From perception to action without nerves and muscles: lessons from plants

As sessile organisms, plants face a constantly changing environment with no means of escape. Thus, despite their lack of nerves and muscles, they have evolved unique mechanisms to perceive and respond to external physical signals. In this seminar, I will illustrate this ability through two emblematic plant responses. First, I will discuss plant gravitropism - the growth response and reorientation of plants to changes in tilt - and show how the plant gravity sensor uses an intracellular active granular medium to achieve high sensitivity. In a second part, I will present the sensitive plant Mimosa pudica, which folds its leaves in a second when touched, as a model system for plant motility based on fast hydraulic actuation.