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.

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.

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.

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.

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.

Identifying pollen grains of Typha latifolia, Typha angustifolia, and Typha ×glauca

2003 ◽  
Vol 81 (9) ◽  
pp. 985-990 ◽  
Author(s):  
Sarah A Finkelstein
Keyword(s):  
Typha Latifolia ◽  
Pollen Grains ◽  
Pollen Record ◽  
Typha Angustifolia ◽  
North American Continent ◽  
Statistical Confidence ◽  
The North ◽  
Pollen Diagrams ◽  
Sparganium Eurycarpum ◽  
Typha Glauca

Typha angustifolia L. and Typha ×glauca Godron have increased their ranges on the North American continent over the past 150 years, and the pollen record has potential to document this spread. In T. angustifolia, pollen disperses as a reticulate, monoporate monad, similar in appearance to the pollen of Sparganium eurycarpum Engelm. Typha angustifolia and Sparganium are generally not distinguished, and T. ×glauca is rarely shown on pollen diagrams. My study of pollen reference material shows that Typha monads and Sparganium can be separated using diameter and roundness at a known level of statistical confidence. Typha monads are on average significantly smaller in diameter (mean and standard deviation = 22.7 ± 2.6 µm) than Sparganium (25.3 ± 2.7 µm). The incidence of angularity is higher in T. angusti folia pollen grains, whereas Sparganium grains are more often rounded. The pollen signature of T. ×glauca consists of mostly monads, but can contain up to 30% dyads, and (or) 14% tetrads, and (or) 10% triads. I suggest that T. angusti folia and T. ×glauca can be identified as one category in the pollen record and, where their dates of arrival are known, this category may be used as a chronostratigraphic indicator.Key words: Typha, Sparganium, pollen, invasive species, wetlands.

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.

Suberin lamellae of the onion root endodermis: their pattern of development and continuity

Botany ◽  
2008 ◽  
Vol 86 (6) ◽  
pp. 623-632 ◽  
Author(s):  
C. Ishari Waduwara ◽  
Shantel E. Walcott ◽  
Carol A. Peterson
Keyword(s):  
Laser Scanning ◽  
Three Dimensional ◽  
Nile Red ◽  
Laser Scanning Microscopy ◽  
Root Tip ◽  
Confocal Laser ◽  
Suberin Lamellae ◽  
Almost All ◽  
Passage Cells ◽  
Root Endodermis

In many plant species, suberin lamellae are deposited in the cells of the endodermis. Some cells near the xylem poles tend to remain without these lamellae and are known as “passage cells”. To develop a three-dimensional picture of the pattern of suberin lamella deposition, procedures were developed to isolate large pieces of onion endodermis and to stain their suberin lamellae for various types of microscopy. Sudan red 7B proved satisfactory with white-light, Fluorol yellow and berberine with epifluorescence, and Nile red with confocal laser scanning microscopy (CLSM). Lamella deposition commenced in a few cells 10 mm from the root tip and then proceeded in a scattered manner. However, lamella deposition in more cells (seen 125–155 mm from the root tip) resulted in the formation of longitudinal files of cells with lamellae alternating with files of passage cells. In older regions (255–285 mm from the tip), almost all cells had deposited suberin lamellae, leaving only a few passage cells. At higher magnification, three-dimensional reconstructions of CLSM images of endodermal suberin lamellae revealed that they are perforated by pores all along the roots. Such pores could serve as points for water and ions to enter the cytoplasm of the endodermis.

Current insights into the development, structure, and chemistry of the endodermis and exodermis of roots

2003 ◽  
Vol 81 (5) ◽  
pp. 405-421 ◽  
Author(s):  
Fengshan Ma ◽  
Carol A Peterson
Keyword(s):  
Passive Movement ◽  
Root Tip ◽  
Main Function ◽  
Casparian Bands ◽  
Fluorescence And Electron Microscopy ◽  
Suberin Lamellae ◽  
Apoplastic Barriers ◽  
Molecular Aspects ◽  
Development Structure ◽  
Future Work

The endodermis and exodermis are the inner- and outermost cortical layers, respectively, of a root. Both are characterized by the development of Casparian bands in their anticlinal walls. Endodermal Casparian bands normally appear within 10 mm of the root tip, while exodermal Casparian bands are typically deposited farther from the tip. All Casparian bands contain the biopolymers lignin and suberin, allowing the endodermis and exodermis to serve as filtration sites for the passive movement of ions between the soil solution and the stele. Later in development, suberin lamellae are frequently deposited as secondary walls, which will reduce the transmembrane transport of ions and water. In some species, tertiary walls are also formed; their main function is postulated to be mechanical support of the root. Recent research with fluorescence and electron microscopy has revealed some important details of development and structure of these wall modifications. Further, chemical analyses of enzymatically isolated wall modifications have shown the chemical basis for the endodermis and exodermis as apoplastic barriers. Studies of Arabidopsis at the molecular level are shedding light on the genetic control of endodermal morphogenesis. In contrast, molecular aspects of exodermal development are totally unknown. Future work will benefit from a combined molecular and biochemical approach to the endodermis and exodermis.Key words: Casparian band, endodermis, exodermis, lignin, molecular biology, suberin, suberin lamella, tertiary wall.

Widespread cytonuclear discordance in narrow-leaved cattail (Typha angustifolia) does not explain the dominance of its invasive hybrid (Typha × glauca)

Hydrobiologia ◽  
2016 ◽  
Vol 792 (1) ◽  
pp. 53-65 ◽  
Author(s):  
Joanna R. Freeland ◽  
Claudia Ciotir ◽  
Laura Wensink ◽  
Marcel Dorken
Keyword(s):  
Typha Angustifolia ◽  
Typha Glauca

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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