DIFFERENTIAL ALLELOCHEMICAL DETOXIFICATION MECHANISM IN TISSUE-CULTURES OF ANTENNARIA-MICROPHYLLA AND EUPHORBIA-ESULA

Callus and suspension cultures of Antennaria microphylla (small everlasting) and the noxious weed Euphorbia esula (leafy spurge) can glucosylate benzene-1,4-diol (hydroquinone) to the corresponding monoglucoside, arbutin, HPLC analysis of extracts from callus tissue corroborates the presence of hydroquinone in the cells of small everlasting. Constitutive levels of a UDPG-dependent glucosyltransferase were detected in cell-free extracts of this tissue. Although this detoxification enzyme was induced in leafy spurge suspension culture cells grown in the presence of hydroquinone, the activity was six-fold lower than that measured in small everlasting. Differential ability to detoxify hydroquinone provides a basis for the observed allelopathic interaction between small everlasting and leafy spurge.