Epidermal cell division and cell elongation in two Aegilops species with contrasting leaf elongation rates

2003 ◽  
Vol 30 (4) ◽  
pp. 425 ◽  
Author(s):  
Lieve Bultynck ◽  
Fabio Fiorani ◽  
Elizabeth Van Volkenburgh ◽  
Hans Lambers
Keyword(s):  
Cell Division ◽  
Cell Elongation ◽  
Aegilops Tauschii ◽  
Growth Zone ◽  
Elongation Rate ◽  
Main Stem ◽  
Leaf Number ◽  
Leaf Elongation ◽  
Division Rate ◽  
Dividing Cells

The 2-fold difference in final length of leaf number three on the main stem between the fast-growing Aegilops tauschii L. and the slow-growing Aegilops caudata L. is correlated with a difference in leaf elongation rate (LER), and not in duration of leaf elongation. In this paper the cellular basis of inherent differences in LER between these species was investigated.The dynamics of abaxial epidermal cells along the growth zone of leaf number three on the main stem of both species was analysed by means of a kinematic analysis. The faster LER of Ae. tauschii compared with that of Ae.�caudata was associated with (i) a larger leaf basal meristem and cell elongation-only zone, and (ii) a faster cell production rate owing to a larger number of dividing cells. Cell division rate, mature cell size and cell elongation rate did not differ between the two species. The lack of variation in cell expansion rate between the species was supported by a similar capacity of both species to extend their isolated cell walls upon acidification.These data suggest that differences in the number of dividing cells can bring about differences in the number of simultaneously elongating cells, and hence in LER.

scholarly journals Stable inheritance of Sinorhizobium meliloti cell growth polarity requires an FtsN-like protein and an amidase

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Elizaveta Krol ◽  
Lisa Stuckenschneider ◽  
Joana M. Kästle Silva ◽  
Peter L. Graumann ◽  
Anke Becker
Keyword(s):  
Cell Division ◽  
Cell Polarity ◽  
Chromosome Segregation ◽  
Cell Elongation ◽  
Sinorhizobium Meliloti ◽  
Growth Zone ◽  
Cell Pole ◽  
Growth Polarity ◽  
Selection Of

AbstractIn Rhizobiales bacteria, such as Sinorhizobium meliloti, cell elongation takes place only at new cell poles, generated by cell division. Here, we show that the role of the FtsN-like protein RgsS in S. meliloti extends beyond cell division. RgsS contains a conserved SPOR domain known to bind amidase-processed peptidoglycan. This part of RgsS and peptidoglycan amidase AmiC are crucial for reliable selection of the new cell pole as cell elongation zone. Absence of these components increases mobility of RgsS molecules, as well as abnormal RgsS accumulation and positioning of the growth zone at the old cell pole in about one third of the cells. These cells with inverted growth polarity are able to complete the cell cycle but show partially impaired chromosome segregation. We propose that amidase-processed peptidoglycan provides a landmark for RgsS to generate cell polarity in unipolarly growing Rhizobiales.

A two-pinhole technique to determine distribution profiles of relative elemental growth rates in the growth zone of grass leaves

2000 ◽  
Vol 27 (12) ◽  
pp. 1187
Author(s):  
Urs Schmidhalter ◽  
Yuncai Hu
Keyword(s):  
Spatial Distribution ◽  
Growth Rates ◽  
Growth Zone ◽  
Elongation Rate ◽  
New Technique ◽  
Leaf Elongation ◽  
Distribution Profile

A new modified pricking technique, a two-pinhole method, was designed to determine the spatial distribution of leaf elongation of grasses. This new technique makes it possible to obtain the distribution profiles of relative elemental growth rates in the growth zone, to evaluate the effect of pricking on the distribution profile of leaf elongation in the growth zone and to decrease the reduction in the elongation rate of grass leaves due to pricking.

