A YEAST BASED SCREENING METHOD FOR ARABIDOPSIS ZEARALENONE-METABOLISM MUTANTS

Arabidopsis thalianaand other plants are able to rapidly metabolize the estrogenicFusariummetabolite zearalenone (ZON) into ZON-glucoside and further unknown compounds. We present here a rapid and efficient method to screen forArabidopsismutants unable to metabolize ZON.Arabidopsisseedling are grown in 96 well microtiter plates and subsequently incubated with ZON and β-glucosidase. The remaining ZON in the supernatant is detected with an engineered estrogen-responsive yeast strain. Extracellular ZON-4-O-glucoside (ZON-Glc), which is not detected by the indicator strain, is converted back to ZON by the added almond β-glucosidase. WildtypeArabidopsisseedlings inactivate 2 ppm ZON in three days, which is easily detected by the colorimetric readout. The assay should be useful to identify mutants affected in ZON metabolism.