Plant cytokinesis is orchestrated by a specialized structure, the phragmoplast. The phragmoplast first occurred in representatives of Charophyte algae and then became the main division apparatus in land plants. Major cellular activities, including cytoskeletal dynamics, vesicle trafficking, membrane assembly, and cell wall biosynthesis, cooperate in the phragmoplast under the guidance of a complex signaling network. Furthermore, the phragmoplast combines plant-specific features with the conserved cytokinetic processes of animals, fungi, and protists. As such, the phragmoplast represents a useful system for understanding both plant cell dynamics and the evolution of cytokinesis. We recognize that future research and knowledge transfer into other fields would benefit from standardized terminology. Here, we propose such a lexicon of terminology for specific structures and processes associated with plant cytokinesis.

• Klíčová slova
• cell plate, cytokinesis, division plane, phragmoplast, preprophase band,
• MeSH
• biologické modely MeSH
• buněčná membrána metabolismus   MeSH
• buněčné dělení MeSH
• chromozomy rostlin metabolismus   MeSH
• cytokineze * MeSH
• cytoplazma metabolismus   MeSH
• cytoskelet metabolismus   MeSH
• mikrotubuly metabolismus   MeSH
• rostlinné buňky metabolismus   MeSH
• terminologie jako téma * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH

Progression of mitosis and cytokinesis depends on the reorganization of cytoskeleton, with microtubules driving the segregation of chromosomes and their partitioning to two daughter cells. In dividing plant cells, microtubules undergo global reorganization throughout mitosis and cytokinesis, and with the aid of various microtubule-associated proteins (MAPs), they form unique systems such as the preprophase band (PPB), the acentrosomal mitotic spindle, and the phragmoplast. Such proteins include nucleators of de novo microtubule formation, plus end binding proteins involved in the regulation of microtubule dynamics, crosslinking proteins underlying microtubule bundle formation and members of the kinesin superfamily with microtubule-dependent motor activities. The coordinated function of such proteins not only drives the continuous remodeling of microtubules during mitosis and cytokinesis but also assists the positioning of the PPB, the mitotic spindle, and the phragmoplast, affecting tissue patterning by controlling cell division plane (CDP) orientation. The affinity and the function of such proteins is variably regulated by reversible phosphorylation of serine and threonine residues within the microtubule binding domain through a number of protein kinases and phosphatases which are differentially involved throughout cell division. The purpose of the present review is to provide an overview of the function of protein kinases and protein phosphatases involved in cell division regulation and to identify cytoskeletal substrates relevant to the progression of mitosis and cytokinesis and the regulation of CDP orientation.

• Klíčová slova
• microtubule-associated proteins, microtubules, mitotic spindle, phragmoplast, protein kinase, protein phosphatase,
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

Land plants evolved from charophytic algae, among which Charophyceae possess the most complex body plans. We present the genome of Chara braunii; comparison of the genome to those of land plants identified evolutionary novelties for plant terrestrialization and land plant heritage genes. C. braunii employs unique xylan synthases for cell wall biosynthesis, a phragmoplast (cell separation) mechanism similar to that of land plants, and many phytohormones. C. braunii plastids are controlled via land-plant-like retrograde signaling, and transcriptional regulation is more elaborate than in other algae. The morphological complexity of this organism may result from expanded gene families, with three cases of particular note: genes effecting tolerance to reactive oxygen species (ROS), LysM receptor-like kinases, and transcription factors (TFs). Transcriptomic analysis of sexual reproductive structures reveals intricate control by TFs, activity of the ROS gene network, and the ancestral use of plant-like storage and stress protection proteins in the zygote.

