Skip to main content
SpringerLink
Log in

A biophysical analysis of root growth under mechanical stress

  • Published:
Plant and Soil Aims and scope Submit manuscript

Abstract

The factors controlling root growth in hard soils are reviewed alongside summarised results from our recent studies. The turgor in cells in the elongation zone of roots pushes the apex forward, resisted by the external pressure of the soil and the tension in the cell walls. The external pressure of the soil consists of the pressure required to deform the soil, plus a component of frictional resistance between the root and soil. This frictional component is probably small due to the continuous sloughing of root cap cells forming a low-friction lining surrounding the root. Mechanically impeded roots are not only thicker, but are differently shaped, continuing to increase in diameter for a greater distance behind the root tip than in unimpeded roots. The osmotic potential decreases in mechanically impeded roots, possibly due to accumulation of solutes as a result of the slower root extension rate. This more negative osmotic potential is not always translated into increased turgor pressure, and the reasons for this require further investigation. The persistent effect of mechanical impedance on root growth is associated with both a stiffening of cell walls in the axial direction, and with a slowing of the rate of cell production.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  • Abdalla AM, Hettiaratchi D R P and Reece A R 1969 The mechanics of root growth in granular media. J. Agric. Eng. Res. 14, 236-248.

    Google Scholar 

  • Atwell B J 1990a The effect of soil compaction on wheat during early tillering. II. Concentrations of cell constituents. New Phytol. 115, 17-41.

    Google Scholar 

  • Atwell B J 1990b The effect of soil compaction on wheat during early tillering. I. Growth, development and root structure. New Phytol. 115, 29-35.

    Google Scholar 

  • Atwell B J and Newsome J C 1990 Turgor pressure in mechanically impeded lupin roots. Aust. J. Plant Physiol. 17, 49-56.

    Google Scholar 

  • Barber D A and Gunn K B 1974 The effect of mechanical forces on the exudation of organic substances by the roots of cereal plants. New Phytol. 73, 39-45.

    Google Scholar 

  • Barley K P 1962 The effects of mechanical stress on the growth of roots. J. Exp. Bot. 13, 95-110.

    Google Scholar 

  • Barley K P 1963 Influence of soil strength on growth of roots. Soil Sci. 96, 175-180.

    Google Scholar 

  • Barlow P W 1978a The ultrastructure of the regenerating root cap of Zea maysL. Ann. Bot. 42, 791-799.

    Google Scholar 

  • Barlow P W 1978b Cell displacement through the columella of the root cap of Zea maysL. Ann. Bot. 42, 783-790.

    Google Scholar 

  • Barlow P W 1989 Anatomical controls of root growth. Aspects Appl. Biol. 22, 57-66.

    Google Scholar 

  • Bengough A G 1992 Penetrometer resistance equation-its derivation and the effect of soil adhesion. J. Agric. Eng. Res. 53, 163-168.

    Google Scholar 

  • Bengough A G and Mackenzie C J 1994 Simultaneous measurement of root force and elongation for seedling pea roots. J. Exp. Bot. 45, 95-102.

    Google Scholar 

  • Bengough A G and McKenzie B M 1997 Sloughing of root cap cells decreases the frictional resistance to maize (Zea maysL) root growth. J. Exp. Bot. (In press)

  • Bengough A G and Mullins C E 1991 Penetrometer resistance, root penetration resistance and root elongation rate in 2 sandy loam soils. Plant Soil 131, 59-66.

    Google Scholar 

  • Bengough A G and Young I M 1993 Root elongation of seedling peas through layered soil of different penetration resistances. Plant Soil 149, 129-139.

    Google Scholar 

  • Boeuf-Tremblay V, Plantureux S and Guckert A 1995 Influence of mechanical impedance on root exudation of maize seedlings at two development stages. Plant Soil 172, 279-287.

    Google Scholar 

  • Clark L J, Whalley WR, Dexter A R, Barraclough P B and Leigh R A 1996 Complete mechanical impedance increases the turgor of cells in the apex of pea roots. Plant Cell Environ. 19, 1099-1102.

