Mutations in the HYDRA1 gene of Arabidopsis perturb cell shape and disrupt embryonic and seedling morphogenesis

Development ◽  
1997 ◽  
Vol 124 (21) ◽  
pp. 4415-4424 ◽  
Author(s):  
J.F. Topping ◽  
V.J. May ◽  
P.R. Muskett ◽  
K. Lindsey
Keyword(s):  
Cell Expansion ◽  
Cell Shape ◽  
Bilateral Symmetry ◽  
Variable Number ◽  
Morphological Development ◽  
Size And Shape ◽  
Radial Patterning ◽  
Protein Functions ◽  
Expansion System ◽  
Embryonic Root

Mutations in the HYDRA1 (HYD1) gene of Arabidopsis thaliana can prevent normal morphological development of embryos and seedlings. Three allelic mutants (hydra 1–1, hydra1-2 and hydra1-3) have been identified, and in each the seedling is characterized by having a variable number of cotyledons, a short and wide hypocotyl and a much reduced root system. hydra1 embryos appear to develop normally to the octant stage, but fail to establish a distinct protoderm and lack bilateral symmetry, developing multiple cotyledonary primordia of irregular size and shape. Cells of the embryo proper, but not the suspensor, exhibit abnormalities in size and shape. The hydra1 embryo fails to develop an embryonic root, but embryos and seedlings express molecular markers of apical-basal polarity. Mutant seedlings produce leaves to form a small cabbage-like habit and may occasionally produce sterile flowers, though the mutation is commonly seedling-lethal. hydra1 seedlings exhibit abnormal radial patterning, but nevertheless express at least one molecular marker of vascular cell differentiation. A model is proposed in which the HYDRA1 protein functions as an essential component of the cell expansion system.

The effects of 2-thiouracil on growth and metabolism in the root. Ι. Growth of excised root tissue

1967 ◽  
Vol 169 (1014) ◽  
pp. 77-88 ◽  
Keyword(s):  
Acetic Acid ◽  
Cell Expansion ◽  
Actinomycin D ◽  
Extension Growth ◽  
Root Tissue ◽  
Morphological Development ◽  
Entire Cell ◽  
Simple Sugar ◽  
Indole 3 Acetic Acid ◽  
Expansion Period

In this investigation isolated 2 to 4 mm subapical pea root segments were used to study the effect of 2-thiouracil on extension growth. 2-Thiouracil stimulated an increase in the lengths, fresh and dry weights, and polysaccharide material of the expanding segments, but only in the presence of a simple sugar. To produce the maximum stimulation it must be in contact with the tissue through out the entire cell expansion period. Uracil was an antagonist of 2-thiouracil stimulation. The analogue did not alter the morphological development of cells, xylem an d phloem formation being unaffected. Substances which are known to affect either growth (indole-3-acetic acid) or metabolism (D-threochloramphenicol and actinomycin D) were found to decrease or even abolish the stimulation caused by 2-thiouracil. 2-Thiouracil stimulation was also dependent on temperature, the maximum stimulation being observed at 25 to 30 °C.

Molecular analysis of SCARECROW function reveals a radial patterning mechanism common to root and shoot

Development ◽  
2000 ◽  
Vol 127 (3) ◽  
pp. 595-603 ◽  
Author(s):  
J.W. Wysocka-Diller ◽  
Y. Helariutta ◽  
H. Fukaki ◽  
J.E. Malamy ◽  
P.N. Benfey
Keyword(s):  
Bundle Sheath ◽  
Quiescent Center ◽  
Ground Tissue ◽  
Tissue Layer ◽  
Radial Pattern ◽  
Radial Patterning ◽  
Bundle Sheath Cells ◽  
Root Analysis ◽  
Tight Correlation ◽  
Embryonic Root

Mutation of the SCARECROW (SCR) gene results in a radial pattern defect, loss of a ground tissue layer, in the root. Analysis of the shoot phenotype of scr mutants revealed that both hypocotyl and shoot inflorescence also have a radial pattern defect, loss of a normal starch sheath layer, and consequently are unable to sense gravity in the shoot. Analogous to its expression in the endodermis of the root, SCR is expressed in the starch sheath of the hypocotyl and inflorescence stem. The SCR expression pattern in leaf bundle sheath cells and root quiescent center cells led to the identification of additional phenotypic defects in these tissues. SCR expression in a pin-formed mutant background suggested the possible origins of the starch sheath in the shoot inflorescence. Analysis of SCR expression and the mutant phenotype from the earliest stages of embryogenesis revealed a tight correlation between defective cell divisions and SCR expression in cells that contribute to ground tissue radial patterning in both embryonic root and shoot. Our data provides evidence that the same molecular mechanism regulates the radial patterning of ground tissue in both root and shoot during embryogenesis as well as postembryonically.

