Nano-indentation reveals a potential role for gradients of cell wall stiffness in directional movement of the resurrection plant Selaginella lepidophylla

AbstractThe FtsZ protein is a central component of the bacterial cell division machinery. It polymerizes at mid-cell and recruits more than 30 proteins to assemble into a macromolecular complex to direct cell wall constriction. FtsZ polymers exhibit treadmilling dynamics, driving the processive movement of enzymes that synthesize septal peptidoglycan (sPG). Here, we combine theoretical modelling with single-molecule imaging of live bacterial cells to show that FtsZ’s treadmilling drives the directional movement of sPG enzymes via a Brownian ratchet mechanism. The processivity of the directional movement depends on the binding potential between FtsZ and the sPG enzyme, and on a balance between the enzyme’s diffusion and FtsZ’s treadmilling speed. We propose that this interplay may provide a mechanism to control the spatiotemporal distribution of active sPG enzymes, explaining the distinct roles of FtsZ treadmilling in modulating cell wall constriction rate observed in different bacteria.

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Cell Wall Characteristics and Structure of Hydrated and Dry leaves of the Resurrection Plant Craterostigma wilmsii, a Microscopical Study

Journal of Plant Physiology ◽

10.1016/s0176-1617(99)80088-1 ◽

1999 ◽

Vol 155 (6) ◽

pp. 719-726 ◽

Cited By ~ 52

Author(s):

M. Vicré ◽

H.W. Sherwin ◽

A. Driouich ◽

M.A. Jaffer ◽

J.M. Farrant

Keyword(s):

Cell Wall ◽

Microscopical Study ◽

Resurrection Plant

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Molecular cloning and differential expression of sHSP gene family members from the resurrection plant Boea hygrometrica in response to abiotic stresses

Biologia ◽

10.2478/s11756-013-0204-4 ◽

2013 ◽

Vol 68 (4) ◽

Cited By ~ 7

Author(s):

Zhennan Zhang ◽

Bo Wang ◽

Dongmei Sun ◽

Xin Deng

Keyword(s):

Molecular Chaperones ◽

Abiotic Stresses ◽

Potential Role ◽

Resurrection Plant ◽

High Calcium ◽

Shsp Gene ◽

Alkaline Conditions ◽

Boea Hygrometrica ◽

Shock Proteins

AbstractSmall heat shock proteins (sHSPs) are a class of molecular chaperones that bind to and prevent aggregation of proteins. To assess the potential role of sHSPs in protection against abiotic stresses, we conducted a screening of sHSP genes from the desiccation-tolerant resurrection plant Boea hygrometrica, which is widespread in East Asia in alkaline, calcium-rich limestone crevices. In total, 25 sHSP genes, belonging to six subgroups, were identified from the desiccated leaves of B. hygrometrica. Ten of these genes were cloned and named according to the nomenclature proposed for sHSPs. Transcripts of all these BhsHSPs were detectable in fresh leaves, but only 6 genes were induced after desiccation, and remained high during rehydration. Four of the cytosol-targeted BhsHSP genes were up-regulated under treatments, such as heat, cold, alkaline conditions, high calcium, oxidation, or application of the phytohormone abscisic acid. Together, these results demonstrate that CI and CII sHSPs, especially Bh17.9CI and Bh17.4BCII, are associated with abiotic stresses, and may function in the maintenance of protein stability, aiding in the adaptations to extreme environmental conditions in which B. hygrometrica can survive.

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Touch-induced seedling morphological changes are determined by ethylene-regulated pectin degradation

Science Advances ◽

10.1126/sciadv.abc9294 ◽

2020 ◽

Vol 6 (48) ◽

pp. eabc9294

Author(s):

Qingqing Wu ◽

Yue Li ◽

Mohan Lyu ◽

Yiwen Luo ◽

Hui Shi ◽

...

Keyword(s):

Cell Wall ◽

Morphological Changes ◽

Mechanical Forces ◽

Ethylene Signaling ◽

Pectin Degradation ◽

Force Microscopy ◽

Mechanical Responses ◽

Atomic Force ◽

Wall Stiffness ◽

Molecular Framework

How mechanical forces regulate plant growth is a fascinating and long-standing question. After germination underground, buried seedlings have to dynamically adjust their growth to respond to mechanical stimulation from soil barriers. Here, we designed a lid touch assay and used atomic force microscopy to investigate the mechanical responses of seedlings during soil emergence. Touching seedlings induced increases in cell wall stiffness and decreases in cell elongation, which were correlated with pectin degradation. We revealed that PGX3, which encodes a polygalacturonase, mediates touch-imposed alterations in the pectin matrix and the mechanics of morphogenesis. Furthermore, we found that ethylene signaling is activated by touch, and the transcription factor EIN3 directly associates with PGX3 promoter and is required for touch-repressed PGX3 expression. By uncovering the link between mechanical forces and cell wall remodeling established via the EIN3-PGX3 module, this work represents a key step in understanding the molecular framework of touch-induced morphological changes.

