1
|
Gu Y, Rasmussen CG. Cell biology of primary cell wall synthesis in plants. THE PLANT CELL 2022; 34:103-128. [PMID: 34613413 PMCID: PMC8774047 DOI: 10.1093/plcell/koab249] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 10/01/2021] [Indexed: 05/07/2023]
Abstract
Building a complex structure such as the cell wall, with many individual parts that need to be assembled correctly from distinct sources within the cell, is a well-orchestrated process. Additional complexity is required to mediate dynamic responses to environmental and developmental cues. Enzymes, sugars, and other cell wall components are constantly and actively transported to and from the plasma membrane during diffuse growth. Cell wall components are transported in vesicles on cytoskeletal tracks composed of microtubules and actin filaments. Many of these components, and additional proteins, vesicles, and lipids are trafficked to and from the cell plate during cytokinesis. In this review, we first discuss how the cytoskeleton is initially organized to add new cell wall material or to build a new cell wall, focusing on similarities during these processes. Next, we discuss how polysaccharides and enzymes that build the cell wall are trafficked to the correct location by motor proteins and through other interactions with the cytoskeleton. Finally, we discuss some of the special features of newly formed cell walls generated during cytokinesis.
Collapse
Affiliation(s)
- Ying Gu
- Author for correspondence: (Y.G.), (C.G.R.)
| | | |
Collapse
|
2
|
Methods to Visualize the Actin Cytoskeleton During Plant Cell Division. Methods Mol Biol 2021. [PMID: 34705230 DOI: 10.1007/978-1-0716-1744-1_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/29/2023]
Abstract
Cell division in plants consists of separating the mother cell in two daughter cells by the centrifugal growth of a new wall. This process involves the reorganization of the structural elements of the cell, namely the microtubules and actin cytoskeleton which allow the coordination, the orientation, and the progression of mitosis. In addition to its implication in those plant-specific structures, the actin cytoskeleton, in close association with the plasma membrane, exhibits specific patterning at the cortex of the dividing cells, and might act as a signaling component. This review proposes an overview of the techniques available to visualize the actin cytoskeleton in fixed tissues or living cells during division, including electron, fluorescent, and super-resolution microscopy techniques.
Collapse
|
3
|
Leelarasamee N, Zhang L, Gleason C. The root-knot nematode effector MiPFN3 disrupts plant actin filaments and promotes parasitism. PLoS Pathog 2018; 14:e1006947. [PMID: 29543900 PMCID: PMC5871015 DOI: 10.1371/journal.ppat.1006947] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Revised: 03/27/2018] [Accepted: 02/21/2018] [Indexed: 12/03/2022] Open
Abstract
Root-knot nematodes secrete effectors that manipulate their host plant cells so that the nematode can successfully establish feeding sites and complete its lifecycle. The root-knot nematode feeding structures, their “giant cells,” undergo extensive cytoskeletal remodeling. Previous cytological studies have shown the cytoplasmic actin within the feeding sites looks diffuse. In an effort to study root-knot nematode effectors that are involved in giant cell organogenesis, we have identified a nematode effector called MiPFN3 (Meloidogyne incognita Profilin 3). MiPFN3 is transcriptionally up-regulated in the juvenile stage of the nematode. In situ hybridization experiments showed that MiPFN3 transcribed in the nematode subventral glands, where it can be secreted by the nematode stylet into the plant. Moreover, Arabidopsis plants that heterologously expressed MiPFN3 were more susceptible to root-knot nematodes, indicating that MiPFN3 promotes nematode parasitism. Since profilin proteins can bind and sequester actin monomers, we investigated the function of MiPFN3 in relation to actin. Our results show that MiPFN3 suppressed the aberrant plant growth phenotype caused by the misexpression of reproductive actin (AtACT1) in transgenic plants. In addition, it disrupted actin polymerization in an in vitro assay, and it reduced the filamentous actin network when expressed in Arabidopsis protoplasts. Over a decade ago, cytological studies showed that the cytoplasmic actin within nematode giant cells looked fragmented. Here we provide the first evidence that the nematode is secreting an effector that has significant, direct effects on the plant’s actin cytoskeleton. Root-knot nematodes are microscopic plant pests that infect plant roots and significantly reduce yields of many crop plants. The nematodes enter the plant roots and modify plant cells into complex, multinuclear feeding sites called giant cells. The formation and maintenance of giant cells is critical to nematode survival. During giant cell organogenesis, the progenitor plant cells undergo many morphological changes, including a re-organization of the cytoplasmic actin cytoskeleton. As a result, the giant cell cytoplasmic actin appears fragmented and disorganized. Plant cells can regulate their actin filament assembly, in part, through the expression of actin binding proteins such as profilins. Here we show that infectious nematode juveniles express a profilin called MiPFN3. Expression of MiPFN3 in Arabidopsis plants made the plants more susceptible to root-knot nematodes, indicating that MiPFN3 acts as an effector that aids parasitism. We show evidence that the expression MiPFN3 in plant cells causes the fragmentation of plant actin filaments. The work here demonstrates that nematode effector MiPFN3 can directly affect plant actin filaments, whose reorganization is necessary for giant cell formation.
Collapse
Affiliation(s)
- Natthanon Leelarasamee
- Department of Plant Molecular Biology and Physiology, Albrecht von Haller Institute, Georg August University, Göttingen, Germany
| | - Lei Zhang
- Department of Plant Pathology, Washington State University, Pullman, WA, United States of America
| | - Cynthia Gleason
- Department of Plant Molecular Biology and Physiology, Albrecht von Haller Institute, Georg August University, Göttingen, Germany
- Department of Plant Pathology, Washington State University, Pullman, WA, United States of America
- * E-mail:
| |
Collapse
|
4
|
Paez-Garcia A, Sparks JA, de Bang L, Blancaflor EB. Plant Actin Cytoskeleton: New Functions from Old Scaffold. PLANT CELL MONOGRAPHS 2018. [DOI: 10.1007/978-3-319-69944-8_6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
5
|
Kozgunova E, Suzuki T, Ito M, Higashiyama T, Kurihara D. Haspin has Multiple Functions in the Plant Cell Division Regulatory Network. PLANT & CELL PHYSIOLOGY 2016; 57:848-61. [PMID: 26872832 DOI: 10.1093/pcp/pcw030] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Accepted: 02/03/2016] [Indexed: 05/22/2023]
Abstract
Progression of cell division is controlled by various mitotic kinases. In animal cells, phosphorylation of histone H3 at Thr3 by the kinase Haspin (haploid germ cell-specific nuclear protein kinase) promotes centromeric Aurora B localization to regulate chromosome segregation. However, less is known about the function of Haspin in regulatory networks in plant cells. Here, we show that inhibition of Haspin with 5-iodotubercidin (5-ITu) in Bright Yellow-2 (BY-2) cells delayed chromosome alignment. Haspin inhibition also prevented the centromeric localization of Aurora3 kinase (AUR3) and disrupted its function. This suggested that Haspin plays a role in the specific positioning of AUR3 on chromosomes in plant cells, a function conserved in animals. The results also indicated that Haspin and AUR3 are involved in the same pathway, which regulates chromosome alignment during prometaphase/metaphase. Remarkably, Haspin inhibition by 5-ITu also led to a severe cytokinesis defect, resulting in binuclear cells with a partially formed cell plate. The 5-ITu treatment did not affect microtubules, AUR1/2 or the NACK-PQR pathway; however, it did alter the distribution of actin filaments on the cell plate. Together, these results suggested that Haspin has several functions in regulating cell division in plant cells: in the localization of AUR3 on centromeres and in regulating late cell plate expansion during cytokinesis.
Collapse
Affiliation(s)
- Elena Kozgunova
- Division of Biological Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8602 Japan
| | - Takamasa Suzuki
- College of Bioscience and Biotechnology, Chubu University, Matsumoto-cho, Kasugai, Aichi, 478-8501 Japan Higashiyama Live-Holonics Project, ERATO, JST, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8602 Japan
| | - Masaki Ito
- Division of Biological Science, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8601 Japan JST, CREST, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8601 Japan
| | - Tetsuya Higashiyama
- Division of Biological Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8602 Japan Higashiyama Live-Holonics Project, ERATO, JST, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8602 Japan Institute of Transformative Bio-Molecules (ITbM), Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8602 Japan
| | - Daisuke Kurihara
- Division of Biological Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8602 Japan Higashiyama Live-Holonics Project, ERATO, JST, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8602 Japan
| |
Collapse
|
6
|
Nie Z, Kang G, Duan C, Li Y, Dai L, Zeng R. Profiling Ethylene-Responsive Genes Expressed in the Latex of the Mature Virgin Rubber Trees Using cDNA Microarray. PLoS One 2016; 11:e0152039. [PMID: 26985821 PMCID: PMC4795647 DOI: 10.1371/journal.pone.0152039] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 02/22/2016] [Indexed: 12/19/2022] Open
Abstract
Ethylene is commonly used as a latex stimulant of Hevea brasiliensis by application of ethephon (chloro-2-ethylphosphonic acid); however, the molecular mechanism by which ethylene increases latex production is not clear. To better understand the effects of ethylene stimulation on the laticiferous cells of rubber trees, a latex expressed sequence tag (EST)-based complementary DNA microarray containing 2,973 unique genes (probes) was first developed and used to analyze the gene expression changes in the latex of the mature virgin rubber trees after ethephon treatment at three different time-points: 8, 24 and 48 h. Transcript levels of 163 genes were significantly altered with fold-change values ≥ 2 or ≤ –2 (q-value < 0.05) in ethephon-treated rubber trees compared with control trees. Of the 163 genes, 92 were up-regulated and 71 down-regulated. The microarray results were further confirmed using real-time quantitative reverse transcript-PCR for 20 selected genes. The 163 ethylene-responsive genes were involved in several biological processes including organic substance metabolism, cellular metabolism, primary metabolism, biosynthetic process, cellular response to stimulus and stress. The presented data suggest that the laticifer water circulation, production and scavenging of reactive oxygen species, sugar metabolism, and assembly and depolymerization of the latex actin cytoskeleton might play important roles in ethylene-induced increase of latex production. The results may provide useful insights into understanding the molecular mechanism underlying the effect of ethylene on latex metabolism of H. brasiliensis.
