High resolution scanning electron microscopy of plasmodesmata

• Published in: Planta Vol. 234; no. 4; pp. 749 - 758
• Main Authors: Brecknock, Sarah, Dibbayawan, Teresa P., Vesk, Maret, Vesk, Peter A., Faulkner, Christine, Barton, Deborah A., Overall, Robyn L.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer 01.10.2011; Springer-Verlag; Springer Nature B.V
• Subjects: Agriculture; Australia; Biological and medical sciences; Biomedical and Life Sciences; Cell membranes; Cell Wall - chemistry; Cell Wall - ultrastructure; Cell walls; Cellulose; Chara - ultrastructure; Ecology; Epidermal cells; Ferns - ultrastructure; Forestry; Fundamental and applied biological sciences. Psychology; Imaging, Three-Dimensional - methods; Life Sciences; Meristem - ultrastructure; Microscopy, Electron, Scanning - methods; Microscopy, Electron, Transmission - methods; Onions - ultrastructure; Original Article; Pectins; Plant cells; Plant Sciences; Plants; Plasmodesmata; Plasmodesmata - ultrastructure; Root tips; Scanning electron microscopy; Sinuses; Sleeves; Plasmodesmata; High-resolution scanning electron microscopy; Cell-to-cell communication; Scanning electron microscopy; High resolution; High-resolution scanning electron microcopy; Algae; Charophyta; Plasmodesm; Plant biology; Chara; Intercellular communication
• ISSN: 0032-0935; 1432-2048
• DOI: 10.1007/s00425-011-1440-x

Symplastic transport occurs between neighbouring plant cells through functionally and structurally dynamic channels called plasmodesmata (PD). Relatively little is known about the composition of PD or the mechanisms that facilitate molecular transport into neighbouring cells. While transmission electron microscopy (TEM) provides 2-dimensional information about the structural components of PD, 3-dimensional information is difficult to extract from ultrathin sections. This study has exploited high-resolution scanning electron microscopy (HRSEM) to reveal the 3-dimensional morphology of PD in the cell walls of algae, ferns and higher plants. Varied patterns of PD were observed in the walls, ranging from uniformly distributed individual PD to discrete clusters. Occasionally the thick walls of the giant alga Chara were fractured, revealing the surface morphology of PD within. External structures such as spokes, spirals and mesh were observed surrounding the PD. Enzymatic digestions of cell wall components indicate that cellulose or pectin either compose or stabilise the extracellular spokes. Occasionally, the PD were fractured open and desmotubule-like structures and other particles were observed in their central regions. Our observations add weight to the argument that Chara PD contain desmotubules and are morphologically similar to higher plant PD.