Planta

, Volume 206, Issue 3, pp 378–387 | Cite as

Effect of aluminum on cytoplasmic Ca2+ homeostasis in root hairs of Arabidopsis thaliana (L.)

  • David L. Jones
  • Simon Gilroy
  • Paul B. Larsen
  • Stephen H. Howell
  • Leon V. Kochian
Article

Abstract.

Aluminum inhibition of root growth is a major world agricultural problem where the cause of toxicity has been linked to changes in cellular calcium homeostasis. Therefore, the effect of aluminum ions (Al) on changes in cytoplasmic free calcium concentration ([Ca2+]c) was followed in root hairs of wild-type, Al-sensitive and Al-resistant mutants of Arabidopsis thaliana (L.) Heynh. Generally, Al exposure resulted in prolonged elevations in tip-localized [Ca2+]c in both wild-type and Al-sensitive root hairs. However, these Al-induced increases in [Ca2+]c were not tightly correlated with growth inhibition, occurring up to 15 min after Al had induced growth to stop. Also, in 32% of root hairs examined growth stopped without a detectable change in [Ca2+]c. In contrast, Al-resistant mutants showed little growth inhibition in response to AlCl3 exposure and in no case was a change in [Ca2+]c observed. Of the other externally applied stresses tested (oxidative and mechanical stress), both were found to inhibit root hair growth, but only oxidative stress (H2O2, 10 μM) caused a prolonged rise in [Ca2+]c similar to that induced by Al. Again this increase occurred after growth had been inhibited. The lack of a tight correlation between Al exposure, growth inhibition and altered [Ca2+]c dynamics suggests that although exposure of root hairs to toxic levels of Al causes an alteration in cellular Ca2+ homeostasis, this may not be a required event for Al toxicity. The elevation in [Ca2+]c induced by Al also strongly suggests that the phytotoxic action of Al in root hairs is not through blockage of Ca2+-permeable channels required for Ca2+ influx into the cytoplasm.

Key words: Aluminum Arabidopsis (Al toxicity) Cytoplasmic calcium Mutant (Arabidopsis Al sensitivity) Root hair Touch 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Copyright information

© Springer-Verlag Berlin Heidelberg 1998

Authors and Affiliations

  • David L. Jones
    • 1
  • Simon Gilroy
    • 2
  • Paul B. Larsen
    • 3
  • Stephen H. Howell
    • 4
  • Leon V. Kochian
    • 5
  1. 1.School of Agricultural and Forest Sciences, University of Wales, Bangor, Gwynedd, LL57 2UW, UKGB
  2. 2.Department of Biology, The Pennsylvania State University, University Park, PA 16802, USAUS
  3. 3.Department of Botany, University of Maryland, College Park, MD 20742, USAUS
  4. 4.Boyce Thompson Institute, Cornell University, Ithaca, NY 14853, USAUS
  5. 5.U.S. Plant, Soil & Nutrition Laboratory, USDA-ARS, Cornell University, Ithaca, NY 14853, USAUS

Personalised recommendations