Regulation by Gibberellins of the Orientation of Cortical Microtubules in Plant Cells

1993 ◽  
Vol 20 (5) ◽  
pp. 461 ◽  
Author(s):  
H Shibaoka
Keyword(s):  
Plasma Membrane ◽  
Cell Expansion ◽  
Plant Cells ◽  
Cellulose Microfibrils ◽  
Molecular Architecture ◽  
Cortical Microtubules ◽  
Microtubule Stability ◽  
The Stability ◽  
The Way

Gibberellins control the direction of expansion of plant cells. They change the orientation of cellulose microfibrils by changing the orientation of cortical microtubules and, hence, the direction of cell expansion. When gibberellins change the orientation of cortical microtubules, they also change their stability. If the way in which gibberellins change the orientation of microtubules is identical to the way in which they change microtubule stability, then studies on the mechanism that regulates this stability should give us some clues to the mechanism that regulates the orientation of microtubules. With this possibility in mind, we undertook a series of studies on the stability of cortical microtubules. These revealed that the association of cortical microtubules with the plasma membrane is an important part of the mechanism for their stabilisation. Gibberellins seem to change the stability of microtubules by affecting their association with the plasma membrane. To study the way in which the gibberellins affect this association, it is necessary to clarify the molecular architecture of the structure that links cortical microtubules with the plasma membrane.

scholarly journals Inhibition of cell expansion enhances cortical microtubule stability in the root apex of Arabidopsis thaliana

2021 ◽  
Vol 28 (1) ◽  
Author(s):  
Veronica Giourieva ◽  
Emmanuel Panteris
Keyword(s):  
Arabidopsis Thaliana ◽  
Cell Wall ◽  
Cell Expansion ◽  
Cortical Microtubule ◽  
Root Apex ◽  
Cellulose Synthase ◽  
Cellulose Biosynthesis ◽  
Cortical Microtubules ◽  
Wild Type ◽  
Microtubule Stability

Abstract Background Cortical microtubules regulate cell expansion by determining cellulose microfibril orientation in the root apex of Arabidopsis thaliana. While the regulation of cell wall properties by cortical microtubules is well studied, the data on the influence of cell wall to cortical microtubule organization and stability remain scarce. Studies on cellulose biosynthesis mutants revealed that cortical microtubules depend on Cellulose Synthase A (CESA) function and/or cell expansion. Furthermore, it has been reported that cortical microtubules in cellulose-deficient mutants are hypersensitive to oryzalin. In this work, the persistence of cortical microtubules against anti-microtubule treatment was thoroughly studied in the roots of several cesa mutants, namely thanatos, mre1, any1, prc1-1 and rsw1, and the Cellulose Synthase Interacting 1 protein (csi1) mutant pom2-4. In addition, various treatments with drugs affecting cell expansion were performed on wild-type roots. Whole mount tubulin immunolabeling was applied in the above roots and observations were performed by confocal microscopy. Results Cortical microtubules in all mutants showed statistically significant increased persistence against anti-microtubule drugs, compared to those of the wild-type. Furthermore, to examine if the enhanced stability of cortical microtubules was due to reduced cellulose biosynthesis or to suppression of cell expansion, treatments of wild-type roots with 2,6-dichlorobenzonitrile (DCB) and Congo red were performed. After these treatments, cortical microtubules appeared more resistant to oryzalin, than in the control. Conclusions According to these findings, it may be concluded that inhibition of cell expansion, irrespective of the cause, results in increased microtubule stability in A. thaliana root. In addition, cell expansion does not only rely on cortical microtubule orientation but also plays a regulatory role in microtubule dynamics, as well. Various hypotheses may explain the increased cortical microtubule stability under decreased cell expansion such as the role of cell wall sensors and the presence of less dynamic cortical microtubules.

Structure and development of cortical microtubule arrays in plant cells

1978 ◽  
Vol 36 (2) ◽  
pp. 264-265
Author(s):  
A.R. Hardham ◽  
B.E.S. Gunning
Keyword(s):  
Cell Wall ◽  
Plasma Membrane ◽  
Cortical Microtubule ◽  
Plant Cells ◽  
Original Description ◽  
Cell Cortex ◽  
Cortical Microtubules ◽  
Fundamental Part ◽  
Cellulose Component

Microtubules in the plant cell cortex are usually aligned parallel to microfibrils of cellulose that are being deposited in the cell wall, and are considered to function in guiding or orienting cellulose synthetase complexes that lie in or on the plasma membrane. The cellulose component is largely responsible for the mechanical reaction of the wall to turgor forces, thereby determining cell size and shape, and therefore the role of the cortical microtubules is a fundamental part of the overall morphogenetic process in plants. It is important to determine the structure of cortical arrays of microtubules and to learn how the cell regulates their development, neither of these aspects having been investigated adequately since the original description likened the microtubules to “hundreds of hoops around the cell”.

