Far-red light stimulates internode elongation, cell division, cell elongation, and gibberellin levels in bean

1996 ◽  
Vol 74 (5) ◽  
pp. 743-752 ◽  
Author(s):  
Frederick D. Beall ◽  
Edward C. Yeung ◽  
Richard P. Pharis
Keyword(s):  
Cell Division ◽  
Cell Elongation ◽  
Red Light ◽  
Cell Labeling ◽  
Internode Elongation ◽  
Bean Plants ◽  
Gas Chromatography Mass Spectroscopy ◽  
Division Cell ◽  
Lower Magnitude

The contributions of cell division and cell elongation and the potential role of gibberellins in the far-red light stimulation of bean internode elongation were investigated. When bean plants, Phaseolus vulgaris cv. Kentucky Wonder, were grown in white light supplemented with far-red light a significant increase, up to threefold, in internode elongation was observed. Microscopic examination revealed that cell lengths were also increased but by a lower magnitude than internode length. Cell-labeling studies with [3H]thymidine showed that nuclei labeling was increased in internodes receiving supplemental far-red light. Thus far-red light induced increased internode elongation is a result of both increased cell elongation and increased cell division. Gibberellins A1, A20, A19, A44, and A4 and kaurenoic acid were identified in extracts of internode tissue by gas chromatography – mass spectroscopy using [2H2]-labeled internal standards for quantification. It thus appears that the early C-13 hydroxylation pathway is operative in the elongating internode. Endogenous GA1 and GA20 were approximately twofold higher in the first internodes of plants receiving supplemental far-red light. A comparison of the metabolism of exogenously supplied [2H2]GA19 suggested that GA turnover was greater in tissues exposed to supplemental far-red light. These results indicate that both cell division and elongation contribute to the enhanced elongation response of bean internodes to far-red light and that these processes are correlated with an increase in GA levels and (or) metabolism. Keywords: Phaseolus, gibberellins, phytochrome, far-red light.

scholarly journals Actin isovariant ACT7 regulates root meristem development in Arabidopsis through modulating auxin and ethylene responses

2021 ◽  
Author(s):  
Takahiro Numata ◽  
Kenji Sugita ◽  
Arifa Ahamed Rahman ◽  
Abidur Rahman
Keyword(s):  
Cell Division ◽  
Cell Elongation ◽  
Root Meristem ◽  
Primary Role ◽  
Arabidopsis Root ◽  
Meristem Development ◽  
Constant Cell ◽  
Division Cell ◽  
Auxin Efflux Carriers

Meristem, which sustains a reservoir of niche cells at its apex, is the most functionally dynamic part in a plant body. The shaping of the meristem requires constant cell division and cell elongation, that are regulated by hormones and cell cytoskeletal components, actin. Although the roles of hormones in regulating meristem development have been extensively studied, the role of actin in this process is still elusive. Using the single and double mutants of the vegetative class actin, we demonstrate that ACT7 plays a primary role in regulating the root meristem development. In absence of ACT7, but not ACT8 and ACT2, cellular depolymerization of actin is observed. Consistently, act7 mutant shows reduced cell division, cell elongation and meristem length. Intracellular distribution and trafficking of auxin transport proteins in the actin mutants revealed that ACT7 specifically functions in root meristem to facilitate the trafficking of auxin efflux carriers PIN1 and PIN2, and consequently the transport of auxin. Compared with act7, act7act8 double mutant shows slightly enhanced phenotypic response and altered intracellular trafficking. The altered distribution of auxin in act7 and act7act8 affects the roots response to ethylene but not to cytokinin. Collectively, our results suggest that Arabidopsis root meristem development is primarily controlled through actin isovariant ACT7 mediated modulation of auxin-ethylene response.

Anatomy of Wild Garlic Bulbs During and Subsequent to After-Ripening

Weed Science ◽  
1972 ◽  
Vol 20 (3) ◽  
pp. 233-237 ◽  
Author(s):  
J. F. Stritzke ◽  
E. J. Peters
Keyword(s):  
Cell Division ◽  
Microscopic Examination ◽  
Cell Elongation ◽  
Leaf Primordia ◽  
Root Primordia ◽  
Ripening Period ◽  
Shoot Primordia ◽  
Division Cell ◽  
Wild Garlic

Microscopic examination of central and soft offset bulbs of wild garlic(Allium vinealeL.) at senescence of the parent plants in May and June revealed embryonic plants with numerous root primordia and four or five shoot primordia. Hardshell bulbs and aerial bulblets contained only one or two root primordia and three leaf primordia. The embryonic plants of central, soft offset, and hardshell bulbs elongated slowly during the after-ripening period. Rapid cell division, cell elongation, and initiation of new leaves took place after termination of the after-ripening period in all but the dormant hardshell bulbs. In November, new hardshell bulbs could be seen at the base of plants developed from central and soft offset bulbs.

