A close-up view of the wood cell wall ultrastructure and its mechanics at different cutting angles by atomic force microscopy

Planta ◽  
2018 ◽  
Vol 247 (5) ◽  
pp. 1123-1132 ◽  
Author(s):  
Kirstin Casdorff ◽  
Tobias Keplinger ◽  
Markus Rüggeberg ◽  
Ingo Burgert
Botany ◽  
2008 ◽  
Vol 86 (4) ◽  
pp. 385-397 ◽  
Author(s):  
Haley D.M. Wyatt ◽  
Neil W. Ashton ◽  
Tanya E.S. Dahms

The moss Physcomitrella patens (Hedw.) Bruch & Schimp. in B.S.G. serves as a nonvascular plant model system suitable for studying many plant developmental phenomena. The tip-growing filamentous protonemal stage of its life cycle exhibits polarized growth and various tropic responses. Conventional staining and light microscopy (LM) were used to provide the first direct evidence that protonemal cells of P. patens lack a cuticle. Atomic force microscopy (ATM) images reveal detailed surface structures identified by scanning electron microscopy (SEM). The cell wall ultrastructure is characterized by rounded protrusions that are uniformly distributed along each caulonemal filament, and longer fibrillar structures, which are disorganized at the apex, but become oriented in longitudinal arrays parallel to the growth axis in more proximal regions of caulonemal apical cells. The subapical cells are characterized by a polylamellated texture. There was no difference in gross surface ultrastructure between light-grown and dark-grown filaments, but the dimensions of the rounded protrusions at the apices of caulonemata cultured in the light and in darkness were significantly different. The convex and concave cell wall surfaces of a curved, gravitropically responding dark-grown caulonema appear structurally different. This investigation is the first to use AFM to probe the cell wall ultrastructure of a bryophyte. The data further elaborate a simple model of cell wall development in the caulonemata of P. patens that was proposed for other tip-growing filamentous plants.


2018 ◽  
pp. 335-347 ◽  
Author(s):  
Thomas Torode ◽  
Marina Linardic ◽  
J. Louis Kaplan ◽  
Siobhan A. Braybrook

IAWA Journal ◽  
2019 ◽  
Vol 40 (4) ◽  
pp. 645-672
Author(s):  
Lloyd A. Donaldson

ABSTRACTIn the last 100 years, major advances have been made in understanding wood cell wall ultrastructure in tracheids, fibres, vessels and parenchyma and its relationship with xylem function and wood properties. This review will focus on how the development of imaging techniques and their application to wood cell walls has led to an understanding of cell wall organisation and the relationship between micro and macro scale properties in wood and wood-based materials. Topics such as wood formation, wood chemistry and reaction wood have recently been reviewed elsewhere and are considered only briefly in this review. Two features of wood cell walls have dominated the literature; orientation and layering of cellulose which determines the longitudinal stiffness of wood, and the distribution (topochemistry) of lignin which determines compression strength and pulping properties.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
A. Amir Hassan ◽  
Miguel V. Vitorino ◽  
Tiago Robalo ◽  
Mário S. Rodrigues ◽  
Isabel Sá-Correia

Abstract The influence that Burkholderia cenocepacia adaptive evolution during long-term infection in cystic fibrosis (CF) patients has on cell wall morphology and mechanical properties is poorly understood despite their crucial role in cell physiology, persistent infection and pathogenesis. Cell wall morphology and physical properties of three B. cenocepacia isolates collected from a CF patient over a period of 3.5 years were compared using atomic force microscopy (AFM). These serial clonal variants include the first isolate retrieved from the patient and two late isolates obtained after three years of infection and before the patient’s death with cepacia syndrome. A consistent and progressive decrease of cell height and a cell shape evolution during infection, from the typical rods to morphology closer to cocci, were observed. The images of cells grown in biofilms showed an identical cell size reduction pattern. Additionally, the apparent elasticity modulus significantly decreases from the early isolate to the last clonal variant retrieved from the patient but the intermediary highly antibiotic resistant clonal isolate showed the highest elasticity values. Concerning the adhesion of bacteria surface to the AFM tip, the first isolate was found to adhere better than the late isolates whose lipopolysaccharide (LPS) structure loss the O-antigen (OAg) during CF infection. The OAg is known to influence Gram-negative bacteria adhesion and be an important factor in B. cenocepacia adaptation to chronic infection. Results reinforce the concept of the occurrence of phenotypic heterogeneity and adaptive evolution, also at the level of cell size, form, envelope topography and physical properties during long-term infection.


Yeast ◽  
2010 ◽  
Vol 27 (8) ◽  
pp. 673-684 ◽  
Author(s):  
Etienne Dague ◽  
Rajaa Bitar ◽  
Hubert Ranchon ◽  
Fabien Durand ◽  
Hélène Martin Yken ◽  
...  

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