Involvement of the Octadecanoid Pathway and Protein Phosphorylation in Fungal Elicitor-Induced Expression of Terpenoid Indole Alkaloid Biosynthetic Genes in Catharanthus roseus

• Published in: Plant physiology (Bethesda) Vol. 119; no. 4; pp. 1289 - 1296
• Main Authors: Frank L. H. Menke, Stefanie Parchmann, Mueller, Martin J., Kijne, Jan W., Memelink, Johan
• Format: Journal Article
• Language: English
• Published: Rockville, MD American Society of Plant Physiologists 01.04.1999
• Subjects: Biological and medical sciences; Biosynthesis; Catharanthus roseus; Cell Biology and Signal Transduction; Cell lines; Fundamental and applied biological sciences. Psychology; Fungal plant pathogens; Genes; Messenger RNA; Pathology, epidemiology, host-fungus relationships. Damages, economic importance; Phosphorylation; Phytopathology. Animal pests. Plant and forest protection; Plant cells; Plant physiology and development; Plants; Protease inhibitors; RNA; Signal transduction; Tissue cultures, protoplasts; Terpenoid; Cell culture; Enzyme; Lyases; Biosynthesis; Catharanthus roseus; Gene expression; Carbon-nitrogen lyases; Medicinal plant; Apocynaceae; Signal transduction; Carbon-carbon lyases; Alkaloid; Amine-lyases; Carboxy-lyases; Dicotyledones; Angiospermae; Aromatic-L-amino-acid decarboxylase; Spermatophyta; Elicitation; Models; Indole derivatives; Strictosidine synthase
• ISSN: 0032-0889; 1532-2548
• DOI: 10.1104/pp.119.4.1289

Two key genes in terpenoid indole alkaloid biosynthesis, Tdc and Str, encoding tryptophan decarboxylase and strictosidine synthase, respectively, are coordinately induced by fungal elicitors in suspension-cultured Catharanthus roseus cells. We have studied the roles of the jasmonate biosynthetic pathway and of protein phosphorylation in signal transduction initiated by a partially purified elicitor from yeast extract. In addition to activating Tdc and Str gene expression, the elicitor also induced the biosynthesis of jasmonic acid. The jasmonate precursor α-linolenic acid or methyl jasmonate (MeJA) itself induced Tdc and Str gene expression when added exogenously. Diethyldithiocarbamic acid, an inhibitor of jasmonate biosynthesis, blocked both the elicitor-induced formation of jasmonic acid and the activation of terpenoid indole alkaloid biosynthetic genes. The protein kinase inhibitor K-252a abolished both elicitor-induced jasmonate biosynthesis and MeJA-induced Tdc and Str gene expression. Analysis of the expression of Str promoter/gusA fusions in transgenic C. roseus cells showed that the elicitor and MeJA act at the transcriptional level. These results demonstrate that the jasmonate biosynthetic pathway is an integral part of the elicitor-triggered signal transduction pathway that results in the coordinate expression of the Tdc and Str genes and that protein kinases act both upstream and downstream of jasmonates.