By means of gas-liquid chromatography the contents of free amino acids of the duckweed Spirodela polyrhiza have been determined after growth inhibition by L-valine, L-isoleucine and L-leucine. The most remarkable changes were when growth was inhibited with (1) valine; accumulation of a-aminobutyric acid, decrease in the isoleucine content and increase in that of leucine, (2) isoleucine: decrease in the leucine content and increase in that of valine, (3) leucine: decrease in both the valine content and isoleucine content. It is concluded that valine inhibits isoleucine synthesis by blocking acetohydroxy acid synthetase, isoleucine inhibits leucine synthesis, and leucine inhibits a common enzymatic step of the valine-isoleucine pathway.

Acta botanica neerlandica

CC BY 3.0 NL ("Naamsvermelding")

Koninklijke Nederlandse Botanische Vereniging

A.C. Borstlap. (1972). Changes in the free amino acids of Spirodela polyrhiza (L.) Schleiden during growth inhibition by L-valine, L-isoleucine, or L-leucine. A gas chromatographic study. Acta botanica neerlandica, 21(4), 404–416.