Changes in the chemical composition of a cambial cell during its differentiation into xylem and phloem tissue in trees. 1. Main components

Abstract

A quantitative determination has been made of the changes that occurred in the composition of a cambial cell during its differentiation and subsequent maturation in four species of tree, Acer pseudoplatanus, Betula platyphylla, Fraxinus elatior and Pinus ponderosa. The weight of [alpha]-cellulose, hemicellulose, lignin and pectic substances in the cell wall of a single cell in the cambium, sapwood and heartwood of each tree has been determined. Comparison of the composition of these regions showed that secondary thickening of the cambial cell involved the deposition of [alpha] -cellulose, hemicellulose and lignin. This thickening resulted more from [alpha] -cellulose than hemicellulose, the cambial cell having equal amounts of each. The amount of pectic substances per cell remained constant during the formation of the sapwood cell, but in the heartwood cell, there was an almost complete absence of this fraction. The composition of the cambial cell in each species was very similar,.