Une synthèse sur le fonctionnement et la régulation des processus cellulaires de la formation du bois

Wood accounts for a major portion of land biomass and is an essential resource for man. The cells that make up wood are produced by the vascular cambium, a secondary meristem situated between the wood and bark. It is during the first fundamental process of xylogenesis — cell division — that the cambial cells produce what later become the xylem cells. They then got through a differentiation programme involving a succession of four phases before reaching their mature functional state: cell enlargement, secondary cell wall deposition, cell wall thickening and programmed cell death (apoptosis). These processes of xylogenesis determine the size and structure of the rings that are formed and hence the quantity and quality of the wood produced. At a time when efforts are being made to better understand the impact of climate change on wood formation and on optimising wood supply, thorough knowledge of the five cell processes involved in wood formation seems essential. This article offers an overview of this sequence.