The Formation of Phenolic Compounds in Plant Cell and Tissue Cultures and the Possibility of its Regulation

Abstract

This chapter discusses the formation of phenolic compounds in plant cell and tissue cultures, and the possibility of its regulation. The phenolic compounds or polyphenols are very important secondary compounds produced by higher plants. The number of known natural phenolic compounds exceeds 4000, being inferior only to the alkaloids and terpenoids. However, in contrast to the alkaloids and several other secondary compounds, some phenolics and isoprenoids are synthesized by each plant and perhaps by each plant cell. The role of the phenolic compounds is so far not clear with the exception of their participation in the formation of lignin, a very important plant polymer, and as defense agents during pathogen attack. However, their synthesis in chloroplasts, rapid turnover, and high in vivo and in vitro activities in various biological systems indicate their great importance in plant life. The chapter discusses the possibility of coordinated induction of enzymes operating in the phenylpropanoid and flavonoid stages of phenolic biosynthesis. Such induction is accompanied by the de novo formation of the corresponding enzyme proteins and mRNAs. An important role of light and its spectral composition in the production of phenolic compounds has also been established in cultured cells and tissues. Phytohormones and growth regulators or hormone-like effectors play an important role in the formation of phenolic compounds.