Structural, chemical, and permeability changes following wounding in onion roots

1984 ◽  
Vol 62 (11) ◽  
pp. 2253-2259 ◽  
Author(s):  
G. J. Moon ◽  
Carol A. Peterson ◽  
R. L. Peterson
Keyword(s):  
Cell Walls ◽  
Cortical Cell ◽  
Root Tip ◽  
Cortical Cells ◽  
Calcofluor White ◽  
Suberin Lamellae ◽  
Histochemical Tests ◽  
Apoplastic Barrier ◽  
Tip Cells ◽  
Root Tip Cells

Onion roots were wounded by scoring them with a needle 80 to 120 mm proximal to the root tip. Cells in the region of the wound were studied immediately after wounding and daily for the next 6 days. By the 2nd day, cortical cells near the wound had produced pit callose and deposited suberin in their walls and air spaces. The amount of suberin deposited increased until 4 days after wounding. No suberin lamellae were observed in cortical cell walls, but histochemical tests and acid digestion confirmed the presence of suberin within the existing wall. Intercellular air spaces adjacent to the wound were totally occluded with an electron-dense material which had characteristics of suberin. Penetration studies using Calcofluor white M2R, a fluorescent apoplastic dye, showed that the wound was completely sealed 4 days after wounding. Thus, in response to wounding, nonlamellar suberin was deposited in the cortical cell walls and air spaces surrounding the wound and was continuous with the suberin present in the normal hypodermis, forming a complete apoplastic barrier.

scholarly journals Domain-specific and cell type-specific localization of two types of cell wall matrix polysaccharides in the clover root tip.

1992 ◽  
Vol 118 (2) ◽  
pp. 467-479 ◽  
Author(s):  
M A Lynch ◽  
L A Staehelin
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Cellular Differentiation ◽  
Cortical Cell ◽  
Middle Lamella ◽  
Root Cap ◽  
Root Tip ◽  
Cortical Cells ◽  
Peripheral Cell ◽  
Clover Root

Using immunocytochemical techniques and antibodies that specifically recognize xyloglucan (anti-XG), polygalacturonic acid/rhamnogalacturonan I (anti-PGA/RG-I), and methylesterified pectins (JIM 7), we have shown that these polysaccharides are differentially synthesized and localized during cell development and differentiation in the clover root tip. In cortical cells XG epitopes are present at a threefold greater density in the newly formed cross walls than in the older longitudinal walls, and PGA/RG-I epitopes are detected solely in the expanded middle lamella of cortical cell corners, even after pretreatment of sections with pectinmethylesterase to uncover masked epitopes. These results suggest that in cortical cells XG and PGA/RG-I are differentially localized not only to particular wall domains, but also to particular cell walls. In contrast to their nonoverlapping distribution in cortical cells, XG epitopes and PGA/RG-I epitopes largely colocalize in the epidermal cell walls. The results also demonstrate that the middle lamella of the longitudinal walls shared by epidermal cells and by epidermal and cortical cells constitutes a barrier to the diffusion of cell wall and mucilage molecules. Synthesis of XG and PGA/RG-I epitope-containing polysaccharides also varies during cellular differentiation in the root cap. The differentiation of gravitropic columella cells into mucilage-secreting peripheral cells is marked by a dramatic increase in the synthesis and secretion of molecules containing XG and PGA/RG-I epitopes. In contrast, JIM 7 epitopes are present at abundant levels in columella cell walls, but are not detectable in peripheral cell walls or in secreted mucilage. There were also changes in the cisternal labeling of the Golgi stacks during cellular differentiation in the root tip. Whereas PGA/RG-I epitopes are detected primarily in cis- and medial Golgi cisternae in cortical cells (Moore, P. J., K. M. M. Swords, M. A. Lynch, and L. A. Staehelin. 1991. J. Cell Biol. 112:589-602), they are localized predominantly in the trans-Golgi cisternae and the trans-Golgi network in epidermal and peripheral root cap cells. These observations suggest that during cellular differentiation the plant Golgi apparatus can be both structurally and functionally reorganized.

Spatial limitations induce spindle tilting and result in oblique phragmoplasts in Vicia faba L. root tip cells, but do not result in oblique cell walls

1997 ◽  
Vol 46 (3) ◽  
pp. 279-290
Author(s):  
N. C. A. De Ruijter ◽  
J Pietrusiewicz ◽  
M. B. Montijn ◽  
J. H. N. Schel ◽  
A. A. M. Van Lammeren
Keyword(s):  
Vicia Faba ◽  
Cell Walls ◽  
Root Tip ◽  
Vicia Faba L ◽  
Tip Cells ◽  
Root Tip Cells

Sunlight decreased genotoxicity of azadirachtin on root tip cells of Allium cepa and Eucrosia bicolor

