Planta

, Volume 197, Issue 2, pp 410–413 | Cite as

Hydrotropism in roots: sensing of a gradient in water potential by the root cap

  • Mamoru Takano
  • Hideyuki Takahashi
  • Tadashi Hirasawa
  • Hiroshi Suge
Rapid Communications

Abstract

Roots of the agravitropic pea (Pisum sativum L.) mutant, ageotropum, responded to a gradient in water potential as small as 0.5 MPa by growing toward the higher water potential. This positive response occurred when a sorbitol-containing agar block was unilaterally applied to the root cap but not when applied to the elongation region. Unilateral application of higher concentrations of sorbitol to the elongation region caused root curvature toward the sorbitol source, presumably because of growth reduction on the water-stressed side. The control blocks of plain agar applied to either the root cap or the elongation region did not cause significant curvature of the roots. These results demonstrate that hydrotropism in roots occurs following perception of a gradient in water potential by the root cap.

Key words

Hydrotropism Mutant (pea) Pisum (ageotropum mutant) Root cap Water potential 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Barlow PW, Zieschang HE (1994) Root movements: towards an understanding through attempts to model the process involved. Plant Soil 165:293–300Google Scholar
  2. Darwin C (1881) The power of movement in plants. John Murray, LondonGoogle Scholar
  3. Fortin MA, Poff KL (1990) Temperature sensing by primary roots of maize. Plant Physiol 94:367–369Google Scholar
  4. Hershey DR (1992) Is hydrotropism all wet? Sci Activities 29: 20–24Google Scholar
  5. Hooker HD Jr (1915) Hydrotropism in roots of Lupinus albus. Ann Bot 29: 265–283Google Scholar
  6. Jackson MB, Barlow PW (1981) Root geotropism and the role of growth regulators from the cap: re-examination. Plant Cell Environ 4:107–123Google Scholar
  7. Jaffe MJ, Takahashi H, Biro RL (1985) A pea mutant for the study of hydrotropism in roots. Science 230:445–441Google Scholar
  8. Juniper BE, Groves S, Landau-Schachar B, Audus LJ (1966) Root cap and the perception of gravity. Nature 209:93–94Google Scholar
  9. Loomis WE, Ewan LM (1936) Hydrotropic responses of roots in soil. Bot Gaz 97:728–743Google Scholar
  10. Molisch H (1883) Untersuchungen über Hydrotropismus. Sitzungsberichte Akad Wiss Wien 88:897–943Google Scholar
  11. Oyanagi A, Takahashi H, Suge H (1995) Interactions between hydrotropism and gravitropism in the primary seminal roots of Triticum aestivum L. Ann Bot 75:229–235Google Scholar
  12. Pilet PE, Nougarède A (1970) RNA, structure, infrastructure et géotropisme radiculaires. Physiol Vég 8:277–300Google Scholar
  13. Sachs J (1872) Ablenkung der Wurzel von ihrer normalen Wachstumsrichtung durch feuchte Körper. Arb D Bot Inst Würzburg 1:209–222Google Scholar
  14. Sharp RE, Kühn Silk W, Hsiao TC (1988) Growth of the maize primary root at low water potentials. I. Spatial distribution of expansive growth. Plant Physiol 87:50–57Google Scholar
  15. Takahashi H, Suge H (1991) Root hydrotropism of an agravitropic pea mutant, ageotropum. Physiol Plant 82:24–31Google Scholar
  16. Takahashi H, Suge H, Jaffe MJ (1991) Agravitropic growth and its relation to the formation of the plumular hook in etiolated shoots of the pea mutant, ageotropum. J Plant Physiol 138:216–222Google Scholar
  17. Takahashi H, Scott TK (1993) Intensity of hydrostimulation for the induction of root hydrotropism and its sensing by the root cap. Plant Cell Environ 16:99–103Google Scholar
  18. Volkmann D, Sievers A (1979) Graviperception in multicellular organs. In:Haupt W, Feinleib ME (eds) Encyclopedia of plant physiology, NS, vol 7. Physiology of movements. Springer, Berlin Heidelberg New York, pp 573–600Google Scholar
  19. Wilkins MB (1984) Gravitropism. In: Wilkins MB (ed) Advanced plant physiology. Pitman Publ. Ltd., London, pp. 163–182Google Scholar

Copyright information

© Springer-Verlag 1995

Authors and Affiliations

  • Mamoru Takano
    • 1
  • Hideyuki Takahashi
    • 1
  • Tadashi Hirasawa
    • 2
  • Hiroshi Suge
    • 1
  1. 1.Institute of Genetic EcologyTohoku UniversitySendaiJapan
  2. 2.Faculty of AgricultureTokyo University of Agriculture and TechnologyTokyoJapan

Personalised recommendations