The Role of Hormones in Controlling Vascular Differentiation

2013 ◽  
pp. 99-139 ◽  
Author(s):  
Roni Aloni
Keyword(s):  
Vascular Differentiation

scholarly journals The role of mechanical stimuli in the vascular differentiation of mesenchymal stem cells

2015 ◽  
Vol 128 (14) ◽  
pp. 2415-2422 ◽  
Author(s):  
Pan Dan ◽  
Émilie Velot ◽  
Véronique Decot ◽  
Patrick Menu
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Mechanical Stimuli ◽  
Vascular Differentiation

The Role of Cytokinin in Organised Differentiation of Vascular Tissues

1993 ◽  
Vol 20 (5) ◽  
pp. 601 ◽  
Author(s):  
R Aloni
Keyword(s):  
Optimal Level ◽  
Ipt Gene ◽  
Vascular Differentiation ◽  
Vascular Tissues ◽  
Plant Body ◽  
Vessel Maturation ◽  
Sieve Tubes ◽  
Sieve Plates ◽  
Vessel Regeneration

The role of cytokinin as a limiting and controlling factor in the differentiation of vascular tissues in the plant body is discussed. Cytokinin controls the early stages of fibre differentiation in Helianthus stems and the regeneration of vessels and sieve tubes around a wound in Coleus internodes. The influence of cytokinin on cell differentiation in the vascular tissues varies according to its physiological levels and the levels of auxin. Cytokinin induces an acropetal polar pattern of vessel regeneration around a wound in internodes of Coleus. Similarly, adventitious roots induce acropetal polar patterns of vessel maturation in hypocotyls of Cucurbita. Cytokinin increases the sensitivity of the vascular cambium to the auxin stimulation, resulting in the highest ratio of phloem/xylem under the optimal level of cytokinin. High levels of cytokinin promote callose production on sieve plates. Studies of transgenic plants with altered levels of cytokinin (overexpressing the ipt gene) confirm the involvement of cytokinin in vascular differentiation.

scholarly journals Deep Imaging Analysis in VISUAL Reveals the Role of YABBY Genes in Vascular Stem Cell Fate Determination

2020 ◽  
Vol 61 (2) ◽  
pp. 255-264
Author(s):  
Alif Meem Nurani ◽  
Yasuko Ozawa ◽  
Tomoyuki Furuya ◽  
Yuki Sakamoto ◽  
Kazuo Ebine ◽  
...  
Keyword(s):  
Stem Cells ◽  
Cell Fate ◽  
Spatial Information ◽  
Secondary Growth ◽  
Vascular Differentiation ◽  
Mesophyll Cells ◽  
Vascular Cell

Abstract Stem cells undergo cell division and differentiation to ensure organized tissue development. Because plant cells are immobile, plant stem cells ought to decide their cell fate prior to differentiation, to locate specialized cells in the correct position. In this study, based on a chemical screen, we isolated a novel secondary cell wall indicator BF-170, which binds to lignin and can be used to image in vitro and in situ xylem development. Use of BF-170 to observe the vascular differentiation pattern in the in vitro vascular cell induction system, VISUAL, revealed that adaxial mesophyll cells of cotyledons predominantly generate ectopic xylem cells. Moreover, phloem cells are abundantly produced on the abaxial layer, suggesting the involvement of leaf adaxial–abaxial polarity in determining vascular cell fate. Analysis of abaxial polarity mutants highlighted the role of YAB3, an abaxial cell fate regulator, in suppressing xylem and promoting phloem differentiation on the abaxial domains in VISUAL. Furthermore, YABBY family genes affected in vivo vascular development during the secondary growth. Our results denoted the possibility that such mediators of spatial information contribute to correctly determine the cell fate of vascular stem cells, to conserve the vascular pattern of land plants.

The Role of Auxin in the Polar Organisation of Apical Meristems

1993 ◽  
Vol 20 (5) ◽  
pp. 541 ◽  
Author(s):  
T Sachs
Keyword(s):  
Leaf Development ◽  
Direct Contact ◽  
Cell Shape ◽  
Cellular Level ◽  
Vascular Differentiation ◽  
Pisum Sativum L ◽  
Stem Internode ◽  
Young Leaves ◽  
Lower Stem

Auxin is a correlative signal, coordinating leaf development with vascular differentiation and other developmental processes throughout the plant. It has a unique influence on the orientation of the differentiation of the cambium and its products. The problem considered was whether auxin has similar correlative roles in the development of meristematic stems. Seedlings of Pisum sativum L. were decapitated and the buds in the axil of the lower bract were used in all experiments. The lower stem internodes of these buds were ≤ 2 mm long and grew to about 50 mm in 6 d. The elongation of a stem internode continued even in the absence of all young leaves. However, vascular differentiation and transverse parenchyma growth correlated with the presence of developing leaves. Auxin replaced leaf effects on all stem tissues. The influence of both leaves and auxin were limited to the direction of the roots and to the sectors of the stem below the point of auxin application. This polarity differed from that of more mature tissues in requiring a direct contact with the roots. Another characteristic of minute stem internodes was that changes of orientation, expressed by cell shape and the axis of vascular differentiation, did not occur readily. However, at a narrow competence window local hormone applications did cause the formation of new stem-like axes. It is concluded that auxin is a correlative signal even within shoot apices and that the information it carries has an essential directional com- ponent. This directionality has not been studied at the cellular level.