• Klíčová slova
• Chara, Phragmoplastophyta, charophyte, phragmoplast, phytohormones, plant evolution, reactive oxygen species, streptophyte, transcriptional regulation,
• MeSH
• biologická evoluce MeSH
• buněčná stěna metabolismus   MeSH
• Chara genetika   růst a vývoj   MeSH
• genom rostlinný * MeSH
• genové regulační sítě MeSH
• pentosyltransferasy genetika   MeSH
• protein-serin-threoninkinasy genetika   metabolismus   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• regulátory růstu rostlin metabolismus   MeSH
• rostlinné proteiny genetika   metabolismus   MeSH
• transkripční faktory genetika   metabolismus   MeSH
• transkriptom MeSH
• vyšší rostliny genetika   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH
• Názvy látek
• 1,4-beta-D-xylan synthase MeSH Prohlížeč
• pentosyltransferasy MeSH
• protein-serin-threoninkinasy MeSH
• reaktivní formy kyslíku MeSH
• regulátory růstu rostlin MeSH
• rostlinné proteiny MeSH
• transkripční faktory MeSH

Mitotic cell division in plants is a dynamic process playing a key role in plant morphogenesis, growth, and development. Since progress of mitosis is highly sensitive to external stresses, documentation of mitotic cell division in living plants requires fast and gentle live-cell imaging microscopy methods and suitable sample preparation procedures. This chapter describes, both theoretically and practically, currently used advanced microscopy methods for the live-cell visualization of the entire process of plant mitosis. These methods include microscopy modalities based on spinning disk, Airyscan confocal laser scanning, structured illumination, and light-sheet bioimaging of tissues or whole plant organs with diverse spatiotemporal resolution. Examples are provided from studies of mitotic cell division using microtubule molecular markers in the model plant Arabidopsis thaliana, and from deep imaging of mitotic microtubules in robust plant samples, such as legume crop species Medicago sativa.

• Klíčová slova
• Arabidopsis, Light-sheet microscopy, Medicago, Microtubules, Mitosis, Phragmoplast, Plant, Preprophase band, Spindle, Superresolution microscopy,
• MeSH
• Arabidopsis metabolismus   fyziologie   MeSH
• mikroskopie metody   MeSH
• mikrotubuly fyziologie   MeSH
• mitóza fyziologie   MeSH
• proteiny asociované s mikrotubuly metabolismus   MeSH
• proteiny huseníčku metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• proteiny asociované s mikrotubuly MeSH
• proteiny huseníčku MeSH

• A mitogen-activated protein kinase kinase kinase (MAPKKK) double mutant, Arabidopsis homologue of nucleus and phragmoplast associated kinase (anp) anp2anp3, and the mitogen-activated protein kinase (MAPK) 4 mutant mpk4 of Arabidopsis thaliana show prominent cytokinetic defects. This prompted the analysis of mitotic and cytokinetic progression as a function of MAPK signalling. Mutants were compared with wild types untreated or treated with the specific MAPKK inhibitor PD98059. • This study included phenotype analysis, expression analysis of the MPK4 promoter, immunofluorescent localization of MPK4, tubulin and MAP65-1, and time-lapse microscopic visualization of the mitotic microtubule (MT) transitions in control, mutant and inhibitor-treated cells. • Mutant and inhibitor-treated cells showed defects in mitosis and cytokinesis, including aberrant spindle and phragmoplast formation and drastically delayed or abortive mitosis and cytokinesis. As a result, bi- and multinucleate cells were formed, ultimately disturbing the vegetative tissue patterning. MPK4 was localized to all stages of the expanding phragmoplast, in a pattern similar to that of its putative substrate MAP65-1. • In this study, MPK4 is shown to be involved in the regulation of mitosis/cytokinesis through modulation of the cell division plane and cytokinetic progression.

• MeSH
• aparát dělícího vřeténka účinky léků   metabolismus   MeSH
• Arabidopsis cytologie   účinky léků   enzymologie   MeSH
• buněčné jádro účinky léků   metabolismus   MeSH
• cytokineze * účinky léků   MeSH
• fenotyp MeSH
• flavonoidy farmakologie   MeSH
• fluorescenční mikroskopie MeSH
• fluorescenční protilátková technika MeSH
• inhibitory proteinkinas farmakologie   MeSH
• meristém cytologie   účinky léků   enzymologie   MeSH
• mikrotubuly účinky léků   metabolismus   MeSH
• mitogenem aktivované proteinkinasy antagonisté a inhibitory   metabolismus   MeSH
• mitóza * účinky léků   MeSH
• mutace genetika   MeSH
• proteiny asociované s mikrotubuly metabolismus   MeSH
• proteiny huseníčku antagonisté a inhibitory   metabolismus   MeSH
• viabilita buněk účinky léků   MeSH
• zobrazování trojrozměrné MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• 2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one MeSH Prohlížeč
• AtMPK4 protein, Arabidopsis MeSH Prohlížeč
• flavonoidy MeSH
• inhibitory proteinkinas MeSH
• MAP65-1 protein, Arabidopsis MeSH Prohlížeč
• mitogenem aktivované proteinkinasy MeSH
• proteiny asociované s mikrotubuly MeSH
• proteiny huseníčku MeSH

