The developmental mechanisms regulating cell differentiation and patterning during the secondary growth of woody tissues are poorly understood. Class III HD ZIP transcription factors are evolutionarily ancient and play fundamental roles in various aspects of plant development. Here we investigate the role of a Class III HD ZIP transcription factor, POPCORONA, during secondary growth of woody st...

We previously gave a picture of the homeostatic characteristics of polyamine (PA) biosynthesis and conjugation in tobacco (Nicotiana tabacum) plant organs during development. In this work, we present the sites and regulation of PA catabolism related to cell division/expansion, cell cycle progression, and vascular development in the tobacco plant. Diamine oxidase (DAO), PA oxidase (PAO), peroxid...

Lignification is a cell wall fortifying process which occurs in xylem tissue in a scheduled manner during tissue differentiation. In this review, enzymes and the genes responsible for lignin biosynthesis have been studied with an emphasis on lignin polymerizing class III secretable plant peroxidases. Our aim is to understand the cell and molecular biology of the polymerization of lignin especia...

In an attempt to elucidate the regulatory mechanism of vessel lignification, we isolated ZPO-C, a novel peroxidase gene of Zinnia elegans that is expressed specifically in differentiating tracheary elements (TEs). The ZPO-C transcript was shown to accumulate transiently at the time of secondary wall thickening of TEs in xylogenic culture of Zinnia cells. In situ hybridization indicated specific...

Lignification is the process of forming the collective of phenylpropanoid macromolecules termed lignin. There are two ways to define lignin: 1) from a chemical point of view (i.e. its chemical composition and structure), and 2) from a functional view that stresses what lignin does within the plant. It has been recognized for 50 years now that lignin is a polymeric material composed of phenylpro...

Lignin quantity and composition are major components of wood quality in eucalypts breeding programs. Optimizing these traits can have a huge economical impact for charcoal and pulp production. However, little is known about the genetic determinism of these traits. Our objective is to establish efficient early selection criteria to identify ideotypes for these traits using gene based markers. To...