Fluorine-Tagged 5-Hydroxytryptophan to Investigate Amino Acid Metabolism In Vivo

Abstract EN

Auxin a plant growth hormone, has a metabolic pathway that includes molecules and enzymes like those in animal brains.

In this study, tomato plant seedlings (Lycopersicon esculenta) were used to investigate the fate of fluorine-tagged 5-hydroxytryptophan (PF-5-HTP) being developed for fluorine spectroscopy and imaging.

Seedlings were treated with high or low concentrations of 5-HTP or PF-5-HTP and compared with controls.

Metabolites of the PF-5-HTP were quantified using a custom immunoassay for the tag.

Serotonin (5-HT) levels were measured with spectrofluorometry and thin-layer chromatography.

Plants in treatment conditions had serotonin levels five to six times higher than controls.

PF-5-HTP served as a precursor for serotonin in a biosynthetic pathway in this plant model, providing evidence for the bioavailability of the novel molecule.

The increase in serotonin in plants grown in media culture supplemented with 5-HTP or PF-5-HTP might have useful applications in pharmacology.