Suberin deposition and band plasmolysis in the corn (Zea mays L.) root exodermis

1997 ◽  
Vol 75 (7) ◽  
pp. 1188-1199 ◽  
Author(s):  
Daryl E. Enstone ◽  
Carol A. Peterson
Keyword(s):  
Zea Mays ◽  
Zea Mays L ◽  
Lateral Roots ◽  
Root Surface ◽  
Casparian Bands ◽  
Suberin Lamellae ◽  
Tight Connection ◽  
Casparian Band ◽  
Apoplastic Barrier ◽  
Suberin Lamella

The exodermal Casparian band in corn (Zea mays L.) was first seen 10 mm distal to the kernel 4 days after planting. From its inception, the band usually occupied most of the radial wall (as seen in a cross section of the root). Subsequent maturation of the band around the root was asynchronous into the region of emerging lateral roots. Thus, a continuous apoplastic barrier would have been absent over much of the young root surface. Suberin lamellae development was also asynchronous, as these structures formed in those cells which had Casparian bands. Frequently, a lamella was initially deposited in patches, progressing centripetally until a continuous lipid layer was formed around the cell protoplast. Many instances of band plasmolysis (typical of the endodermis) were observed in the developing uniform exodermis. It could occur in cells with no detectable Casparian bands, suggesting that the tight connection between the plasmalemma and the wall that causes this phenomenon is not due to hydrophobic attractions. The results are consistent with the idea that there are strong attractions between proteins of the membrane and wall in the region of the Casparian band. The tight connection between the plasmalemma and the wall was broken during the later stages of suberin lamella development. Key words: Zea mays L., Poaceae, band plasmolysis, exodermis, Casparian band, suberin lamella.

Development of Casparian bands and suberin lamellae in the endodermis of onion roots

1992 ◽  
Vol 70 (11) ◽  
pp. 2233-2237 ◽  
Author(s):  
Alban D. Barnabas ◽  
Carol A. Peterson
Keyword(s):  
Allium Cepa ◽  
Small Region ◽  
Root Tip ◽  
Radial Wall ◽  
Casparian Bands ◽  
Suberin Lamellae ◽  
Casparian Band ◽  
Apoplastic Barrier ◽  
Endodermal Cells ◽  
Suberin Lamella

The endodermal Casparian band in onion (Allium cepa L.) roots is first evident 10 mm from the apex. It occupies a small region (20–30%) in the middle of the radial wall for a distance of 70 mm from the apex. However, with the development of suberin lamellae in most cells at greater distances from the root tip, the band expands symmetrically through the wall until, at 80 mm from the root tip, it fills the entire radial wall. Passage cells overlying some xylem poles have a delayed development of suberin lamellae, and in these cells the Casparian bands remain narrow. The sensitive stain, Fluorol yellow 088, detects precursors of the suberin lamellae in the outer tangential walls of the endodermal cells. The presence of complete lamellae is indicated by Sudan red 7B staining and resistance to acid digestion. Growth of the Casparian band during suberin lamella development may play a role in maintaining the apoplastic barrier in this layer by enlarging the contact area between the band and the lamellae. Key words: Casparian band, endodermis, suberin lamella, Allium cepa.

Development of cell wall modifications in the endodermis and exodermis of Allium cepa roots

2001 ◽  
Vol 79 (5) ◽  
pp. 621-634 ◽  
Author(s):  
Fengshan Ma ◽  
Carol A Peterson
Keyword(s):  
Electron Microscopy ◽  
Allium Cepa ◽  
Plasma Membranes ◽  
Casparian Bands ◽  
Transmission Electron ◽  
Allium Cepa L ◽  
Suberin Lamellae ◽  
Pit Field ◽  
Casparian Band ◽  
Suberin Lamella

