Transfer Cells in the Root Epidermis of Atriplex hastata L. As a Response to Salinity: a Comparative Cytological and X-Ray Microprobe Investigation

1978 ◽  
Vol 5 (6) ◽  
pp. 739 ◽  
Author(s):  
D Kramer ◽  
WP Anderson ◽  
J Preston
Keyword(s):  
Root Apex ◽  
Transfer Cells ◽  
Cytological Investigation ◽  
Xylem Parenchyma ◽  
Salt Treatment ◽  
Selective Uptake ◽  
X Ray ◽  
Root Epidermis ◽  
Wall Ingrowths ◽  
Parenchyma Cells

A cytological investigation has been made of the roots of the halophyte Atriplex hastata L. Transfer cells developed in the epidermis in response to salt treatment. They occurred only in a zone 1-3 mm behind the root apex and possessed a labyrinth only in their outer tangential walls (facing the root environment). When the epidermis was damaged, the adjacent exodermal cells then developed wall ingrowths in saline conditions. Ontogenetically this differentiation is correlated with the formation of the Casparian strip and the disintegration of the vessel contents. The X-ray microanalysis data on deep-frozen hydrated root specimens indicate that the epidermal transfer cells concentrate K+, and exclude Cl-, relative to the medium. It is concluded that the epidermal transfer cells function in selective uptake of K+ which is subsequently transported laterally into the stele and secreted into the vessels by the xylem parenchyma cells.

Silica in Woody Stems

1974 ◽  
Vol 22 (2) ◽  
pp. 211 ◽  
Author(s):  
G Scurfield ◽  
CA Anderson ◽  
ER Segnit
Keyword(s):  
The Other ◽  
X Ray Diffraction ◽  
Xylem Parenchyma ◽  
X Ray ◽  
Woody Perennial ◽  
Internal Surfaces ◽  
Parenchyma Cells ◽  
Ray Parenchyma ◽  
Ray Parenchyma Cells ◽  
Scanning Electron

Scanning electron microscopy has been used to examine silica isolated by chemical means from the wood of 32 species of woody perennial. The silica consists of aggregate grains lying free in the lumina or in ray and xylem parenchyma cells in 24 of the species. It occurs as dense silica in the other species, filling the lumina or lining the internal surfaces of vessels (and fibres) in all cases except Gynotroches axillaris where it is deposited in ray parenchyma cells. Infrared spectra and X-ray diffraction diagrams, obtained for specimens of both sorts of silica, are indistinguishable from those for amorphous silica. Aggregate grain and dense silicas are also alike in that their differential thermal analysis curves show a rather broad endothermic peak between 175° and 205°C. The results are discussed in relation to possible modes of deposition of the two sorts of silica and the tendency for silica in ray parenchyma cells to be associated with polyphenols.

The occurrence and ontogeny of transfer cells associated with lateral roots and root nodules in Leguminosae

1979 ◽  
Vol 57 (23) ◽  
pp. 2583-2602 ◽  
Author(s):  
William Newcomb ◽  
R. L. Peterson
Keyword(s):  
Nitrogen Fixation ◽  
Rhizobium Leguminosarum ◽  
Root Nodules ◽  
Lateral Roots ◽  
Transfer Cells ◽  
Xylem Parenchyma ◽  
Cortical Cells ◽  
Nitrogenous Compounds ◽  
Wall Ingrowths ◽  
Xylem Elements

Xylem parenchyma transfer cells are present in the stele of the root tissue adjacent to emergent effective root nodules of garden pea (Pisum sativum), red kidney bean (Phaseolus vulgaris), broad bean (Vicia faba), soybean (Glycine max), and mung bean (Vigna radiata), two types of ineffective pea nodules, and emergent lateral roots of pea. The xylem parenchyma transfer cells contain many polyribosomes and mitochondria near the wall ingrowths which are located adjacent to pits in the xylem elements. Pericycle transfer cells also occur in the three types of pea nodules. In effective pea nodules wall ingrowths begin to form in the pericycle cells 5 days after inoculation with Rhizobium leguminosarum; at this stage rhizobia are only present in the root hair but the cortical cells have enlarged and some have undergone mitosis. The wall ingrowths begin to form in the xylem parenchyma cells 7–8 days after inoculation or the approximate time that rhizobia begin to be released from the infection thread. In both instances the wall ingrowths begin to form before the onset of dinitrogen reduction although previous workers have suggested that a flux of nitrogenous compounds (containing fixed N) induces their formation. The development of wall ingrowths in ineffective pea nodules also occurs independently of nitrogen fixation. Similarly, the wall ingrowths located near soybean nodules also begin to develop before the onset of nitrogen fixation.