Alignment of Cortical Microtubules by Anisotropic Wall Stresses

1990 ◽  
Vol 17 (6) ◽  
pp. 601 ◽  
Author(s):  
RE Williamson
Keyword(s):  
Cell Shape ◽  
Feedback Loop ◽  
Plant Cells ◽  
Cellulose Microfibrils ◽  
Specific Information ◽  
Mechanical Forces ◽  
Cortical Microtubules ◽  
Directional Information ◽  
Cell Position ◽  
Single Protein

Anisotropic mechanical forces exist in the walls of all turgid plant cells except those of spherical unicells. These forces potentially offer the cell important directional information regarding its major and minor axes, and the more complicated force patterns expected in multicellular organs could offer location-specific information. A mechanism is proposed to measure directional forces in the wall as deformations (strain) of molecules associated with cellulose microfibrils and transmit the information across the plasma membrane to orient cortical microtubules. Because microtubules in turn orient the synthesis of the cellulose microfibrils that determine the direction of future cell expansion, a feedback loop is established relating future cell shape to present cell shape and cell position. The loop can provide positive feedback to magnify a small asymmetry in shape, to reinforce an existing growth axis in a cylindrical cell or, by modification of the proteins postulated to convey directional information between wall and cytoplasm, the loop can be broken and the same directional information used to establish a new orientation for cortical microtubules. In this way, modification of a single protein replaces a transverse microtubule array with a helical one.

scholarly journals Endocytic Trafficking Promotes Vacuolar Enlargements for Fast Cell Expansion Rates in Plants

2021 ◽  
Author(s):  
Kai Duenser ◽  
Maria Schoeller ◽  
Christian Loefke ◽  
Nannan Xiao ◽  
Barbora Parizkova ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Cell Surface ◽  
Cell Size ◽  
Plant Cell ◽  
Cell Expansion ◽  
Plant Cells ◽  
Root Cell ◽  
Endocytic Trafficking ◽  
Size Determination ◽  
Space Filling

The vacuole has a space-filling function, allowing a particularly rapid plant cell expansion with very little increase in cytosolic content (Loefke et al., 2015; Scheuring et al., 2016; Duenser et al., 2019). Despite its importance for cell size determination in plants, very little is known about the mechanisms that define vacuolar size. Here we show that the cellular and vacuolar size expansions are coordinated. By developing a pharmacological tool, we enabled the investigation of membrane delivery to the vacuole during cellular expansion. Counterintuitively, our data reveal that endocytic trafficking from the plasma membrane to the vacuole is enhanced in the course of rapid root cell expansion. While this "compromise" mechanism may theoretically at first decelerate cell surface enlargements, it fuels vacuolar expansion and, thereby, ensures the coordinated augmentation of vacuolar occupancy in dynamically expanding plant cells.

Enrichment of vitronectin- and fibronectin-like proteins in NaCI-adapted plant cells and evidence for their involvement in plasma membrane-cell wall adhesion

1993 ◽  
Vol 3 (5) ◽  
pp. 637-646 ◽  
Author(s):  
Jian-Kang Zhu ◽  
Jun Shi ◽  
Utpal Singh ◽  
Sarah E. Wyatt ◽  
Ray A. Bressan ◽  
...  
Keyword(s):  
Cell Wall ◽  
Plasma Membrane ◽  
Plant Cells ◽  
Membrane Cell

scholarly journals Fig mosaic emaravirus p4 protein is involved in cell-to-cell movement

2013 ◽  
Vol 94 (3) ◽  
pp. 682-686 ◽  
Author(s):  
Kazuya Ishikawa ◽  
Kensaku Maejima ◽  
Ken Komatsu ◽  
Osamu Netsu ◽  
Takuya Keima ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Laser Scanning ◽  
Movement Protein ◽  
Rna Virus ◽  
Cell Movement ◽  
Plant Cells ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Series Of Experiments ◽  
Fig Mosaic Virus

Fig mosaic virus (FMV), a member of the newly formed genus Emaravirus, is a segmented negative-strand RNA virus. Each of the six genomic FMV segments contains a single ORF: that of RNA4 encodes the protein p4. FMV-p4 is presumed to be the movement protein (MP) of the virus; however, direct experimental evidence for this is lacking. We assessed the intercellular distribution of FMV-p4 in plant cells by confocal laser scanning microscopy and we found that FMV-p4 was localized to plasmodesmata and to the plasma membrane accompanied by tubule-like structures. A series of experiments designed to examine the movement functions revealed that FMV-p4 has the capacity to complement viral cell-to-cell movement, prompt GFP diffusion between cells, and spread by itself to neighbouring cells. Altogether, our findings demonstrated that FMV-p4 shares several properties with other viral MPs and plays an important role in cell-to-cell movement.

scholarly journals Molecular architecture of the endocytic TPLATE complex

2021 ◽  
Vol 7 (9) ◽  
pp. eabe7999
Author(s):  
Klaas Yperman ◽  
Jie Wang ◽  
Dominique Eeckhout ◽  
Joanna Winkler ◽  
Lam Dai Vu ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Structural Approach ◽  
Eukaryotic Cells ◽  
Molecular Architecture ◽  
Membrane Proteome ◽  
Complex Assembly ◽  
Membrane Interaction ◽  
Structural Insight ◽  
Fresh Insight ◽  
Insight Into

Eukaryotic cells rely on endocytosis to regulate their plasma membrane proteome and lipidome. Most eukaryotic groups, except fungi and animals, have retained the evolutionary ancient TSET complex as an endocytic regulator. Unlike other coatomer complexes, structural insight into TSET is lacking. Here, we reveal the molecular architecture of plant TSET [TPLATE complex (TPC)] using an integrative structural approach. We identify crucial roles for specific TSET subunits in complex assembly and membrane interaction. Our data therefore generate fresh insight into the differences between the hexameric TSET in Dictyostelium and the octameric TPC in plants. Structural elucidation of this ancient adaptor complex represents the missing piece in the coatomer puzzle and vastly advances our functional as well as evolutionary insight into the process of endocytosis.

Four-Color Single-Molecule Imaging with Engineered Tags Resolves the Molecular Architecture of Signaling Complexes in the Plasma Membrane

2021 ◽  
Author(s):  
Junel Sotolongo Bellón ◽  
Oliver Birkholz ◽  
Christian Paolo Richter ◽  
Florian Eull ◽  
Hella Kenneweg ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Single Molecule ◽  
Single Molecule Imaging ◽  
Molecular Architecture
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