Lignification in poplar plantlets fed with deuterium-labelled lignin precursors

Abstract

Lignification was investigated in wild-type (WT) and in transgenic poplar plantlets with a reduced caffeic acid O-methyltansferase (COMT) activity. Coniferin and syringin, deuterated at their methoxyl, were incorporated into the culture medium of microcuttings. The gas chromatography–mass spectrometry (GC-MS) analysis of the thioacidolysis guaiacyl (G) and syringyl (S) lignin-derived monomers revealed that COMT deficiency altered stem lignification. GC-MS analysis proved that the deuterated precursors were incorporated into root lignins and, to a lower extent, in stem lignins without major effect on growth and lignification. Deuterium from coniferin was recovered in G and S lignin units, whereas deuterium from syringin was only found in S units, which further establishes that the conversion of G to S lignin precursors may occur at the level of p-OH cinnamyl alcohols. To cite this article: C. Rolando et al., C. R. Biologies 327 (2004).