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Hydro-Responsive Curling of the Resurrection Plant Selaginella lepidophylla

Scientific Reports ◽

10.1038/srep08064 ◽

2015 ◽

Vol 5 (1) ◽

Cited By ~ 49

Author(s):

Ahmad Rafsanjani ◽

Véronique Brulé ◽

Tamara L. Western ◽

Damiano Pasini

Keyword(s):

Resurrection Plant ◽

Selaginella Lepidophylla

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Lignification of spruce tracheid secondary cell walls related to longitudinal hardness and modulus of elasticity using nano-indentation

Canadian Journal of Botany ◽

10.1139/b02-091 ◽

2002 ◽

Vol 80 (10) ◽

pp. 1029-1033 ◽

Cited By ~ 41

Author(s):

W Gindl ◽

H S Gupta ◽

C Grünwald

Keyword(s):

Cell Wall ◽

Modulus Of Elasticity ◽

Cell Walls ◽

Secondary Cell Wall ◽

Lignin Content ◽

Wood Formation ◽

Nano Indentation ◽

Secondary Cell Walls ◽

Cell Wall Development ◽

The One

The lignin content and the mechanical properties of lignifying and fully lignified spruce tracheid secondary cell walls were determined using UV microscopy and nano-indentation, respectively. The average lignin content of developing tracheids was 0.10 g·g1, as compared with 0.21 g·g1 in mature tracheids. The modulus of elasticity of developing cells was on average 22% lower than the one measured in mature, fully lignified cells. For the longitudinal hardness, a larger difference of 26% was observed. As lignifying cells in the cambial zone are undergoing cell wall development, spaces in the cellulosehemicellulose structure are filled with lignin and the density of the cell wall is believed to increase. It is therefore suggested that the observed difference in modulus of elasticity between developing and fully lignified cell walls is due to the filling of spaces with lignin and an increase of the packing density of the cell wall during lignification. Although remarkably less stiff than the composite polysaccharide structure in the secondary cell wall, lignin may be considered equally hard. Therefore, the observed increase in lignin content may contribute directly to the measured increase of hardness.Key words: secondary cell wall, hardness, lignin, modulus of elasticity, wood formation.

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Reduced photoinhibition with stem curling in the resurrection plant Selaginella lepidophylla

Oecologia ◽

10.1007/bf00317725 ◽

1991 ◽

Vol 88 (4) ◽

pp. 597-604 ◽

Cited By ~ 17

Author(s):

Jefferson G. Lebkuecher ◽

William G. Eickmeier

Keyword(s):

Resurrection Plant ◽

Selaginella Lepidophylla

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Coffee carbohydrates

Brazilian Journal of Plant Physiology ◽

10.1590/s1677-04202006000100012 ◽

2006 ◽

Vol 18 (1) ◽

pp. 165-174 ◽

Cited By ~ 39

Author(s):

Robert Redgwell ◽

Monica Fischer

Keyword(s):

Cell Wall ◽

Potential Role ◽

Structural Features ◽

Coffee Bean ◽

Cell Wall Polysaccharides ◽

Pectic Polysaccharides ◽

Specific Polysaccharide ◽

Chemical Studies ◽

First Time ◽

Detailed Chemical

This review summarises recent advances in the chemistry, physiology and molecular properties of coffee carbohydrates with a particular focus on the cell wall polysaccharides. The results of detailed chemical studies have demonstrated novel structural features of both the galactomannans and the arabinogalactan polysaccharides of the green and roasted coffee bean. For the first time immunological probes based on monoclonal antibodies for specific polysaccharide epitopes were used to reveal the patterns of distribution of the galactomannans, arabinogalactans and pectic polysaccharides in the coffee bean cell wall. Finally, the results of physiological and molecular studies are presented which emphasise the growing awareness of the potential role the metabolic status of the green bean may play in final coffee beverage quality.

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