scholarly journals Turning plants from passive to active material: FERONIA and microtubules independently contribute to mechanical feedback

2021 ◽  
Author(s):  
Alice Malivert ◽  
Özer Erguvan ◽  
Antoine Chevallier ◽  
Antoine Dehem ◽  
Rodrigue Friaud ◽  
...  
Keyword(s):  
Tensile Stress ◽  
Mechanical Stress ◽  
Cell Walls ◽  
Active Material ◽  
Plant Cells ◽  
Soap Bubbles ◽  
Cellulose Deposition ◽  
Stress Levels ◽  
Response To Stress ◽  
Mutant Lines

AbstractTo survive, cells must constantly resist mechanical stress. In plants, this involves the reinforcement of cell walls, notably through microtubule-dependent cellulose deposition, and thus wall sensing. Several receptor-like kinases have been proposed to act as mechanosensors. Here we tested whether the microtubule response to stress acts downstream of known wall sensors. Using a multi-step screen with eleven mutant lines, we identify FERONIA as the primary candidate for controlling the microtubule response to stress. However, when performing mechanical perturbations, we show that the microtubule response to stress can be independent from FER. We reveal that the feronia phenotype can be partially rescued by reducing tensile stress levels. Conversely, in the absence of both microtubules and FER, cells swell and burst like soap bubbles. Altogether, this shows that the microtubule response to stress acts as an independent pathway to resist stress, in parallel to FER. We propose that both pathways are key components to turn plant cells from passive to active material.

scholarly journals FERONIA and microtubules independently contribute to mechanical integrity in the Arabidopsis shoot

PLoS Biology ◽  
2021 ◽  
Vol 19 (11) ◽  
pp. e3001454
Author(s):  
Alice Malivert ◽  
Özer Erguvan ◽  
Antoine Chevallier ◽  
Antoine Dehem ◽  
Rodrigue Friaud ◽  
...  
Keyword(s):  
Tensile Stress ◽  
Mechanical Stress ◽  
Cell Walls ◽  
Plant Cells ◽  
Mechanical Integrity ◽  
Cellulose Deposition ◽  
Stress Levels ◽  
Response To Stress ◽  
Mutant Lines

To survive, cells must constantly resist mechanical stress. In plants, this involves the reinforcement of cell walls, notably through microtubule-dependent cellulose deposition. How wall sensing might contribute to this response is unknown. Here, we tested whether the microtubule response to stress acts downstream of known wall sensors. Using a multistep screen with 11 mutant lines, we identify FERONIA (FER) as the primary candidate for the cell’s response to stress in the shoot. However, this does not imply that FER acts upstream of the microtubule response to stress. In fact, when performing mechanical perturbations, we instead show that the expected microtubule response to stress does not require FER. We reveal that the feronia phenotype can be partially rescued by reducing tensile stress levels. Conversely, in the absence of both microtubules and FER, cells appear to swell and burst. Altogether, this shows that the microtubule response to stress acts as an independent pathway to resist stress, in parallel to FER. We propose that both pathways are required to maintain the mechanical integrity of plant cells.

A Pilot Study

2016 ◽  
Vol 35 (1) ◽  
pp. 25-32 ◽  
Author(s):  
Alice Running ◽  
Laura Hildreth
Keyword(s):  
Intervention Study ◽  
Single Group ◽  
Convenience Sample ◽  
Negative Behaviors ◽  
Stress Levels ◽  
Quasi Experimental ◽  
Response To Stress ◽  
Faculty And Staff ◽  
Energy Therapy ◽  
Reducing Stress

Aim: To examine the effectiveness of a bio-energy intervention on self-reported stress for a convenience sample of University students, faculty, and staff during finals week. We hypothesized that participants would report a decrease in stress after a 20 minute bio-energy intervention. Study Design: A quasi-experimental, single-group, pretest–posttest design was used. Method: Thirty-nine faculty, staff, and students participated. Participants served as their own controls. A specific technique was provided by each bio-energy practitioner for 20 minutes after participants had completed a visual analogue scale identifying level of stress and listing two positive and negative behaviors they were currently using in response to stress. Results: A one-sample t test indicates that bio-energy therapy significantly reduces stress, t(35) = 7.74, p < .0001. A multiple regression analysis further indicates that the decrease in stress levels is significantly greater for higher initial stress levels, t(31) = 4.748, p < .0001); decreases in stress are significantly greater for faculty and staff compared to students, t(31) = −2.223, p = .034; and decreases in stress levels are marginally significantly higher for older participants, t(31) =1.946, p = .061. Conclusion: Bio-energy therapy may have benefit in reducing stress for faculty, staff, and students during final examination week. Further research is needed.