Salt Tolerance of Trifolium alexandrinum L. IV. Ion Measurements by X-Ray Microanalysis in Unfixed, Frozen Hydrated Leaf Cells at Various Stages of Salt Treatment

1982 ◽  
Vol 9 (2) ◽  
pp. 251 ◽  
Author(s):  
E Winter ◽  
J Preston
Keyword(s):  
Single Cells ◽  
Leaf Tissue ◽  
Sampling Interval ◽  
Surrounding Tissue ◽  
Xylem Parenchyma ◽  
Salt Treatment ◽  
X Ray ◽  
Average Percentage ◽  
Young Leaves ◽  
Very High

Bulk-frozen leaf tissue of salt-treated (50 mM NaCI) T. alexandrinum plants harvested at various stages of the salt treatment was fractured in a scanning electron microscope. By means of X-ray microanalysis, Na+ and Cl\- was measured in single cells of the veins and of the surrounding tissue. From the corrected peak values Na+ : K+ ratios were calculated for each cell. For each sampling interval the average percentage of cells falling into various categories of Na+ :K+ and CI- :K+ was determined in all tissues. In the phloem parenchyma the percentage of cells having a very high Na+ :K+ ratio (>4) rose between days 10 and 16 of the salt treatment, whereas the percentage of xylem parenchyma cells falling into this category declined. It is concluded that the increasing Na+ :K+ ratios in the phloem are the result of both an enhanced inflow of Na+ into the veins (measured in a previous experiment) and the retranslocation of Na+ from the xylem to the phloem. The results support the hypothesis of intraveinal recycling of Na+ in salt-stressed young leaves of T. alexandrinum and may explain the gradual damage to the phloem transfer cells observed with progressive salt treatment.

Ontogeny of phloem transfer cells in Hieracium floribundum

1975 ◽  
Vol 53 (23) ◽  
pp. 2745-2758 ◽  
Author(s):  
R. L. Peterson ◽  
E. C. Yeung
Keyword(s):  
Cell Types ◽  
Transfer Cells ◽  
Vascular Cambium ◽  
Secondary Phloem ◽  
Sieve Elements ◽  
Wall Ingrowths ◽  
Wall Ingrowth ◽  
Companion Cells ◽  
Parenchyma Cells ◽  
Cambium Activity

The primary phloem system in the rhizome of Hieracium floribundum has transfer cells that have developed from companion cells and parenchyma cells, which are adjacent to sieve elements. In both cell types changes occur in the cytoplasmic organelles at the time of wall ingrowth formation. Dicytosomes and polyribosomes become more numerous and 'boundary formations' and other multivesiculated structures appear. Few microtubules were found in the cytoplasm at this time. After the wall ingrowths become obvious, the transfer cells develop numerous mitochondria and an enlarged nucleus. The phloem transfer cells become vacuolated with age and the wall ingrowths become less numerous. This may be associated with a change in the translocation pattern in the phloem after the inception of vascular cambium activity. Parenchyma cells in the secondary phloem usually become rather vacuolated and develop few wall ingrowths.

The Influence of Structure on Ba and K Uptake by a Synthetic Phyllomanganate

Clay Minerals ◽  
1994 ◽  
Vol 29 (2) ◽  
pp. 215-222 ◽  
Author(s):  
E. Paterson ◽  
R. Swaffield ◽  
L. Clark
Keyword(s):  
Chemical Analysis ◽  
Cation Exchange ◽  
Exchange Reaction ◽  
Charge Distribution ◽  
Photoelectron Spectroscopy ◽  
Basal Spacing ◽  
K Uptake ◽  
Selective Uptake ◽  
X Ray ◽  
Bulk Chemical

AbstractThe uptake of Ba2+ and K+ by a synthetic Na-phyllomanganate has been studied by chemical analysis, X-ray diffractometry and X-ray photoelectron spectroscopy. The changes in basal spacing arising from cation exchange have been used to monitor the progress of the exchange reaction and confirm the selectivity measured by bulk chemical analysis. However, the selective uptake of Ba2+ over Ca2+ is much greater than that of K+ over Na+ and it is suggested that charge distribution in the interlayer is important. The results are discussed in the light of recent advances in our understanding of the phyllomanganate structure.