    Google Scholar 

  • Clowes F A L 1961 Duration of a mitotic cycle in a meristem. J. Exp. Bot. 12, 283-293.

    Google Scholar 

  • Clowes F A L 1971 The proportion of cells that divide in root meristems of Zea maysL. Ann. Bot. 35, 249-261.

    Google Scholar 

  • Cockroft B, Barley K P and Greacen E L 1969 The penetration of clays by fine probes and root tips. Aust. J. Soil Res. 7, 333-348.

    Google Scholar 

  • Croser C, Bengough A G and Pritchard J 1995a Does soil strength affect root cell production? J. Exp. Bot. 46(Suppl), 29

    Google Scholar 

  • Croser C, Pritchard J and Bengough A G 1995b Measuring osmotic potential in single cells of mechanically impeded roots. 14th Long Ashton Int. Symp. Plant roots-from cells to systems. (Abstract).

  • Eavis B W 1967 Mechanical impedance to root growth. Agric. Eng. Symp., Silsoe Paper 4/F/39, 1-11.

  • Ennos A R 1989 The mechanics of anchorage in seedlings of sun-flower, Helianthus annuusL. New Phytol. 113, 185-192.

    Google Scholar 

  • Erickson R O and Sax K B 1956 Elemental growth rate of the primary root of Zea mays. Proc. Am. Phil. Soc. 100, 487-498.

    Google Scholar 

  • Evans H J, Neary GJ and Tonkinson SM 1957 The use of colchicine as an indicator of mitotic rate in broad bean root meristems. J. Genet. 55, 487-502.

    Google Scholar 

  • Faure A G 1994 Stress field developed by root growth: theoretical approach. J. Agric. Eng. Res. 58, 53-67.

    Google Scholar 

  • Goss M J 1977 Effects of mechanical impedance on root growth in barley (Hordeum vulgareL.). I. Effects on the elongation and branching of seminal root axes. J. Exp. Bot. 28, 96-111.

    Google Scholar 

  • Goss M J and Russell R S 1980 Effects of mechanical impedance on root growth in barley (Hordeum vulgareL.). III. Observation on the mechanism of response. J. Exp. Bot. 31, 577-588.

    Google Scholar 

  • Greacen E L 1986 Root response to soil mechanical properties. Trans. 13th Cong. Int. Soc. Soil Sci. 5, 20-47.

    Google Scholar 

  • Greacen E L, Farrell D A and Cockroft B 1968 Soil resistance to metal probes and plant roots. Trans. 9th Cong. Int. Soc. Soil Sci. 1, 769-779.

    Google Scholar 

  • Greacen E L and Oh J S 1972 Physics of root growth. Nature, New Biol. 235, 24-25.

    Google Scholar 

  • Green P B 1976 Growth and cell pattern formation on an axis: Critique of concepts, terminology, and modes of study. Bot. Gaz. 137, 187-202.

    Google Scholar 

  • Groenvelt P H, Kay B D and Grant C D 1984 Physical assessment of a soil with respect to rooting potential. Geoderma 34, 101-114.

    Google Scholar 

  • Guinel F C and McCully M E 1986 Some water-related physical properties of maize root-cap mucilage. Plant Cell Environ. 9, 657-666.

    Google Scholar 

  • Hettiaratchi D R P and Fergusson C A 1973 Stress deformation behaviour of soil in root growth mechanics. J. Agric. Eng. Res. 18, 309-320.

    Google Scholar 

  • MacDonald I R and Gordon D C 1984 Seedbed and related investigations. Macaulay Inst. Soil Res. Ann. Rep. 1984, 98-101

  • Malone M and Tomos A D 1992 Measurement of gradients of water potential in elongating pea stem by pressure probe and picolitre osmometry. J. Exp. Bot. 43, 1325-1331.

    Google Scholar 

  • McCann M C and Roberts K 1994 Changes in cell wall architecture during cell elongation. J. Exp. Bot. 45, 1683-1691.

    Google Scholar 

  • Misra R K, Dexter A R and Alston A M 1986 Maximum axial and radial growth pressures of plant roots. Plant Soil 95, 315-318.