Asymmetric cell division and differentiation; fern spore germination as a model. II. Ultrastructural studies

1985 ◽  
Vol 86 ◽  
pp. 227-230
Author(s):  
Alix R. Bassel
Keyword(s):  
Cell Division ◽  
Metal Binding ◽  
Asymmetric Cell Division ◽  
Red Light ◽  
Nuclear Migration ◽  
Silver Stain ◽  
Metal Binding Sites ◽  
Ultrastructural Studies ◽  
Fern Spore Germination

SynopsisThe germination of Onoclea spores is a model system with many advantages for the study of asymmetric cell division and cellular differentiation. Our results suggest that both microtubules and a lipophilic site are important in the nuclear migration to one end of the spore prior to asymmetric cell division. A metalbinding region containing pore-like structures in the proximal face of the spore coat may be a source of the inherent polarity of the spore. The pattern of endogenous metal binding during germination has been characterised using a sulphide-silver stain. Metal-binding sites are described in a differentiating system in which polarity is imposed externally using polarised red light. The possibility of a role of ion gradients in determining the direction of nuclear migration is discussed.

Leaf morphogenesis and growth in Cyperus eragrostis (Cyperaoeae)

1996 ◽  
Vol 74 (11) ◽  
pp. 1753-1765 ◽  
Author(s):  
Connie L. Soros ◽  
Nancy G. Dengler
Keyword(s):  
Cell Division ◽  
Cell Elongation ◽  
Leaf Development ◽  
Pulse Labelling ◽  
Leaf Morphogenesis ◽  
Calcofluor White ◽  
Basal Half ◽  
Mitotic Figures ◽  
Division Cell ◽  
Leaf Extension

We identified the zones of leaf extension, cell division, cell elongation, and cell differentiation in developing leaves of a sedge species, Cyperus eragrostis Lam. (Cyperaceae). The zone of leaf extension was located by measuring the separation between pinhole markers and by observing the staining pattern of Calcofluor White after pulse-labelling growing leaves. These observations were supported by determining growth rates of control and punctured leaves and by scanning electron and light microscopy of developing leaves. The location of the zone of cell division was assessed by enumerating mitotic figures, and the zone of cell elongation was established by measuring lengths of epidermal cells in cleared leaves. These studies indicated that the zone of leaf elongation is within the basal 10–15 mm of a leaf and that cell divisions are restricted to the basal 0.2–1 mm. Radial enlargement of internal tissues begins in the basal half of the elongation zone and cells are fully differentiated within a short distance above it. Expanding leaves can be divided into three zones: zone 1, a basal meristematic zone where cell division and some cell elongation occur; zone 2, a zone above the base where cells are elongating but cell division has ceased; and zone 3, a zone where elongation is complete and cells have reached their final length. This pattern of leaf development is similar to, but more condensed than, feat found in the related monocotyledonous family, the Poaceae. Keywords: Cyperus eragrostis, leaf development, leaf extension zone, Cyperaceae, cell enlargement.

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.

scholarly journals Regulation of the Min Cell Division Inhibition Complex by the Rcs Phosphorelay in Proteus mirabilis

2015 ◽  
Vol 197 (15) ◽  
pp. 2499-2507 ◽  
Author(s):  
Kristen E. Howery ◽  
Katy M. Clemmer ◽  
Emrah Şimşek ◽  
Minsu Kim ◽  
Philip N. Rather
Keyword(s):  
Cell Division ◽  
Cell Differentiation ◽  
Proteus Mirabilis ◽  
Cell Elongation ◽  
Response Regulator ◽  
Swarmer Cell ◽  
Content Type ◽  
Expression Of Genes ◽  
Rapid Amplification

ABSTRACTA key regulator of swarming inProteus mirabilisis the Rcs phosphorelay, which repressesflhDC, encoding the master flagellar regulator FlhD4C2. Mutants inrcsB, the response regulator in the Rcs phosphorelay, hyperswarm on solid agar and differentiate into swarmer cells in liquid, demonstrating that this system also influences the expression of genes central to differentiation. To gain a further understanding of RcsB-regulated genes involved in swarmer cell differentiation, transcriptome sequencing (RNA-Seq) was used to examine the RcsB regulon. Among the 133 genes identified,minCandminD, encoding cell division inhibitors, were identified as RcsB-activated genes. A third gene,minE, was shown to be part of an operon withminCD. To examineminCDEregulation, theminpromoter was identified by 5′ rapid amplification of cDNA ends (5′-RACE), and both transcriptionallacZfusions and quantitative real-time reverse transcriptase (qRT) PCR were used to confirm that theminCDEoperon was RcsB activated. Purified RcsB was capable of directly binding theminCpromoter region. To determine the role of RcsB-mediated activation ofminCDEin swarmer cell differentiation, a polarminCmutation was constructed. This mutant formed minicells during growth in liquid, produced shortened swarmer cells during differentiation, and exhibited decreased swarming motility.IMPORTANCEThis work describes the regulation and role of the MinCDE cell division system inP. mirabilisswarming and swarmer cell elongation. Prior to this study, the mechanisms that inhibit cell division and allow swarmer cell elongation were unknown. In addition, this work outlines for the first time the RcsB regulon inP. mirabilis. Taken together, the data presented in this study begin to address howP. mirabiliselongates upon contact with a solid surface.

scholarly journals Patterns of Cell Division, Cell Differentiation and Cell Elongation in Epidermis and Cortex of Arabidopsis pedicels in the Wild Type and in erecta

