Journal of Chemical Ecology

, Volume 19, Issue 2, pp 369–375 | Cite as

Effects of root exudate sorgoleone on photosynthesis

  • Frank A. Einhellig
  • James A. Rasmussen
  • Angela M. Hejl
  • Itamar F. Souza


The aim of this investigation was to determine if sorgoleone (SGL), ap-benzoquinone inSorghum bicolor root exudate, is a photosynthesis inhibitor. Assays usingGlycine max leaf disks showed concentrations as low as 10μM SGL inhibited oxygen evolution more than 50%. Tests conducted on chloroplasts isolated fromPisum sativum showed that SGL is a powerful inhibitor of CO2-dependent oxygen evolution. Using a chloroplast suspension equivalent to 80–100μg chlorophyll, the I50 was approximately 0.2μM SGL. These data indicate inhibition of photosynthesis is part of the explanation for growth reduction caused by this allelochemical.

Key Words

Sorgoleone allelochemical allelopathy photosynthesis chloroplast root exudate Sorghum bicolor 


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Copyright information

© Plenum Publishing Corporation 1993

Authors and Affiliations

  • Frank A. Einhellig
    • 1
  • James A. Rasmussen
    • 2
  • Angela M. Hejl
    • 1
  • Itamar F. Souza
    • 3
  1. 1.Department of BiologyUniversity of South DakotaVermillion
  2. 2.Department of BiologySouthern Arkansas UniversityMagnolia
  3. 3.Minas Gerais Livestock and Agriculture Research InstituteLavrasBrazil

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