The Influence of Indol-3Yl Acetic Acid and Sugar on the Pattern of Induced Differentiation in Plant Tissue Culture

1967 ◽  
Vol 2 (1) ◽  
pp. 77-88
Author(s):  
R. A. JEFFS ◽  
D. H. NORTHCOTE
Keyword(s):  
Tissue Culture ◽  
Acetic Acid ◽  
Callus Tissue ◽  
Vascular Differentiation ◽  
Tissue Mass ◽  
Simple Diffusion ◽  
Induction Process ◽  
Meristematic Activity ◽  
Sugar Derivatives

The induction of vascular differentiation in callus tissue of Phaseolus vulgaris by the application of indol-3yl acetic acid (IAA) and sucrose has been studied by cytological methods. The application of radioactive IAA and sucrose in the induction experiments has enabled the concentration of these substances, which move through the callus tissue mass by simple diffusion, to be estimated. Various monosaccharides, disaccharides, trisaccharides and sugar derivatives have been used instead of sucrose in order to study the biological role of the sugar molecule in the induction process. The results indicate that sucrose and certain other α-glucosyl disaccharides have a specific action in inducing differentiation into nodules containing xylem, phloem and meristematic activity. Evidence is also presented to show that possibly only very young cells, immediately following division, can be induced to differentiate.

scholarly journals Expression of ILK in renal stroma is essential for multiple aspects of renal development

2018 ◽  
Vol 315 (2) ◽  
pp. F374-F385
Author(s):  
Xiaohui Gong ◽  
Xiaoxia Guo ◽  
Ru Huang ◽  
Huimin Liao ◽  
Qingquan Zhang ◽  
...  
Keyword(s):  
Signaling Pathways ◽  
Kidney Development ◽  
Collecting Duct ◽  
Mesenchymal Cell ◽  
Branching Morphogenesis ◽  
Metanephric Mesenchyme ◽  
Vascular Differentiation ◽  
Renal Vasculature ◽  
Developmental Defects

Kidney development involves reciprocal and inductive interactions between the ureteric bud (UB) and surrounding metanephric mesenchyme. Signals from renal stromal lineages are essential for differentiation and patterning of renal epithelial and mesenchymal cell types and renal vasculogenesis; however, underlying mechanisms remain not fully understood. Integrin-linked kinase (ILK), a key component of integrin signaling pathway, plays an important role in kidney development. However, the role of ILK in renal stroma remains unknown. Here, we ablated ILK in renal stromal lineages using a platelet-derived growth factor receptor B ( Pdgfrb) -Cre mouse line, and the resulting Ilk mutant mice presented postnatal growth retardation and died within 3 wk of age with severe renal developmental defects. Pdgfrb-Cre;Ilk mutant kidneys exhibited a significant decrease in UB branching and disrupted collecting duct formation. From E16.5 onward, renal interstitium was disorganized, forming medullary interstitial pseudocysts. Pdgfrb-Cre;Ilk mutants exhibited renal vasculature mispatterning and impaired glomerular vascular differentiation. Impaired glial cell-derived neurotrophic factor/Ret and bone morphogenetic protein 7 signaling pathways were observed in Pdgfrb-Cre;Ilk mutant kidneys. Furthermore, phosphoproteomic and Western blot analyses revealed a significant dysregulation of a number of key signaling pathways required for kidney morphogenesis, including PI3K/AKT and MAPK/ERK in Pdgfrb-Cre;Ilk mutants. Our results revealed a critical requirement for ILK in renal-stromal and vascular development, as well as a noncell autonomous role of ILK in UB branching morphogenesis.

Responses of plant vascular systems to auxin transport inhibition

Development ◽  
1999 ◽  
Vol 126 (13) ◽  
pp. 2979-2991 ◽  
Author(s):  
J. Mattsson ◽  
Z.R. Sung ◽  
T. Berleth
Keyword(s):  
Auxin Transport ◽  
Vascular Tissue ◽  
Vascular System ◽  
Leaf Margin ◽  
Vascular Pattern ◽  
Vascular Differentiation ◽  
Vascular Patterning ◽  
Transport Inhibitor ◽  
Auxin Transport Inhibitor

To assess the role of auxin flows in plant vascular patterning, the development of vascular systems under conditions of inhibited auxin transport was analyzed. In Arabidopsis, nearly identical responses evoked by three auxin transport inhibitor substances revealed an enormous plasticity of the vascular pattern and suggest an involvement of auxin flows in determining the sites of vascular differentiation and in promoting vascular tissue continuity. Organs formed under conditions of reduced auxin transport contained increased numbers of vascular strands and cells within those strands were improperly aligned. In leaves, vascular tissues became progressively confined towards the leaf margin as the concentration of auxin transport inhibitor was increased, suggesting that the leaf vascular system depends on inductive signals from the margin of the leaf. Staged application of auxin transport inhibitor demonstrated that primary, secondary and tertiary veins became unresponsive to further modulations of auxin transport at successive stages of early leaf development. Correlation of these stages to anatomical features in early leaf primordia indicated that the pattern of primary and secondary strands becomes fixed at the onset of lamina expansion. Similar alterations in the leaf vascular responses of alyssum, snapdragon and tobacco plants suggest common functions of auxin flows in vascular patterning in dicots, while two types of vascular pattern alterations in Arabidopsis auxin transport mutants suggest that at least two distinct primary defects can result in impaired auxin flow. We discuss these observations with regard to the relative contributions of auxin transport, auxin sensitivity and the cellular organisation of the developing organ on the vascular pattern.

Role of dactinomycin in the improved survival of children with Wilms' tumor

JAMA ◽  
1966 ◽  
Vol 195 (12) ◽  
pp. 1005-1009 ◽  
Author(s):  
D. J. Fernbach
Keyword(s):  
Wilms Tumor
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