Transcriptional repression of light‐induced flavonoid synthesis by elicitor treatment of cultured parsley cells

Abstract

Cultured parsley Petroselinum crispum cells respond differentially to UV‐containing white light and fungal elicitor. Both stimuli activate the transcription of genes encoding enzymes of partly overlapping phenylpropanoid biosynthetic pathways. Irradiation induces vacuolar accumulation of flavonoids, whereas elicitor treatment stimulates the secretion of furanocoumarins. Simultaneous treatment of parsley cells with UV light and elicitor results in quantitative changes in both responses. Irradiation reduces elicitor‐induced furanocoumarin synthesis, possibly by post‐transcriptional mechanisms, whereas elicitor treatment completely blocks the light‐induced accumulation of flavonoids by repressing the transcription of the chalcone synthase gene. We have identified elicitor‐sensitive regions in the chalcone synthase promoter by transient expression analysis of selected promoter constructs linked to the β‐D‐glucuronidase reporter gene in parsley protoplasts. These regions are identical to those that were found to be sufficient for light inducibility of the chalcone synthase promoter. Copyright © 1991, Wiley Blackwell. All rights reserved