Better explicating the strengths and shortcomings of these models will help refine projections and improve transparency in the years ahead.
Image credit: Witsawat.S.
Edited by David A. Weitz, Harvard University, Cambridge, MA, and approved May 21, 2019 (received for review January 20, 2019)
Significance
Microfibers existing in the tracheary systems of plants are crucial for the plants to survive. These microfilaments are curled up, forming left-handed helices that make the contour of tubes responsible for the transport of water and nutrients from the roots to the leaves. The microfilaments present mechanical properties that vary from plant to plant despite having similar polygonal-helical shapes and cellulose skeletons. Here we show that the surface morphology of the microfilaments, sensed by nematic liquid crystal droplets, is at the origin of entanglements, which are responsible for the mechanical behavior of microfilaments. This work introduces routes for the accurate characterization of plants’ microfilaments and to produce bioinspired textiles.
Abstract
The tracheary system of plant leaves is composed of a cellulose skeleton with diverse hierarchical structures. It is built of polygonally bent helical microfilaments of cellulose-based nanostructures coated by different layers, which provide them high compression resistance, elasticity, and roughness. Their function includes the transport of water and nutrients from the roots to the leaves. Unveiling details about local interactions of tracheary elements with surrounding material, which varies between plants due to adaptation to different environments, is crucial for understanding ascending fluid transport and for tracheary mechanical strength relevant to potential applications. Here we show that plant tracheary microfilaments, collected from Agapanthus africanus and Ornithogalum thyrsoides leaves, have different surface morphologies, revealed by nematic liquid crystal droplets. This results in diverse interactions among microfilaments and with the environment; the differences translate to diverse mechanical properties of entangled microfilaments and their potential applications. The presented study also introduces routes for accurate characterization of plants’ microfilaments.
Footnotes
- ↵1To whom correspondence may be addressed. Email: slobodan.zumer{at}fmf.uni-lj.si or mhg{at}fct.unl.pt.
Author contributions: S.Ž. and M.H.G. designed research; A.P.A., J.C., U.M., S.Č., P.L.A., S.Ž., and M.H.G. performed research; A.P.A., J.C., U.M., S.Č., P.L.A., S.Ž., and M.H.G. analyzed data; and S.Č., P.L.A., S.Ž, and M.H.G. wrote the paper.
The authors declare no conflict of interest.
This article is a PNAS Direct Submission.
This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1901118116/-/DCSupplemental.
- Copyright © 2019 the Author(s). Published by PNAS.
This open access article is distributed under Creative Commons Attribution License 4.0 (CC BY).
Spotting plants’ microfilament morphologies and nanostructures
Article Classifications
- Physical Sciences
- Applied Physical Sciences
Sign up for Article Alerts
Jump to section
You May Also be Interested in
Did the Caribbean sweep into the western Amazon millions of years ago, shaping the region’s rich biodiversity?
Image credit: Tacio Cordeiro Bicudo (University of São Paulo, São Paulo, Brazil), Victor Sacek (University of São Paulo, São Paulo, Brazil), and Lucy Reading-Ikkanda (artist).
Settlements 4,200 years ago may have suffered from overpopulation before drought and lower temperatures ultimately made them unsustainable.
Image credit: Andrea Ricci.
Mara Reed and Michael Manga explore why Yellowstone's Steamboat Geyser resumed erupting in 2018.
Some songbird parents might improve their own fitness by manipulating their offspring into leaving the nest early, at the cost of fledgling survival, a study finds.
Image credit: Gil Eckrich (photographer).