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Updated: May 5, 2026

Author Spotlight: Exploring Plant-Microbe Interactions Through Root Exudates in a Novel Growth System
Published on: November 17, 2023
Effects of root exudate sorgoleone on photosynthesis
F A Einhellig1, J A Rasmussen, A M Hejl
1Department of Biology, University of South Dakota, 57069, Vermillion, South Dakota.
Abstract:
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.
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