A cortical band of gelatinous fibers causes the coiling of redvine tendrils: a model based upon cytochemical and immunocytochemical studies
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A cortical band of fiber cells originate de novo in tendrils of redvine [Brunnichia ovata (Walt.) Shiners] when these convert from straight, supple young filaments to stiffened coiled structures in response to touch stimulation. We have analyzed the cell walls of these fibers by in situ localization techniques to determine their composition and possible role(s) in the coiling process. The fiber cell wall consists of a primary cell wall and two lignified secondary wall layers (S1 and S2) and a less lignified gelatinous (G) layer proximal to the plasmalemma. Compositionally, the fibers are sharply distinct from surrounding parenchyma as determined by antibody and affinity probes. The fiber cell walls are highly enriched in cellulose, callose and xylan but contain no homogalacturonan, either esterified or de-esterified. Rhamnogalacturonan-I (RG-I) epitopes are not detected in the S layers, although they are in both the gelatinous layer and primary wall, indicating a further restriction of RG-I in the fiber cells. Lignin is concentrated in the secondary wall layers of the fiber and the compound middle lamellae/primary cell wall but is absent from the gelatinous layer. Our observations indicate that these fibers play a central role in tendril function, not only in stabilizing its final shape after coiling but also generating the tensile strength responsible for the coiling. This theory is further substantiated by the absence of gelatinous layers in the fibers of the rare tendrils that fail to coil. These data indicate that gelatinous-type fibers are responsible for the coiling of redvine tendrils and a number of other tendrils and vines.
KeywordsCellulose Coiling Fiber cells Immunocytochemistry Lignin Xylan Control of coiling Pectin
Transmission electron microscopy
Thanks are extended to Brian Maxwell for technical assistance on both the growing of the redvine plants and the light microscopic photography in this paper. Extremely helpful discussions with Rick Turley, Tobias Baskin and Roberto Ligrone and comments from three anonymous reviewers are acknowledged here. Generous gifts of antibodies from Andrew Staehelin and Michael Hahn are acknowledged that have greatly enhanced this study. Christopher G. Meloche is supported by the in-house ARS Research Associate program. Mention of a trademark, proprietary product or vendor does not constitute an endorsement by USDA.
- Darwin C (1875) The movements and habits of climbing plants. Henry Murray, LondonGoogle Scholar
- Esau K (1977) Anatomy of seed plants. Wiley, New YorkGoogle Scholar
- Jaffe MJ (1980) On the mechanism of contact coiling of tendrils. In: Skoog F (ed) Plant growth substances 1979. Springer, Berlin Heidelberg New York, pp. 481–495Google Scholar
- Jaffe MJ, Galston AW (1969) The physiology of tendrils. Annu Rev Plant Physiology 417–434Google Scholar
- Renzaglia KS, Vaughn KC (2000) Anatomy, development and classification of hornworts. In: Shaw AJ, Goffinet B (eds) Bryophyte biology. Cambridge University Press, Cambridge, pp. 1–20Google Scholar
- Tomlinson PB (2003) Development of gelatinous (reaction) fibers in stems of Gnetum gnemon (Gnetales). Am J Bot 90:965–972Google Scholar
- Wardrop AB, Dadswell HE (1955) The nature of reaction wood. IV. Variations in cell wall organization of tension wood fibres. Aust J Bot 3:177–187Google Scholar