Mechanisms of hydroquinone-induced growth reduction in leafy spurge


Field observations indicate leafy spurge (Euphorbia esula) is inhibited by the presence of Antennaria microphylla. Hydroquinone (HQ), one of several compounds isolated from A. microphylla has been shown to inhibit leafy spurge seed germination, root elongation, and callus culture growth. The present study was designed to analyze the effects of HQ on water relations and photosynthesis of leafy spurge. Plants grown in 0.25 mM HQ had consistently higher leaf diffusive resistance and lower transpiration rates than control plants (P < 0.05). Chlorophyll fluorescence was significantly lower than controls (P < 0.05) towards the end of the treatment period. At the end of the treatment, tissue from 0.25 mM HQ plants had higher levels of 13C, indicating there had been a sustained interference with stomatal function. These data suggest that a disruption of the plant water balance is one mechanism of leafy spurge inhibition by A. microphylla.



Document Type




13 C isotopes, Allelopathy, Antennaria microphylla Rydb, Chlorophyll fluorescence, Euphorbia esula, Hydroquinone, Leafy spurge, Photosynthesis, Plant water balance, Small everlasting

Publication Date


Journal Title

Journal of Chemical Ecology