Leaf Elongation Rate in Panicum maximum var. trichoglume Following Removal of Water Stress

1977 ◽  
Vol 4 (2) ◽  
pp. 263 ◽  
Author(s):  
MM Ludlow ◽  
TT Ng
Keyword(s):  
Cell Division ◽  
Water Stress ◽  
Water Potential ◽  
Cell Expansion ◽  
Elongation Rate ◽  
Panicum Maximum ◽  
Leaf Elongation ◽  
Leaf Elongation Rate ◽  
Dark Stress ◽  
Different Levels

Different levels of stress were induced in P. maximum var. trichoglume by withholding water for various periods. Leaf elongation rate was measured during dark stress periods and after rewatering in both the light and the dark. Following rewatering, elongation rates of previously stressed plants exceeded those of controls for periods up to 33 h, during which time elongation rate was more related to previous levels of water stress than to current leaf water potential. In addition, there was a transient burst of elongation when plants were rewatered in the light. It is suggested that the stimulated rates result from expansion of cells which have accumulated during the stress because cell division is less sensitive to water stress than is cell expansion. Despite the stimulated rates of elongation after rewatering, the recovery was incomplete such that the final lengths of stressed leaves were less than those of unstressed plants.

scholarly journals Threshold accumulation of a constitutive protein explains E. coli cell division behavior in nutrient upshifts

2020 ◽  
Author(s):  
Mia Panlilio ◽  
Jacopo Grilli ◽  
Giorgio Tallarico ◽  
Ilaria Iuliani ◽  
Bianca Sclavi ◽  
...  
Keyword(s):  
Cell Division ◽  
Mathematical Models ◽  
Single Cell ◽  
Single Cells ◽  
Division Rate ◽  
E Coli ◽  
Size Growth ◽  
Dividing Cells ◽  
Nutrient Changes ◽  
Insight Into

AbstractDespite of a boost of recent progress in dynamic single-cell measurements and analyses in E. coli, we still lack a mechanistic understanding of the determinants of the decision to divide. Specifically, the debate is open regarding the processes linking growth and chromosome replication to division, and on the molecular origin of the observed “adder correlations”, whereby cells divide adding roughly a constant volume independent of their initial volume. In order to gain insight into these questions, we interrogate dynamic size-growth behavior of single cells across nutrient upshifts with a high-precision microfluidic device. We find that the division rate changes quickly after nutrients change, much before growth rate goes to a steady state, and in a way that adder correlations are robustly conserved. Comparison of these data to simple mathematical models falsifies proposed mechanisms where replication-segregation or septum completion are the limiting step for cell division. Instead, we show that the accumulation of a putative constitutively expressed “P-sector divisor” protein explains the behavior during the shift.Significance statementThe mechanism leading to cell division in the bacterium E. coli is unknown, but we know that it results in adding a roughly constant size every cell cycle, regardless of size at birth. While most available studies try to infer information on cell division from steadily dividing cells in constant nutrient conditions, this study leverages on a high-resolution device to monitor single-cell growth division upon nutrient changes. Comparing these data with different mathematical models, the authors are able to discriminate among fundamentally different mechanisms of cell division control, and they show that the data support a model where an unregulated protein accumulates to a threshold and triggers division.

scholarly journals Metabolic and Physical Control of Cell Elongation Rate

1971 ◽  
Vol 47 (3) ◽  
pp. 423-430 ◽  
Author(s):  
P. B. Green ◽  
R. O. Erickson ◽  
J. Buggy
Keyword(s):  
Cell Elongation ◽  
Elongation Rate ◽  
Physical Control

scholarly journals Cytokinesis and Midzone Microtubule Organization inCaenorhabditis elegans Require the Kinesin-like Protein ZEN-4

1998 ◽  
Vol 9 (8) ◽  
pp. 2037-2049 ◽  
Author(s):  
William B. Raich ◽  
Adrienne N. Moran ◽  
Joel H. Rothman ◽  
Jeff Hardin
Keyword(s):  
Cell Division ◽  
Null Allele ◽  
Time Lapse ◽  
Equatorial Region ◽  
Microtubule Organization ◽  
Dividing Cells ◽  
Spindle Midzone ◽  
Cross Links ◽  
Complete Cell