The cytological events of wall modification in the endodermis and exodermis of Allium cepa L. roots were examined with fluorescence and transmission electron microscopy. In the endodermis, Casparian bands, suberin lamellae, and tertiary walls developed in succession. At the site of the future Casparian band, the plasma membrane was bound to the wall before deposition of detectable hydrophobic components in the radial wall. Suberin lamellae were deposited on the inner faces of the primary walls, first along the outer tangential walls and then the inner tangential walls. On both walls, segments of the lamellae were formed earlier in primary pit fields than at nonprimary pit field regions. Suberin lamellae then extended to the radial walls. When they reached the Casparian bands, the lamellae intruded between the bound plasma membranes and the walls, so that the cells' plasma membranes remained intact. In this way, suberin lamellae that were continuous around the cells were laid down. Later, tertiary walls were deposited internal to the suberin lamellae. None of the wall modifications interrupted the symplastic connections of the endodermis. During suberin lamella and tertiary wall formation, more dictyosomes and ER profiles appeared than during Casparian band development. In the exodermis, although Casparian bands were readily detected with fluorescence microscopy, they were rarely detected with electron microscopy. Suberin lamellae were formed in long cells severing their plasmodesmata. As in the endodermis, dictyosomes and ER were prominent during suberin lamella formation. Tertiary walls were not formed in the exodermis.Key words: Allium cepa, Casparian band, endodermis, exodermis, suberin lamella, ultrastructure.

Deposition of Casparian bands and suberin lamellae in the exodermis and endodermis of young corn and onion roots

1986 ◽  
Vol 64 (9) ◽  
pp. 1873-1878 ◽  
Author(s):  
C. J. Perumalla ◽  
Carol A. Peterson
Keyword(s):  
Growth Rate ◽  
Age And Growth ◽  
Root Tip ◽  
Casparian Bands ◽  
Corn Roots ◽  
Suberin Lamellae ◽  
Casparian Band ◽  
The Individual ◽  
Suberin Lamella ◽  
Individual Root

The Casparian band of the exodermis of corn and onion roots matures further from the root tip than its counterpart in the endodermis. A complete suberin lamella in the exodermal cells usually develops about 10 mm proximal to the exodermal Casparian band. The distance between the exodermal Casparian band and suberin lamella in the endodermis was usually much greater than in the exodermis. Both the exodermal Casparian band and suberin lamella matured closer to the tip in onion than in corn roots. The distance from the root tip at which the exodermal Casparian band matured increased with root age during the 5-day period studied in corn grown in hydroponics and vermiculite, and onion grown in hydroponics. This difference was most pronounced in corn, in which the Casparian band matured 20 mm from the root tip when the root was 20 mm long but matured 120 mm from the tip 4 days later when the root was 170 mm long. When the growth rate of corn roots was drastically inhibited by adding polyethylene glycol to the hydroponic medium, the exodermal Casparian band and suberin lamellae were present within 10 mm of the root tip. The position in the root at which the exodermis matures is thus highly variable and can depend on the plant species, and the age and growth rate of the individual root.

The effect of suberin lamellae on the vitality and symplasmic permeability of the onion root exodermis

1996 ◽  
Vol 74 (8) ◽  
pp. 1220-1226 ◽  
Author(s):  
Carol A. Peterson ◽  
Janet L. Waite
Keyword(s):  
Cell Types ◽  
Ion Transfer ◽  
Onion Root ◽  
Cell Vitality ◽  
Casparian Bands ◽  
Allium Cepa L ◽  
Suberin Lamellae ◽  
Form Part ◽  
Wall Permeability ◽  
Suberin Lamella

The onion exodermis is made up of two cell types, i.e., long and short cells. Both form Casparian bands, but suberin lamella development is absent or delayed in the short cells. Long cells did not accumulate fluorescein, a common test for cell vitality, because of reduced wall permeability due to suberin lamella development. Immature, long cells without lamellae stained in 15 min, whereas mature cells with lamellae required a 3.5- to 4-h treatment before staining was visible. Long exposure to fluorescein was needed to show that mature long cells were alive. Their vitality appeared to decline slowly with age but was not affected by drought stress. Fluorescein staining was apparent in the long cells only after treatment of paradermal sections; when dye was applied only externally to root segments, it did not enter the long cells from the epidermis or from the neighbouring short cells. This result indicates that the long cells were connected symplasmically to the cells of the cortex but were either unconnected, or connected by plasmodesmata of small functional diameter, to the epidermal and short cells. If they were unconnected, they would not form part of the symplasmic path of ion transfer into the root. Keywords: Allium cepa L., drought, exodermis, suberin lamella, vitality.

