Xiaojun Yang1, Wenli Deng2. 1. College of Materials Science and Engineering, South China University of Technology, Guangzhou, 510640, China. 2. College of Materials Science and Engineering, South China University of Technology, Guangzhou, 510640, China. wldeng@scut.edu.cn.
Abstract
MAIN CONCLUSION: The attachment of aerial roots of Syngonium podophyllum involves a multi-step process adjusted by multi-scale structures. Helical-crack root hairs are first found in the attachment system, representing specialized structures for surface anchorage. The morphological variability of attachment organs reflects diverse climbing strategies. One such anchoring mode in clinging-climbers involves the time-dependent interaction between roots and the support: By naturally occurring adhesive roots with root hairs, the plant can ascend on supports of any shape and size. As a typical root-climber, Syngonium podophyllum develops elongate aerial roots at nodes. Here, we studied its attachment behavior from the external morphology to the internal structure in detail. Through SEM and LM observation on several root-substrate interfaces, we suggested that the attachment of aerial roots was mediated by a multi-step process, in which root hairs played significant roles in releasing mucilaginous substance and securing the durable anchorage. We summarized all the types of shape changes of root hairs with particular focus on the abnormal transition from a tube to a helical-crack ribbon. We demonstrated our understanding with respect to the formation of the helical-crack root hairs, based on the structural evidence of cellulose microfibrils orientation on the cell wall lamellae. The helical-crack root hairs serving as energy-dissipating units retard the failure of adhesion under high winds and loads.
MAIN CONCLUSION: The attachment of aerial roots of Syngonium podophyllum involves a multi-step process adjusted by multi-scale structures. Helical-crack root hairs are first found in the attachment system, representing specialized structures for surface anchorage. The morphological variability of attachment organs reflects diverse climbing strategies. One such anchoring mode in clinging-climbers involves the time-dependent interaction between roots and the support: By naturally occurring adhesive roots with root hairs, the plant can ascend on supports of any shape and size. As a typical root-climber, Syngonium podophyllum develops elongate aerial roots at nodes. Here, we studied its attachment behavior from the external morphology to the internal structure in detail. Through SEM and LM observation on several root-substrate interfaces, we suggested that the attachment of aerial roots was mediated by a multi-step process, in which root hairs played significant roles in releasing mucilaginous substance and securing the durable anchorage. We summarized all the types of shape changes of root hairs with particular focus on the abnormal transition from a tube to a helical-crack ribbon. We demonstrated our understanding with respect to the formation of the helical-crack root hairs, based on the structural evidence of cellulose microfibrils orientation on the cell wall lamellae. The helical-crack root hairs serving as energy-dissipating units retard the failure of adhesion under high winds and loads.
Authors: Angela T Moles; Ashika Jagdish; Yameng Wu; Suzanna Gooley; Rhiannon L Dalrymple; Phoebe Feng; Jennifer Auld; Georgia Badgery; Matilda Balding; Andrew Bell; Nora Campbell; Mark Clark; Michelle Clark; Kyle M Crawford; Oliver de Lorenzo; Amelia Fletcher; Zoe Ford; Haley Fort; Simon B Z Gorta; Alexander Hagan; Frank A Hemmings; Gabriella S Hoban; Thomasine Hulme; Kit King; Anish Kumar; Angelique Kyriazis; Beatrice Alexandra Laitly; Joshua Markovski; Len Martin; Geoffrey McDonnell; Cindy Pan; Ruby Paroissien; Polly Reeves-Perrin; Michi Sano; Sebastian M Schwarz; Alena Sipka; Michael Sullings; Jing Wei Yeong; William K Cornwell Journal: PLoS One Date: 2019-12-30 Impact factor: 3.240