, 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


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 


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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

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