Cell morphogenesis of trichomes in Arabidopsis: differential control of primary and secondary branching by branch initiation regulators and cell growth

Development ◽  
1997 ◽  
Vol 124 (19) ◽  
pp. 3779-3786 ◽  
Author(s):  
U. Folkers ◽  
J. Berger ◽  
M. Hulskamp
Keyword(s):  
Cell Growth ◽  
Cell Shape ◽  
Normal Development ◽  
Branching Pattern ◽  
Cell Morphogenesis ◽  
Negative Regulators ◽  
Branch Number ◽  
Underlying Mechanisms ◽  
Differential Control ◽  
Trichome Cell

Cell morphogenesis, i.e. the acquisition of a particular cell shape, can be examined genetically in the three-branched trichomes that differentiate from single epidermal cells on the leaves of Arabidopsis thaliana. In normal development, the growing trichome cell undergoes two successive branching events, resulting in a proximal side stem and a distal main stem which subsequently splits in two branches. Using new and previously described trichome mutants, we have analyzed the branching pattern in single and double mutants affecting branch number or cell size in order to determine underlying mechanisms. Our results suggest that primary branching is genetically distinct from subsequent branching events and that the latter, secondary events are initiated in response to positive and negative regulators of branching as well as subject to control by cell growth. We propose a model of how trichome cell morphogenesis is regulated during normal development.

scholarly journals Orchestration of microtubules and the actin cytoskeleton in trichome cell shape determination by a plant-unique kinesin

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Juan Tian ◽  
Libo Han ◽  
Zhidi Feng ◽  
Guangda Wang ◽  
Weiwei Liu ◽  
...  
Keyword(s):  
Actin Filaments ◽  
Cell Shape ◽  
Shape Control ◽  
Live Cell Imaging ◽  
Cell Morphogenesis ◽  
Calmodulin Binding ◽  
Cytoskeletal Regulation ◽  
Shape Determination ◽  
Cell Shape Control ◽  
Trichome Cell

Microtubules (MTs) and actin filaments (F-actin) function cooperatively to regulate plant cell morphogenesis. However, the mechanisms underlying the crosstalk between these two cytoskeletal systems, particularly in cell shape control, remain largely unknown. In this study, we show that introduction of the MyTH4-FERM tandem into KCBP (kinesin-like calmodulin-binding protein) during evolution conferred novel functions. The MyTH4 domain and the FERM domain in the N-terminal tail of KCBP physically bind to MTs and F-actin, respectively. During trichome morphogenesis, KCBP distributes in a specific cortical gradient and concentrates at the branching sites and the apexes of elongating branches, which lack MTs but have cortical F-actin. Further, live-cell imaging and genetic analyses revealed that KCBP acts as a hub integrating MTs and actin filaments to assemble the required cytoskeletal configuration for the unique, polarized diffuse growth pattern during trichome cell morphogenesis. Our findings provide significant insights into the mechanisms underlying cytoskeletal regulation of cell shape determination.

scholarly journals Crowding tunes 3D collagen fibrils and reveals matrix regulation of cancer cell morphogenesis

2018 ◽  
Author(s):  
A. Han ◽  
S. Ranamukhaarachchi ◽  
D. O. Velez ◽  
A. Kumar ◽  
A. J. Engler ◽  
...  
Keyword(s):  
Cancer Cell ◽  
Collagen Fibril ◽  
Cell Shape ◽  
Cell Phenotype ◽  
Cell Morphogenesis ◽  
Collagen Matrices ◽  
3D Collagen ◽  
Collagen Density ◽  
Underlying Mechanisms ◽  
Fibril Length

AbstractIt is well established that the collagenous extracellular matrix surrounding solid tumors significantly influences the dissemination of cancer cells. However, the underlying mechanisms remain poorly understood, in part because of a lack of methods to modulate collagen fibril topology in the presence of embedded cells. In this work, we develop a technique to tune the fibril architecture of cell-laden 3D collagen matrices using PEG as an inert molecular crowding agent. With this approach, we demonstrate that fibril length and pore size can be modulated independently of bulk collagen density and stiffness. Using live cell imaging and quantitative analysis, we show that matrices with long fibrils induce cell elongation and single cell migration, while shorter fibrils induce cell rounding, collective migration, and morphogenesis. We conclude that fibril architecture is an independent regulator of cancer cell phenotype and that cell shape and invasion strategy are functions of collagen fibril length.