Members of the MKLP1 subfamily of kinesin motor proteins localize to the equatorial region of the spindle midzone and are capable of bundling antiparallel microtubules in vitro. Despite these intriguing characteristics, it is unclear what role these kinesins play in dividing cells, particularly within the context of a developing embryo. Here, we report the identification of a null allele ofzen-4, an MKLP1 homologue in the nematodeCaenorhabditis elegans, and demonstrate that ZEN-4 is essential for cytokinesis. Embryos deprived of ZEN-4 form multinucleate single-celled embryos as they continue to cycle through mitosis but fail to complete cell division. Initiation of the cytokinetic furrow occurs at the normal time and place, but furrow propagation halts prematurely. Time-lapse recordings and microtubule staining reveal that the cytokinesis defect is preceded by the dissociation of the midzone microtubules. We show that ZEN-4 protein localizes to the spindle midzone during anaphase and persists at the midbody region throughout cytokinesis. We propose that ZEN-4 directly cross-links the midzone microtubules and suggest that these microtubules are required for the completion of cytokinesis.

scholarly journals Cell Elongation and Cell Death ofHelicobacter pyloriIs Modulated by the Disruption ofcdrA(Cell Division-Related Gene A)

2006 ◽  
Vol 50 (7) ◽  
pp. 487-497 ◽  
Author(s):  
Hiroaki Takeuchi ◽  
Teruko Nakazawa ◽  
Takeshi Okamoto ◽  
Mutsunori Shirai ◽  
Mitsuo Kimoto ◽  
...  
Keyword(s):  
Cell Death ◽  
Cell Division ◽  
Cell Elongation ◽  
Related Gene

fumble Encodes a Pantothenate Kinase Homolog Required for Proper Mitosis and Meiosis in Drosophila melanogaster

Genetics ◽  
2001 ◽  
Vol 157 (3) ◽  
pp. 1267-1276
Author(s):  
Katayoun Afshar ◽  
Pierre Gönczy ◽  
Stephen DiNardo ◽  
Steven A Wasserman
Keyword(s):  
Cell Division ◽  
Chromosome Segregation ◽  
Cell Division Cycle ◽  
Protein Isoforms ◽  
Pantothenate Kinase ◽  
Male Germline ◽  
Dividing Cells ◽  
Mutant Cells ◽  
Mitosis And Meiosis

Abstract A number of fundamental processes comprise the cell division cycle, including spindle formation, chromosome segregation, and cytokinesis. Our current understanding of these processes has benefited from the isolation and analysis of mutants, with the meiotic divisions in the male germline of Drosophila being particularly well suited to the identification of the required genes. We show here that the fumble (fbl) gene is required for cell division in Drosophila. We find that dividing cells in fbl-deficient testes exhibit abnormalities in bipolar spindle organization, chromosome segregation, and contractile ring formation. Cytological analysis of larval neuroblasts from null mutants reveals a reduced mitotic index and the presence of polyploid cells. Molecular analysis demonstrates that fbl encodes three protein isoforms, all of which contain a domain with high similarity to the pantothenate kinases of A. nidulans and mouse. The largest Fumble isoform is dispersed in the cytoplasm during interphase, concentrates around the spindle at metaphase, and localizes to the spindle midbody at telophase. During early embryonic development, the protein localizes to areas of membrane deposition and/or rearrangement, such as the metaphase and cellularization furrows. Given the role of pantothenate kinase in production of Coenzyme A and in phospholipid biosynthesis, this pattern of localization is suggestive of a role for fbl in membrane synthesis. We propose that abnormalities in synthesis and redistribution of membranous structures during the cell division cycle underlie the cell division defects in fbl mutant cells.

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