Chapter 17
Atomic Force Microscopy to Study Cell Wall Mechanics
in Plants
Mateusz Majda
Abstract
Atomic force microscopy (AFM) is an indentation technique used to reconstruct the topography of various
materials and organisms. AFM can also measure the mechanical properties of the sample. In plants, AFM is
applied to image cell wall structural details and measure the elastic properties in the outer cell walls. Here, I
describe the use of high-resolution AFM to measure the elasticity of resin-embedded ultrathin sections of
leaf epidermal cell walls. This approach allows to access the fine details within the wall matrix and eliminate
the influence of the topography or the turgor on mechanical measurements. In this chapter, the sample
preparation, AFM image acquisition, and processing of force curves are described. Altogether, these
methods allow to measure the wall stiffness and compare different cell wall regions.
Key words Atomic force microscopy, AFM, Indentation, Elastic modulus, Elasticity, Cell walls,
Anticlinal walls, Epidermis, Pavement cells
1 Introduction
Plant cells are surrounded by rigid cell walls, which provide protection and support for cells and tissues. In growing and turgid cells,
the cell wall consists of cellulose microfibrils (CMFs) embedded in a
matrix of polysaccharides and structural proteins [1]. CMFs are the
stiffest and largest wall composites, which display load-bearing
properties. Individual CMFs are arranged in highly oriented arrays,
which define the growth anisotropy and determine the growth
directions [2]. The matrix of polysaccharides consists of much
softer hemicelluloses (xyloglucans, xylans, and mannans) and pectins [3]. Walls are extremely elastic to withstand high levels of stress
induced by turgor pressure. They are also very plastic and dynamic,
adjusting their properties to facilitate rapid cellular growth. All the
wall components are spatially arranged and connected. CMFs form
biochemical hotspots by crosslinking to each other or by interacting
with matrix polysaccharides such as xyloglucans or pectins [4–
6]. Due to the activity of wall modifiers, such as expansins, the
Jose J. Sanchez-Serrano and Julio Salinas (eds.), Arabidopsis Protocols, Methods in Molecular Biology, vol. 2200,
https://doi.org/10.1007/978-1-0716-0880-7_17, © Springer Science+Business Media, LLC, part of Springer Nature 2021
349
Atomic Force Microscopy to Study Cell Wall Mechanics
in Plants
Mateusz Majda
Abstract
Atomic force microscopy (AFM) is an indentation technique used to reconstruct the topography of various
materials and organisms. AFM can also measure the mechanical properties of the sample. In plants, AFM is
applied to image cell wall structural details and measure the elastic properties in the outer cell walls. Here, I
describe the use of high-resolution AFM to measure the elasticity of resin-embedded ultrathin sections of
leaf epidermal cell walls. This approach allows to access the fine details within the wall matrix and eliminate
the influence of the topography or the turgor on mechanical measurements. In this chapter, the sample
preparation, AFM image acquisition, and processing of force curves are described. Altogether, these
methods allow to measure the wall stiffness and compare different cell wall regions.
Key words Atomic force microscopy, AFM, Indentation, Elastic modulus, Elasticity, Cell walls,
Anticlinal walls, Epidermis, Pavement cells
1 Introduction
Plant cells are surrounded by rigid cell walls, which provide protection and support for cells and tissues. In growing and turgid cells,
the cell wall consists of cellulose microfibrils (CMFs) embedded in a
matrix of polysaccharides and structural proteins [1]. CMFs are the
stiffest and largest wall composites, which display load-bearing
properties. Individual CMFs are arranged in highly oriented arrays,
which define the growth anisotropy and determine the growth
directions [2]. The matrix of polysaccharides consists of much
softer hemicelluloses (xyloglucans, xylans, and mannans) and pectins [3]. Walls are extremely elastic to withstand high levels of stress
induced by turgor pressure. They are also very plastic and dynamic,
adjusting their properties to facilitate rapid cellular growth. All the
wall components are spatially arranged and connected. CMFs form
biochemical hotspots by crosslinking to each other or by interacting
with matrix polysaccharides such as xyloglucans or pectins [4–
6]. Due to the activity of wall modifiers, such as expansins, the
Jose J. Sanchez-Serrano and Julio Salinas (eds.), Arabidopsis Protocols, Methods in Molecular Biology, vol. 2200,
https://doi.org/10.1007/978-1-0716-0880-7_17, © Springer Science+Business Media, LLC, part of Springer Nature 2021
349