ABSTRACT
Figure 1. Wood structure classically observed in poplar (Populustremula x Populusalba, accession 717-1B4). A. Cross section of poplar stem with a schematic localization of the four main developmental stages of xylem formation. B. Higher magnifi cation of the cambial zone with the different types of cells. C. Schematic view of the auxin and gibberellin repartitions and of the cytokinin responsive genes in the cambial zone.
