title: Investigating the rheological properties of native plant latex.
abstract: Plant latex, the source of natural rubber, has been of interest to mankind for millennia, with much of the research on its rheological (flow) properties focused towards industrial application. However, little is known regarding the rheology of the native material as produced by the plant, a key factor in determining latex's biological functions. In this study, we outline a method for rheological comparison between native latices that requires a minimum of preparatory steps. Our approach provides quantitative insights into the coagulation mechanisms of Euphorbia and Ficus latex allowing interpretation within a comparative evolutionary framework. Our findings reveal that in laboratory conditions both latices behave like non-Newtonian materials with the coagulation of Euphorbia latex being mediated by a slow evaporative process (more than 60 min), whereas Ficus appears to use additional biochemical components to increase the rate of coagulation (more than 30 min). Based on these results, we propose two different primary defensive roles for latex in these plants: the delivery of anti-herbivory compounds (Euphorbia) and rapid wound healing (Ficus).
authors.affiliation: Plant Biomechanics Group, Botanic Garden, Faculty of Biology, University of Freiburg, , Schänzlestraße 1, Freiburg 79104, Germany.
authors.forename: Georg
authors.initials: G
authors.lastname: Bauer
authors.forename: Christian
authors.initials: C
authors.lastname: Friedrich
authors.forename: Carina
authors.initials: C
authors.lastname: Gillig
authors.forename: Fritz
authors.initials: F
authors.lastname: Vollrath
authors.forename: Thomas
authors.initials: T
authors.lastname: Speck
authors.forename: Chris
authors.initials: C
authors.lastname: Holland
mesh_terms: D028481:Euphorbia / Q000378:metabolism*; D030681:Ficus / Q000378:metabolism*; D007700:Kinetics; D007840:Latex / Q000737:chemistry* / Q000302:isolation & purification; D012212:Rheology
chemical_list: D007840:Latex
keywords: Euphorbia; Ficus; coagulation; evolution; latex; rheology