Rachel Gorman in The Scientist:
An insect lands on the open leaves of a Venus flytrap plant, drawn to an appealing scent. It noses around and accidentally brushes one of the trap’s trigger hairs. An action potential shoots across the leaf blade. The insect keeps moving and bends another trigger hair, propagating a second action potential; suddenly, the leaves snap shut, trapping the insect, enveloping it in digestive juices, and absorbing the bug’s rich nutrients. How these two light touches trigger abrupt shutting of the leaves has been hypothesized, but never proven. Now, in a new study published in Current Biology, a team of researchers knocked out two ion channels, making it harder to produce action potentials and proving the channels’ importance in leaf closing.1 “The paper is a very big technical advance,” said plant biophysicist Rainer Hedrich at the University of Wurzburg who was not involved in the study. “It is possible to knock out genes in an excitable plant and test hypotheses.”
More here.