Electron Microscope Observations of Plastids in the Root Cells of Some Hydrophytes

Kawamatu, Sigenobu

doi:10.1508/cytologia.32.157

Cited by 5 publications

(1 citation statement)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, duckweeds have not yet been used to any great extent as subjeets for ultrastructural studies. In recent years there have been brief descriptions of the fine structure of Wotffia arrhiza (Anderson, Thotnpson & Swader, 1973) and Eemna perpusitta (Chiu & Falk, 1975), and a more detailed investigation into the development of sieve elements in the root of L, minor (Melaragno & Walsh, 1976), The other existing ultrastruetural investigations on tnembers of the Lemnaeeae deal with chloroplast differentiation (Le Pabic, 1972, 1976, changes in chloroplast structure as a result of various treatments (Gtob & Rufener, 1969;Porath & Ben-Shaul, 1971;Grob & Eichenberger, 1973;De Kock, Vaughan & Hall, 1978), the presence of plastids in root cells (Kawamatu, 1967;Mollenhauer, 1967;Wroblewski, 1973), and the structure of callus cells (Pan & Chen, 1976), Spirodela polyrrhiza is the largest member of the Letnnaceae and is interesting in that it forms tnodified dormant buds or turions under a variety of cotiditions (Jacobs, 1947;Henssen, 1954;Czopek, 1959), S. polyrrhiza also forms turions in aseptic culture in response to exogenously applied ABA (: Perry & Byrne, 1969;Stewart, 1969). However, information regarding the ultrastructure of the turion is virtually non-existent.…”

Section: Introductionmentioning

confidence: 99%

Abscisic‐acid‐induced turion formation in Spirodela polyrrhiza L. II. Ultrastructure of the turion; a stereological analysis

Smart

Trewavas

1983

Plant Cell & Environment

View full text Add to dashboard Cite

The ultrastructural features of the abscisicacid-induced turion of Spirodeta polyrrhiza are briefly described and a comparison between turion and vegetative frond tissue was tnade by stereological analysis. The turion is characterized by its small size, renifonn shape, and dark-brown coloration; the mesophyll is undifferentiated and totally laeking the substantial aerenchyma development found in the vegetative frond. The turion cells have a stnaller vacuole and a denser cytoplastn than the cells of the vegetative frond. Stereological analysis showed that the tissues differed quantitatively only in three main respects; air space formation, vacuolation, and starch and cell wall material accumulation. During development, it is suggested that the cells of the turion, while reaching the satne final size as the vegetative frond cells, accumulate numerous starch grains, thick cell walls, and large deposits of tannins and anthocyanin pigment at the expense of the vacuolar expansion characteristic of the nortnal maturity progratnme. Certain features of the turion ultrastructure indicate a differential cell sensitivity to ABA. fCev-

show abstract

Section: Introductionmentioning

confidence: 99%

Abscisic‐acid‐induced turion formation in Spirodela polyrrhiza L. II. Ultrastructure of the turion; a stereological analysis

Smart

Trewavas

1983

Plant Cell & Environment

View full text Add to dashboard Cite

show abstract

Trichoblasts in Hydrocharis. I. Origin. Differentiation, Dimensions and Growth

Cutter

Feldman

1970

American J of Botany

View full text Add to dashboard Cite

In the root epidermis of Hydrocharis morsus‐ranae L. distinctive trichoblasts, which later grow out as root hairs, are formed by the unequal division of protodermal (immature epidermal) cells. The trichoblast is the more proximal product of this division. Trichoblasts differ from adjacent epidermal cells in manner of growth, in size, amount of cytoplasm, degree of succinic dehydrogenase and cytochrome oxidase activity, and in the structure of their plastids. Plastids in the trichoblasts gradually become colorless and of less complex structure with increasing distance from the root tip, in contrast to those in adjacent epidermal cells. The trichoblasts do not divide, but they elongate to a considerable extent in the most distal 3000 μ of the root tip and less extensively in the next 3000 μ. By contrast the sister cells and their products divide, but the individual products do not become markedly longer than the mother cell until situated more than 3000 μ from the root tip, when they undergo extensive elongation. The trichoblasts are thus characterized by delayed maturation and inhibition of cytokinesis; it is suggested that delayed maturation is a necessary prerequisite for differentiation of root hairs in this and other species.

show abstract

Ultrastructural Features of Developing Sieve Elements in Lemna Minor L.—the Protoplast

Melaragno

Walsh

1976

American J of Botany

View full text Add to dashboard Cite

The occurrence and precise arrangement of phloem tissue is reported for the first time in the root of the duckweed, Lemna minor L. Since these plants are small enough to be prepared intact for electron microscopy, the induction of artifacts as a result of mechanical manipulation during specimen preparation is virtually eliminated. Ultrastructural features of the complete sequence of sieve‐element development are presented and are in some respects similar to what has been described in other monocotyledons (e.g., nuclear degeneration, aggregation of ER, elaboration of electron‐dense crystalline plastid inclusions). Mature sieve elements in Lemna are enucleate, lack P‐protein, contain a plasmalemma, ER‐aggregations, mitochondria, plastids and, in many instances, intact vacuoles. It is suggested that structural modification required for the sieve element to assume a transport function may not be very drastic, apart from the degeneration of the nucleus.

show abstract

Electron Microscope Observations of Plastids in the Root Cells of Some Hydrophytes

Cited by 5 publications

References 7 publications

Abscisic‐acid‐induced turion formation in Spirodela polyrrhiza L. II. Ultrastructure of the turion; a stereological analysis

Abscisic‐acid‐induced turion formation in Spirodela polyrrhiza L. II. Ultrastructure of the turion; a stereological analysis

Trichoblasts in Hydrocharis. I. Origin. Differentiation, Dimensions and Growth

Ultrastructural Features of Developing Sieve Elements in Lemna Minor L.—the Protoplast

Contact Info

Product

Resources

About