Collapse
Affiliation(s)
- Zhiyi Nie
- Key Laboratory of Biology and Genetic Resources of Rubber Tree, Ministry of Agriculture, Rubber Research Institute, Chinese Academy of Tropical Agricultural Sciences (CATAS), Danzhou, Hainan, China
| | - Guijuan Kang
- Key Laboratory of Biology and Genetic Resources of Rubber Tree, Ministry of Agriculture, Rubber Research Institute, Chinese Academy of Tropical Agricultural Sciences (CATAS), Danzhou, Hainan, China
| | - Cuifang Duan
- Key Laboratory of Biology and Genetic Resources of Rubber Tree, Ministry of Agriculture, Rubber Research Institute, Chinese Academy of Tropical Agricultural Sciences (CATAS), Danzhou, Hainan, China
| | - Yu Li
- Key Laboratory of Biology and Genetic Resources of Rubber Tree, Ministry of Agriculture, Rubber Research Institute, Chinese Academy of Tropical Agricultural Sciences (CATAS), Danzhou, Hainan, China
| | - Longjun Dai
- Key Laboratory of Biology and Genetic Resources of Rubber Tree, Ministry of Agriculture, Rubber Research Institute, Chinese Academy of Tropical Agricultural Sciences (CATAS), Danzhou, Hainan, China
| | - Rizhong Zeng
- Key Laboratory of Biology and Genetic Resources of Rubber Tree, Ministry of Agriculture, Rubber Research Institute, Chinese Academy of Tropical Agricultural Sciences (CATAS), Danzhou, Hainan, China
| |
Collapse
|
7
|
Liu J, Tie H, Chen H, Han R. The distribution of profilin in root-tip cells of wheat seedlings exposed to enhanced UV-B radiation. FRONTIERS IN LIFE SCIENCE 2015. [DOI: 10.1080/21553769.2015.1075434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
8
|
Zhou Z, Munteanu EL, He J, Ursell T, Bathe M, Huang KC, Chang F. The contractile ring coordinates curvature-dependent septum assembly during fission yeast cytokinesis. Mol Biol Cell 2014; 26:78-90. [PMID: 25355954 PMCID: PMC4279231 DOI: 10.1091/mbc.e14-10-1441] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Cytokinesis in fission yeast is accomplished by inward growth of the cell wall septum guided by the contractile ring. The ring promotes local septum growth in a curvature-dependent manner, allowing even a misshapen septum to grow into a more regular shape. This suggests that the ring regulates cell wall assembly through a mechanosensitive mechanism. The functions of the actin-myosin–based contractile ring in cytokinesis remain to be elucidated. Recent findings show that in the fission yeast Schizosaccharomyces pombe, cleavage furrow ingression is driven by polymerization of cell wall fibers outside the plasma membrane, not by the contractile ring. Here we show that one function of the ring is to spatially coordinate septum cell wall assembly. We develop an improved method for live-cell imaging of the division apparatus by orienting the rod-shaped cells vertically using microfabricated wells. We observe that the septum hole and ring are circular and centered in wild-type cells and that in the absence of a functional ring, the septum continues to ingress but in a disorganized and asymmetric manner. By manipulating the cleavage furrow into different shapes, we show that the ring promotes local septum growth in a curvature-dependent manner, allowing even a misshapen septum to grow into a more regular shape. This curvature-dependent growth suggests a model in which contractile forces of the ring shape the septum cell wall by stimulating the cell wall machinery in a mechanosensitive manner. Mechanical regulation of the cell wall assembly may have general relevance to the morphogenesis of walled cells.
Collapse
Affiliation(s)
- Zhou Zhou
- Department of Microbiology and Immunology, Columbia University College of Physicians and Surgeons, New York, NY 10032
| | - Emilia Laura Munteanu
- Department of Microbiology and Immunology, Columbia University College of Physicians and Surgeons, New York, NY 10032
| | - Jun He
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Tristan Ursell
- Department of Bioengineering, Stanford University, Stanford, CA 94305
| | - Mark Bathe
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Kerwyn Casey Huang
- Department of Bioengineering, Stanford University, Stanford, CA 94305 Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305
| | - Fred Chang
- Department of Microbiology and Immunology, Columbia University College of Physicians and Surgeons, New York, NY 10032
| |
Collapse
|
9
|
Kojo KH, Higaki T, Kutsuna N, Yoshida Y, Yasuhara H, Hasezawa S. Roles of cortical actin microfilament patterning in division plane orientation in plants. PLANT & CELL PHYSIOLOGY 2013; 54:1491-503. [PMID: 23825219 DOI: 10.1093/pcp/pct093] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
In land plant cells, division planes are precisely predicted by the microtubule preprophase band and cortical actin microfilament pattern called the actin-depleted zone or actin microfilament twin peaks. However, the function of cortical actin microfilament patterning is not clear. In this study, we report that treatment with the inhibitor 2,3,5-triiodobenzonic acid (TIBA) or jasplakinolide increased the amount of thick actin microfilaments in tobacco BY-2 cells at interphase. However, during the division of BY-2 cells, these inhibitors did not induce visible alteration of actin microfilament thickness but altered cortical actin microfilament patterning without significant disorganization of the microtubule preprophase band. TIBA treatment induced a single intensity peak of actin microfilament distribution around the cell center, whereas jasplakinolide caused the appearance of triple peaks relative to the distribution of actin microfilament around the cell center, in approximately one-third of the cells at metaphase. Dual observations of microtubules and actin microfilaments revealed that abnormal cortical actin microfilament patterning with single or triple peaks is correlated with oblique mitotic spindles in BY-2 cells. In addition, oblique cell plates were frequently observed in BY-2 cells and Arabidopsis thaliana root cells treated with TIBA or jasplakinolide. These results provide evidence for the critical roles of cortical actin microfilament patterning in spindle and cell plate orientation.
Collapse
Affiliation(s)
- Kei H Kojo
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha Kashiwa, Chiba, 277-8562 Japan
| | | | | | | | | | | |
Collapse
|
10
|
Xu C, Liu Z, Zhang L, Zhao C, Yuan S, Zhang F. Organization of actin cytoskeleton during meiosis I in a wheat thermo-sensitive genic male sterile line. PROTOPLASMA 2013; 250:415-422. [PMID: 22350736 DOI: 10.1007/s00709-012-0386-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2011] [Accepted: 01/30/2012] [Indexed: 05/31/2023]
Abstract
BS366 is a thermo-sensitive male sterile line of wheat (Triticum aestivum L.) for two-line hybrid breeding, which exhibits aberrant meiotic cytokinesis under low temperature. Through transcriptome analysis, a possible regulatory role for plant actin cytoskeleton was suggested. However, the organization of actin cytoskeleton in meiosis has been poorly understood so far. Here, fixed microsporocytes during meiosis were labeled with tetramethylrhodamine isothiocyanate-phalloidin and 4',6-diamidino-2-phenylindole. Quantities of fluorescent micrographs were captured using a confocal microscope, including the transient state from metaphase to telophase. We observed that actin filaments were abundant in typical kariokinetic spindle, central spindle (parallel microtubules or actin fibers between two separated chromosomes in anaphase), and phragmoplast. Interestingly, we identified the Chinese lantern-shaped actin phragmoplast in wheat meiosis for the first time. Under low temperature, phragmoplast actin filaments were chaotic and normal cell plate failed to form. These data provide new insights into the organization of actin filaments during male meiosis of plant and support a role of actin cytoskeleton in bringing about thermo-sensitive male sterility in wheat.
Collapse
Affiliation(s)
- Chenguang Xu
- Beijing Engineering and Technique Research Center for Hybrid Wheat, Beijing Academy of Agricultural and Forestry Sciences, Beijing 100097, China
| | | | | | | | | | | |
Collapse
|
11
|
De Storme N, Copenhaver GP, Geelen D. Production of diploid male gametes in Arabidopsis by cold-induced destabilization of postmeiotic radial microtubule arrays. PLANT PHYSIOLOGY 2012; 160:1808-26. [PMID: 23096158 PMCID: PMC3510112 DOI: 10.1104/pp.112.208611] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Accepted: 10/24/2012] [Indexed: 05/18/2023]
Abstract
Whole-genome duplication through the formation of diploid gametes is a major route for polyploidization, speciation, and diversification in plants. The prevalence of polyploids in adverse climates led us to hypothesize that abiotic stress conditions can induce or stimulate diploid gamete production. In this study, we show that short periods of cold stress induce the production of diploid and polyploid pollen in Arabidopsis (Arabidopsis thaliana). Using a combination of cytological and genetic analyses, we demonstrate that cold stress alters the formation of radial microtubule arrays at telophase II and consequently leads to defects in postmeiotic cytokinesis and cell wall formation. As a result, cold-stressed male meiosis generates triads, dyads, and monads that contain binuclear and polynuclear microspores. Fusion of nuclei in binuclear and polynuclear microspores occurs spontaneously before pollen mitosis I and eventually leads to the formation of diploid and polyploid pollen grains. Using segregation analyses, we also found that the majority of cold-induced dyads and triads are genetically equivalent to a second division restitution and produce diploid gametes that are highly homozygous. In a broader perspective, these findings offer insights into the fundamental mechanisms that regulate male gametogenesis in plants and demonstrate that their sensitivity to environmental stress has evolutionary significance and agronomic relevance in terms of polyploidization.
Collapse
Affiliation(s)
- Nico De Storme
- Department of Plant Production, Faculty of Bioscience Engineering, University of Ghent, 9000 Ghent, Belgium (N.D.S., D.G.); Department of Biology and Carolina Center for Genome Sciences, University of North Carolina, Chapel Hill, North Carolina 27599 (G.P.C.); and Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, North Carolina 27599 (G.P.C.)
| | - Gregory P. Copenhaver
- Department of Plant Production, Faculty of Bioscience Engineering, University of Ghent, 9000 Ghent, Belgium (N.D.S., D.G.); Department of Biology and Carolina Center for Genome Sciences, University of North Carolina, Chapel Hill, North Carolina 27599 (G.P.C.); and Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, North Carolina 27599 (G.P.C.)
| | - Danny Geelen
- Department of Plant Production, Faculty of Bioscience Engineering, University of Ghent, 9000 Ghent, Belgium (N.D.S., D.G.); Department of Biology and Carolina Center for Genome Sciences, University of North Carolina, Chapel Hill, North Carolina 27599 (G.P.C.); and Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, North Carolina 27599 (G.P.C.)
| |
Collapse
|
12
|
van der Honing HS, Kieft H, Emons AMC, Ketelaar T. Arabidopsis VILLIN2 and VILLIN3 are required for the generation of thick actin filament bundles and for directional organ growth. PLANT PHYSIOLOGY 2012; 158:1426-38. [PMID: 22209875 PMCID: PMC3291277 DOI: 10.1104/pp.111.192385] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2011] [Accepted: 12/21/2011] [Indexed: 05/18/2023]
Abstract
In plant cells, actin filament bundles serve as tracks for myosin-dependent organelle movement and play a role in the organization of the cytoplasm. Although virtually all plant cells contain actin filament bundles, the role of the different actin-bundling proteins remains largely unknown. In this study, we investigated the role of the actin-bundling protein villin in Arabidopsis (Arabidopsis thaliana). We used Arabidopsis T-DNA insertion lines to generate a double mutant in which VILLIN2 (VLN2) and VLN3 transcripts are truncated. Leaves, stems, siliques, and roots of vln2 vln3 double mutant plants are twisted, which is caused by local differences in cell length. Microscopy analysis of the actin cytoskeleton showed that in these double mutant plants, thin actin filament bundles are more abundant while thick actin filament bundles are virtually absent. In contrast to full-length VLN3, truncated VLN3 lacking the headpiece region does not rescue the phenotype of the vln2 vln3 double mutant. Our results show that villin is involved in the generation of thick actin filament bundles in several cell types and suggest that these bundles are involved in the regulation of coordinated cell expansion.
