Regulation of induction of phenylalanine ammonia lyase and its role in production of phenolic compounds in plants

Abstract

Phenylalanine ammonia lyase or PAL is known to be the first committed enzyme of phenylpropanoid pathway which produces trans-cinnamic acid, the precursor of polyphenol biosynthesis. Some facts related to the physiology, enzymology and biochemistry of Phenylalanine ammonia lyase (PAL) from different organisms has been reviewed. Emphasis is given on the biological aspects of regulation of the induction of PAL by various stimuli and its role in producing polyphenolic compounds in plants. Levels of the enzyme are mainly affected by light, wounding, infection, ethylene level, concentration of plant growth regulators and metals. The possibility that PAL is involved in the control of polyphenol production has also been examined.