Gelatinous fibers are widespread in coiling tendrils and twining vines

Abstract

Although the coiling of tendrils and the twining of vines has been investigated since Darwin's time, a full understanding of the mechanism(s) of this coiling and twining ability has not yet been obtained. In a previous study (Planta 225: 485-498), gelatinous (G) fibers in tendrils of redvine occurred concomitantly with the ability to coil, strongly indicating their role in the coiling process. In this study, tendrils and twining vines of a number of species were examined using microscopic and immunocytochemical techniques to determine if a similar presence and distribution of these fibers exists in other plant species. Tendrils that coiled in many different directions had a cylinder of cortical G fibers, similar to redvine. However, tendrils that coiled only in a single direction had gelatinous fibers only along the inner surface of the coil. In tendrils with adhesive tips, the gelatinous fibers occurred in the central/core region of the tendril. Coiling occurred later in development in these tendrils, after the adhesive pad had attached. In twining stems, G fibers were not observed during the rapid circumnutation stage, but were found at later stages when the vine's position was fixed, generally one or two nodes below the node still circumnutating. The number and extent of fiber development correlated roughly with the amount of torsion required for the vine to ascend a support. In contrast, species that use adventitious roots for climbing or were trailing/scrambling-type vines did not have G fibers. These data strongly support the concept that coiling and twining in vines is caused by the presence of G fibers.

Maturation Stress Generation in Poplar Tension Wood Studied by Synchrotron Radiation Microdiffraction

“…In poplar (Populus deltoides 3 Populus trichocarpa), as in most temperate tree species, tension wood fibers are characterized by the presence of a specific layer, called the G-layer (Jourez et al, 2001;Fang et al, 2008), where the matrix is almost devoid of lignin (Pilate et al, 2004) and the microfibrils are oriented parallel to the fiber axis (Fujita et al, 1974). This type of reaction cell is common in plant organs whose function involves the bending or contraction of axes, such as tendrils, twining vines (Bowling and Vaughn, 2009), or roots (Fisher, 2008).…”

Nanospherical arabinogalactan proteins are a key component of the high-strength adhesive secreted by English ivy

“…These substances presumably arise from the encapsulation of partial components of the plant cell wall within the cured adhesive, a phenomenon that has been detailed in the previous studies (15,18). Given that AGs and pectic substances have been identified to be two of the predominant components in the majority of botanic adhesives, including those obtained from the climbing organs of Virginia creeper, Boston ivy, and Ficus pumila, as shown in the previous cytochemical analyses ( [14][15][16][17][48][49][50], it is logical to expect that these two acidic polysaccharides possess exceptional capacity to effectively support the adhesive function of the sticky exudates at the interface. In particular, for the mucilage secreted by the root hairs of English ivy, the pectic acids may exist alone and/or be covalently bonded to the AGPs within the ivy nanoparticles as interpreted above.…”

“…In addition, the tensile strength of this reconstructed ivy-mimetic adhesive composite was ∼3.9-, 1.6-, 3.8-, and 1.7-fold stronger than respective adhesive composites consisting of ivy nanoparticles with Ca molecular events within the botanic adhesives, and, accordingly, little is known about the adhesion mechanisms underlying these mucilages. In recent years, the chemical components of several types of botanic adhesives produced by Virginia creeper (Parthenocissus quinquefolia), Boston ivy, and F. pumila have been examined by immunocytochemical identification and cytochemical stains (12,(14)(15)(16)(17). Consistently, acidic polysaccharides and glycoproteins, involving pectic acids, AGs, and AGPs, are recognized as the predominant constituents of these adhesive substances.…”

“…Among them, one subfamily of hydroxyproline (Hyp)-rich glycoproteins (HRGPs), AGPs, seem to be the ideal candidates due to their vital roles in supporting the morphogenesis and function of root hairs (24)(25)(26)(27)(28). In the meantime, the AGPs have been detected in some other botanic adhesives (14)(15)(16)(17). Additionally, the tertiary structure of the AGPs has theoretically been predicted to be spheroidal according to a wattle-blossom model, which was established to describe their 3D structure by analyzing the constituents and flexibility of the AGPs as a whole (24,(29)(30)(31).…”

“…Nevertheless, the role of the glue-like viscous exudates that are observed on the majority of these organs and that cement the plants to the substrates has been less explored (10,12,13). Diverse polysaccharides and glycoproteins, comprising mucilaginous pectins, arabinogalactans, arabinogalactan proteins (AGPs), and many others, have been identified to be the predominant components in these adhesive substances (14)(15)(16)(17); however, the molecular mechanisms underlying the high-strength adhesion remain elusive.…”