Collapse
Affiliation(s)
- Hannie S. van der Honing
- Laboratory of Cell Biology, Wageningen University, 6708 PB Wageningen, The Netherlands (H.S.v.d.H., H.K., A.M.C.E., T.K.); and Department of Biomolecular Systems, Stichting voor Fundamenteel Onderzoek der Materie Institute for Atomic and Molecular Physics, 1098 SG Amsterdam, The Netherlands (A.M.C.E.)
| | - Henk Kieft
- Laboratory of Cell Biology, Wageningen University, 6708 PB Wageningen, The Netherlands (H.S.v.d.H., H.K., A.M.C.E., T.K.); and Department of Biomolecular Systems, Stichting voor Fundamenteel Onderzoek der Materie Institute for Atomic and Molecular Physics, 1098 SG Amsterdam, The Netherlands (A.M.C.E.)
| | - Anne Mie C. Emons
- Laboratory of Cell Biology, Wageningen University, 6708 PB Wageningen, The Netherlands (H.S.v.d.H., H.K., A.M.C.E., T.K.); and Department of Biomolecular Systems, Stichting voor Fundamenteel Onderzoek der Materie Institute for Atomic and Molecular Physics, 1098 SG Amsterdam, The Netherlands (A.M.C.E.)
| | - Tijs Ketelaar
- Laboratory of Cell Biology, Wageningen University, 6708 PB Wageningen, The Netherlands (H.S.v.d.H., H.K., A.M.C.E., T.K.); and Department of Biomolecular Systems, Stichting voor Fundamenteel Onderzoek der Materie Institute for Atomic and Molecular Physics, 1098 SG Amsterdam, The Netherlands (A.M.C.E.)
| |
Collapse
|
13
|
van der Honing HS, van Bezouwen LS, Emons AMC, Ketelaar T. High expression of Lifeact in Arabidopsis thaliana reduces dynamic reorganization of actin filaments but does not affect plant development. Cytoskeleton (Hoboken) 2011; 68:578-87. [PMID: 21948789 DOI: 10.1002/cm.20534] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2010] [Revised: 09/01/2011] [Accepted: 09/09/2011] [Indexed: 01/12/2023]
Abstract
Lifeact is a novel probe that labels actin filaments in a wide range of organisms. We compared the localization and reorganization of Lifeact:Venus-labeled actin filaments in Arabidopsis root hairs and root epidermal cells of lines that express different levels of Lifeact: Venus with that of actin filaments labeled with GFP:FABD2, a commonly used probe in plants. Unlike GFP:FABD2, Lifeact:Venus labeled the highly dynamic fine F-actin in the subapical region of tip-growing root hairs. Lifeact:Venus expression at varying levels was not observed to affect plant development. However, at expression levels comparable to those of GFP:FABD2 in a well-characterized marker line, Lifeact:Venus reduced reorganization rates of bundles of actin filaments in root epidermal cells. Reorganization rates of cytoplasmic strands, which reflect the reorganization of the actin cytoskeleton, were also reduced in these lines. Moreover, in the same line, Lifeact:Venus-decorated actin filaments were more resistant to depolymerization by latrunculin B than those in an equivalent GFP:FABD2-expressing line. In lines where Lifeact: Venus is expressed at lower levels, these effects are less prominent or even absent. We conclude that Lifeact: Venus reduces remodeling of the actin cytoskeleton in Arabidopsis in a concentration-dependent manner. Since this reduction occurs at expression levels that do not cause defects in plant development, selection of normally growing plants is not sufficient to determine optimal Lifeact expression levels. When correct expression levels of Lifeact have been determined, it is a valuable probe that labels dynamic populations of actin filaments such as fine F-actin, better than FABD2 does.
Collapse
|
14
|
Esseling-Ozdoba A, Kik RA, van Lammeren AA, Kleijn JM, Emons AMC. Flexibility contra stiffness: the phragmoplast as a physical barrier for beads but not for vesicles. PLANT PHYSIOLOGY 2010; 152:1065-1072. [PMID: 19939943 PMCID: PMC2815859 DOI: 10.1104/pp.109.150417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2009] [Accepted: 11/16/2009] [Indexed: 05/28/2023]
Abstract
In plant cells, Golgi vesicles are transported to the division plane to fuse with each other, forming the cell plate, the initial membrane-bordered cell wall separating daughter cells. Vesicles, but not organelles, move through the phragmoplast, which consists of two opposing cylinders of microtubules and actin filaments, interlaced with endoplasmic reticulum membrane. To study physical aspects of this transport/inhibition process, we microinjected fluorescent synthetic 1,2-dioleoyl-sn-glycero-3-phospho-rac-1-glycerol (DOPG) vesicles and polystyrene beads into Tradescantia virginiana stamen hair cells. The phragmoplast was nonselective for DOPG vesicles of a size up to 150 nm in diameter but was a physical barrier for polystyrene beads having a diameter of 20 and 40 nm and also when beads were coated with the same DOPG membrane. We conclude that stiffness is a parameter for vesicle transit through the phragmoplast and discuss that cytoskeleton configurations can physically block such transit.
Collapse
|
15
|
Hauser M, Roulias A, Ferreira F, Egger M. Panallergens and their impact on the allergic patient. Allergy Asthma Clin Immunol 2010; 6:1. [PMID: 20298513 PMCID: PMC2830198 DOI: 10.1186/1710-1492-6-1] [Citation(s) in RCA: 197] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2009] [Accepted: 01/18/2010] [Indexed: 12/16/2022] Open
Abstract
The panallergen concept encompasses families of related proteins, which are involved in general vital processes and thus, widely distributed throughout nature. Plant panallergens share highly conserved sequence regions, structure, and function. They are responsible for many IgE cross-reactions even between unrelated pollen and plant food allergen sources. Although usually considered as minor allergens, sensitization to panallergens might be problematic as it bears the risk of developing multiple sensitizations. Clinical manifestations seem to be tightly connected with geographical and exposure factors. Future population- and disease-based screenings should provide new insights on panallergens and their contribution to disease manifestations. Such information requires molecule-based diagnostics and will be valuable for developing patient-tailored prophylactic and therapeutic approaches. In this article, we focus on profilins, non-specific lipid transfer proteins, polcalcins, and Bet v 1-related proteins and discuss possible consequences of panallergen sensitization for the allergic patient. Based on their pattern of IgE cross-reactivity, which is reflected by their distribution in the plant kingdom, we propose a novel classification of panallergens into ubiquitously spread "real panallergens" (e.g. profilins) and widespread "eurallergens" (e.g. polcalcins). "Stenallergens" display more limited distribution and cross-reactivity patterns, and "monallergens" are restricted to a single allergen source.
Collapse
Affiliation(s)
- Michael Hauser
- Christian Doppler Laboratory for Allergy Diagnosis and Therapy, Department of Molecular Biology, University of Salzburg, Hellbrunnerstrasse 34, A-5020 Salzburg, Austria
| | | | | | | |
Collapse
|
16
|
Schapire AL, Valpuesta V, Botella MA. Plasma membrane repair in plants. TRENDS IN PLANT SCIENCE 2009; 14:645-652. [PMID: 19819752 DOI: 10.1016/j.tplants.2009.09.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2009] [Revised: 09/01/2009] [Accepted: 09/09/2009] [Indexed: 05/28/2023]
Abstract
Resealing is the membrane-repair process that enables cells to survive disruption, preventing the loss of irreplaceable cell types and eliminating the cost of replacing injured cells. Given that failure in the resealing process in animal cells causes diverse types of muscular dystrophy, plasma membrane repair has been extensively studied in these systems. Animal proteins with Ca(2+)-binding domains such as synaptotagmins and dysferlin mediate Ca(2+)-dependent exocytosis to repair plasma membranes after mechanical damage. Until recently, no components or proof for membrane repair mechanisms have been discovered in plants. However, Arabidopsis SYT1 is now the first plant synaptotagmin demonstrated to participate in Ca(2+)-dependent repair of membranes. This suggests a conservation of membrane repair mechanisms between animal and plant cells.
Collapse
Affiliation(s)
- Arnaldo L Schapire
- Laboratorio de Bioquímica y Biotecnología Vegetal, Departamento de Biología Molecular y Bioquímica, Facultad de Ciencias, Universidad de Málaga, Campus Teatinos s/n, Spain
| | | | | |
Collapse
|
17
|
Rapid formin-mediated actin-filament elongation is essential for polarized plant cell growth. Proc Natl Acad Sci U S A 2009; 106:13341-6. [PMID: 19633191 DOI: 10.1073/pnas.0901170106] [Citation(s) in RCA: 118] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Formins are present in all eukaryotes and are essential for the creation of actin-based structures responsible for diverse cellular processes. Because multicellular organisms contain large formin gene families, establishing the physiological functions of formin isoforms has been difficult. Using RNAi, we analyzed the function of all 9 formin genes within the moss Physcomitrella patens. We show that plants lacking class II formins (For2) are severely stunted and composed of spherical cells with disrupted actin organization. In contrast, silencing of all other formins results in normal elongated cell morphology and actin organization. Consistent with a role in polarized growth, For2 are apically localized in growing cells. We show that an N-terminal phosphatase tensin (PTEN)-like domain mediates apical localization. The PTEN-like domain is followed by a conserved formin homology (FH)1-FH2 domain, known to promote actin polymerization. To determine whether apical localization of any FH1-FH2 domain mediates polarized growth, we performed domain swapping. We found that only the class II FH1-FH2, in combination with the PTEN-like domain, rescues polarized growth, because it cannot be replaced with a similar domain from a For1. We used in vitro polymerization assays to dissect the functional differences between these FH1-FH2 domains. We found that both the FH1 and the FH2 domains from For2 are required to mediate exceptionally rapid rates of actin filament elongation, much faster than any other known formin. Thus, our data demonstrate that rapid rates of actin elongation are critical for driving the formation of apical filamentous actin necessary for polarized growth.