Katanin is the only microtubule severing protein identified in plants so far. Previous studies have documented its role in regulating cortical microtubule organization during cell growth and morphogenesis. Although, some cell division defects are reported in KATANIN mutants, it is not clear whether or how katanin activity may affect microtubule dynamics in interphase cells, as well as the progression of mitosis and cytokinesis and the orientation of cell division plane (CDP). For this reason, we characterized microtubule organization and dynamics in growing and dividing cotyledon cells of Arabidopsis ktn1-2 mutant devoid of KATANIN 1 activity. In interphase epidermal cells of ktn1-2 cortical microtubules exhibited aberrant and largely isotropic organization, reduced bundling and showed excessive branched microtubule formation. End-wise microtubule dynamics were not much affected, although a significantly slower rate of microtubule growth was measured in the ktn1-2 mutant where microtubule severing was completely abolished. KATANIN 1 depletion also brought about significant changes in preprophase microtubule band (PPB) organization and dynamics. In this case, many PPBs exhibited unisided organization and splayed appearance while in most cases they were broader than those of wild type cells. By recording PPB maturation, it was observed that PPBs in the mutant narrowed at a much slower pace compared to those in Col-0. The form of the mitotic spindle and the phragmoplast was not much affected in ktn1-2, however, the dynamics of both processes showed significant differences compared to wild type. In general, both mitosis and cytokinesis were considerably delayed in the mutant. Additionally, the mitotic spindle and the phragmoplast exhibited extensive rotational motions with the equatorial plane of the spindle being essentially uncoupled from the division plane set by the PPB. However, at the onset of its formation the phragmoplast undergoes rotational motion rectifying the expansion of the cell plate to match the original cell division plane. Conclusively, KATANIN 1 contributes to microtubule dynamics during interphase, regulates PPB formation and maturation and is involved in the positioning of the mitotic spindle and the phragmoplast.

• Klíčová slova
• Arabidopsis, cell division, interphase, katanin, live imaging, microtubules, preprophase band, super resolution microscopy,
• Publikační typ
• časopisecké články MeSH

The role of YODA MITOGEN ACTIVATED PROTEIN KINASE KINASE KINASE 4 (MAPKKK4) upstream of MITOGEN ACTIVATED PROTEIN KINASE 6 (MPK6) was studied during post-embryonic root development of Arabidopsis thaliana. Loss- and gain-of-function mutants of YODA (yda1 and ΔNyda1) were characterized in terms of root patterning, endogenous auxin content and global proteomes. We surveyed morphological and cellular phenotypes of yda1 and ΔNyda1 mutants suggesting possible involvement of auxin. Endogenous indole-3-acetic acid (IAA) levels were up-regulated in both mutants. Proteomic analysis revealed up-regulation of auxin biosynthetic enzymes tryptophan synthase and nitrilases in these mutants. The expression, abundance and phosphorylation of MPK3, MPK6 and MICROTUBULE ASSOCIATED PROTEIN 65-1 (MAP65-1) were characterized by quantitative polymerase chain reaction (PCR) and western blot analyses and interactions between MAP65-1, microtubules and MPK6 were resolved by quantitative co-localization studies and co-immunoprecipitations. yda1 and ΔNyda1 mutants showed disoriented cell divisions in primary and lateral roots, abortive cytokinesis, and differential subcellular localization of MPK6 and MAP65-1. They also showed deregulated expression of TANGLED1 (TAN1), PHRAGMOPLAST ORIENTING KINESIN 1 (POK1), and GAMMA TUBULIN COMPLEX PROTEIN 4 (GCP4). The findings that MPK6 localized to preprophase bands (PPBs) and phragmoplasts while the mpk6-4 mutant transformed with MPK6AEF (alanine (A)-glutamic acid (E)-phenylanine (F)) showed a root phenotype similar to that of yda1 demonstrated that MPK6 is an important player downstream of YODA. These data indicate that YODA and MPK6 are involved in post-embryonic root development through an auxin-dependent mechanism regulating cell division and mitotic microtubule (PPB and phragmoplast) organization.