PLoS ONE ◽  
2012 ◽  
Vol 7 (9) ◽  
pp. e46262 ◽  
Author(s):  
Mark G. R. Bundy ◽  
Olivia A. Thompson ◽  
Matthew T. Sieger ◽  
Elena D. Shpak
Keyword(s):  
Cell Division ◽  
Cell Differentiation ◽  
Cell Elongation ◽  
Wild Type ◽  
In The Wild ◽  
Division Cell

scholarly journals Transcriptome analysis and identification of genes associated with fruiting branch internode elongation in upland cotton

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Feiyan Ju ◽  
Shaodong Liu ◽  
Siping Zhang ◽  
Huijuan Ma ◽  
Jing Chen ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Cell Division ◽  
Molecular Mechanism ◽  
Cell Elongation ◽  
Plant Architecture ◽  
Plant Hormone ◽  
Signal Transduction Pathway ◽  
Transduction Pathway ◽  
Internode Elongation ◽  
Short Internodes

Abstract Background Appropriate plant architecture can improve the amount of cotton boll opening and allow increased planting density, thus increasing the level of cotton mechanical harvesting and cotton yields. The internodes of cotton fruiting branches are an important part of cotton plant architecture. Thus, studying the molecular mechanism of internode elongation in cotton fruiting branches is highly important. Results In this study, we selected internodes of cotton fruiting branches at three different stages from two cultivars whose internode lengths differed significantly. A total of 76,331 genes were detected by transcriptome sequencing. By KEGG pathway analysis, we found that DEGs were significantly enriched in the plant hormone signal transduction pathway. The transcriptional data and qRT-PCR results showed that members of the GH3 gene family, which are involved in auxin signal transduction, and CKX enzymes, which can reduce the level of CKs, were highly expressed in the cultivar XLZ77, which has relatively short internodes. Genes related to ethylene synthase (ACS), EIN2/3 and ERF in the ethylene signal transduction pathway and genes related to JAR1, COI1 and MYC2 in the JA signal transduction pathway were also highly expressed in XLZ77. Plant hormone determination results showed that the IAA and CK contents significantly decreased in cultivar XLZ77 compared with those in cultivar L28, while the ACC (the precursor of ethylene) and JA contents significantly increased. GO enrichment analysis revealed that the GO categories associated with promoting cell elongation, such as cell division, the cell cycle process and cell wall organization, were significantly enriched, and related genes were highly expressed in L28. However, genes related to the sphingolipid metabolic process and lignin biosynthetic process, whose expression can affect cell elongation, were highly expressed in XLZ77. In addition, 2067 TFs were differentially expressed. The WRKY, ERF and bHLH TF families were the top three largest families whose members were active in the two varieties, and the expression levels of most of the genes encoding these TFs were upregulated in XLZ77. Conclusions Auxin and CK are positive regulators of internode elongation in cotton branches. In contrast, ethylene and JA may act as negative regulators of internode elongation in cotton branches. Furthermore, the WRKY, ERF and bHLH TFs were identified as important inhibitors of internode elongation in cotton. In XLZ77(a short-internode variety), the mass synthesis of ethylene and amino acid conjugation of auxin led to the inhibition of plant cell elongation, while an increase in JA content and degradation of CKs led to a slow rate of cell division, which eventually resulted in a phenotype that presented relatively short internodes on the fruiting branches. The results of this study not only provide gene resources for the genetic improvement of cotton plant architecture but also lay a foundation for improved understanding of the molecular mechanism of the internode elongation of cotton branches.

Cell division, cell elongation and the co-ordination of crystallin gene expression during lens morphogenesis in the rat

Development ◽  
1978 ◽  
Vol 45 (1) ◽  
pp. 271-281
Author(s):  
J. W. McAvoy
Keyword(s):  
Cell Division ◽  
Cell Elongation ◽  
Posterior Part ◽  
Temporal And Spatial Distribution ◽  
Alpha Crystallin ◽  
Pit Cells ◽  
Specific Proteins ◽  
Lens Vesicle ◽  
Temporal And Spatial ◽  
Division Cell

A quantitative analysis of cell division and cell elongation was carried out during lens morphogenesis in the rat. At 13 days of development elongating cells in the posterior part of the lens vesicle (presumptive fibre cells) have a lower mitotic activity than cells in the anterior vesicle. By 14 days these elongating cells do not divide. Thus at 14 days of development the lens can be separated into two compartments; a proliferation compartment in the anterior lens and an elongation compartment in the posterior lens. The three main groups of lens-specific proteins, α-,β- and γ-crystallins, were localized by immunofiuorescence. Alpha-crystallin is the first crystallin to be detected and is localized in some lens pit cells at 12 days of development. By 14 days all lens cells contain α-crystallin. Beta- and β-crystallins are detected later at 12½ days and are localized in some cells situated primarily in the posterior part of the lens vesicle. At later stages of development these crystallins are restricted to cells of the elongation compartment, i.e. presumptive fibre and fibre cells. Possible mechanisms that govern the temporal and spatial distribution of crystallins are discussed.

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