A cytological study of the oat coleoptile

1964 ◽  
Vol 12 (2) ◽  
pp. 135 ◽  
Author(s):  
AB Wardrop ◽  
RC Foster
Keyword(s):  
Cell Wall ◽  
Cytological Study ◽  
Peripheral Zone ◽  
Extension Growth ◽  
Extension Phase ◽  
Dark Light ◽  
Wall Formation ◽  
Before And After ◽  
Cytoplasmic Organization ◽  
Vesicular Secretion

A study has been made of the cytoplasmic organization of epidermal and sub- epidermal parenchyma of oat coleoptiles both before and after the onset of extension growth. In the youngest cells studied (coleoptiles 0.5 mm long) the epidermal parenchyma was characterized by large stellate vacuoles and by the secretion of vesicles through the plasmalemma into the external periclinal cell wall. Vesicular secretion was not observed in the anticlinal walls or into the walls of subepidermal parenchyma. The subepidermal parenchyma was characterized by the presence of numerous thick-walled vacuolar structures and plastids rich in starch. In the extension phase (coleoptiles > 10 mm long) vesicular secretion was not observed, starch was absent from the plastids, and the cells contained large vacuoles with only a thin peripheral zone of cytoplasm. During the later stages of this phase the plasmalemma appeared to consist of two darkly stained membranes separated by a light zone, or of elaborations of this structure, e.g. dark, light, dark, light, dark. By contrast, in the pre-extension phase the plasmalemma appeared as a single membrane. The implications of these observations are discussed in relation to the process of wall formation.

Changes in cell wall organization resulting from surface growth in parenchyma of oat coleoptiles

1958 ◽  
Vol 6 (2) ◽  
pp. 89 ◽  
Author(s):  
AB Wardrop ◽  
J Cronshaw
Keyword(s):  
Cell Wall ◽  
Outer Surface ◽  
Secondary Wall ◽  
Surface Growth ◽  
Extension Growth ◽  
Primary Wall ◽  
Cell Wall Formation ◽  
Wall Formation ◽  
Cell Wall Organization ◽  
Mechanism Of Growth

The primary walls present during the phase of extension growth in oat coleoptiles possess an almost transverse microfibril orientation on their inner surfaces but on the outer surface the microfibrils are considerably disoriented from this direction, which is consistent with the concept of multi-net mechanism of growth. Coleoptile segments grown at 2°C to depress cell wall formation show no difference in orientation on their inner and outer surfaces; this is also considered to be consistent with the multi-net mechanism. It is shown that the longitudinal ribs of microfibrils present at the cell corners, and hitherto referred to as secondary thickening, are on the outer surface of the cell wall and are considered to arise from a disorientation of microfibrils as a result of multi-net growth. As a result of this microfibril disorientation there is a tendency for the pit fields to be reduced in area. After surface growth has ceased a secondary wall is formed with a well-defined helical organization distinctly different from that of the primary wall. The implications of these results in terms of previous investigations are discussed.

Ethylene effects on cambial activity and cell wall formation in hypocotyls of Picea abies seedlings

1991 ◽  
Vol 82 (2) ◽  
pp. 219-224 ◽  
Author(s):  
Barbro S. M. Ingemarsson ◽  
Leif Eklund ◽  
Lennart Eliasson
Keyword(s):  
Cell Wall ◽  
Picea Abies ◽  
Cambial Activity ◽  
Cell Wall Formation ◽  
Wall Formation

Arabidopsis Callose Synthase Gene GSL8 is Required for Cell Wall Formation and Establishment and Maintenance of Quiescent Center

2014 ◽  
Vol 48 (4) ◽  
pp. 389-397
Author(s):  
Liu Lin ◽  
Quan Xianqing ◽  
Zhao Xiaomei ◽  
Huang Lihua ◽  
Feng Shangcai ◽  
...  
Keyword(s):  
Cell Wall ◽  
Quiescent Center ◽  
Cell Wall Formation ◽  
Callose Synthase ◽  
Wall Formation

scholarly journals MYB Transcription Factors and Its Regulation in Secondary Cell Wall Formation and Lignin Biosynthesis during Xylem Development

