Discovery of a novel phenylalanine degradation pathway in plants

Plants are anticipated to be a more sustainable platform for chemical production than fossil-fuel-based chemical production, as plants can produce various natural products using CO2 as a solo carbon source.

In plants, phenylalanine (Phe) is an aromatic amino acid that acts as precursors of numerous Phe-derived specialized metabolites, many of which are utilized for nutritional, pharmaceutical, and biomaterial uses in our society.

Whereas plants produce a large amount of Phe to produce such abundant Phe derivatives, Phe itself is so toxic and must be somehow safely detoxified to balance its biosynthesis and degradation.

Despite a growing body of knowledge on Phe biosynthesis, however, little is known about Phe degradation, because a plant Phe degradation pathway has not been discovered, unlike the well-characterized Phe degradation in animals.

This knowledge gap has been a long-term mystery in the plant metabolism research field for decades, making plant-based chemical production for Phe-derived natural products difficult on a commercial scale.

The applicant has studied the biosynthesis of Phe in plants and found a piece of evidence for a putative Phe degradation pathway in Arabidopsis.

Combining biochemistry and plant genetics with start-of-art metabolomics, this proposal will aim to identify enzymes mediating a novel Phe degradation pathway and elucidate the roles of Phe degradation in plant metabolism.

These potential findings will uncover the unique plant Phe degradation that has never been described in animals and accelerate the development of plant-based chemical production for Phe-derived high-value chemicals.