Demonstration of a complete Casparian strip in <i>Avena</i> and <i>Ipomoea</i> by a fluorescent staining technique

Peirson, David R.; Dumbroff, E. B.

doi:10.1139/b69-274

Cited by 19 publications

(10 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…5) (20). With an elegant fluorescent staining technique, the Casparian strip in roots of Avena and Ipomoea has been shown to be complete (36 (Fig. 5).…”

Section: Discussionmentioning

confidence: 99%

Lateral Transport of Ions into the Xylem of Corn Roots

1971

View full text Add to dashboard Cite

When an excised corn (Zea mays) root pretreated with chloride was exposed for 10 minutes to pulse labeling with 'Cl and then transferred to unlabeled chloride, the activity in the xylem exudate reached a maximum about 4 minutes after pulse labeling was discontinued and then declined sharply. The rate at which labeled chloride was transported across the root into the xylem and basipetally therein was on the order of 75 to 250 centimeters per hour. Consequently, symplasmic movement of chloride in corn roots is fast and may not be rate-limiting in transfer from the root surface to the xylem. Experiments on pulse labeling with 'Na gave similar results. A large fraction of the absorbed 'Na was not translocated into the exudate but was tightly sequestered in a cell compartment, probably the vacuole.Electron probe analysis was used to reveal the pattern of potassium distribution in cross sections taken 10 to 11 millimeters from the tip. The cytoplasm and vacuoles of the xylem parenchyma cells accumulated potassium to a much greater extent than cortical and other stelar cells. Ultrastructural studies showed that the cytoplasm of the xylem parenchyma cells contains numerous membrane systems. It was concluded that the xylem parenchyma cells secrete ions from the symplasm into the conducting vessels, and it was suggested that this secretion is driven across the plasmalemma by a carrier-mediated transport.According to the classical Crafts-Broyer hypothesis on lateral transport of ions in roots (11), the stele does not participate actively in transfer from the symplasm to the xylem vessels. The membranes of the stelar cells are deemed permeable to ions, and hence ions simply leak into the vessels. The Casparian strip of the endodermis functions to prevent ions from diffusing backwards into the outer space of the cortex.Laties (25), Laties and Budd (26), and Luittge and Laties

show abstract

“…5) (20). With an elegant fluorescent staining technique, the Casparian strip in roots of Avena and Ipomoea has been shown to be complete (36 (Fig. 5).…”

Section: Discussionmentioning

confidence: 99%

Lateral Transport of Ions into the Xylem of Corn Roots

1971

View full text Add to dashboard Cite

show abstract

“…It was expected that the isolated Casparian strips would consist of a continuous web of radial cell walls completely surrounding the central cylinder of the root (Peirson and Dumbroff 1969). This demand was fulfilled since there was a continuous web of radial cell walls enclosing the xylem vessels of the central cylinder (Fig.…”

Section: Ri R2mentioning

confidence: 99%

Chemical composition of Casparian strips isolated from Clivia miniata Reg. roots: evidence for lignin

Schreiber

1996

Planta

View full text Add to dashboard Cite

Abstract. Endodermal cell walls and xylem vessels were isolated enzymatically from Clivia miniata Reg. roots. Transmission-electron-microscopic investigation of crosssections of intact C. miniata roots and scanningelectron-microscopic investigation of isolated endodermal cell walls indicated that the root endodermis of C. miniata is essentially in its primary state of development. Isolated Casparian strips and xylem vessels were subjected to two different degradation methods usually applied to prove the existence of lignin, namely, cupric oxide oxidation and thioacidolysis. The reaction products obtained were typical aromatic derivatives of the natural lignin precursors coniferyl and sinapyl alcohols, and, in traces, of p-coumaryl alcohol, indicating the occurrence of lignin in the polymers from both Casparian strips and xylem vessels. The qualitative chemical compositions of the polymers from the two sources were similar, whereas the quantitative compositions were different, indicating that the molecular structure of the lignin polymer in the Casparian strips was different from that in the xylem vessels. Thus, for the first time, direct chemical evidence has been obtained that Casparian strips of C. miniata roots contain lignin as a major cell wall polymer.

show abstract

“…Other sections were cleared in 1 % NaOH and stained with Chelidonium majus root extract, which contains fluorochromes for suberin and lignin (Peirson and Dumbroff, 1969;Weerdenburg and Peterson, 1983). These sections were then observed with violet light as described above.…”

Section: Anatomy and Histochemistrymentioning

confidence: 99%

“…Transverse and longitudinal, freehand sections of fresh tissue were either left untreated, or stained with Sudan IV to test for lipids (Johansen, 1940) or phloroglucinol/HCl for lignin (Jensen, 1962). Other sections were cleared in 1 % NaOH and stained with Chelidonium majus root extract, which contains fluorochromes for suberin and lignin (Peirson and Dumbroff, 1969;Weerdenburg and Peterson, 1983). These sections were then observed with violet light as described above.…”

Section: Anatomy and Histochemistrymentioning

confidence: 99%

The Effect of Lateral Root Outgrowth on the Structure and Permeability of the Onion Root Exodermis

Peterson

Moon

1993

Botanica Acta

View full text Add to dashboard Cite

Lateral root development in onion is accompanied by a variety of anatomical and permeability changes in some cells of the adventitious root. The endodermal Casparian band of the parent root is disrupted early in the development of the lateral but later extends so as to be continuous with the developing Casparian band of the new root. The lateral root emerges through a longitudinal split in the adventitious root exodermis and epidermis. Following this, the cell walls and intercellular air spaces adjacent to the lateral become incrusted with suberin and a small amount of lignin, forming a collar of modified tissue around the lateral. Subsequent radial expansion of the lateral distorts the adjacent cells of the adventitious root and forces a tight association between it and the lateral. The apoplastic permeability of lateral/parent root junctions was tested using Cellufluor, an apoplastic fluorescent dye which binds to cellulose. Prior to lateral root emergence, no dye enters the parent root cortex due to the Casparian band of the exodermis. Immediately after emergence, dye often penetrates through the break in the exodermal Casparian band and diffuses into the first cortical cell layer. However, when the collar of suberized cells develops (two days after lateral root emergence), movement of the dye into an undisturbed adventitious root is usually prevented (i.e., in 77% of the cases examined). In contrast, only 17% of the root systems which were transplanted just prior to treatment excluded the dye. This indicates that the apoplastic seals around the laterals are sensitive to movement and we recommend that only undisturbed root systems be used for permeability studies.

show abstract

Demonstration of a complete Casparian strip in Avena and Ipomoea by a fluorescent staining technique

Abstract: A new combination of embedding material and high contrast stain has provided the means for demonstrating, photographically, tangential sections of endodermal cells showing complete Casparian strips.

Cited by 19 publications

References 0 publications

Lateral Transport of Ions into the Xylem of Corn Roots

Lateral Transport of Ions into the Xylem of Corn Roots

Chemical composition of Casparian strips isolated from Clivia miniata Reg. roots: evidence for lignin

The Effect of Lateral Root Outgrowth on the Structure and Permeability of the Onion Root Exodermis

Contact Info

Product

Resources

About