Journal of Chemical Ecology

, Volume 30, Issue 11, pp 2181–2191

The Allelochemical Sorgoleone Inhibits Root H+-ATPase and Water Uptake

  • Angela M. Hejl
  • Karen L. Koster
Article

DOI: 10.1023/B:JOEC.0000048782.87862.7f

Cite this article as:
Hejl, A.M. & Koster, K.L. J Chem Ecol (2004) 30: 2181. doi:10.1023/B:JOEC.0000048782.87862.7f

Abstract

Sorghum plants inhibit the growth of some adjacent species. Root exudates from grain sorghum (Sorghum bicolor), consisting primarily of the quinone sorgoleone, are phytotoxic to several plant species, yet the mechanisms of growth inhibition remain to be fully explained. Disruption of electron transport functions in isolated mitochondria and chloroplasts has been reported as one explanation for growth inhibition. In the studies reported here, however, soybean seedlings grown in nutrient solution with 10, 50, or 100 μM sorgoleone showed no disruption of photosynthesis, as measured by leaf fluorescence and oxygen evolution, yet their mean leaf surface area was less when grown in 100 μM sorgoleone. Furthermore, in the presence of these same concentrations of sorgoleone, decreased nutrient solution use by soybean seedlings and decreased H+-ATPase activity in corn root microsomal membranes were observed. This suggests that impairment of essential plant processes, such as solute and water uptake, driven by proton-pumping across the root cell plasmalemma should also be considered as a mechanism contributing to observed plant growth inhibition by sorgoleone.

Sorgoleone Glycine max Zea mays Sorghum bicolor H+−ATPase water uptake sorghum root exudate allelopathy photosynthesis respiration 

Copyright information

© Springer Science+Business Media, Inc. 2004

Authors and Affiliations

  • Angela M. Hejl
    • 1
  • Karen L. Koster
    • 1
  1. 1.Department of BiologyThe University of South DakotaVermillionUSA

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