Metabolism of14C-labeled epibrassinolide in intact seedlings of cucumber and wheat

The metabolism of exogenously applied14C-24-epibrassinolide (14C-EBR) in seedlings of cucumber and wheat was examined. Total lipids were extracted with isopropanol and chloroform, and then partitioned with water. More than 80% of radioactivity was distributed to chloroform-phase. Concentrated chloroform-phase was applied to silica gel plate and was developed with chloroform-ethanol (5:1 v/v). Rf value of original14C-EBR was about 0.6. In cucumber leaves harvested after 2 day-culture, three peaks were detected at Rf 0.11, 0.47 and 0.84. In cucumber petioles of 2 day-culture, however, a major peak was detected at Rf 0.90. But14C-EBR was hardly metabolized in hypocotyls and roots after 2 days.