High porosity with tiny pore constrictions and unbending pathways characterize the 3D structure of intervessel pit membranes in angiosperm xylem

Autor: Lucian Kaack, Paul Walther, Steven Jansen, Tabea Matei, Cora Carmesin, H. Jochen Schenk, Matthias Weber, Volker Schmidt, Ya Zhang, Matthias M. Klepsch, Martyna M. Kotowska
Rok vydání: 2019
Předmět:
0106 biological sciences
0301 basic medicine
Physiology
Cinnamomum camphora
Embolism
Plant Science
Cellulose fibrils
Gold Colloid
01 natural sciences
Tortuosity
Bordered pit membranes
Diffusion
Atomic force microscopy
Fagus
bordered pit membranes
cellulose fibrils
dehydration
modelling
pore constriction size
porous media
Porous materials
Dehydration
Wirkungsgrad
Constriction
Membrane
ddc:580
Populus
Transmission electron microscopy
Volume fraction
Gefäß
Porosity
Pore constriction size
Materials science
EFFICIENCY
Liriodendron
Porous media
Soil permeability
Acer
Modelling
03 medical and health sciences
TORTUOSITY
Magnoliopsida
Corylus
Microscopy
Electron
Transmission
Xylem
SNAP-OFF
CAVITATION RESISTANCE
Gef����
Water transport
Persea
HYDRAULIC CONDUCTIVITY
Water
Biological Transport
030104 developmental biology
Chemical engineering
VESSEL
DDC 580 / Botanical sciences
Porous medium
Mesoporous material
010606 plant biology & botany
Zdroj: Plant, cellenvironmentREFERENCES. 43(1)
ISSN: 1365-3040
Popis: Pit membranes between xylem vessels play a major role in angiosperm water transport. Yet, their three-dimensional (3D) structure as fibrous porous media remains unknown, largely due to technical challenges and sample preparation artefacts. Here, we applied a modelling approach based on thickness measurements of fresh and fully shrunken pit membranes of seven species. Pore constrictions were also investigated visually by perfusing fresh material with colloidal gold particles of known sizes. Based on a shrinkage model, fresh pit membranes showed tiny pore constrictions of ca. 20 nm, but a very high porosity (i.e. pore volume fraction) of on average 0.81. Perfusion experiments showed similar pore constrictions in fresh samples, well below 50 nm based on transmission electron microscopy. Drying caused a 50% shrinkage of pit membranes, resulting in much smaller pore constrictions. These findings suggest that pit membranes represent a mesoporous medium, with the pore space characterized by multiple constrictions. Constrictions are much smaller than previously assumed, but the pore volume is large and highly interconnected. Pores do not form highly tortuous, bent, or zigzagging pathways. These insights provide a novel view on pit membranes, which is essential to develop a mechanistic, 3D understanding of air-seeding through this porous medium.
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Databáze: OpenAIRE
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