2021 ◽  
Vol 22 (7) ◽  
pp. 3560
Author(s):  
Ruixue Xiao ◽  
Chong Zhang ◽  
Xiaorui Guo ◽  
Hui Li ◽  
Hai Lu
Keyword(s):  
Cell Wall ◽  
Transcription Factors ◽  
Secondary Wall ◽  
Secondary Cell Wall ◽  
Lignin Biosynthesis ◽  
Cell Wall Formation ◽  
Long Distance ◽  
Secondary Cell Wall Formation ◽  
Myb Transcription Factors ◽  
Wall Formation

The secondary wall is the main part of wood and is composed of cellulose, xylan, lignin, and small amounts of structural proteins and enzymes. Lignin molecules can interact directly or indirectly with cellulose, xylan and other polysaccharide molecules in the cell wall, increasing the mechanical strength and hydrophobicity of plant cells and tissues and facilitating the long-distance transportation of water in plants. MYBs (v-myb avian myeloblastosis viral oncogene homolog) belong to one of the largest superfamilies of transcription factors, the members of which regulate secondary cell-wall formation by promoting/inhibiting the biosynthesis of lignin, cellulose, and xylan. Among them, MYB46 and MYB83, which comprise the second layer of the main switch of secondary cell-wall biosynthesis, coordinate upstream and downstream secondary wall synthesis-related transcription factors. In addition, MYB transcription factors other than MYB46/83, as well as noncoding RNAs, hormones, and other factors, interact with one another to regulate the biosynthesis of the secondary wall. Here, we discuss the biosynthesis of secondary wall, classification and functions of MYB transcription factors and their regulation of lignin polymerization and secondary cell-wall formation during wood formation.

scholarly journals Spatial Distribution of a Porphyrin-Based Photosensitizer Reveals Mechanism of Photodynamic Inactivation of Candida albicans

2021 ◽  
Vol 8 ◽  
Author(s):  
Thomas Voit ◽  
Fabian Cieplik ◽  
Johannes Regensburger ◽  
Karl-Anton Hiller ◽  
Anita Gollmer ◽  
...  
Keyword(s):  
Cell Wall ◽  
Candida Albicans ◽  
Fungal Infections ◽  
Cell Envelope ◽  
Antimicrobial Photodynamic Therapy ◽  
Fungal Cell ◽  
Before And After ◽  
Antifungal Action ◽  
Complete Cell ◽  
Further Development

The antimicrobial photodynamic therapy (aPDT) is a promising approach for the control of microbial and especially fungal infections such as mucosal mycosis. TMPyP [5,10,15, 20-tetrakis(1-methylpyridinium-4-yl)-porphyrin tetra p-toluenesulfonate] is an effective photosensitizer (PS) that is commonly used in aPDT. The aim of this study was to examine the localization of TMPyP in Candida albicans before and after irradiation with visible light to get information about the cellular mechanism of antifungal action of the photodynamic process using this PS. Immediately after incubation of C. albicans with TMPyP, fluorescence microscopy revealed an accumulation of the PS in the cell envelope. After irradiation with blue light the complete cell showed red fluorescence, which indicates, that aPDT is leading to a damage in the cell wall with following influx of PS into the cytosol. Incubation of C. albicans with Wheat Germ Agglutinin (WGA) could confirm the cell wall as primary binding site of TMPyP. The finding that the porphyrin accumulates in the fungal cell wall and does not enter the interior of the cell before irradiation makes it unlikely that resistances can emerge upon aPDT. The results of this study may help in further development and modification of PS in order to increase efficacy against fungal infections such as those caused by C. albicans.

scholarly journals Role of cytoskeleton in plant cell wall formation

2020 ◽  
Vol 50 (2) ◽  
pp. 176-186
Author(s):  
Yi MAN ◽  
RuiLi LI ◽  
YuFen BU ◽  
Na SUN ◽  
YanPing JING ◽  
...  
Keyword(s):  
Cell Wall ◽  
Plant Cell ◽  
Plant Cell Wall ◽  
Cell Wall Formation ◽  
Wall Formation
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