Collapse
|
18
|
Zhang Y, Zhang W, Baluska F, Menzel D, Ren H. Dynamics and roles of phragmoplast microfilaments in cell plate formation during cytokinesis of tobacco BY-2 cells. Sci Bull (Beijing) 2009. [DOI: 10.1007/s11434-009-0265-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
19
|
Cheng JS, Yuan YJ. Release of proteins: Insights into oxidative response of Taxus cuspidata cells induced by shear stress. ACTA ACUST UNITED AC 2009. [DOI: 10.1016/j.molcatb.2008.11.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
20
|
|
21
|
Morales S, Jiménez-López JC, Castro AJ, Rodríguez-García MI, Alché JD. Olive pollen profilin (Ole e 2 allergen) co-localizes with highly active areas of the actin cytoskeleton and is released to the culture medium during in vitro pollen germination. J Microsc 2008; 231:332-41. [PMID: 18778430 DOI: 10.1111/j.1365-2818.2008.02044.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Pollen allergens offer a dual perspective of study: some of them are considered key proteins for pollen physiology, but they are also able to trigger allergy symptoms in susceptible humans after coming in contact with their tissues. Profilin (Ole e 2 allergen) has been characterized, to some extent, as one of the major allergens from Olea europaea L. pollen, a highly allergenic species in the Mediterranean countries. In order to obtain clues regarding the biological role of this protein, we have analyzed both its cellular localization and the organization of actin throughout pollen hydration and early pollen tube germination. The localization of the cited proteins was visualized by confocal laser scanning microscopy immunofluorescence using different antibodies. Upon pollen hydration and pollen germination, a massive presence of profilin was detected close to the site of pollen tube emergence, forming a ring-like structure around the 'effective' apertural region. Profilin was also detected in the pollen exine of the germinating pollen grains and in the germination medium. After using a permeabilization-enhanced protocol for immunolocalization, profilin was also localized in the cytoplasm of the pollen tube, particularly at both the proximal and apical ends. Noticeable accumulations of actin were observed in the cytoplasm of the pollen tube; particularly, in both the apical region and the area immediately close to the aperture. Actin filaments were not observed, probably due to the need of further enhanced fixation procedures. The ultrastructural localization of profilin showed the presence of the protein in the cytoplasm of both the mature pollen grain and the pollen tube. The results shown here could be interpreted as signs of a massive dissociation of the actin-profilin complexes, mobilization of actin monomers, and therefore, an intense activity of the actin cytoskeleton. The extensive release of allergenic proteins from the pollen grain into the surrounding aqueous media, as described here for profilin, may help us to understand the mechanisms by which these allergens might come in contact with the human mucosa, therefore triggering the symptoms of allergy.
Collapse
Affiliation(s)
- S Morales
- Department of Biochemistry, Cell and Molecular Biology of Plants, Estación Experimental del Zaidin. CSIC, Profesor Albareda, 1, 18008 Granada, Spain
| | | | | | | | | |
Collapse
|
22
|
Esseling-Ozdoba A, Vos JW, van Lammeren AAM, Emons AMC. Synthetic lipid (DOPG) vesicles accumulate in the cell plate region but do not fuse. PLANT PHYSIOLOGY 2008; 147:1699-709. [PMID: 18583535 PMCID: PMC2492608 DOI: 10.1104/pp.108.119842] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2008] [Accepted: 06/19/2008] [Indexed: 05/23/2023]
Abstract
The cell plate is the new cell wall, with bordering plasma membrane, that is formed between two daughter cells in plants, and it is formed by fusion of vesicles (approximately 60 nm). To start to determine physical properties of cell plate forming vesicles for their transport through the phragmoplast, and fusion with each other, we microinjected fluorescent synthetic lipid vesicles that were made of 1,2-dioleoyl-sn-glycero-3-[phospho-rac-(1-glycerol)] (DOPG) into Tradescantia virginiana stamen hair cells. During interphase, the 60-nm wide DOPG vesicles moved inside the cytoplasm comparably to organelles. During cytokinesis, they were transported through the phragmoplast and accumulated in the cell plate region together with the endogenous vesicles, even inside the central cell plate region. Because at this stage microtubules are virtually absent from that region, while actin filaments are present, actin filaments may have a role in the transport of vesicles toward the cell plate. Unlike the endogenous vesicles, the synthetic DOPG vesicles did not fuse with the developing cell plate. Instead, they redistributed into the cytoplasm of the daughter cells upon completion of cytokinesis. Because the redistribution of the vesicles occurs when actin filaments disappear from the phragmoplast, actin filaments may be involved in keeping the vesicles inside the developing cell plate region.
Collapse
|
23
|
Higaki T, Kutsuna N, Sano T, Hasezawa S. Quantitative analysis of changes in actin microfilament contribution to cell plate development in plant cytokinesis. BMC PLANT BIOLOGY 2008; 8:80. [PMID: 18637163 PMCID: PMC2490694 DOI: 10.1186/1471-2229-8-80] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2008] [Accepted: 07/17/2008] [Indexed: 05/19/2023]
Abstract
BACKGROUND Plant cells divide by the formation of new cross walls, known as cell plates, from the center to periphery of each dividing cell. Formation of the cell plate occurs in the phragmoplast, a complex structure composed of membranes, microtubules (MTs) and actin microfilaments (MFs). Disruption of phragmoplast MTs was previously found to completely inhibit cell plate formation and expansion, indicative of their crucial role in the transport of cell plate membranes and materials. In contrast, disruption of MFs only delays cell plate expansion but does not completely inhibit cell plate formation. Despite such findings, the significance and molecular mechanisms of MTs and MFs remain largely unknown. RESULTS Time-sequential changes in MF-distribution were monitored by live imaging of tobacco BY-2 cells stably expressing the GFP-actin binding domain 2 (GFP-ABD2) fusion protein, which vitally co-stained with the endocytic tracer, FM4-64, that labels the cell plate. During cytokinesis, MFs accumulated near the newly-separated daughter nuclei towards the emerging cell plate, and subsequently approached the expanding cell plate edges. Treatment with an actin polymerization inhibitor caused a decrease in the cell plate expansion rate, which was quantified using time-lapse imaging and regression analysis. Our results demonstrated time-sequential changes in the contribution of MFs to cell plate expansion; MF-disruption caused about a 10% decrease in the cell plate expansion rate at the early phase of cytokinesis, but about 25% at the late phase. MF-disruption also caused malformation of the emerging cell plate at the early phase, indicative of MF involvement in early cell plate formation and expansion. The dynamic movement of endosomes around the cell plate was also inhibited by treatment with an actin polymerization inhibitor and a myosin ATPase inhibitor, respectively. Furthermore, time-lapse imaging of the endoplasmic reticulum (ER) revealed that MFs were involved in ER accumulation in the phragmoplast at the late phase. CONCLUSION By expression of GFP-ABD2 and vital staining with FM4-64, the dynamics of MFs and the cell plate could be followed throughout plant cytokinesis in living cells. Pharmacological treatment and live imaging analysis also allowed us to quantify MF contribution to cell plate expansion during cytokinesis. Our results suggest that MFs play significant roles in cell plate formation and expansion via regulation of endomembrane dynamics.
Collapse
Affiliation(s)
- Takumi Higaki
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwanoha Kashiwa, Chiba 277-8562, Japan
| | - Natsumaro Kutsuna
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwanoha Kashiwa, Chiba 277-8562, Japan
- Institute for Bioinformatics Research and Development (BIRD), Japan Science and Technology Agency (JST), Chiyoda-ku, Tokyo 102-8666, Japan
| | - Toshio Sano
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwanoha Kashiwa, Chiba 277-8562, Japan
- Institute for Bioinformatics Research and Development (BIRD), Japan Science and Technology Agency (JST), Chiyoda-ku, Tokyo 102-8666, Japan
| | - Seiichiro Hasezawa
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwanoha Kashiwa, Chiba 277-8562, Japan
- Institute for Bioinformatics Research and Development (BIRD), Japan Science and Technology Agency (JST), Chiyoda-ku, Tokyo 102-8666, Japan
| |
Collapse
|
24
|
Seguí-Simarro J, Nuez F. Pathways to doubled haploidy: chromosome doubling during androgenesis. Cytogenet Genome Res 2008; 120:358-69. [DOI: 10.1159/000121085] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/14/2007] [Indexed: 01/04/2023] Open
|
25
|
Higaki T, Goh T, Hayashi T, Kutsuna N, Kadota Y, Hasezawa S, Sano T, Kuchitsu K. Elicitor-induced cytoskeletal rearrangement relates to vacuolar dynamics and execution of cell death: in vivo imaging of hypersensitive cell death in tobacco BY-2 cells. PLANT & CELL PHYSIOLOGY 2007; 48:1414-25. [PMID: 17704529 DOI: 10.1093/pcp/pcm109] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Disintegration of the vacuolar membrane (VM) has been proposed to be a crucial event in various types of programmed cell death (PCD) in plants. However, its regulatory mechanisms are mostly unknown. To obtain new insights on the regulation of VM disintegration during hypersensitive cell death, we investigated the structural dynamics and permeability of the VM, as well as cytoskeletal reorganization during PCD in tobacco BY-2 cells induced by a proteinaceous elicitor, cryptogein. From sequential observations, we have identified the following remarkable events during PCD. Stage 1: bulb-like VM structures appear within the vacuolar lumen and the cortical microtubules are disrupted, while the cortical actin microfilaments are bundled. Simultaneously, transvacuolar strands including endoplasmic microtubules and actin microfilaments are gradually disrupted and the nucleus moves from the center to the periphery of the cell. Stage 2: cortical actin microfilament bundles and complex bulb-like VM structures disappear. The structure of the large central vacuole becomes simpler, and small spherical vacuoles appear. Stage 3: the VM is disintegrated and a fluorescent dye, BCECF, leaks out of the vacuoles just prior to PCD. Application of an actin polymerization inhibitor facilitates both the disappearance of bulb-like vacuolar membrane structures and induction of cell death. These results suggest that the elicitor-induced reorganization of actin microfilaments is involved in the regulation of hypersensitive cell death via modification of the vacuolar structure to induce VM disintegration.
