![]() (E) Descriptive statistics of the angular displacement and torque threshold for double deflections that initiated trap closure. The experiment shown in (C) is indicated. (D) Individual measurements showing the double deflection that led to trap triggering (green circles) and the preceding, nontriggering one (red triangles). ![]() (C) Successive double deflections of the sensory hair at increasing angular displacement (“disp.”) with recorded torque and voltage. Angular displacement θ, angular velocity ω, and the torque τ can be determined (for details, see Materials and methods and Fig 2D). The sensory hair is deflected by a linear movement of the sensor probe whereby the force F is measured. The metal levers prevent the trap to close upon triggering and simultaneously measure the snap force via a load cell. (A) Experimental setup showing a MEMS-based force sensor placed next to a sensory hair. Double deflection and sustained displacement of sensory hairs. In addition, using a noninvasive method, we measured APs to test the deflection conditions under which they are generated.įig 1. In this way, we were able to accurately quantify the parameter range in which hair deflection leads to trap closure, while a second force sensor measured the generated snap force ( Fig 2). To overcome these shortcomings, we used a microelectromechanical system (MEMS)-based force sensor mounted on a microrobotic system to precisely control the velocity and amplitude of the deflection and to simultaneously measure the applied force in vivo (Figs 1A and 1B and 2). Previous attempts to correlate the mechanical stimuli to the generation of APs suffered from the lack of appropriate instrumentation and thus were not quantitative, and/or the experiments were done in fixated or dissected, nonfunctional traps. While these putative channels are open, a receptor potential (RP) builds up, and, if the deflection is large enough, the RP reaches a threshold above which an AP is elicited. Although there is a general agreement that sensory-hair deflection opens mechanosensitive ion channels, such channels have not yet been identified. Here, we focus on the translation of the mechanical stimulation of the sensory hairs into an electrical signal. Further APs triggered by the struggling prey induce jasmonic acid biosynthesis and signaling, which seals the trap tightly and eventually leads to the formation of the “green stomach,” a digestive cocktail that mobilizes prey-derived nutrients. A second touch-triggered AP within about 30 s causes the trap to snap, and the prey is caught. While exploring the trap for food, wandering insects accidentally touch one of the six sensory hairs distributed on the two lobes of the trap, thereby triggering an action potential (AP). Starving plants attract insects through the secretion of volatile compounds. Since then, the individual phases-from trap triggering to reopening after successful digestion-have been investigated from different angles (reviewed in ). Only in the 1830s, Curtis realized that the traps were specifically devoted to catching animal prey. The hunting mechanism of the carnivorous Venus flytrap ( Dionaea muscipula), according to Darwin “the most wonderful plant in the world”, has attracted the interest of many scientists, starting with the observations made by Edwards and Nutall, who described the excitability of the sensory hairs but still thought that the capture of insects was accidental. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Ĭompeting interests: The authors have declared that no competing interests exist. ![]() The source code for the ECB model is available on GitHub ( ) as well as via Zenodo ( ) and can be cited by using the DOI 10.5281/zenodo.3799873 (all versions).įunding: This work was supported by the University of Zurich, the ETH Zurich, and a grant from the Swiss National Science Foundation (Interdisciplinary Grant CR22I2_166110) to UG, BJN, and HJH. Data underlying the plots are available in the supporting data file S1 Data. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.ĭata Availability: All relevant data are within the paper and its Supporting Information files. Received: NovemAccepted: Published: July 10, 2020Ĭopyright: © 2020 Burri et al. PLoS Biol 18(7):Īcademic Editor: Mark Estelle, UCSD, UNITED STATES (2020) A single touch can provide sufficient mechanical stimulation to trigger Venus flytrap closure. Citation: Burri JT, Saikia E, Läubli NF, Vogler H, Wittel FK, Rüggeberg M, et al.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |