Figure 5

Working hypothesis on signal formation and propagation in the trigger hair. Schematic drawing of a trigger hair (left) and the magnification of a sensory podium cell (right). Mechanical stimulation activates MSL10 (pink) and OSCA1.7 (green) which results in a depolarization an increased [Ca²⁺]_cyt, which further increases via calcium induced calcium release (light green) of the endoplasmic reticulum. Ca²⁺ induced activation of anion channels (blue) completes the depolarisation phase of the AP, which is repolarised by activation of potassium channels (red). The resting calcium concentration is restored by the ECA1 (yellow) and ACA2/10 (purple) pumps. Apoplastic glutamate activates GLR3.6 channels (orange) and transits the Ca²⁺ signal into the unstimulated trap. The application of ether (red) most likely suppresses Ca²⁺ signalling into the trap by blocking these glutamate receptors and thus the electrical AP in the trap remains absent.