Distribution of Esterified Phenolic Acids in Cell Walls of Immature Bamboo

Abstract

モウソウチク (Phyllostachys pubescence Mazel) の幼竹 (高さ6m) を用いて竹の成長に伴うエステル結合したフェルラ酸及びp-クマール酸の分布を紫外線・蛍光顕微鏡法により調べた。エステル結合した両フェノール酸は幼竹の組織中に広く分布しており, 両者の分布には明確な相違が認められた。後生道管細胞壁中には成長の初期にエステル結合したフェルラ酸が存在するが, 木化が進行するにしたがいp-クマール酸が堆積した。また, 繊維細胞壁中にはエステル結合したフェルラ酸が多く含まれており, 維管束鞘の内部から外側に向かって堆積した。柔細胞壁中のフェルラ酸のエステルは上記の組織に比較して少なく, その堆積が遅いことがわかった。

Variation of distribution of esterified ferulic acid and p-coumaric acid during growth of mosobamboo (Phyllostachys pubescence Mazel) was investigated by ultraviolet and fluorescence microscopic techniques. The results indicate that the esterified phenolic acids was widely distributed in the tissue of immature bamboo having 6 m in height, but some distinctive differences in distribution of both acids were detected. Metaxylem vessel cell walls contained feruloyl groups at young stage of growth, and accummulated p-coumaric acid with progress of lignification. Fiber cell walls were rich in esterified ferulic acid and their accummulation progressed from inner to outer layers of vascular bundle. Degree of esterification of parenchyma cell walls was lower than these two cells, and the esterification progressed slowly with growth.