Indoleacetaldehyde in Cucumber Seedlings

The presence of indoleacetaldehyde in cucumber (Cucumis sativus L.) cotyledons was demonstrated by thin layer chromatographic $\text{R}_{\text{F}}$ values in three solvent systems, by the formation and hydrolysis of a bisulfite adduct, and by chemical reduction to indoleethanol and oxidation to indoleacetic acid. Bioassays indicated a minimum indoleacetaldehyde content in etiolated cotyledons of 0.7 μg per kg fresh weight. Tissue samples from all parts of both green and etiolated cucumber seedlings reduced exogenously supplied indoleacetaldehyde to indoleethanol.