Collapse
Affiliation(s)
- Takumi Higaki
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwanoha Kashiwa, Chiba, 277-8562 Japan
| | | | | | | | | | | | | | | |
Collapse
|
26
|
Kandasamy MK, Burgos-Rivera B, McKinney EC, Ruzicka DR, Meagher RB. Class-specific interaction of profilin and ADF isovariants with actin in the regulation of plant development. THE PLANT CELL 2007; 19:3111-26. [PMID: 17933902 PMCID: PMC2174723 DOI: 10.1105/tpc.107.052621] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2007] [Revised: 09/06/2007] [Accepted: 09/24/2007] [Indexed: 05/20/2023]
Abstract
Two ancient and highly divergent actin-based cytoskeletal systems have evolved in angiosperms. Plant genomes encode complex actin and actin binding protein (ABP) gene families, most of which are phylogenetically grouped into gene classes with distinct vegetative or constitutive and reproductive expression patterns. In Arabidopsis thaliana, ectopic expression of high levels of a reproductive class actin, ACT1, in vegetative tissues causes severe dwarfing of plants with aberrant organization of most plant organs and cell types due to a severely altered actin cytoskeletal architecture. Overexpression of the vegetative class actin ACT2 to similar levels, however, produces insignificant phenotypic changes. We proposed that the misexpression of the pollen-specific ACT1 in vegetative cell types affects the dynamics of actin due to its inappropriate interaction with endogenous vegetative ABPs. To examine the functionally distinct interactions among the major classes of actins and ABPs, we ectopically coexpressed reproductive profilin (PRF4) or actin-depolymerizing factor (ADF) isovariants (e.g., ADF7) with ACT1. Our results demonstrated that the coexpression of these reproductive, but not vegetative, ABP isovariants suppressed the ectopic ACT1 expression phenotypes and restored wild-type stature and normal actin cytoskeletal architecture to the double transgenic plants. Thus, the actins and ABPs appear to have evolved class-specific, protein-protein interactions that are essential to the normal regulation of plant growth and development.
Collapse
Affiliation(s)
- Muthugapatti K Kandasamy
- Department of Genetics, Davison Life Sciences Building, University of Georgia, Athens, Georgia 30602, USA
| | | | | | | | | |
Collapse
|
27
|
van der Honing HS, Emons AMC, Ketelaar T. Actin based processes that could determine the cytoplasmic architecture of plant cells. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2007; 1773:604-14. [PMID: 16962185 DOI: 10.1016/j.bbamcr.2006.07.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2006] [Revised: 06/09/2006] [Accepted: 07/21/2006] [Indexed: 10/24/2022]
Abstract
Actin polymerisation can generate forces that are necessary for cell movement, such as the propulsion of a class of bacteria, including Listeria, and the protrusion of migrating animal cells. Force generation by the actin cytoskeleton in plant cells has not been studied. One process in plant cells that is likely to depend on actin-based force generation is the organisation of the cytoplasm. We compare the function of actin binding proteins of three well-studied mammalian models that depend on actin-based force generation with the function of their homologues in plants. We predict the possible role of these proteins, and thus the role of actin-based force generation, in the production of cytoplasmic organisation in plant cells.
Collapse
Affiliation(s)
- Hannie S van der Honing
- Laboratory of Plant Cell Biology, Wageningen University, Arboretumlaan 4, 6703BD Wageningen, The Netherlands
| | | | | |
Collapse
|
28
|
Szechyńska-Hebda M, Wedzony M, Dubas E, Kieft H, van Lammeren A. Visualisation of microtubules and actin filaments in fixed BY-2 suspension cells using an optimised whole mount immunolabelling protocol. PLANT CELL REPORTS 2006; 25:758-66. [PMID: 16528566 DOI: 10.1007/s00299-005-0089-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2005] [Revised: 09/02/2005] [Accepted: 10/31/2005] [Indexed: 05/03/2023]
Abstract
Excellent visualisation of microtubules and actin filaments was obtained in fixed tobacco BY-2 suspension cells after optimising a protocol for whole mount immunolabelling. The procedure is based on modification of fixation, cell wall digestion, dimethyl sulfoxide (DMSO) treatment, post fixation, and blocking. The most critical aspects of successful preservation and visualization of cytoskeletal elements appeared to be: a two-step fixation with paraformaldehyde and glutaraldehyde before enzymatic cell wall digestion and a post fixation with aldehydes thereafter. The method allows the improved visualization of the organisation of the microtubular and actin filament arrays during the successive stages of cell division and at interphase. Although we present the application of our protocols for cytoskeleton labelling, the excellent results show the potential of using this method for the analysis of various proteins and molecules in plant cells.
Collapse
Affiliation(s)
- Magdalena Szechyńska-Hebda
- Laboratory for Plant Cell Biology, Wageningen University, Arboretumlaan 4, 6703 BD, Wageningen, The Netherlands
| | | | | | | | | |
Collapse
|
29
|
Higaki T, Kutsuna N, Okubo E, Sano T, Hasezawa S. Actin microfilaments regulate vacuolar structures and dynamics: dual observation of actin microfilaments and vacuolar membrane in living tobacco BY-2 Cells. PLANT & CELL PHYSIOLOGY 2006; 47:839-52. [PMID: 16672254 DOI: 10.1093/pcp/pcj056] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Actin microfilaments (MFs) participate in many fundamental processes in plant growth and development. Here, we report the co-localization of the actin MF and vacuolar membrane (VM), as visualized by vital VM staining with FM4-64 in living tobacco BY-2 cells stably expressing green fluorescent protein (GFP)-fimbrin (BY-GF11). The MFs were intensively localized on the VM surface and at the periphery of the cytoplasmic strands rather than at their center. The co-localization of MFs and VMs was confirmed by the observation made using transient expression of red fluorescent protein (RFP)-fimbrin in tobacco BY-2 cells stably expressing GFP-AtVam3p (BY-GV7) and BY-2 cells stably expressing gamma-tonoplast intrinsic protein (gamma-TIP)-GFP fusion protein (BY-GG). Time-lapse imaging revealed dynamic movement of MF structures which was parallel to that of cytoplasmic strands. Disruption of MF structures disorganized cytoplasmic strand structures and produced small spherical vacuoles in the VM-accumulating region. Three-dimensional reconstructions of the vacuolar structures revealed a disconnection of these small spherical vacuoles from the large vacuoles. Real-time observations and quantitative image analyses demonstrated rapid movements of MFs and VMs near the cell cortex, which were inhibited by the general myosin ATPase inhibitor, 2,3-butanedion monoxime (BDM). Moreover, both bistheonellide A (BA) and BDM treatment inhibited the reorganization of the cytoplasmic strands and the migration of daughter cell nuclei at early G1 phase, suggesting a requirement for the acto-myosin system for vacuolar morphogenesis during cell cycle progression. These results suggest that MFs support the vacuolar structures and that the acto-myosin system plays an essential role in vacuolar morphogenesis.
Collapse
Affiliation(s)
- Takumi Higaki
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwanoha, Kashiwa, Chiba 277-8562 Japan
| | | | | | | | | |
Collapse
|
30
|
Abstract
Animal and plant cytokineses appear morphologically distinct. Recent studies, however, have revealed that these cellular processes have many things in common, including the requirement of co-ordinated membrane trafficking and cytoskeletal dynamics. At the intersection of these two processes are the members of the dynamin family of ubiquitous eukaryotic GTPases. In this review, we highlight the conserved contribution of classical dynamin and dynamin-related proteins during cytokinesis in both animal and plant systems.
Collapse
Affiliation(s)
- Catherine A. Konopka
- Department of Biochemistry and Program in Cellular and Molecular Biology, University of Wisconsin – Madison, Madison, WI 53706, USA
| | - Justin B. Schleede
- Department of Genetics and Medical Genetics, University of Wisconsin – Madison, Madison, WI 53706, USA
| | - Ahna R. Skop
- Department of Genetics and Medical Genetics, University of Wisconsin – Madison, Madison, WI 53706, USA
- Corresponding author: Ahna R. Skop, ; Sebastian Y. Bednarek,
| | - Sebastian Y. Bednarek
- Department of Biochemistry and Program in Cellular and Molecular Biology, University of Wisconsin – Madison, Madison, WI 53706, USA
- Corresponding author: Ahna R. Skop, ; Sebastian Y. Bednarek,
| |
Collapse
|
31
|
Yu M, Yuan M, Ren H. Visualization of actin cytoskeletal dynamics during the cell cycle in tobacco (Nicotiana tabacum L. cv Bright Yellow) cells. Biol Cell 2006; 98:295-306. [PMID: 16359279 DOI: 10.1042/bc20050074] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND INFORMATION The actin cytoskeleton forms distinct actin arrays which fulfil their functions during cell cycle progression. Reorganization of the actin cytoskeleton occurs during transition from one actin array to another. Although actin arrays have been well described during cell cycle progression, the dynamic organization of the actin cytoskeleton during actin array transition remains to be dissected. RESULTS In the present study, a GFP (green fluorescent protein)-mTalin (mouse talin) fusion gene was introduced into suspension-cultured tobacco BY-2 (Nicotiana tabacum L. cv Bright Yellow) cells by a calli-cocultivation transformation method to visualize the reorganization of the actin cytoskeleton in vivo during the progression of the cell cycle. Typical actin structures were indicated by GFP-mTalin, such as the pre-prophase actin band, mitotic spindle actin filament cage and phragmoplast actin arrays. In addition, dynamic organization of actin filaments was observed during the progression of the cell from metaphase to anaphase. In late metaphase, spindle actin filaments gradually shrank to the equatorial plane along both the long and short axes. Soon after the separation of sister chromosomes, actin filaments aligned in parallel at the cell division plane, forming a cylinder-like structure. During the formation of the cell plate, one cylinder-like structure changed into two cylinder-like structures: the typical actin arrays of the phragmoplast. However, the two actin arrays remained overlapping at the margin of the centrally growing cell plate, forming an actin wreath. When the cell plate matured further, an actin filament network attached to the cell plate was formed. CONCLUSIONS Our results clearly describe the dynamic organization of the actin cytoskeleton during mitosis and cytokinesis of a plant cell. This demonstrates that GFP-mTalin-transformed tobacco BY-2 cells are a valuable tool to study actin cytoskeleton functions in the plant cell cycle.