• Klíčová slova
• Arabidopsis, MAP65-1, MAPKKK, MPK6, YODA, cell division plane, microtubules, root,
• MeSH
• Arabidopsis cytologie   účinky léků   embryologie   enzymologie   MeSH
• buněčné dělení * účinky léků   MeSH
• cytokineze účinky léků   MeSH
• epidermis rostlin cytologie   MeSH
• fenotyp MeSH
• fluorescenční protilátková technika MeSH
• fosforylace účinky léků   MeSH
• interfáze MeSH
• kořeny rostlin anatomie a histologie   cytologie   embryologie   MeSH
• kyseliny indoloctové metabolismus   farmakologie   MeSH
• MAP kinasy kinas (kinas) metabolismus   MeSH
• meristém cytologie   účinky léků   MeSH
• mikrotubuly účinky léků   metabolismus   MeSH
• mitogenem aktivované proteinkinasy metabolismus   MeSH
• mitóza účinky léků   MeSH
• mutace genetika   MeSH
• proteiny huseníčku metabolismus   MeSH
• proteomika MeSH
• transport proteinů účinky léků   MeSH
• upregulace * účinky léků   MeSH
• vazba proteinů účinky léků   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• alpha-(2,4-dimethylphenylethyl-2-oxo)indole-3-acetic acid MeSH Prohlížeč
• kyseliny indoloctové MeSH
• MAP kinasy kinas (kinas) MeSH
• mitogenem aktivované proteinkinasy MeSH
• MPK6 protein, Arabidopsis MeSH Prohlížeč
• proteiny huseníčku MeSH
• YODA protein, Arabidopsis MeSH Prohlížeč

The phragmoplast separates daughter cells during cytokinesis by constructing the cell plate, which depends on interaction between cytoskeleton and membrane compartments. Proteins responsible for these interactions remain unknown, but formins can link cytoskeleton with membranes and several members of formin protein family localize to the cell plate. Progress in functional characterization of formins in cytokinesis is hindered by functional redundancies within the large formin gene family. We addressed this limitation by employing Small Molecular Inhibitor of Formin Homology 2 (SMIFH2), a small-molecule inhibitor of formins. Treatment of tobacco (Nicotiana tabacum) tissue culture cells with SMIFH2 perturbed localization of actin at the cell plate; slowed down both microtubule polymerization and phragmoplast expansion; diminished association of dynamin-related proteins with the cell plate independently of actin and microtubules; and caused cell plate swelling. Another impact of SMIFH2 was shortening of the END BINDING1b (EB1b) and EB1c comets on the growing microtubule plus ends in N. tabacum tissue culture cells and Arabidopsis thaliana cotyledon epidermis cells. The shape of the EB1 comets in the SMIFH2-treated cells resembled that of the knockdown mutant of plant Xenopus Microtubule-Associated protein of 215 kDa (XMAP215) homolog MICROTUBULE ORGANIZATION 1/GEMINI 1 (MOR1/GEM1). This outcome suggests that formins promote elongation of tubulin flares on the growing plus ends. Formins AtFH1 (A. thaliana Formin Homology 1) and AtFH8 can also interact with EB1. Besides cytokinesis, formins function in the mitotic spindle assembly and metaphase to anaphase transition. Our data suggest that during cytokinesis formins function in: (1) promoting microtubule polymerization; (2) nucleating F-actin at the cell plate; (3) retaining dynamin-related proteins at the cell plate; and (4) remodeling of the cell plate membrane.

