Fineran B A, Gilbertson J M
Eur J Cell Biol. 1980 Dec;23(1):66-72.
Lanthanum nitrate and uranyl acetate were used as opaque tracers in electron microscopy to demonstrate an apoplastic pathway within external and internal glands in the trap of the bladderwort Utricularia monanthos. Deposits of the tracers occurred in the cell walls but not in the protoplasts of intact cells. Cytochemical staining for polysaccharides showed that the tracers were confined to the non-impregnated regions of the wall. Only in the arms of quadrifids and bifids and the terminal cell of external glands an apoplastic pathway, extending from the external medium through the walls of the terminal cells and into the wall ingrowths of the pedestal cell, was demonstrated by the penetration of the tracers. The lateral cell wall of the pedestal cell is impermeable to the movement of tracers where it is completely impregnated. The routes that these apoplastic pathways might provide for water transport during the resetting of the trap are discussed.
硝酸镧和醋酸双氧铀在电子显微镜下用作不透明示踪剂，以证明狸藻属单花狸藻捕虫囊的外部和内部腺体中存在质外体途径。示踪剂沉积在细胞壁中，而完整细胞的原生质体中没有。多糖的细胞化学染色表明，示踪剂局限于壁的未浸渍区域。仅在四裂和二裂的臂以及外部腺体的末端细胞中，示踪剂的渗透证明了质外体途径，该途径从外部介质穿过末端细胞的壁并进入基座细胞的壁内突。基座细胞的外侧细胞壁在完全浸渍的地方对示踪剂的移动是不可渗透的。讨论了这些质外体途径在捕虫囊重置过程中可能为水分运输提供的途径。
