Insect-damaged Arabidopsis moves like wounded Mimosa pudica

Leaves display constant and complex movements. We found that the petioles of undamaged leaves of Arabidopsis thaliana undergo minute deformations when insects fed on other leaves. These deformations reported in real time the arrival and architecture of damage-triggered electrical signals called slow wave potentials. Mutants affecting cell walls in xylem vessels altered these petiole deformations, suggesting that water fluxes coincide with the passage of the electrical signals through tissues. Further analyses revealed that whole leaves distal to wounds displayed slow downward motions following the arrival of electrical signals. Monitoring insect-triggered tissue deformations in different genetic backgrounds can yield mechanistic insights into electrical signalling and may increase our understanding of the basis of plant movement.