Improvement on Surface Tracking and Tensile Stress of Insulator via the Used of Aluminium Oxide Filler

2016 ◽  
Vol 705 ◽  
pp. 98-102
Author(s):  
Nutsopin Nilbunpot ◽  
Amnart Suksri
Keyword(s):  
Tensile Stress ◽  
Transmission Line ◽  
Epoxy Resin ◽  
Mechanical Stress ◽  
Electrical Power ◽  
Mechanical Effect ◽  
Electrical Insulation ◽  
Insulator Surface ◽  
Surface Tracking ◽  
Tracking Time

Mechanical effect is one of many causes that influence surface tracking activity of electrical insulation. Mechanical stress is also a main cause that deteriorates the property of cable spacer used in delivered electrical power through transmission line. This paper investigates on surface tracking and tensile stress performance of composite insulator material in order to improve insulator property. Specimen were made from epoxy resin and additive fillers tested under the condition of contamination. The filler ratio were used from 0 to 50% with incremental of 10%.The result showed that fillers have significance improvement on inhibition of the degradation on insulators when the concentration of filler is increased, the tracking time has increased until 40% of filler. Moreover, the improvement on the tensile stress is also increased. It is clearly showed that addition of filler not only improve on the time for surface tracking on insulator surface but also helps improve on mechanical stress property of insulators as well.

scholarly journals Cytokinins Stimulate Plasmodesmatal Transport in Leaves

2021 ◽  
Vol 12 ◽  
Author(s):  
Wilson Horner ◽  
Jacob O. Brunkard
Keyword(s):  
Cell Walls ◽  
Fluorescent Protein ◽  
Plant Cells ◽  
Plant Biology ◽  
Negative Regulator ◽  
Cytokinin Signaling ◽  
Dynamic Changes ◽  
Cytokinin Receptors ◽  
Green Fluorescent ◽  
Development Regulation

Plant cells are connected by plasmodesmata (PD), nanoscopic channels in cell walls that allow diverse cytosolic molecules to move between neighboring cells. PD transport is tightly coordinated with physiology and development, although the range of signaling pathways that influence PD transport has not been comprehensively defined. Several plant hormones, including salicylic acid (SA) and auxin, are known to regulate PD transport, but the effects of other hormones have not been established. In this study, we provide evidence that cytokinins promote PD transport in leaves. Using a green fluorescent protein (GFP) movement assay in the epidermis of Nicotiana benthamiana, we have shown that PD transport significantly increases when leaves are supplied with exogenous cytokinins at physiologically relevant concentrations or when a positive regulator of cytokinin responses, ARABIDOPSIS HISTIDINE PHOSPHOTRANSFER PROTEIN 5 (AHP5), is overexpressed. We then demonstrated that silencing cytokinin receptors, ARABIDOPSIS HISTIDINE KINASE 3 (AHK3) or AHK4 or overexpressing a negative regulator of cytokinin signaling, AAHP6, significantly decreases PD transport. These results are supported by transcriptomic analysis of mutants with increased PD transport (ise1–4), which show signs of enhanced cytokinin signaling. We concluded that cytokinins contribute to dynamic changes in PD transport in plants, which will have implications in several aspects of plant biology, including meristem patterning and development, regulation of the sink-to-source transition, and phytohormone crosstalk.

scholarly journals Ionic Relations of Cells of Ohara Australis I. Ion Exchange in the Cell Wall

1959 ◽  
Vol 12 (4) ◽  
pp. 395 ◽  
Author(s):  
J Dainty ◽  
AB Hope
Keyword(s):  
Cell Wall ◽  
Ion Exchange ◽  
Free Space ◽  
Cell Walls ◽  
Plant Cells ◽  
External Solution ◽  
Exchangeable Cations ◽  
Intact Cells ◽  
Donnan Free Space ◽  
Isolated Cell

Measurements of ion exchange were made between isolated cell walls of Ohara australis and an external solution. Comparison between intact cells and cell walls showed that nearly all the easily exchangeable cations are located in the cell wall. The wall is hown to consist of "water free space" (W.F.S.) and "Donnan free space" (D.F.S.); the concentration of in diffusible anions in the D.F.S. is about O� 6 equivjl. This finding is contrary to past suggestions that the D.F.S. is in the cytoplasm of plant cells.

Repetitive tensile stress to rat caudal vertebrae inducing cartilage formation in the spinal ligaments: a possible role of mechanical stress in the development of ossification of the spinal ligaments

2006 ◽  
Vol 5 (3) ◽  
pp. 234-242 ◽  
Author(s):  
Nobuaki Tsukamoto ◽  
Takeshi Maeda ◽  
Hiromasa Miura ◽  
Seiya Jingushi ◽  
Akira Hosokawa ◽  
...  
Keyword(s):  
Tensile Stress ◽  
Mechanical Stress ◽  
Tensile Force ◽  
Bone Morphogenetic Protein 2 ◽  
Woven Bone ◽  
Morphogenetic Protein ◽  
Caudal Vertebrae ◽  
Spinal Ligaments

