The disease-resistance response of plant cells is composed of a multitude of biochemical events, and the activation of one of these, the phenylpropanoid metabolism, is pivotal for the survival of cells under stress conditions. The basic features of this facet of the disease-resistance response are beginning to be unraveled in model plant cell culture systems. These studies revealed a novel, alternative pathway for the synthesis of cell wall bound hydroxycinnamoyl esters and lignin. The investigations have, therefore, set the stage for a detailed analysis of the induction process that includes fast, posttranslational activation mechanisms as well as de novo enzyme synthesis. The biosynthesis of phenolic compounds destined for the cell wall is considered to reach far beyond the mere physical strengthening of the cells and includes additional functions, e.g., the release of antimycotic hydroxybenzaldehydes, which are vital for stress compensation. Key words: elicitor-induced phenylpropanoids, cell wall reinforcement, hydroxycinnamoyl esters, lignin, caffeoyl-CoA-specific 3-O-methyltransferase, disease resistance response, parsley (Petroselinum crispum) cell cultures.
Plant cell wall-mediated immunity: cell wall changes trigger disease resistance responses
