, experiments conducted by a team led by physicist Yoël Forterre of the French National Centre for Scientific Research and Aix-Marseille University measured the time for water to move across the leaf tissue and found it took 30 to 60 seconds, far too slow to explain a closure that can occur in as little as one-tenth of a second.