Trichome cell morphogenesis in Arabidopsis: a continuum of cellular decisionsThis review is one of a selection of papers published in the Special Issue on Plant Cell Biology.

2006 ◽  
Vol 84 (4) ◽  
pp. 604-612 ◽  
Author(s):  
Jaideep Mathur
Keyword(s):  
Cell Biology ◽  
Cell Shape ◽  
Cell Morphogenesis ◽  
Cell Type ◽  
Special Issue ◽  
Cell Form ◽  
Model Cell ◽  
Unique Cell ◽  
Selection Of ◽  
Trichome Cell

In keeping with the myriad functions carried out by plants, their component cells display an amazing diversity of shapes and sizes. How is a precise cell form achieved? In recent years, the single-celled, branched, aerial epidermal trichome of Arabidopsis thaliana L. (Heynh) has emerged as a model cell for understanding the cell biological and molecular basis underlying the development of cell shape in plants. Here, I critique the recent information gleaned from dissecting trichome cell morphogenesis in Arabidopsis and identify areas and questions that can be further addressed using this unique cell type.

The microtubule-associated protein WDL4 modulates auxin distribution to promote apical hook opening in Arabidopsis

2021 ◽  
Author(s):  
Jia Deng ◽  
Xiangfeng Wang ◽  
Ziqiang Liu ◽  
Tonglin Mao
Keyword(s):  
Cell Growth ◽  
Plant Cell ◽  
Positive Role ◽  
Apical Hook ◽  
Auxin Distribution ◽  
Differential Cell ◽  
Dicotyledonous Plants ◽  
Underlying Mechanisms ◽  
Temporal Expression Pattern ◽  
Plant Cell Growth

AbstractThe unique apical hook in dicotyledonous plants protects the shoot apical meristem and cotyledons when seedlings emerge through the soil. Its formation involves differential cell growth under the coordinated control of plant hormones, especially ethylene and auxin. Microtubules are essential players in plant cell growth that are regulated by multiple microtubule-associated proteins (MAPs). However, the role and underlying mechanisms of MAP-microtubule modules in differential cell growth are poorly understood. In this study, we found that the previously uncharacterized Arabidopsis MAP WAVE-DAMPENED2-LIKE4 (WDL4) protein plays a positive role in apical hook opening. WDL4 exhibits a temporal expression pattern during hook development in dark-grown seedlings that is directly regulated by ethylene signaling. WDL4 mutants showed a delayed hook opening phenotype while overexpression of WDL4 resulted in enhanced hook opening. In particular, wdl4-1 mutants exhibited stronger auxin accumulation in the concave side of the apical hook. Furthermore, the regulation of the auxin maxima and trafficking of the auxin efflux carriers PIN-FORMED1 (PIN1) and PIN7 in the hook region is critical for WDL4-mediated hook opening. Together, our study demonstrates that WDL4 positively regulates apical hook opening by modulating auxin distribution, thus unraveling a mechanism for MAP-mediated differential plant cell growth.

Negative regulators of cell growth

1986 ◽  
Vol 11 (1) ◽  
pp. 24-26 ◽  
Author(s):  
John L. Wang ◽  
Yen-Ming Hsu
Keyword(s):  
Cell Growth ◽  
Negative Regulators

scholarly journals Dependency relationships between IFT-dependent flagellum elongation and cell morphogenesis in Leishmania

Open Biology ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 180124 ◽  
Author(s):  
Jack Daniel Sunter ◽  
Flavia Moreira-Leite ◽  
Keith Gull
Keyword(s):  
Fluorescence Microscopy ◽  
Cell Shape ◽  
Electron Tomography ◽  
Intraflagellar Transport ◽  
Flagellar Pocket ◽  
Cell Morphogenesis ◽  
Multiple Functions ◽  
Cell Shape Changes ◽  
Shape Changes

