超薄切片処理法による道管壁中のリグニン分布

Abstract

道管二次壁の層構成は3層構造, 1層構造および多層構造の三つのタイプがある。それぞれのタイプに属する樹種の道官壁中におけるリグニン分布をUV顕微鏡法および超薄切片にHF処理, NaClO_2処理, KMnO_4, 後染色を行ない電顕で観察する方法によって調べた。道管のリグニン濃度は木繊維や周囲仮道管のそれよりも高く, また柔細胞のそれと比較しでも一般にわずかに高いか同程度であった。三つのタイプの道管壁中におけるリグニン分布はほとんど同じであった。すなわち, 細胞間層でリグニン濃度が高く, 続いて一次壁, 二次壁とリグニン濃度は減少した。二次壁中ではリグニン濃度は均一であった。

Three types of the layered structure are present in vessel secondary walls; i. e. three, one and multilayered structures. In this paper the lignin distribution across vessel walls was studied in each species of these three types by using an ultraviolet microscope, and examing by electron microscope of the ultrathin section treated with hydrofluoric acid, sodium chlorite, and post-stained with potassium permanganate. The lignin concentration of vessels was higher than that of wood fibers, and was comparable or somewhat higher compared to that of parenchyma. The lignin distribution across vessel walls was much the same among three types. The lignin was highly concentrated in the intercellular layers and then decreased in the primary walls. The secondary walls showed low and uniform lignin distribution.