Collapse
Affiliation(s)
- Miaomiao Yu
- Key Laboratory of Cell Proliferation and Regulation Biology of Ministry of Education, Beijing Normal University, People's Republic of China
| | | | | |
Collapse
|
32
|
Schütz I, Gus-Mayer S, Schmelzer E. Profilin and Rop GTPases are localized at infection sites of plant cells. PROTOPLASMA 2006; 227:229-35. [PMID: 16736261 DOI: 10.1007/s00709-005-0151-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2005] [Accepted: 09/08/2005] [Indexed: 05/09/2023]
Abstract
We have found 5 profilin cDNAs in cultured parsley cells, representing a small gene family of about 5 members in parsley. Specific antibodies were produced using heterologously expressed parsley profilin as antigen. Western blot analysis revealed the occurrence of similar amounts of profilin in roots and green parts of parsley plants. Immunocytochemical staining of parsley cells infected with the oomycetous plant pathogen Phytophthora infestans clearly revealed that profilin accumulates at the site on the plasma membrane subtending the oomycetous appressorium, where the actin cables focus. We also observed the accumulation of Rop GTPases around this site, which might point to a potential function in signaling to the cytoskeleton.
Collapse
Affiliation(s)
- I Schütz
- Central Microscopy, Max Planck Institute for Plant Breeding Research, Cologne
| | | | | |
Collapse
|
33
|
Dauphin A, De Ruijter NCA, Emons AMC, Legué V. Actin organization during eucalyptus root hair development and its response to fungal hypaphorine. PLANT BIOLOGY (STUTTGART, GERMANY) 2006; 8:204-11. [PMID: 16547865 DOI: 10.1055/s-2006-923767] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
The fungus Pisolithus microcarpus establishes an ectomycorrhiza with Eucalyptus globulus. This symbiosis involves a fungal synthesis and secretion of hypaphorine, an indolic compound. Previous studies have shown that hypaphorine induces an alteration in the actin cytoskeleton of elongating root hairs and inhibits hair elongation. Using an alternative approved method, we analyzed the effects of hypaphorine on the E. globulus root hair cyto-architecture and actin configuration in more detail and provide new results. One mM hypaphorine stops root hair elongation within 20 min, and changes the hair cyto-architecture. Semi-quantitative analysis of the actin cytoskeleton before and after treatment with hypaphorine shows that hypaphorine induces a shift from fine F-actin to F-actin bundles in the sub-apex of the hair, which occurs first in the mid-plane of the cell. This creates a sub-apical cell centre free of filamentous actin, an actin configuration that differs from that during developmental growth arrest. The mechanism of action of hypaphorine is discussed.
Collapse
Affiliation(s)
- A Dauphin
- Unité Mixte de Recherche UMR INRA-UHP 1136 Interactions Arbres/Micro-Organismes, Université Nancy I, Faculté des Sciences, BP 239, 54506 Vandoeuvre Cedex, France
| | | | | | | |
Collapse
|
34
|
Hussey PJ, Ketelaar T, Deeks MJ. Control of the actin cytoskeleton in plant cell growth. ANNUAL REVIEW OF PLANT BIOLOGY 2006; 57:109-25. [PMID: 16669757 DOI: 10.1146/annurev.arplant.57.032905.105206] [Citation(s) in RCA: 200] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Plant cells grow through increases in volume and cell wall surface area. The mature morphology of a plant cell is a product of the differential rates of expansion between neighboring zones of the cell wall during this process. Filamentous actin arrays are associated with plant cell growth, and the activity of actin-binding proteins is proving to be essential for proper cell morphogenesis. Actin-nucleating proteins participate in cell expansion and cell plate formation whereas the recycling of actin monomers is required to maintain actin dynamics and controlled growth. Coordination of actin-binding protein activity and other aspects of cytoskeletal behavior during cell development maintains cohesive cell expansion. Emerging plant signaling networks are proving to be powerful regulators of morphology-shaping cytoskeletal activity, and in this review we highlight current research in actin network regulation.
Collapse
Affiliation(s)
- Patrick J Hussey
- 1The Integrative Cell Biology Laboratory, School of Biological and Biomedical Sciences, University of Durham, Science Laboratories, Durham DH1 3LE, United Kingdom.
| | | | | |
Collapse
|
35
|
Wang HY, Yu Y, Chen ZL, Xia GX. Functional characterization of Gossypium hirsutum profilin 1 gene (GhPFN1) in tobacco suspension cells. Characterization of in vivo functions of a cotton profilin gene. PLANTA 2005; 222:594-603. [PMID: 16001260 DOI: 10.1007/s00425-005-0005-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2005] [Accepted: 04/23/2005] [Indexed: 05/03/2023]
Abstract
Cotton fiber is an extremely long plant cell. Fiber elongation is a complex process and the genes that are crucial for elongation are largely unknown. We previously cloned a cDNA encoding an isoform of cotton profilin and found that the gene (designated GhPFN1) was preferentially expressed in cotton fibers. In the present study, we have further analyzed the expression pattern of GhPFN1 during fiber development and studied its cellular function using tobacco suspension cells as an experimental system. We report that expression of GhPFN1 is tightly associated with fast elongation of cotton fibers whose growth requires an intact actin cytoskeleton. Overexpression of GhPFN1 in the transgenic tobacco cells was correlated with the formation of elongated cells that contained thicker and longer microfilament cables. Quantitative analyses revealed a 2.5-3.6 fold increase in total profilin levels and a 1.6-2.6 fold increase in the F-actin levels in six independent transgenic lines. In addition to the effect on cell elongation, we also observed delayed cell cycle progression and a slightly lower mitotic index in the transgenic cells. Based on these data, we propose that GhPFN1 may play a critical role in the rapid elongation of cotton fibers by promoting actin polymerization.
Collapse
Affiliation(s)
- Hai-Yun Wang
- National Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100080, China
| | | | | | | |
Collapse
|
36
|
Ingouff M, Fitz Gerald JN, Guérin C, Robert H, Sørensen MB, Van Damme D, Geelen D, Blanchoin L, Berger F. Plant formin AtFH5 is an evolutionarily conserved actin nucleator involved in cytokinesis. Nat Cell Biol 2005; 7:374-80. [PMID: 15765105 DOI: 10.1038/ncb1238] [Citation(s) in RCA: 131] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2005] [Accepted: 01/15/2005] [Indexed: 11/08/2022]
Abstract
Formins are actin-organizing proteins that are involved in cytokinesis and cell polarity. In the plant Arabidopsis thaliana, there are more than 20 formin homologues, all of which have unknown roles. In this study, we characterize specific cellular and molecular functions of the Arabidopsis formin AtFH5. Despite the low identity of AtFH5 to yeast and mammalian formins, the AtFH5 protein interacts with the barbed end of actin filaments and nucleates actin-filament polymerization in vitro, as is the case in yeast and mammals. In vivo, the AtFH5-GFP fusion protein localizes to the cell plate, a plant-specific membranous component that is assembled at the plane of cell division. Consistent with these data, loss of function of atfh5 compromises cytokinesis in the seed endosperm. Furthermore, endogenous AtFH5 transcripts accumulate in the posterior pole of the endosperm and loss of function of atfh5 perturbs proper morphogenesis of the endosperm posterior pole. Although cytokinesis in animals, yeast and plants occurs through morphologically distinct mechanisms, our study finds that formin recruitment to sites of actin assembly is a common feature of cell division among eukaryotes.
Collapse
Affiliation(s)
- Mathieu Ingouff
- EMBO YIP team, Unité Mixte de Recherche 5667, Institut Fédératif de Recherche 128 BioSciences Lyon-Gerland, Ecole Normale Supérieure de Lyon, 46 allée d'Italie, F-69364 Lyon cedex 07, France
| | | | | | | | | | | | | | | | | |
Collapse
|
37
|
Huang S, Robinson RC, Gao LY, Matsumoto T, Brunet A, Blanchoin L, Staiger CJ. Arabidopsis VILLIN1 generates actin filament cables that are resistant to depolymerization. THE PLANT CELL 2005; 17:486-501. [PMID: 15659626 PMCID: PMC548821 DOI: 10.1105/tpc.104.028555] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2004] [Accepted: 12/02/2004] [Indexed: 05/10/2023]
Abstract
Dynamic cytoplasmic streaming, organelle positioning, and nuclear migration use molecular tracks generated from actin filaments arrayed into higher-order structures like actin cables and bundles. How these arrays are formed and stabilized against cellular depolymerizing forces remains an open question. Villin and fimbrin are the best characterized actin-filament bundling or cross-linking proteins in plants and each is encoded by a multigene family of five members in Arabidopsis thaliana. The related villins and gelsolins are conserved proteins that are constructed from a core of six homologous gelsolin domains. Gelsolin is a calcium-regulated actin filament severing, nucleating and barbed end capping factor. Villin has a seventh domain at its C terminus, the villin headpiece, which can bind to an actin filament, conferring the ability to crosslink or bundle actin filaments. Many, but not all, villins retain the ability to sever, nucleate, and cap filaments. Here we have identified a putative calcium-insensitive villin isoform through comparison of sequence alignments between human gelsolin and plant villins with x-ray crystallography data for vertebrate gelsolin. VILLIN1 (VLN1) has the least well-conserved type 1 and type 2 calcium binding sites among the Arabidopsis VILLIN isoforms. Recombinant VLN1 binds to actin filaments with high affinity (K(d) approximately 1 microM) and generates bundled filament networks; both properties are independent of the free Ca(2+) concentration. Unlike human plasma gelsolin, VLN1 does not nucleate the assembly of filaments from monomer, does not block the polymerization of profilin-actin onto barbed ends, and does not stimulate depolymerization or sever preexisting filaments. In kinetic assays with ADF/cofilin, villin appears to bind first to growing filaments and protects filaments against ADF-mediated depolymerization. We propose that VLN1 is a major regulator of the formation and stability of actin filament bundles in plant cells and that it functions to maintain the cable network even in the presence of stimuli that result in depolymerization of other actin arrays.
Collapse
Affiliation(s)
- Shanjin Huang
- Department of Biological Sciences and Purdue Motility Group, Purdue University, West Lafayette, Indiana 47907-2064, USA
| | | | | | | | | | | | | |
Collapse
|
38
|
Abstract
Cytokinesis partitions the cytoplasm between two or more nuclei. In higher plants, cytokinesis is initiated by cytoskeleton-assisted targeted delivery of membrane vesicles to the plane of cell division, followed by local membrane fusion to generate tubulo-vesicular networks. This initial phase of cytokinesis is essentially the same in diverse modes of plant cytokinesis whereas the subsequent transformation of the tubulo-vesicular networks into the partitioning membrane may be different between systems. This review focuses on membrane and cytoskeleton dynamics in cell plate formation and expansion during somatic cytokinesis.