• MeSH
• aktiny metabolismus   MeSH
• Arabidopsis účinky léků   genetika   fyziologie   MeSH
• cytokineze účinky léků   genetika   MeSH
• cytoskelet účinky léků   metabolismus   MeSH
• forminy genetika   metabolismus   MeSH
• mikrotubuly účinky léků   metabolismus   MeSH
• tabák účinky léků   genetika   fyziologie   MeSH
• thioketony farmakologie   MeSH
• tubulin metabolismus   MeSH
• uracil analogy a deriváty   farmakologie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH
• Názvy látek
• aktiny MeSH
• forminy MeSH
• SMIFH2 compound MeSH Prohlížeč
• thioketony MeSH
• tubulin MeSH
• uracil MeSH

Microtubules (MTs) are essential for many processes in plant cells. MT-associated proteins (MAPs) influence MT polymerization dynamics and enable them to perform their functions. The molecular chaperone Hsp90 has been shown to associate with MTs in animal and plant cells. However, the role of Hsp90-MT binding in plants has not yet been investigated. Here, we show that Hsp90 associates with cortical MTs in tobacco cells and decorates MTs in the phragmoplast. Further, we show that tobacco Hsp90_MT binds directly to polymerized MTs in vitro. The inhibition of Hsp90 by geldanamycin (GDA) severely impairs MT re-assembly after cold-induced de-polymerization. Our results indicate that the plant Hsp90 interaction with MTs plays a key role in cellular events, where MT re-organization is needed.

• MeSH
• benzochinony farmakologie   MeSH
• fylogeneze MeSH
• makrocyklické laktamy farmakologie   MeSH
• mikrotubuly účinky léků   metabolismus   MeSH
• molekulární sekvence - údaje MeSH
• polymerizace účinky léků   MeSH
• proteiny tepelného šoku HSP90 chemie   izolace a purifikace   metabolismus   MeSH
• rekombinantní proteiny izolace a purifikace   metabolismus   MeSH
• repetitivní sekvence aminokyselin MeSH
• rostlinné proteiny metabolismus   MeSH
• rýže (rod) účinky léků   metabolismus   MeSH
• sekvence aminokyselin MeSH
• tabák cytologie   účinky léků   metabolismus   MeSH
• transport proteinů účinky léků   MeSH
• tubulin metabolismus   MeSH
• vazba proteinů účinky léků   MeSH
• zelené fluorescenční proteiny metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• benzochinony MeSH
• geldanamycin MeSH Prohlížeč
• makrocyklické laktamy MeSH
• proteiny tepelného šoku HSP90 MeSH
• rekombinantní proteiny MeSH
• rostlinné proteiny MeSH
• tubulin MeSH
• zelené fluorescenční proteiny MeSH

SH3P2 (At4g34660), an Arabidopsis thaliana SH3 and Bin/amphiphysin/Rvs (BAR) domain-containing protein, was reported to have a specific role in cell plate assembly, unlike its paralogs SH3P1 (At1g31440) and SH3P3 (At4g18060). SH3P family members were also predicted to interact with formins-evolutionarily conserved actin nucleators that participate in microtubule organization and in membrane-cytoskeleton interactions. To trace the origin of functional specialization of plant SH3Ps, we performed phylogenetic analysis of SH3P sequences from selected plant lineages. SH3Ps are present in charophytes, liverworts, mosses, lycophytes, gymnosperms, and angiosperms, but not in volvocal algae, suggesting association of these proteins with phragmoplast-, but not phycoplast-based cell division. Separation of three SH3P clades, represented by SH3P1, SH3P2, and SH3P3 of A. thaliana, appears to be a seed plant synapomorphy. In the yeast two hybrid system, Arabidopsis SH3P3, but not SH3P2, binds the FH1 and FH2 domains of the formin FH5 (At5g54650), known to participate in cytokinesis, while an opposite binding specificity was found for the dynamin homolog DRP1A (At5g42080), confirming earlier findings. This suggests that the cytokinetic role of SH3P2 is not due to its interaction with FH5. Possible determinants of interaction specificity of SH3P2 and SH3P3 were identified bioinformatically.

• Klíčová slova
• cell plate, cytokinesis, evolution, formin, interaction specificity, phylogeny,
• MeSH
• Arabidopsis MeSH
• cytokineze * MeSH
• dynaminy metabolismus   MeSH
• fylogeneze MeSH
• molekulární evoluce * MeSH
• proteiny huseníčku klasifikace   genetika   metabolismus   MeSH
• transportní proteiny klasifikace   genetika   metabolismus   MeSH
• vazba proteinů MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• dynaminy MeSH
• proteiny huseníčku MeSH
• SH3P2 protein, Arabidopsis MeSH Prohlížeč
• transportní proteiny MeSH