Faculty Opinions recommendation of Morlin, an inhibitor of cortical microtubule dynamics and cellulose synthase movement.

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.

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Towards correlative imaging of plant cortical microtubule arrays: combining ultrastructure with real-time microtubule dynamics

Journal of Microscopy ◽

10.1111/j.1365-2818.2009.03224.x ◽

2009 ◽

Vol 235 (3) ◽

pp. 241-251 ◽

Cited By ~ 3

Author(s):

D.A. BARTON ◽

J.C. GARDINER ◽

R.L. OVERALL

Keyword(s):

Real Time ◽

Cortical Microtubule ◽

Microtubule Dynamics ◽

Correlative Imaging

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FRA1 modulates cortical microtubule localization of CMU proteins

10.1101/760389 ◽

2019 ◽

Author(s):

Anindya Ganguly ◽

Chuanmei Zhu ◽

Weizu Chen ◽

Ram Dixit

Keyword(s):

Arabidopsis Thaliana ◽

Cell Wall ◽

Molecular Mechanisms ◽

Cortical Microtubule ◽

Cellulose Synthase ◽

Lateral Stability ◽

Cortical Microtubules ◽

Tail Region ◽

Opposing Effect ◽

Growth And Reproduction

ABSTRACTConstruction of the cell wall demands harmonized deposition of cellulose and matrix polysaccharides. Cortical microtubules orient the deposition of cellulose by guiding the trajectory of plasma membrane-embedded cellulose synthase complexes. Vesicles containing matrix polysaccharides are thought to be transported by the FRA1 kinesin to facilitate their secretion along cortical microtubules. The cortical microtubule cytoskeleton thus provides a platform to coordinate the delivery of cellulose and matrix polysaccharides, but the underlying molecular mechanisms remain unknown. Here, we show that the tail region of the FRA1 kinesin physically interacts with CMU proteins which are important for the microtubule-dependent guidance of cellulose synthase complexes. Interaction with CMUs did not affect microtubule binding or motility of the FRA1 kinesin but had an opposing effect on the cortical microtubule localization of CMU1 and CMU2 proteins, thus regulating the lateral stability of cortical microtubules. Phosphorylation of the FRA1 tail region by CKL6 inhibited binding to CMUs and consequently reversed the extent of cortical microtubule decoration by CMU1 and CMU2. Genetic experiments demonstrated the significance of this interaction to the growth and reproduction of Arabidopsis thaliana plants. We propose that modulation of CMU’s microtubule localization by FRA1 provides a mechanism to control the coordinated deposition of cellulose and matrix polysaccharides.

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A computational framework for cortical microtubule dynamics in realistically shaped plant cells

PLoS Computational Biology ◽

10.1371/journal.pcbi.1005959 ◽

2018 ◽

Vol 14 (2) ◽

pp. e1005959 ◽

Cited By ~ 26

Author(s):

Bandan Chakrabortty ◽

Ikram Blilou ◽

Ben Scheres ◽

Bela M. Mulder

Keyword(s):

Cortical Microtubule ◽

Plant Cells ◽

Microtubule Dynamics ◽

Computational Framework

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Growth and cortical microtubule dynamics in shoot organs under microgravity and hypergravity conditions

Plant Signaling & Behavior ◽

10.1080/15592324.2017.1422468 ◽

2018 ◽

Vol 13 (1) ◽

pp. e1422468 ◽

Cited By ~ 4

Author(s):

Kouichi Soga ◽

Kazuyuki Wakabayashi ◽

Takayuki Hoson

Keyword(s):

Cortical Microtubule ◽

Microtubule Dynamics

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Associations between phytohormones and cellulose biosynthesis in land plants

Annals of Botany ◽

10.1093/aob/mcaa121 ◽

2020 ◽

Vol 126 (5) ◽

pp. 807-824

Author(s):

Liu Wang ◽

Bret E Hart ◽

Ghazanfar Abbas Khan ◽

Edward R Cruz ◽

Staffan Persson ◽

...

Keyword(s):

Cell Wall ◽

Plant Growth ◽

Growth And Development ◽

Cortical Microtubule ◽

Cellulose Synthase ◽

Current Understanding ◽

Signalling Pathways ◽

Cellulose Biosynthesis ◽

Plant Growth And Development ◽

Cellulose Deposition

Abstract Background Phytohormones are small molecules that regulate virtually every aspect of plant growth and development, from basic cellular processes, such as cell expansion and division, to whole plant environmental responses. While the phytohormone levels and distribution thus tell the plant how to adjust itself, the corresponding growth alterations are actuated by cell wall modification/synthesis and internal turgor. Plant cell walls are complex polysaccharide-rich extracellular matrixes that surround all plant cells. Among the cell wall components, cellulose is typically the major polysaccharide, and is the load-bearing structure of the walls. Hence, the cell wall distribution of cellulose, which is synthesized by large Cellulose Synthase protein complexes at the cell surface, directs plant growth. Scope Here, we review the relationships between key phytohormone classes and cellulose deposition in plant systems. We present the core signalling pathways associated with each phytohormone and discuss the current understanding of how these signalling pathways impact cellulose biosynthesis with a particular focus on transcriptional and post-translational regulation. Because cortical microtubules underlying the plasma membrane significantly impact the trajectories of Cellulose Synthase Complexes, we also discuss the current understanding of how phytohormone signalling impacts the cortical microtubule array. Conclusion Given the importance of cellulose deposition and phytohormone signalling in plant growth and development, one would expect that there is substantial cross-talk between these processes; however, mechanisms for many of these relationships remain unclear and should be considered as the target of future studies.

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A Framework to Simulate Cortical microtubule Dynamics in Arbitrary Shaped Plant Cells

10.1101/169797 ◽

2017 ◽

Author(s):

Bandan Chakrabortty ◽

Ben Scheres ◽

Bela Mulder

Keyword(s):

Cortical Microtubule ◽

Three Dimensional ◽

Plant Cells ◽

Microtubule Dynamics ◽

Hedera Helix ◽

Directional Growth ◽

Pavement Cells ◽

Microtubule Array ◽

Individual Contributions ◽

The Individual

AbstractPlant morphogenesis is strongly dependent on the directional growth and the subsequent oriented division of individual cells. It has been shown that the plant cortical microtubule array plays a key role in controlling both these processes. This ordered structure emerges as the collective result of stochastic interactions between large numbers of dynamic microtubules. To elucidate this complex self-organization process a number of analytical and computational approaches to study the dynamics of cortical microtubules have been proposed. To date, however, these models have been restricted to 2D planes or geometrically simple surfaces in 3D, which strongly limits their applicability as plant cells display a wide variety of shapes. This limitation is even more acute, as both local as well as global geometrical features of cells are expected to influence the overall organization of the array. Here we describe a framework for efficiently simulating microtubule dynamics on triangulated approximations of arbitrary three dimensional surfaces. This allows the study of microtubule array organization on realistic cell surfaces obtained by segmentation of microscopic images. We validate the framework against expected or known results for the spherical and cubical geometry. We then use it to systematically study the individual contributions of global geometry, edge-induced catastrophes and cell face-induced stability to array organization in a cuboidal geometry. Finally, we apply our framework to analyze the highly non-trivial geometry of leaf pavement cells of Nicotiana benthamiana and Hedera helix. We show that our simulations can predict multiple features of the array structure in these cells, revealing, among others, strong constraints on the orientation of division planes.

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