Collapse
Affiliation(s)
- Gerd Jürgens
- ZMBP, Entwicklungsgenetik, Universität Tübingen, 72076 Tübingen, Germany.
| |
Collapse
|
39
|
Ketelaar T, Anthony RG, Hussey PJ. Green fluorescent protein-mTalin causes defects in actin organization and cell expansion in Arabidopsis and inhibits actin depolymerizing factor's actin depolymerizing activity in vitro. PLANT PHYSIOLOGY 2004; 136:3990-8. [PMID: 15563618 PMCID: PMC535831 DOI: 10.1104/pp.104.050799] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2004] [Revised: 09/23/2004] [Accepted: 09/29/2004] [Indexed: 05/19/2023]
Abstract
Expression of green fluorescent protein (GFP) linked to an actin binding domain is a commonly used method for live cell imaging of the actin cytoskeleton. One of these chimeric proteins is GFP-mTalin (GFP fused to the actin binding domain of mouse talin). Although it has been demonstrated that GFP-mTalin colocalizes with the actin cytoskeleton, its effect on actin dynamics and cell expansion has not been studied in detail. We created Arabidopsis (Arabidopsis thaliana) plants harboring alcohol inducible GFP-mTalin constructs to assess the effect of GFP-mTalin expression in vivo. We focused on the growing root hair as this is a model cell for studying cell expansion and root hair tip growth that requires a highly dynamic and polar actin cytoskeleton. We show that alcohol inducible expression of GFP-mTalin in root hairs causes severe defects in actin organization, resulting in either the termination of growth, cell death, and/or changes in cell shape. Fluorescence recovery after photobleaching experiments demonstrate that the interaction of GFP-mTalin and actin filaments is highly dynamic. To assess how GFP-mTalin affects actin dynamics we performed cosedimentation assays of GFP-mTalin with actin on its own or in the presence of the actin modulating protein, actin depolymerizing factor. We show that that GFP-mTalin does not affect actin polymerization but that it does inhibit the actin depolymerizing activity of actin depolymerizing factor. These observations demonstrate that GFP-mTalin can affect cell expansion, actin organization, and the interaction of actin binding proteins with actin.
Collapse
Affiliation(s)
- Tijs Ketelaar
- The Integrative Cell Biology Laboratory, School of Biological and Biomedical Sciences, University of Durham, Durham, DH1 3LE, United Kingdom
| | | | | |
Collapse
|
40
|
Takemoto D, Hardham AR. The cytoskeleton as a regulator and target of biotic interactions in plants. PLANT PHYSIOLOGY 2004; 136:3864-76. [PMID: 15591444 PMCID: PMC535820 DOI: 10.1104/pp.104.052159] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2004] [Revised: 10/15/2004] [Accepted: 10/18/2004] [Indexed: 05/18/2023]
Affiliation(s)
- Daigo Takemoto
- Plant Cell Biology Group, Research School of Biological Sciences, The Australian National University, Canberra, ACT 2601, Australia
| | | |
Collapse
|
41
|
Peterman TK, Ohol YM, McReynolds LJ, Luna EJ. Patellin1, a novel Sec14-like protein, localizes to the cell plate and binds phosphoinositides. PLANT PHYSIOLOGY 2004; 136:3080-94; discussion 3001-2. [PMID: 15466235 PMCID: PMC523369 DOI: 10.1104/pp.104.045369] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2004] [Revised: 07/23/2004] [Accepted: 07/23/2004] [Indexed: 05/19/2023]
Abstract
Membrane trafficking is central to construction of the cell plate during plant cytokinesis. Consequently, a detailed understanding of the process depends on the characterization of molecules that function in the formation, transport, targeting, and fusion of membrane vesicles to the developing plate, as well as those that participate in its consolidation and maturation into a fully functional partition. Here we report the initial biochemical and functional characterization of patellin1 (PATL1), a novel cell-plate-associated protein that is related in sequence to proteins involved in membrane trafficking in other eukaryotes. Analysis of the Arabidopsis genome indicated that PATL1 is one of a small family of Arabidopsis proteins, characterized by a variable N-terminal domain followed by two domains found in other membrane-trafficking proteins (Sec14 and Golgi dynamics domains). Results from immunolocalization and biochemical fractionation studies suggested that PATL1 is recruited from the cytoplasm to the expanding and maturing cell plate. In vesicle-binding assays, PATL1 bound to specific phosphoinositides, important regulators of membrane trafficking, with a preference for phosphatidylinositol(5)P, phosphatidylinositol(4,5)P(2), and phosphatidylinositol(3)P. Taken together, these findings suggest a role for PATL1 in membrane-trafficking events associated with cell-plate expansion or maturation and point to the involvement of phosphoinositides in cell-plate biogenesis.
Collapse
Affiliation(s)
- T Kaye Peterman
- Department of Biological Sciences, Wellesley College, Wellesley, Massachusetts 02481, USA.
| | | | | | | |
Collapse
|
42
|
Bassil E, Hu H, Brown PH. Use of phenylboronic acids to investigate boron function in plants. Possible role of boron in transvacuolar cytoplasmic strands and cell-to-wall adhesion. PLANT PHYSIOLOGY 2004; 136:3383-95. [PMID: 15466241 PMCID: PMC523397 DOI: 10.1104/pp.104.040527] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2004] [Revised: 03/31/2004] [Accepted: 04/07/2004] [Indexed: 05/18/2023]
Abstract
The only defined physiological role of boron in plants is as a cross-linking molecule involving reversible covalent bonds with cis-diols on either side of borate. Boronic acids, which form the same reversible bonds with cis-diols but cannot cross-link two molecules, were used to selectively disrupt boron function in plants. In cultured tobacco (Nicotiana tabacum cv BY-2) cells, addition of boronic acids caused the disruption of cytoplasmic strands and cell-to-cell wall detachment. The effect of the boronic acids could be relieved by the addition of boron-complexing sugars and was proportional to the boronic acid-binding strength of the sugar. Experiments with germinating petunia (Petunia hybrida) pollen and boronate-affinity chromatography showed that boronic acids and boron compete for the same binding sites. The boronic acids appear to specifically disrupt or prevent borate-dependent cross-links important for the structural integrity of the cell, including the organization of transvacuolar cytoplasmic strands. Boron likely plays a structural role in the plant cytoskeleton. We conclude that boronic acids can be used to rapidly and reversibly induce boron deficiency-like responses and therefore are useful tools for investigating boron function in plants.
Collapse
Affiliation(s)
- Elias Bassil
- Pomology Department, University of California, Davis, California 95616, USA
| | | | | |
Collapse
|
43
|
Liu AX, Zhang SB, Xu XJ, Ren DT, Liu GQ. Soluble expression and characterization of a GFP-fused pea actin isoform (PEAc1). Cell Res 2004; 14:407-14. [PMID: 15538972 DOI: 10.1038/sj.cr.7290241] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
A pea actin isoform PEAc1 with green fluorescent protein (GFP) fusion to its C-terminus and His-tag to its N-terminus, was expressed in prokaryotic cells in soluble form, and highly purified with Ni-Chelating Sepharose Fast Flow column. The purified fusion protein (PEAc1-GFP) efficiently inhibited DNase I activities before polymerization, and activated the myosin Mg-ATPase activities after polymerization. The PEAc1-GFP also polymerized into green fluorescent filamentous structures with a critical concentration of 0.75 uM. These filamentous structures were labeled by TRITC-phalloidin, a specific agent for staining actin microfilaments, and identified as having 9 nm diameters by negative staining. These results indicated that PEAc1 preserved the essential characteristics of actin even with His-tag and GFP fusion, suggesting a promising potential to use GFP fusion protein in obtaining soluble plant actin isoform to analyze its physical and biochemical properties in vitro. The PEAc1-GFP was also expressed in tobacco BY2 cells, which offers a new pathway for further studying its distribution and function in vivo.
Collapse
Affiliation(s)
- Ai Xiao Liu
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Science, China Agricultural University, Beijing 100094, China.
| | | | | | | | | |
Collapse
|
44
|
Holweg C, Süsslin C, Nick P. Capturing in vivo dynamics of the actin cytoskeleton stimulated by auxin or light. PLANT & CELL PHYSIOLOGY 2004; 45:855-863. [PMID: 15295068 DOI: 10.1093/pcp/pch102] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We present here a transient expression system that allows the response of actin microfilaments to physiological stimuli (changes in auxin content, light) to be observed in single cells in vivo. Etiolated, intact rice seedlings are attached to glass slides, transfected biolistically with talin fused to yellow-fluorescent protein to visualize actin microfilaments, and either treated with auxin or irradiated. The talin marker labels distinct populations of actin that are differentially expressed depending on the physiological state of the coleoptile (active elongation versus ceased elongation). Whereas longitudinal transvacuolar bundles prevail in cells that have ceased to elongate, fine cortical strands are characteristic for elongating cells. The visualized actin structures remain dynamic and responsive to signals. Exogenous auxin triggers a loosening of the bundles and an extension of the cortical strands, whereas irradiation reorientates cortical strands into longitudinal arrays. These responses correspond in quality and timing to the signal responses inferred previously from fixed specimens and biochemical studies. In big advantage over those methods it is now possible to observe them directly at the single cell level. Thus, the rice coleoptile system can be used as a convenient model to study actin dynamics in vivo, in response to physiologically relevant stimuli.
Collapse
Affiliation(s)
- Carola Holweg
- Institut für Biologie II, Schänzlestrasse 1, D-79104 Freiburg, Germany.
| | | | | |
Collapse
|
45
|
Drøbak BK, Franklin-Tong VE, Staiger CJ. The role of the actin cytoskeleton in plant cell signaling. THE NEW PHYTOLOGIST 2004; 163:13-30. [PMID: 33873778 DOI: 10.1111/j.1469-8137.2004.01076.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
The plant actin cytoskeleton provides a dynamic cellular component which is involved in the maintenance of cell shape and structure. It has been demonstrated recently that the actin cytoskeleton and its associated elements provide a key target in many signaling events. In addition to acting as a target, the actin cytoskeleton can also act as a transducer of signal information. In this review we describe some newly discovered aspects of the roles of the actin cytoskeleton in plant cell signaling. In addition to a summary of the roles played by actin-binding proteins, we also briefly review the progress made in understanding how the actin cytoskeleton participates in the self-incompatibility response in pollen tubes. Finally, the emerging importance of the actin cytoskeleton in the perception and responses to stimuli such as gravity, touch and cold stress exposure are discussed. Contents I. Introduction - the actin cytoskeleton 13 II. Actin-binding proteins 14 III. The actin cytoskeleton as a target and mediator of plant cell signaling 20 IV. Summary and conclusion 25 References 25 Acknowledgements 25.
