Research Article Gravity Affects the Closure of the Traps in Dionaea muscipula Camilla Pandolfi, 1 Elisa Masi, 1 Boris Voigt, 2 Sergio Mugnai, 1 Dieter Volkmann, 2 and Stefano Mancuso 1 1 DISPAA, University of Florence, Viale delle idee 30, 50019 Sesto Fiorentino, Italy 2 IZMB, University of Bonn, Kirschallee 1, 53115 Bonn, Germany Correspondence should be addressed to Camilla Pandoli; camilla.pandoli@unii.it Received 12 May 2014; Accepted 27 June 2014; Published 15 July 2014 Academic Editor: Monica Monici Copyright © 2014 Camilla Pandoli et al. his is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Venus lytrap (Dionaea muscipula Ellis) is a carnivorous plant known for its ability to capture insects thanks to the fast snapping of its traps. his fast movement has been long studied and it is triggered by the mechanical stimulation of hairs, located in the middle of the leaves. Here we present detailed experiments on the efect of microgravity on trap closure recorded for the irst time during a parabolic light campaign. Our results suggest that gravity has an impact on trap responsiveness and on the kinetics of trap closure. he possible role of the alterations of membrane permeability induced by microgravity on trap movement is discussed. Finally we show how the Venus lytrap could be an easy and efective model plant to perform studies on ion channels and aquaporin activities, as well as on electrical activity in vivo on board of parabolic lights and large diameter centrifuges. 1. Introduction he response of Venus lytrap (Dionaea muscipula) to mechanical stimulation has long been known, and it is one of the most rapid movements in the plant kingdom [1, 2]. he plant produces a rosette of leaves, each divided into two parts: a lower part called the lamina and the upper part called the trap. he trap catches prey thanks to a very rapid movement of its bilobed halves that shut when the trigger hairs are stimulated. At room temperature, two touches acti- vate the trap, which snaps shut in a fraction of second [3]. At higher temperature only one stimulus is required for trap closure [4]. he stimulation of the trigger hairs activates mechanosensitive ion channels and generates receptor poten- tials, inducing the action potentials (APs) that initiate the closure [5]; electrical signals are the immediate cause of the trap movements, irrespective of the way in which the signal is triggered (mechanical stimulation or electrostimulation) [5]. Once the insect is caught, the lobes seal tightly allowing diges- tion to take place [6, 7]. he APs in Dionaea muscipula have been extensively studied (e.g., [5, 8, 9]). Trigger hair-induced generation of action potentials is not exclusively associated with the trap closure. he struggling of the entrapped prey in the closed trap results in the generation of further action potentials which cease to occur just when the prey stops moving. hese APs may induce inhibition of the dark reaction of photosynthesis [10] showing that chlorophyll-A luores- cence is under electrochemical control [11]. Although this spectacular example of plant movement has long fascinated scientists, the mechanism by which the trap works remains poorly understood [12]. Some explanations proposed involve an irreversible cell wall loosening, induced by the acidiica- tion of the cells [6], or a rapid loss of turgor pressure similarly to what happens in stomata [13]. However, the validity of both mechanisms has been questioned because they cannot explain the speed at which the movement happens. More recently, other two models have been proposed: the elastic deformation that results from a snap-buckling instability [14] and a hydroelastic curvature mechanism based on the fast opening of water channels [9]. Both models may convincingly account for the speed of the movement. he possibility to study the efect of microgravity on living organisms is a unique opportunity to observe the alteration of phenomena in the absence of the otherwise omnipresent gravity force. Although the understanding of the efect of gravity on animal and plant bodies is crucial, in view of the possible future space travels, the research is moving slowly if Hindawi Publishing Corporation BioMed Research International Volume 2014, Article ID 964203, 5 pages http://dx.doi.org/10.1155/2014/964203