Intercellular communications in Chaetopteris plumosa (Sphacelariales, Phaeophyceae)

This article provides information about the ultrastructure of intercellular communications in Chaetopteris plumosa. The structure and variants of plasmodesmata localization in its cells are described, data on the distances between plasmodesmata and the density of their location in cell walls are provided. In C. plumosa, both independent plasmodesmata and cell wall areas with multiple closely spaced plasmodesmata were found. Such localization of intercellular connections may represent a transitional variant between independent plasmodesmata and pit fields or another variant of plasmodesmata organization previously not described in brown algae. The arrangement of plasmodesmata in Sphacelariaceae is discussed. The plasmodesmata in C. plumosa have a structure typical of brown algae. In the longitudinal walls of the medulla, there are independent plasmodesmata, the distance between which on sections is (268 ± 147) nm (mean ± SD, n = 255). In the longitudinal and transverse walls of corticating rhizoids, plasmodesmata are often located much more densely and evenly, the distance between them is (90 ± 29) nm (n = 2863), and there are 39 ± 4 (n = 54) plasmodesmata per 1 μm2. It is advisable to classify this variant of localization of plasmodesmata as pit fields or transitional variant between independent plasmodesmata and pit fields.