G-fibres in storage roots of Trifolium pratense (Fabaceae): tensile stress generators for contraction.

Root contraction has been described for many species within the plant kingdom for over a century, and many suggestions have been made for mechanisms behind these contractions. To move the foliage buds deeper into the soil, the proximal part of the storage root of Trifolium pratense contracts by up to 30%. Anatomical studies have shown undeformed fibres next to strongly deformed tissues. Raman imaging revealed that these fibres are chemically and structurally very similar to poplar (Populus) tension wood fibres, which are known to generate high tensile stresses and bend leaning stems or branches upright. Analogously, an almost pure cellulosic layer is laid down in the lumen of certain root fibres, on a thin lignified secondary cell wall layer. To reveal its stress generation capacities, the thick cellulosic layer, reminiscent of a gelatinous layer (G-layer) in tension wood, was selectively removed by enzymatic treatment. A substantial change in the dimensions of the isolated wood fibre bundles was observed. This high stress relaxation indicates the presence of high tensile stress for root contraction. These findings indicate a mechanism of root contraction in T. pratense (red clover) actuated via tension wood fibres, which follows the same principle known for poplar tension wood.

[1]  G. Burns.  Eccentric Growth and the Formation of Redwood in the Main Stem of Conifers , 2012 .

[2]  A. Bowling,et al.  Gelatinous fibers are widespread in coiling tendrils and twining vines. , 2009, American journal of botany.

[3]  George Jeronimidis,et al.  Stress generation in the tension wood of poplar is based on the lateral swelling power of the G-layer. , 2008, The Plant journal : for cell and molecular biology.

[4]  J. Fisher.  Anatomy of axis contraction in seedlings from a fire prone habitat. , 2008, American journal of botany.

[5]  A. Bowling,et al.  Immunocytochemical characterization of tension wood: Gelatinous fibers contain more than just cellulose. , 2008, American journal of botany.

[6]  N. Gierlinger,et al.  Topochemical investigation on tension wood fibres of Acer spp., Fagus sylvatica L. and Quercus robur L. , 2008 .

[7]  R. Funada,et al.  Gibberellin-induced formation of tension wood in angiosperm trees , 2008, Planta.

[8]  L. Davin,et al.  Reaction tissue formation and stem tensile modulus properties in wild-type and p-coumarate-3-hydroxylase downregulated lines of alfalfa, Medicago sativa (Fabaceae). , 2007, American journal of botany.

[9]  B. Sundberg,et al.  Xyloglucan endo-transglycosylase (XET) functions in gelatinous layers of tension wood fibers in poplar--a glimpse into the mechanism of the balancing act of trees. , 2007, Plant & cell physiology.

[10]  F. Yamamoto,et al.  An Overview of the Biology of Reaction Wood Formation , 2007 .

[11]  K. Vaughn,et al.  A cortical band of gelatinous fibers causes the coiling of redvine tendrils: a model based upon cytochemical and immunocytochemical studies , 2006, Planta.

[12]  M. Burghammer,et al.  Direct investigation of the structural properties of tension wood cellulose microfibrils using microbeam X-ray fibre diffraction , 2006 .

[13]  N. Pütz.  Seedling establishment, underground kinetics, and clonal reiteration: How do Potentilla inclinata and Inula ensifolia get their multifunctional subterranean systems? , 2006 .

[14]  Notburga Gierlinger,et al.  Chemical Imaging of Poplar Wood Cell Walls by Confocal Raman Microscopy , 2006, Plant Physiology.

[15]  Hiroyuki Yamamoto.  Role of the gelatinous layer on the origin of the physical properties of the tension wood , 2004, Journal of Wood Science.

[16]  B. Sundberg,et al.  Patterns of Auxin Distribution during Gravitational Induction of Reaction Wood in Poplar and Pine1 , 2004, Plant Physiology.