scholarly journals Aluminum in corn plants: influence on growth and morpho-anatomy of root and leaf

2013 ◽  
Vol 37 (1) ◽  
pp. 177-187 ◽  
Author(s):  
Michelli Fernandes Batista ◽  
Ismar Sebastião Moscheta ◽  
Carlos Moacir Bonato ◽  
Marcelo Augusto Batista ◽  
Odair José Garcia de Almeida ◽  
...  
Keyword(s):  
Zea Mays ◽  
Root Growth ◽  
Plant Height ◽  
Dry Matter ◽  
Zea Mays L ◽  
Lateral Roots ◽  
Dry Weight ◽  
Al Toxicity ◽  
Limiting Factors ◽  
Corn Plants

Aluminum (Al) toxicity is one of the most limiting factors for productivity. This research was carried out to assess the influence of Al nutrient solution on plant height, dry weight and morphoanatomical alterations in corn (Zea mays L.) roots and leaves. The experiment was conducted in a greenhouse with five treatments consisting of Al doses (0, 25, 75, 150, and 300 µmol L-1) and six replications. The solutions were constantly aerated, and the pH was initially adjusted to 4.3. The shoot dry matter, root dry matter and plant height decreased significantly with increasing Al concentrations. Compared to the control plants, it was observed that the root growth of corn plants in Al solutions was inhibited, there were fewer lateral roots and the development of the root system reduced. The leaf anatomy of plants grown in solutions containing 75 and 300 µmol L-1 Al differed in few aspects from the control plants. The leaf sheaths of the plants exposed to Al had a uniseriate epidermis coated with a thin cuticle layer, and the cells of both the epidermis and the cortex were less developed. In the vascular bundle, the metaxylem and protoxylem had no secondary walls, and the diameter of both was much smaller than of the control plants.

scholarly journals Effects of crude extract of Microcystis aeruginosa Kütz.on germination, growth and chlorophyll content of Zea mays L.

2014 ◽  
Vol 42 (2) ◽  
pp. 295-300
Author(s):  
Mostafa M El Sheekh ◽  
Hanan M Khairy ◽  
Rania El Shenody
Keyword(s):  
Zea Mays ◽  
Chlorophyll Content ◽  
Microcystis Aeruginosa ◽  
Crude Extract ◽  
Zea Mays L ◽  
Growth Parameters ◽  
Lateral Roots ◽  
Inhibitory Effect ◽  
Pigment Contents ◽  
Death Phase

Effects of crude extract of Microcystis aeruginosa containing microcystin-LR on the germination, growth and chlorophyll content of Zea mays was studied. Soaking of Z. mays seeds for 24 hrs in the cell-free medium during death phase of M. aeruginosa induced a significant reduction in root, shoot lengths, number of lateral roots, fresh and dry weights, leaf area and pigment contents. Soaking of Z. mays seeds for 24 hours in different concentrations of crude extracts of M. aeruginosa (100, 200, 300, 500 and 800 ?g dry cells/ml) from log phase showed inhibitory effect of growth parameters and germination. DOI: http://dx.doi.org/10.3329/bjb.v42i2.18033 Bangladesh J. Bot. 42(2): 295-300, 2013 (December)

Development of the endodermis and hypodermis of Typha glauca Godr. and Typha angustifolia L. roots

