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. 1987 Jul;84(3):847–850. doi: 10.1104/pp.84.3.847

Effect of Inhibitors of Auxin Transport and of Calmodulin on a Gravisensing-Dependent Current in Maize Roots 1

Thomas Björkman 1,2, A Carl Leopold 1
PMCID: PMC1056681  PMID: 11539682

Abstract

Some characteristics of the gravity sensing mechanism in maize root caps were investigated using a bioelectric current as an indicator of gravity sensing. This technique involves the measurement of a change in the current density which arises at the columella region coincidently with the presentation time. Two inhibitors of auxin transport, triiodobenzoic acid and naphthylphthalamic acid, blocked gravitropic curvature but not the change in current density. Two inhibitors of calmodulin activity, compound 48/80 and calmidazolium, blocked both curvature and gravity-induced current. The results suggest that auxin transport is not a component of gravity sensing in the root cap. By contrast, the results suggest that calmodulin plays an intrinsic role in gravity sensing.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Björkman T., Leopold A. C. An electric current associated with gravity sensing in maize roots. Plant Physiol. 1987;84:841–846. doi: 10.1104/pp.84.3.841. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Gaither D. H. Sites of auxin action: regulation of geotropism, growth, and ethylene production by inhibitors of auxin transport. Plant Physiol. 1975 Sep;56(3):404–409. doi: 10.1104/pp.56.3.404. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Gietzen K., Adamczyk-Engelmann P., Wüthrich A., Konstantinova A., Bader H. Compound 48/80 is a selective and powerful inhibitor of calmodulin-regulated functions. Biochim Biophys Acta. 1983 Dec 7;736(1):109–118. doi: 10.1016/0005-2736(83)90175-x. [DOI] [PubMed] [Google Scholar]
  4. Gietzen K. Comparison of the calmodulin antagonists compound 48/80 and calmidazolium. Biochem J. 1983 Dec 15;216(3):611–616. doi: 10.1042/bj2160611. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Lee J. S., Mulkey T. J., Evans M. L. Gravity-Induced Polar Transport of Calcium across Root Tips of Maize. Plant Physiol. 1983 Dec;73(4):874–876. doi: 10.1104/pp.73.4.874. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Lee J. S., Mulkey T. J., Evans M. L. Inhibition of polar calcium movement and gravitropism in roots treated with auxin-transport inhibitors. Planta. 1984;160:536–543. [PubMed] [Google Scholar]
  7. Lin C. T., Sun D., Song G. X., Wu J. Y. Calmodulin: localization in plant tissues. J Histochem Cytochem. 1986 May;34(5):561–567. doi: 10.1177/34.5.3084624. [DOI] [PubMed] [Google Scholar]
  8. Moore R., Evans M. L. How roots perceive and respond to gravity. Am J Bot. 1986 Apr;73(4):574–587. [PubMed] [Google Scholar]
  9. Rossi J. P., Rega A. F., Garrahan P. J. Compound 48/80 and calmodulin modify the interaction of ATP with the (Ca2+ + Mg2+)-ATPase of red cell membranes. Biochim Biophys Acta. 1985 Jun 27;816(2):379–386. doi: 10.1016/0005-2736(85)90505-x. [DOI] [PubMed] [Google Scholar]
  10. Scharff O., Foder B. Effect of trifluoperazine, compound 48/80, TMB-8 and verapamil on the rate of calmodulin binding to erythrocyte Ca2+-ATPase. Biochim Biophys Acta. 1984 Apr 25;772(1):29–36. doi: 10.1016/0005-2736(84)90514-5. [DOI] [PubMed] [Google Scholar]
  11. Stinemetz C. L., Evans M. L. Correlated changes in calmodulin activity and gravitropic sensitivity in roots of maize. Physiologist. 1985 Dec;28(6 Suppl):S121–S122. [PubMed] [Google Scholar]
  12. Tuana B. S., MacLennan D. H. Calmidazolium and compound 48/80 inhibit calmodulin-dependent protein phosphorylation and ATP-dependent Ca2+ uptake but not Ca2+-ATPase activity in skeletal muscle sarcoplasmic reticulum. J Biol Chem. 1984 Jun 10;259(11):6979–6983. [PubMed] [Google Scholar]
  13. de Guzman C. C., Dela Fuente R. K. Polar calcium flux in sunflower hypocotyl segments : I. The effect of auxin. Plant Physiol. 1984 Oct;76(2):347–352. doi: 10.1104/pp.76.2.347. [DOI] [PMC free article] [PubMed] [Google Scholar]

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