Silencing of hydroxycinnamoyl-coenzyme A shikimate/quinate hydroxycinnamoyltransferase affects phenylpropanoid biosynthesis

• Published in: The Plant cell 2004-06, Vol.16 (6), p.1446-1465
• Main Authors: Hoffmann, L, Besseau, S, Geoffroy, P, Ritzenthaler, C, Meyer, D, Lapierre, C, Pollet, B, Legrand, M
• Format: Article
• Language: English
• Subjects: acyltransferases; Acyltransferases - antagonists & inhibitors; Acyltransferases - genetics; Acyltransferases - immunology; Acyltransferases - metabolism; Antibodies; Arabidopsis - enzymology; Arabidopsis - genetics; Arabidopsis - growth & development; Arabidopsis - metabolism; Arabidopsis thaliana; Biosynthesis; Cell Wall - metabolism; Cell walls; Cellulase - metabolism; chemical constituents of plants; Chromatography, High Pressure Liquid; complementary DNA; enzyme activity; Enzymes; Esters; Gene Expression Regulation, Plant; gene silencing; Hematocrit; histochemistry; Immune Sera - immunology; Immune Sera - pharmacology; Immunohistochemistry; Isomerism; Lignification; Lignin; Lignin - analysis; Lignin - biosynthesis; Lignin - chemistry; Molecular Sequence Data; Nicotiana - enzymology; Nicotiana - genetics; Nicotiana - growth & development; Nicotiana - metabolism; Nicotiana benthamiana; Nicotiana tabacum; nucleotide sequences; Phenotypes; phenylpropanoids; Plant Roots - enzymology; Plant Stems - enzymology; Plant Stems - metabolism; Plant tissues; Plants; Quinic Acid - analogs & derivatives; Quinic Acid - metabolism; RNA Interference; RNA-mediated posttranscriptional gene silencing; roots; Solubility; stems; tobacco; virus induced gene silencing; Xylem
• ISSN: 1040-4651; 1532-298X; 1532-298X
• DOI: 10.1105/tpc.020297

The hydroxyl group in the 3-position of the phenylpropanoid compounds is introduced at the level of coumarate shikimate/quinate esters, whose synthesis implicates an acyltransferase activity. Specific antibodies raised against the recombinant tobacco (Nicotiana tabacum) acyltransferase revealed the accumulation of the enzyme in stem vascular tissues of tobacco, in accordance with a putative role in lignification. For functional analysis, the acyltransferase gene was silenced in Arabidopsis thaliana and N. benthamiana by RNA-mediated posttranscriptional gene silencing. In Arabidopsis, gene silencing resulted in a dwarf phenotype and changes in lignin composition as indicated by histochemical staining. An in-depth study of silenced N. benthamiana plants by immunological, histochemical, and chemical methods revealed the impact of acyltransferase silencing on soluble phenylpropanoids and lignin content and composition. In particular, a decrease in syringyl units and an increase in p-hydroxyphenyl units were recorded. Enzyme immunolocalization by confocal microscopy showed a correlation between enzyme accumulation levels and lignin composition in vascular cells. These results demonstrate the function of the acyltransferase in phenylpropanoid biosynthesis.