Collapse
Affiliation(s)
- B K Drøbak
- Cell Signaling Group, Department of Disease and Stress Biology, John Innes Centre, Norwich Research Park, Colney Lane, Norwich NR4 7UH, UK
| | - V E Franklin-Tong
- School of Biosciences, The University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - C J Staiger
- Purdue Motility Group, Department of Biological Sciences, Purdue University, 333 Hansen Life Sciences Building, 201 S. University Street, West Lafayette, IN 47907-2064, USA
| |
Collapse
|
46
|
McKenna ST, Vidali L, Hepler PK. Profilin inhibits pollen tube growth through actin-binding, but not poly-L-proline-binding. PLANTA 2004; 218:906-915. [PMID: 14712393 DOI: 10.1007/s00425-003-1174-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2003] [Accepted: 11/03/2003] [Indexed: 05/24/2023]
Abstract
Previously, we have shown that excess profilin inhibits pollen tube growth at significantly lower concentrations than it blocks cytoplasmic streaming. To elucidate the mechanism by which profilin achieves this function, we have employed mutant profilins from Schizosaccharomyces pombe [J. Lu and T.D. Pollard (2001) Mol Biol Cell 12:1161-1175], which have defects in actin-binding, ability to inhibit polymerization, and poly- l-proline (PLP)-binding. Using Lilium longiflorum L. pollen and S. pombe profilins as wild-type (wt) standards, mutant profilins have been injected into pollen tubes of Lilium, and examined for their effects on growth rate and cell morphology. Our results show that mutant Y5D (68% actin-binding; 1.1% PLP-binding) is indistinguishable from wt-standard profilins. However mutant K81F (2.7% actin-binding; 77% PLP-binding) and especially mutant K67E (<1% actin-binding; 100% PLP-binding) are significantly less effective than wt-standard profilins in their ability to inhibit pollen tube growth. PLP also inhibits pollen tube growth. However, PLP is not different from K67E/PLP combined, which has no actin-binding, suggesting that PLP does not function by binding to profilin. In addition, there are differences in the morphology and F-actin organization in cells injected with PLP versus wt-profilin. Whereas wt-profilin causes a fragmentation and marked reduction in the amount of F-actin [L. Vidali et al. (2001) Mol Biol Cell 12:2534-2545], PLP generates an extensive disorganization without any apparent reduction in the amount of F-actin. We conclude that along with actin-binding activity of profilin, PLP-containing proteins also participate in the growth control process, and can do so independently of binding to profilin.
Collapse
|
47
|
Seguí-Simarro JM, Austin JR, White EA, Staehelin LA. Electron tomographic analysis of somatic cell plate formation in meristematic cells of Arabidopsis preserved by high-pressure freezing. THE PLANT CELL 2004; 16:836-56. [PMID: 15020749 PMCID: PMC412860 DOI: 10.1105/tpc.017749] [Citation(s) in RCA: 215] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2003] [Accepted: 01/28/2004] [Indexed: 05/17/2023]
Abstract
We have investigated the process of somatic-type cytokinesis in Arabidopsis (Arabidopsis thaliana) meristem cells with a three-dimensional resolution of approximately 7 nm by electron tomography of high-pressure frozen/freeze-substituted samples. Our data demonstrate that this process can be divided into four phases: phragmoplast initials, solid phragmoplast, transitional phragmoplast, and ring-shaped phragmoplast. Phragmoplast initials arise from clusters of polar microtubules (MTs) during late anaphase. At their equatorial planes, cell plate assembly sites are formed, consisting of a filamentous ribosome-excluding cell plate assembly matrix (CPAM) and Golgi-derived vesicles. The CPAM, which is found only around growing cell plate regions, is suggested to be responsible for regulating cell plate growth. Virtually all phragmoplast MTs terminate inside the CPAM. This association directs vesicles to the CPAM and thereby to the growing cell plate. Cell plate formation within the CPAM appears to be initiated by the tethering of vesicles by exocyst-like complexes. After vesicle fusion, hourglass-shaped vesicle intermediates are stretched to dumbbells by a mechanism that appears to involve the expansion of dynamin-like springs. This stretching process reduces vesicle volume by approximately 50%. At the same time, the lateral expansion of the phragmoplast initials and their CPAMs gives rise to the solid phragmoplast. Later arriving vesicles begin to fuse to the bulbous ends of the dumbbells, giving rise to the tubulo-vesicular membrane network (TVN). During the transitional phragmoplast stage, the CPAM and MTs disassemble and then reform in a peripheral ring phragmoplast configuration. This creates the centrifugally expanding peripheral cell plate growth zone, which leads to cell plate fusion with the cell wall. Simultaneously, the central TVN begins to mature into a tubular network, and ultimately into a planar fenestrated sheet (PFS), through the removal of membrane via clathrin-coated vesicles and by callose synthesis. Small secondary CPAMs with attached MTs arise de novo over remaining large fenestrae to focus local growth to these regions. When all of the fenestrae are closed, the new cell wall is complete. Few endoplasmic reticulum (ER) membranes are seen associated with the phragmoplast initials and with the TVN cell plate that is formed within the solid phragmoplast. ER progressively accumulates thereafter, reaching a maximum during the late PFS stage, when most cell plate growth is completed.
Collapse
Affiliation(s)
- José M Seguí-Simarro
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder 80309-0347, USA
| | | | | | | |
Collapse
|
48
|
Vos JW, Dogterom M, Emons AMC. Microtubules become more dynamic but not shorter during preprophase band formation: a possible "search-and-capture" mechanism for microtubule translocation. CELL MOTILITY AND THE CYTOSKELETON 2004; 57:246-58. [PMID: 14752808 DOI: 10.1002/cm.10169] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The dynamic behavior of the microtubule cytoskeleton plays a crucial role in cellular organization, but the physical mechanisms underlying microtubule (re)organization in plant cells are poorly understood. We investigated microtubule dynamics in tobacco BY-2 suspension cells during interphase and during the formation of the preprophase band (PPB), the cytoskeletal structure that defines the site of cytokinesis. Here we show that after 2 h of microtubule accumulation in the PPB and concurrent disappearance elsewhere in the cortex, the PPB is completed and starts to breakdown exponentially already 20 min before the onset of prometaphase. During formation of the PPB, the dynamic instability, i.e., the stochastic alternating between growing and shrinking phases, of the cortical microtubules outside the PPB increases significantly, but the microtubules do not become shorter. Based on this, as well as on the cross-linking of microtubules in the PPB and the lack of evidence for motor involvement, we propose a "search-and-capture" mechanism for PPB formation, in which the regulation of dynamic instability causes the cortical microtubules to become more dynamic and possibly longer, while the microtubule cross-linking activity of the developing PPB preferentially stabilizes these "searching" microtubules. Thus, microtubules gradually disappear from the cortex outside the PPB and aggregate to the forming PPB.
Collapse
Affiliation(s)
- Jan W Vos
- Laboratory of Plant Cell Biology, Wageningen University, Wageningen, The Netherlands.
| | | | | |
Collapse
|
49
|
Scherp P, Hasenstein KH. Microinjection--a tool to study gravitropism. ADVANCES IN SPACE RESEARCH : THE OFFICIAL JOURNAL OF THE COMMITTEE ON SPACE RESEARCH (COSPAR) 2003; 31:2221-2227. [PMID: 14686436 DOI: 10.1016/s0273-1177(03)00248-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Despite extensive studies on plant gravitropism this phenomenon is still poorly understood. The separation of gravity sensing, signal transduction and response is a common concept but especially the mechanism of gravisensing remains unclear. This paper focuses on microinjection as powerful tool to investigate gravisensing in plants. We describe the microinjection of magnetic beads in rhizoids of the green alga Chara and related subsequent manipulation of the gravisensing system. After injection, an external magnet can control the movement of the magnetic beads. We demonstrate successful injection of magnetic beads into rhizoids and describe a multitude of experiments that can be carried out to investigate gravitropism in Chara rhizoids. In addition to examining mechanical properties, bead microinjection is also useful for probing the function of the cytoskeleton by coating beads with drugs that interfere with the cytoskeleton. The injection of fluorescently labeled beads or probes may reveal the involvement of the cytoskeleton during gravistimulation and response in living cells.
Collapse
Affiliation(s)
- P Scherp
- Biology Department, University of Louisiana at Lafayette, LA 70504-2451, USA
| | | |
Collapse
|
50
|
Hasezawa S, Kumagai F. Dynamic changes and the role of the cytoskeleton during the cell cycle in higher plant cells. INTERNATIONAL REVIEW OF CYTOLOGY 2002; 214:161-91. [PMID: 11893165 DOI: 10.1016/s0074-7696(02)14005-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
In higher plant cells microtubules (MTs) show dynamic structural changes during cell cycle progression and play significant roles in cell morphogenesis. The cortical MT (CMT), preprophase band (PPB), and phragmoplast, all of which are plant-specific MT structures, can be observed during interphase, from the late G2 phase to prophase, and from anaphase to telophase, respectively. The CMT controls cell shape, either irreversibly or reversibly, by orientating cellulose microfibril (CMF) deposition in the cell wall; the PPB is involved in determining the site of division; and the phragmoplast forms the cell plate at cytokinesis. The appearance and disappearance of these MT structures during the cell cycle have been extensively studied by immunofluorescence microscopy using highly synchronized tobacco BY-2 cells. Indeed, these studies, together with visualization of MT dynamics in living plant cells using the green fluorescent protein, have revealed much about the modes of MT structural organization, for example, of CMTs at the M/G1 interphase. The microfilaments which also show dynamic changes during the cell cycle, being similar to MTs at particular stages and different at other stages, appear to play roles in supporting MTs. In this article, we summarize our ongoing research and that of related studies of the structure and function of the plant cytoskeleton during cell cycle progression.
Collapse
Affiliation(s)
- Seiichiro Hasezawa
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, University of Tokyo, Kashiwa, Chiba, Japan
| | | |
Collapse
|