INHIBITION OF WATER CONDUCTIVITY CAUSED BY WATERMARK DISEASE IN SALIX SACHALINENSIS

IAWA Journal ◽  
2000 ◽  
Vol 21 (1) ◽  
pp. 49-60 ◽  
Author(s):  
Yasuaki Sakamoto ◽  
Yuzou Sano
Keyword(s):  
Wood Anatomy ◽  
High Moisture ◽  
Water Conductivity ◽  
X Ray ◽  
Salix Sachalinensis ◽  
Water Conduction ◽  
Parenchyma Cells ◽  
Ray Parenchyma ◽  
High Moisture Level ◽  
Ray Parenchyma Cells

Water conduction and wood anatomy of Salix sachalinensis attacked by watermark disease were investigated. The internal symptom, the watermark, appeared as a brown to brown-black stained zone in sapwood. Dye injection tests revealed that water conduction did not take place in the watermark. However, soft X-ray photography and cryo-scanning electron microscopy revealed that the watermark had a high moisture level. In the watermark, some of the vessels were plugged with tyloses and masses of bacteria, and some of the ray parenchyma cells caused necrosis. Hence, the non-conductive watermark in sapwood can be considered similar to discoloured wood or wetwood.

scholarly journals The Cell Wall Structure of Xylem Parenchyma

1952 ◽  
Vol 5 (2) ◽  
pp. 223 ◽  
Author(s):  
AB Wardrop ◽  
HE Dadswell
Keyword(s):  
Cell Wall ◽  
Fine Structure ◽  
Secondary Cell Wall ◽  
Primary Cell Wall ◽  
Wall Structure ◽  
Xylem Parenchyma ◽  
Cell Axis ◽  
X Ray ◽  
Ray Methods ◽  
Longitudinal Cell

The fine structure of the cell wall of both ray and vertical parenchyma has been investigated. In all species examined secondary thickening had occurred. In the primary cell wall the micellar orientation was approximately trans"erse to the longitudiJ)aI cell axis. Using optical and X-ray methods the secondary cell wall was shown to possess a helical micellar organization, the micelles being inclined between 30� and 60� to the longitudinal cell axis.

A light and electron microscope investigation of the transfer cell region of maize caryopses

1990 ◽  
Vol 68 (3) ◽  
pp. 471-479 ◽  
Author(s):  
Ronald W. Davis ◽  
J. D. Smith ◽  
B. Greg Cobb
Keyword(s):  
Cell Wall ◽  
Cross Section ◽  
Close Association ◽  
Transfer Cells ◽  
Transfer Cell ◽  
Cell Region ◽  
Maternal Tissue ◽  
X Ray ◽  
Numerous Cell ◽  
Electron Microscopes

The transfer cell zones from 23-day postpollination corn caryopses were examined using light and electron microscopes and X-ray elemental analysis. The transfer cells were sectioned in cross and longitudinal planes and were characterized by having numerous cell-wall extensions in the form of anastomosing lamellae. The most basal transfer cells had more cell-wall extensions than those that were successively deeper in the endosperm. Cytoplasm, rich with mitochondria, filled the interstices of cell-wall extensions, and many vesiculate areas could be found along the plasma membrane. Some transfer cells contained crystals within plastids. The crystals were composed of magnesium, phosphorus, calcium, and zinc. Other cells had large aggregations of endoplasmic reticulum that were often in close association with mitochondria or unidentified, single membrane bounded organelles. When viewed in cross section, the cell-wall extensions of contiguous cells tended to originate from common loci. Plasmodesmata were absent in the bottom parts of the basal transfer cells where they contacted the maternal tissue but were abundant in the upper parts of these cells and in the transfer cells found deeper in the endosperm. The plasmodesmata were found in clusters and alternated with the wall extension areas.

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