2010 ◽  
Vol 73 (5) ◽  
pp. 949-954 ◽  
Author(s):  
W. Kwankua ◽  
S. Sengsai ◽  
C. Kuleung ◽  
N. Euawong
Keyword(s):  
Allium Cepa ◽  
Root Tip ◽  
Tip Cells ◽  
Root Tip Cells

Salt Stress-induced Programmed Cell Death in Rice Root Tip Cells

2007 ◽  
Vol 49 (4) ◽  
pp. 481-486 ◽  
Author(s):  
Jian-You Li ◽  
Ai-Liang Jiang ◽  
Wei Zhang
Keyword(s):  
Cell Death ◽  
Salt Stress ◽  
Programmed Cell Death ◽  
Rice Root ◽  
Root Tip ◽  
Tip Cells ◽  
Root Tip Cells

Cytological evidence bearing on the origin of the B genome in polyploid wheats

Genome ◽  
1988 ◽  
Vol 30 (1) ◽  
pp. 36-43 ◽  
Author(s):  
K. Kerby ◽  
J. Kuspira
Keyword(s):  
Dna Hybridization ◽  
Triticum Turgidum ◽  
Root Tip ◽  
Cytological Evidence ◽  
B Genome ◽  
Genome Donor ◽  
The One ◽  
Genome Donors ◽  
Tip Cells ◽  
Root Tip Cells

To help elucidate the origin of the B genome in polyploid wheats, karyotypes of Triticum turgidum, Triticum monoccum, and all six purported B genome donors were compared. The analysis utilized a common cytological procedure that employed the most advanced equipment for the measurement of chromosome lengths at metaphase in root tip cells. A comparison of the karyotypes of T. turgidum and T. monococcum permitted the identification of B genome chromosomes of T. turgidum. These consist of two SAT pairs, one ST pair, three SM pairs, and one M pair of homologues. Comparisons of the chromosomes of the B genome of T. turgidum with the karyotypes of the six putative B genome donors showed that only the karyotype of Aegilops searsii was similar to the one deduced for the donor of the B genome in T. turgidum, suggesting that Ae. searsii is, therefore, the most likely donor of the B genome to the polyploid wheats. Support for this conclusion has been derived from geographic, DNA-hybridization, karyotype, morphological, and protein data reported since 1977. Reasons why the B genome donor has not been unequivocally identified are discussed.Key words: phylogeny, karyotypes, Triticum turgidum, Triticum monococcum, B genome, B genome donors.

scholarly journals Squash Preparations of Living Root-Tip Cells

Nature ◽  
1949 ◽  
Vol 164 (4178) ◽  
pp. 930-930 ◽  
Author(s):  
J. CHAYEN
Keyword(s):  
Root Tip ◽  
Living Root ◽  
Tip Cells ◽  
Root Tip Cells

The effect of cytochalasin D on preprophase band organization in root tip cells of Allium

1992 ◽  
Vol 103 (4) ◽  
pp. 989-998 ◽  
Author(s):  
E.P. Eleftheriou ◽  
B.A. Palevitz
Keyword(s):  
Preprophase Band ◽  
Cytochalasin D ◽  
Root Tip ◽  
Average Width ◽  
Exact Position ◽  
The Relationship ◽  
Tip Cells ◽  
Root Tip Cells ◽  
Control Samples

The relationship between microfilaments (Mfs) and microtubules (Mts) in the organization of the preprophase band (PPB) was investigated in Allium root tip cells subjected to treatment with cytochalasin D (CD). Mts and Mfs were visualized by indirect immunofluorescence and various parameters such as PPB width were analyzed quantitatively. In control samples, the PPB first appears as a wide Mt band that progressively narrows to an average width of 4 micrometre in mid-prophase. Randomly oriented Mfs are present throughout the cytoplasm of most interphase control cells. Preprophase and prophase cells, however, contain cortical Mfs arranged parallel to the PPB. The Mfs initially occupy much of the cortex but in most cells they progressively become restricted to an area wider than the PPB. In the presence of CD, the PPB fails to narrow and remains at least two-fold wider than in control cells. PPB width expressed as a percentage of nuclear or cell length also increases compared to controls. Widening is concentration dependent, and the effect of 10 micromolar CD is near maximal only 15 min after application of the drug. This rapid response suggests that a rebroadening of already condensed PPBs takes place. After as little as 15 min in CD, Mfs are replaced by many small specks and rods. Dual localizations of both Mts and Mfs show that prophase cells contain broad PPBs without Mfs. The rapid disorganization of Mfs, by CD, therefore coincides with the rebroadening of PPBs. CD-treated cells in metaphase, anaphase and telophase contain larger actin aggregates at the poles, as previously reported. The results indicate that Mfs play an important role in the narrowing of the PPB, which in turn is essential for determination of the exact position of the plane of division. They also indicate that movement of intact Mts is important in PPB organization.

Sign in / Sign up

Export Citation Format

Share Document