    Google Scholar 

  • Monteith J L 1986 How do crops manipulate water supply and demand? Phil. Trans. R. Soc. Lond. A 316, 245-259.

    Google Scholar 

  • Passioura JB 1991 Soil structure and plant-growth. Aust. J. Soil Res. 29, 717-728.

    Google Scholar 

  • Passioura J B and Fry S C 1992 Turgor and cell expansion: Beyond the Lockhart equation. Aust. J. Plant Physiol. 19, 565-576.

    Google Scholar 

  • Pritchard J 1994 The control of cell expansion in roots. New Phytol. 127, 3-26.

    Google Scholar 

  • Pritchard J, Barlow P W, Adams J S and Tomos A D 1990 Biophysics of the inhibition of the growth of maize roots by lowered temperature. Plant Physiol. 93, 222-230.

    Google Scholar 

  • Pritchard J, Jones R G W and Tomos A D 1991 Turgor, growth and rheological gradients of wheat roots following osmotic-stress. J. Exp. Bot. 42, 1043-1049.

    Google Scholar 

  • Richards B G and Greacen E L 1986 Mechanical stresses on an expanding cylindrical root analogue in granular media. Aust. J. Soil Res. 24, 393-404.

    Google Scholar 

  • Russell R S 1977 Plant root systems. Their function and interaction with the soil. McGraw Hill, Maidenhead.

    Google Scholar 

  • Russell R S and Goss M J 1974 Physical aspects of soil fertility-The response of roots to mechanical impedance. Neth. J. Agric. Sci. 22, 305-318.

    Google Scholar 

  • Scholefield D and Hall D M 1985 Constricted growth of grass roots through rigid pores. Plant Soil 85, 153-162.

    Google Scholar 

  • Silk W K, Lord E M and Eckard K J 1989 Growth patterns inferred from anatomical records. Plant Physiol. 90, 708-713.

    Google Scholar 

  • Stolzy L H and Barley K P 1968 Mechanical resistance encountered by roots entering compact soils. Soil Sci. 105, 297-301.

    Google Scholar 

  • Taylor H M and Ratliff L H 1969 Root elongation rates of cotton and peanuts as a function of soil strength and water content. Soil Sci. 108, 113-119.

    Google Scholar 

  • Veen B W 1982 The influence of mechanical impedance on the growth of maize roots. Plant Soil 66, 101-109.

    Google Scholar 

  • Voorhees W B, Farrell D A and Larson W E 1975 Soil strength and aeration effects of root elongation. Soil Sci. Soc. Am. Proc. 39, 948-953.

    Google Scholar 

  • Whiteley G M, Hewitt J S and Dexter A R 1982 The buckling of plant roots. Physiol. Plant 54, 333-342.

    Google Scholar 

  • Whiteley G M, Utomo W H and Dexter A R 1981 A comparison of penetrometer pressures and the pressures exerted by roots. Plant Soil 61, 351-364.

    Google Scholar 

  • Wiersum L K 1957 The relationship of the size and structural rigidity of pores to their penetration by roots. Plant Soil 9, 75-85.

    Google Scholar 

  • Wilson A J, Robards AW and Goss MJ 1977 Effects of mechanical impedance on root growth in barley, Hordeum vulgareL. II. Effects on cell development in seminal roots. J. Exp. Bot. 28, 1216-1227.

    Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Scottish Crop Research Institute, Dundee, DD2 5DA, UK

    A.G. Bengough & C. Croser

  2. School of Biological Sciences, University of Birmingham, UK

    J. Pritchard

Authors
  1. A.G. Bengough
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. C. Croser
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. J. Pritchard
    View author publications

    You can also search for this author in PubMed Google Scholar

Rights and permissions

Reprints and permissions

About this article

Cite this article

Bengough, A., Croser, C. & Pritchard, J. A biophysical analysis of root growth under mechanical stress. Plant and Soil 189, 155–164 (1997). https://doi.org/10.1023/A:1004240706284

Download citation

  • Issue Date:

  • DOI: https://doi.org/10.1023/A:1004240706284

Search

Navigation