Annika Eberle, Kenny Quinn, and Lori Bassman
Department of Engineering
Harvey Mudd College, Claremont, CA 91711 USA

Tendrils are structural supports that extend from a plant stem. Once the distal tip of a tendril touches an object, contact coiling follows rapidly to tether the tendril to the support. After the tip is secured, free coiling of the tendril occurs along the length to draw the stem closer to the support. While these growth processes are not well understood, it is believed that contact coiling results from chemical responses similar to ion fluxes, and free coiling results from differential dorsal/ventral growth caused by asymmetric response to auxin distribution.1 Because a tendril typically is anchored on one end by the plant stem and on the other by the support, the process of free coiling requires the tendril maintain zero net twist along its length. This results in the formation of at least one reversal in the direction of winding (Figure 1). We are seeking to understand in detail the structural changes that cause free coiling.


Experimental Study

We have utilized 30