作者: M. G. Erwee , P. B. Goodwin
DOI: 10.1007/BF00395891
关键词: Cortex (botany) 、 Root cap 、 Botany 、 Epidermis (botany) 、 Egeria densa 、 Plasmodesma 、 Symplast 、 Biophysics 、 Biology 、 Apex (geometry) 、 Fluorescein
摘要: A set of hydrophilic fluorescent dyes known molecular weight has been used to determine the exclusion limit and extent apical, epidermal cortical symplasts in root, stem leaf Egeria densa. These are unable pass plasmalemma, so that any cell-to-cell movement injected dye must occur via symplast. The shoot-apex symplast a high limit, excluding with 749 dalton (fluorescein hexaglycine) greater but allowing up 665 diglutamic acid) pass. is similar apex: fluorescein pentaglycine (674 dalton) moves limited extent, hexaglycine immobile. Stem root cells have lower only 6-carboxyfluorescein (376 able move from cell-to-cell. Cortical tissues both permeabilities. However, barrier (6-carboxyfluorescein) found between epidermis cortex organs. Barriers also at nodes expanded internodes. barriers not unexpanded near shoot tip; apparently they formed early during internode expansion. In tip, cap remainder root. Plasmodesmata linking all cell types studied, even where occur. Thus, plant, far being one uniform symplast, consists large number domains, which may or differ limit.