1999 ◽  
Vol 77 (1) ◽  
pp. 122-134 ◽  
Author(s):  
James L Seago, Jr. ◽  
Carol A Peterson ◽  
Daryl E Enstone ◽  
Chris A Scholey
Keyword(s):  
Longitudinal Direction ◽  
Strong Acid ◽  
Intermediate Stage ◽  
Root Tip ◽  
Typha Angustifolia ◽  
Outermost Layer ◽  
Suberin Lamellae ◽  
Casparian Band ◽  
Apoplastic Barrier ◽  
Typha Glauca

The development of the endodermis and hypodermis in adventitious roots of Typha angustifolia L. and Typha glauca Godr. was followed from the apical meristem to full maturity. The endodermis was typical, developing a thin Casparian band near the root tip, followed by suberin lamellae and asymmetric, secondary, lignified walls (C-type at maturity). Passage cells were present at an intermediate stage but eventually disappeared when all cells developed lamellae and secondary walls. The hypodermis was multiple (four to six layers at maturity) and began differentiating near the root tip. Here, the radial and transverse walls of the outermost layer did not dissolve in strong acid and the former were wavy in the longitudinal direction, both features characteristic of a Casparian band, but these walls were permeable to berberine. No other indication of a wall modification was seen for 3 weeks, at which time the root had become determinate and aerenchyma was beginning to form in the midcortex. Casparian bands, which were impermeable to berberine, matured in the hypodermis; thus, it proved to be an exodermis. Different forms of Casparian band were detected: one was typical and occupied the radial and transverse walls of the outermost layer, but others were novel and included tangential walls, often forming an H-shaped structure (as seen in cross section of the root). We propose calling the latter type an H-type Casparian band. It functioned as an apoplastic barrier to berberine applied either externally or internally by injection into the cortical aerenchyma. Following maturation of the Casparian band, the outer two layers of the exodermis soon produced suberin lamellae. These continued to be deposited in a centripetal pattern until they were found in all layers of the multiple exodermis. Development of the suberin wall modifications correlates with the development of the aerenchyma and may play a role in preventing gas exchange between the root and the rhizosphere. Later, all exodermal cells produced lignified, secondary walls. These were asymmetric in the outermost and innermost layers of the hypodermis (like the C-type endodermis); eventually, all layers had Casparian wall materials. Thus, the mature hypodermis consisted of two to six layers of exodermis, except at the tips of determinate roots where the exodermis was uniseriate with typical Casparian bands.Key words: cattail, endodermis, exodermis, hypodermis, roots, Typha.

Cortical ontogeny in roots of the aquatic plant, Hydrocharis morsus-ranae L.

1999 ◽  
Vol 77 (1) ◽  
pp. 113-121
Author(s):  
James L Seago, Jr. ◽  
Carol A Peterson ◽  
Daryl E Enstone
Keyword(s):  
Cell Death ◽  
Aquatic Plant ◽  
Root Apex ◽  
Acid Digestion ◽  
Aerenchyma Formation ◽  
Casparian Bands ◽  
Unique System ◽  
Suberin Lamellae ◽  
Radial Cell ◽  
Casparian Band

Tissues in adventitious roots of Hydrocharis morsus-ranae L. developed from a four-tiered apical meristem. A set of periclinal divisions in the outermost layer of the ground meristem produced a hypodermis, which was normally uniformly biseriate. Aerenchyma formed from the adjacent inner layer of the cortex by a series of cell divisions and cell lyses; three- to five-celled, radial aerenchyma strands formed by periclinal divisions in radial cell files 0.3-5 mm behind the apex. Intervening cells underwent anticlinal and periclinal divisions followed by cell lyses within 1 mm of the apex to produce air spaces. Aerenchyma formation in this species is unusual and presents a unique system suitable for a study of developmentally programmed cell death in parenchyma cells. The endodermis formed a complete Casparian band about 10 mm behind the root apex and did not develop further; it had neither suberin lamellae nor secondary walls. The hypodermis was parenchymatous and was without Casparian bands, suberin lamellae, and secondary walls. Following acid digestion, the wavy walls of the endodermis and the walls of the epidermis remained.Key words: aerenchyma, cell death, endodermis, Hydrocharis, hypodermis, root development.

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