Flagella have multiple functions that are associated with different axonemal structures. Motile flagella typically have a 9 + 2 arrangement of microtubules, whereas sensory flagella normally have a 9 + 0 arrangement. Leishmania exhibits both of these flagellum forms and differentiation between these two flagellum forms is associated with cytoskeletal and cell shape changes. We disrupted flagellum elongation in Leishmania by deleting the intraflagellar transport (IFT) protein IFT140 and examined the effects on cell morphogenesis. Δift140 cells have no external flagellum, having only a very short flagellum within the flagellar pocket. This short flagellum had a collapsed 9 + 0 (9v) axoneme configuration reminiscent of that in the amastigote and was not attached to the pocket membrane. Although amastigote-like changes occurred in the flagellar cytoskeleton, the cytoskeletal structures of Δift140 cells retained their promastigote configurations, as examined by fluorescence microscopy of tagged proteins and serial electron tomography. Thus, Leishmania promastigote cell morphogenesis does not depend on the formation of a long flagellum attached at the neck. Furthermore, our data show that disruption of the IFT system is sufficient to produce a switch from the 9 + 2 to the collapsed 9 + 0 (9v) axonemal structure, echoing the process that occurs during the promastigote to amastigote differentiation.

The actin cytoskeleton is required to elaborate and maintain spatial patterning during trichome cell morphogenesis in Arabidopsis thaliana

Development ◽  
1999 ◽  
Vol 126 (24) ◽  
pp. 5559-5568 ◽  
Author(s):  
J. Mathur ◽  
P. Spielhofer ◽  
B. Kost ◽  
N. Chua
Keyword(s):  
Arabidopsis Thaliana ◽  
Actin Cytoskeleton ◽  
Spatial Patterning ◽  
Actin Microfilaments ◽  
Cell Morphogenesis ◽  
Actin Organization ◽  
Cytoskeleton Organization ◽  
Branch Formation ◽  
Actin Cytoskeleton Organization ◽  
Trichome Cell

Arabidopsis thaliana trichomes provide an attractive model system to dissect molecular processes involved in the generation of shape and form in single cell morphogenesis in plants. We have used transgenic Arabidopsis plants carrying a GFP-talin chimeric gene to analyze the role of the actin cytoskeleton in trichome cell morphogenesis. We found that during trichome cell development the actin microfilaments assumed an increasing degree of complexity from fine filaments to thick, longitudinally stretched cables. Disruption of the F-actin cytoskeleton by actin antagonists produced distorted but branched trichomes which phenocopied trichomes of mutants belonging to the ‘distorted’ class. Subsequent analysis of the actin cytoskeleton in trichomes of the distorted mutants, alien, crooked, distorted1, gnarled, klunker and wurm uncovered actin organization defects in each case. Treatments of wild-type seedlings with microtubule-interacting drugs elicited a radically different trichome phenotype characterized by isotropic growth and a severe inhibition of branch formation; these trichomes did not show defects in actin cytoskeleton organization. A normal actin cytoskeleton was also observed in trichomes of the zwichel mutant which have reduced branching. ZWICHEL, which was previously shown to encode a kinesin-like protein is thought to be involved in microtubule-linked processes. Based on our results we propose that microtubules establish the spatial patterning of trichome branches whilst actin microfilaments elaborate and maintain the overall trichome pattern during development.

scholarly journals Paediatrician’s guide to epigenetics

2019 ◽  
Vol 104 (3) ◽  
pp. 297-301 ◽  
Author(s):  
Lauren Byrne ◽  
Amanda Jane Drake
Keyword(s):  
Life Events ◽  
Early Life ◽  
Normal Development ◽  
Disease Risk ◽  
Regulation Of Gene Expression ◽  
High Quality ◽  
High Quality Research ◽  
Growth Development ◽  
Underlying Mechanisms ◽  
Early Life Events

Epigenetic regulation of gene expression is critical for normal development. Dysregulation of the epigenome can lead to the development and progression of a number of diseases relevant to paediatricians, including disorders of genomic imprinting and malignancies. It has long been recognised that early life events have implications for future disease risk, and epigenetic modifications may play a role in this, although further high-quality research is needed to better understand the underlying mechanisms. Research in the field of epigenetics will contribute to a greater understanding of growth, development and disease; however, paediatricians need to be able to interpret such research critically, in order to use the potential advances brought about through epigenetic studies while appreciating their limitations.

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