[17]  K. Ruel,et al.  Detection in situ and characterization of lignin in the G-layer of tension wood fibres of Populus deltoides , 2004, Planta.

[18]  Tapani Vuorinen,et al.  Ultra Violet Resonance Raman Spectroscopy in Lignin Analysis: Determination of Characteristic Vibrations of p-Hydroxyphenyl, Guaiacyl, and Syringyl Lignin Structures , 2003, Applied spectroscopy.

[19]  M. Kwon,et al.  Induced compression wood formation in Douglas fir (Pseudotsuga menziesii) in microgravity. , 2001, Phytochemistry.

[20]  H. Edwards,et al.  FT Raman microscopy of untreated natural plant fibres. , 1997, Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy.

[21]  S. Ralph,et al.  FT-Raman Spectroscopy of Wood: Identifying Contributions of Lignin and Carbohydrate Polymers in the Spectrum of Black Spruce (Picea Mariana) , 1997 .

[22]  N. Pütz.  Underground plant movement III. The corm of Sauromatum guttatum (Wall.) Schott (Araceae) , 1996 .

[23]  N. Pütz.  Underground Plant Movement , 1993 .

[24]  J. Jernstedt,et al.  Root contraction in hyacinth IV. Orientation of cellulose microfibrils in radial longitudinal and transverse cell walls , 1990, Protoplasma.

[25]  J. Jernstedt.  ROOT CONTRACTION IN HYACINTH. I. EFFECTS OF IAA ON DIFFERENTIAL CELL EXPANSION , 1984 .

[26]  R. Archer,et al.  Apical control of branch movements and tension wood in black cherry and white ash trees , 1983 .

[27]  J. Fisher,et al.  Occurrence of Reaction Wood in Branches of Dicotyledons and Its Role in Tree Architecture , 1981, Botanical Gazette.

[28]  R. Archer,et al.  REACTION WOOD: INDUCTION AND MECHANICAL ACTION! , 1977 .

[29]  1. A. Rimbach: Die Verbreitung der Wurzelverkürzung im Pflanzenreich , 1929, Berichte der Deutschen Botanischen Gesellschaft.

[30]  14. A. Rimbach: Die Geschwindigkeit und Dauer der Wurzelverkürzung , 1927, Berichte der Deutschen Botanischen Gesellschaft.

[31]  Notburga Gierlinger,et al.  The potential of Raman microscopy and Raman imaging in plant research , 2007 .

[32]  M. Fournier,et al.  Tension wood and opposite wood in 21 tropical rain forest species : occurence and efficiency of the G.-Layer , 2006 .

[33]  N. Pütz,et al.  Seedling establishment, bud movement, and subterranean diversity of geophilous systems in Apiaceae , 2002 .

[34]  Hiroyuki Yamamoto,et al.  Growth stresses in tension wood: role of microfibrils and lignification , 1994 .

[35]  J. Boyd,et al.  BASIC CAUSE OF DIFFERENTIATION OF TENSION WOOD AND COMPRESSION WOOD. , 1977 .

[36]  A. Huang.  Enzymatic hydrolysis of cellulose to sugar. , 1975, Biotechnology and bioengineering symposium.

[37]  Huang Aa.  Enzymatic hydrolysis of cellulose to sugar. , 1975 .

[38]  K. Wilson,et al.  Root Contraction in Hyacinthus orientalis , 1966 .

[39]  H. Meier,et al.  Physical and Chemical Properties of the Gelatinous Layer in Tension Wood Fibres of Aspen (Populus tremula L.) , 1966 .

[40]  A. Wardrop.  The Reaction Anatomy of Arborescent Angiosperms , 1964 .

[41]  A. Wardrop.  The nature of reaction wood. V. The distribution and formation of tension wood in some species of Eucalyptus , 1956 .

[42]  E. Münch.  Statik und Dynamik des schraubigen Baues der Zellwand, besonders des Druck- und Zugholzes. , 1938 .