Scaling up clinical T cell expansion in a Xuri™ cell expansion system

Cytotherapy ◽  
2015 ◽  
Vol 17 (6) ◽  
pp. S22
Author(s):  
Carin Mölleryd ◽  
Claudia Nunes ◽  
Ulrica Eistrand
Keyword(s):  
T Cell ◽  
Cell Expansion ◽  
Scaling Up ◽  
Expansion System ◽  
T Cell Expansion

Evaluating the use of Terumo Quantum® cell expansion system for large scale expansion of mesenchymal stem (stromal) cells in xeno- and serum-free media

Cytotherapy ◽  
2017 ◽  
Vol 19 (5) ◽  
pp. S163-S164
Author(s):  
S. Khan ◽  
M. Salkhordeh ◽  
J. Schafhauser ◽  
F. Hussein ◽  
S. Hodgins ◽  
...  
Keyword(s):  
Stromal Cells ◽  
Cell Expansion ◽  
Large Scale ◽  
Serum Free ◽  
Expansion System ◽  
Scale Expansion ◽  
Free Media

scholarly journals Identification of genera of tubificid worms in Bangladesh through morphological study

2016 ◽  
Vol 2 (1) ◽  
pp. 27-32 ◽  
Author(s):  
Mariom ◽  
Sharmin Nahar Liza ◽  
Md Fazlul Awal Mollah
Keyword(s):  
Morphological Study ◽  
Aquatic Invertebrates ◽  
Cylindrical Body ◽  
Bilateral Symmetry ◽  
Live Food ◽  
Body Segment ◽  
Body Segments ◽  
Size And Shape ◽  
The World ◽  
Tubificid Worms

Tubificids are aquatic oligochaete worms (F- Naididae, O- Haplotaxida, P- Annelida) distributed all over the world. The worms are very important as they are used as live food for fish and other aquatic invertebrates. A step was taken to identify the genera of tubicifid worms that exist in Mymensingh district, Bangladesh on the basis of some external features including the shape of their anterior (prostomium) and posterior end, number of body segment and arrangement of setae. The study result indicated the existence of three genera among the tubificid worms. These were Tubifex, Limnodrilus and Aulodrilus. All these three genera possessed a cylindrical body with a bilateral symmetry formed by a series of metameres. The number of body segments ranged from 34 to 120 in Tubifex, 50 to 87 in Limnodrilus, and 35 to 100 in Aulodrilus. In Tubifex, the first segment, with the prostomium, was round or triangular bearing appendages, whereas, in Limnodrilus and Aulodrilus, the prostomium without appendages was triangular and conical, respectively. Three types of setae i.e., hair setae, pectinate setae and bifid setae of various sizes were found in Tubifex, whereas, Limnodrilus possessed pectinate setae and bifid setae of more or less similar size and shape; and Aulodrilus possessed only hair setae and bifid setae of different size.Asian J. Med. Biol. Res. March 2016, 2(1): 27-32

scholarly journals A morpho-transcriptomic map of brassinosteroid action in the Arabidopsis root

2021 ◽  
Author(s):  
Moritz Graeff ◽  
Surbhi Rana ◽  
Jos R. Wendrich ◽  
Julien Dorier ◽  
Thomas Eekhout ◽  
...  
Keyword(s):  
Single Cell ◽  
Cell Expansion ◽  
Cell Shape ◽  
Negative Impact ◽  
Arabidopsis Root ◽  
Proliferation Capacity ◽  
Brassinosteroid Signaling ◽  
Growth Vigor ◽  
Cell Transcriptome ◽  
Single Cell Transcriptome

The effects of brassinosteroid signaling on shoot and root development have been characterized in great detail but did not identify a simple consistent positive or negative impact on a basic cellular parameter that would comprehensively explain the phenotype of brassinosteroid-related mutants. Here we combined digital 3D single-cell shape analysis and single-cell mRNA sequencing to characterize root meristems and mature root segments of brassinosteroid-blind mutants and wildtype. These data demonstrate that brassinosteroid signaling neither affects cell volume nor cell proliferation capacity. Instead, brassinosteroid signaling is essential for the precise orientation of cell division planes and the extent and timing of anisotropic cell expansion. Moreover, we found that the cell-aligning effects of brassinosteroid signaling can propagate to normalize the anatomy of both adjacent and distant brassinosteroid-blind cells through non-cell-autonomous functions, which are sufficient to restore overall root growth vigor. Finally, single-cell transcriptome data discern directly brassinosteroid-responsive genes from genes that can react to non-cell-autonomous brassinosteroid-dependent signals and highlight arabinogalactans as sentinels of brassinosteroid-dependent anisotropic cell expansion.

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