Mechanical factors contributing to the Venus flytrap's rate-dependent response to stimuli

Area of Science:

• Plant mechanobiology
• Biophysics of sensory perception
• Insect-plant interactions

Background:

• Venus flytraps use sensory hairs to detect prey via mechanical stimuli.
• Action potentials (APs) are triggered by sufficient stimulation, with two APs causing trap closure.
• Previous studies identified stimulus thresholds but lacked cellular-level deformation data.

Purpose of the Study:

• To investigate cellular-level kinematics in Venus flytrap sensory hairs.
• To understand the role of viscoelasticity and intercellular fluid transport in stimulus transduction.
• To link mechanical stimuli to cellular responses at different rates.

Main Methods:

• Developed a multi-scale numerical model of the Venus flytrap's sensory hair.
• Conducted sustained deflection tests to determine viscoelastic properties.
• Simulated hair deflection at various loading rates to analyze cellular kinematics.

Main Results:

• Established a multi-scale kinematic link between angular velocity and cell wall stretch.
• Found that the rate of cell wall stretch is proportional to angular velocity.
• Estimated viscoelastic material properties of the sensory hair tissue.

Conclusions:

• Viscoelasticity and intercellular fluid transport influence the Venus flytrap's rate-dependent mechanical response.
• Cellular stretch rate, not just magnitude, may be a key factor for mechanosensitive ion channels.
• This study provides insights into the biophysical mechanisms underlying Venus flytrap prey detection.