Phenylalanine ammonia-lyase environmental regulation

The general phenylpropanoid pathway begins with the deamination of L-phenylalanine to cinnamic acid catalyzed by phenylalanine ammonia lyase (PAL), Fig. (1), the branch-point enzyme between primary (shikimate pathway) and secondary (phenylpropanoid) metabolism [5-7]. Due to the position of PAL at the entry point of phenylpropanoid metabolism, this enzyme has the potential to play a regulatory role in phenolic-compound production. The importance of this is illustrated by the high degree of regulation both during development as well as in response to environmental stimuli. 

Liang, X., Dron, M., Cramer, C.L., Dixon, R.A. Lamb, C.J. (19896). Differential regulation of phenylalanine ammonia-lyase genes during plant development and by environmental cues. Journal of Biological Chemistry 264, 14486-92. 

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