Object Mechanical stress has been considered one of the important factors in ossification of the spinal ligaments. According to previous clinical and in vitro studies, the accumulation of tensile stress to these ligaments may be responsible for ligament ossification. To elucidate the relationship between such mechanical stress and the development of ossification of the spinal ligaments, the authors established an animal experimental model in which the in vivo response of the spinal ligaments to direct repetitive tensile loading could be observed. Methods The caudal vertebrae of adult Wistar rats were studied. After creating a novel stimulating apparatus, cyclic tensile force was loaded to rat caudal spinal ligaments at 10 N in 600 to 1800 cycles per day for up to 2 weeks. The morphological responses were then evaluated histologically and immunohistochemically. After the loadings, ectopic cartilaginous formations surrounded by proliferating round cells were observed near the insertion of the spinal ligaments. Several areas of the cartilaginous tissue were accompanied by woven bone. Bone morphogenetic protein–2 expression was clearly observed in the cytoplasm of the proliferating round cells. The histological features of the rat spinal ligaments induced by the tensile loadings resembled those of spinal ligament ossification observed in humans. Conclusions The findings obtained in the present study strongly suggest that repetitive tensile stress to the spinal ligaments is one of the important causes of ligament ossification in the spine.

Reduced Cell Expansion and Changes in Cell Walls of Plant Cells Adapted to NaCl

1990 ◽  
pp. 137-171 ◽  
Author(s):  
Ray A. Bressan ◽  
Donald E. Nelson ◽  
Naim M. Iraki ◽  
P. Christopher LaRosa ◽  
Narendra K. Singh ◽  
...  
Keyword(s):  
Cell Expansion ◽  
Cell Walls ◽  
Plant Cells

scholarly journals Plasmodesmata-Related Structural and Functional Proteins: The Long Sought-After Secrets of a Cytoplasmic Channel in Plant Cell Walls

2019 ◽  
Vol 20 (12) ◽  
pp. 2946 ◽  
Author(s):  
Xiao Han ◽  
Li-Jun Huang ◽  
Dan Feng ◽  
Wenhan Jiang ◽  
Wenzhuo Miu ◽  
...  
Keyword(s):  
Cell Wall ◽  
Plant Cell ◽  
Cell Walls ◽  
Plasma Membranes ◽  
Plant Cell Wall ◽  
Plant Cells ◽  
Protein Composition ◽  
Cell Contact ◽  
Plant Cell Walls ◽  
Cell Organelles

Plant cells are separated by cellulose cell walls that impede direct cell-to-cell contact. In order to facilitate intercellular communication, plant cells develop unique cell-wall-spanning structures termed plasmodesmata (PD). PD are membranous channels that link the cytoplasm, plasma membranes, and endoplasmic reticulum of adjacent cells to provide cytoplasmic and membrane continuity for molecular trafficking. PD play important roles for the development and physiology of all plants. The structure and function of PD in the plant cell walls are highly dynamic and tightly regulated. Despite their importance, plasmodesmata are among the few plant cell organelles that remain poorly understood. The molecular properties of PD seem largely elusive or speculative. In this review, we firstly describe the general PD structure and its protein composition. We then discuss the recent progress in identification and characterization of PD-associated plant cell-wall proteins that regulate PD function, with particular emphasis on callose metabolizing and binding proteins, and protein kinases targeted to and around PD.

A system for studying the effect of mechanical stress on the elongation behavior of immobilized plant cells

2006 ◽  
Vol 49 (2) ◽  
pp. 165-174 ◽  
Author(s):  
Jing Zhou ◽  
Bochu Wang ◽  
Liqing Zhu ◽  
Yi Li ◽  
Yichuan Wang
Keyword(s):  
Mechanical Stress ◽  
Plant Cells ◽  
Immobilized Plant Cells

Isothermal Stress Relaxation in Al, Alcu and A1vpd Films

1996 ◽  
Vol 436 ◽  
Author(s):  
J. P. Lokker ◽  
J. F. Jongste ◽  
G. C. A. M. Janssen ◽  
S. Radelaar
Keyword(s):  
Stress Relaxation ◽  
Integrated Circuits ◽  
Tensile Stress ◽  
Thermal Cycling ◽  
Mechanical Behavior ◽  
Mechanical Stress ◽  
Plasma Etching ◽  
Isothermal Treatment ◽  
Aluminum Metallization ◽  
Curvature Measurements

AbstractMechanical stress and its relaxation in aluminum metallization in integrated circuits (IC) are a major concern for the reliability of the material. It is known that adding Cu improves the reliability but complicates plasma etching and increases corrosion sensitivity. The mechanical behavior of AlVPd, AlCu and Al blanket films is investigated by wafer curvature measurements. During thermal cycling between 50°C and 400°C the highest tensile stress is found in AlVPd. In a subsequent experiment, the cooling was interrupted at several temperatures to investigate the stress behavior during an eight hour isothermal treatment. Isothermal stress relaxation has been observed in the three types of films and is discussed.

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