Effect of decreased rate of water absorption on water balance of leaf tissue

1970 ◽  
Vol 12 (6) ◽  
pp. 395-400
Author(s):  
Jana Pospíšilová
Keyword(s):  
Water Balance ◽  
Water Absorption ◽  
Leaf Tissue

Absorption de l'eau atmosphérique par la partie aérienne d'un chaméphyte de la Tunisie présaharienne : l’Anthyllis henoniana (Fabaceae)

1994 ◽  
Vol 72 (8) ◽  
pp. 1222-1227 ◽  
Author(s):  
Jean-Marc Ourcival ◽  
André Berger ◽  
Édouard Le Floc'h
Keyword(s):  
Water Balance ◽  
Water Absorption ◽  
Water Potential ◽  
Key Words ◽  
Cross Sections ◽  
Vascular System ◽  
Atmospheric Water ◽  
Atmospheric Humidity ◽  
The Many ◽  
Made In

Measurements of predawn water potential made in the presaharian Tunisia (Médenine) on A. henoniana suggest that this species is able to absorb directly atmospheric water through its leaves and (or) stems. Measurements of water potential were also made on several plants in controlled conditions. Cross sections of stems of various ages and of leaves were examined. There was a good correlation between the thickness of the cortical parenchymatous tissue in leaves and young stems and the ability of a plant to maintain a less negative water potential in conditions of high atmospheric humidity. The water is apparently taken up by the vascular system. This ability would allow A. henoniana to benefit from the many dew days observed in its area of distribution and would improve its water balance. Key words: Anthyllis henoniana, dew, water potential, water absorption, water balance.

Water balance in leaf tissue

1969 ◽  
Vol 11 (2) ◽  
pp. 119-129 ◽  
Author(s):  
Jana Pospíšilová
Keyword(s):  
Water Balance ◽  
Leaf Tissue

Water Balance in Manduca Sexta Caterpillars: Water Recycling From the Rectum

1989 ◽  
Vol 141 (1) ◽  
pp. 33-45 ◽  
Author(s):  
STUART E. REYNOLDS ◽  
KAREN BELLWARD
Keyword(s):  
Epithelial Cells ◽  
Water Balance ◽  
Water Absorption ◽  
Water Content ◽  
Manduca Sexta ◽  
Rectal Wall ◽  
Tobacco Hornworm ◽  
Water Recycling ◽  
Water Reabsorption ◽  
Ultrastructural Appearance

Tobacco hornworm (Manduca sexta) caterpillars are able to regulate the water content of their body when fed on diets of markedly different water content. This regulation extends to the water content of food within the gut. Regulation of body water is achieved by adjusting the amounts of water lost with the faeces. The rectum is shown to be the principal site of water reabsorption from the faeces. The rate of rectal water absorption is shown to vary with the water content of the food and thus according to need. Water reabsorbed from the rectal contents is recycled and added to the contents of the midgut. The ultrastructural appearance of epithelial cells in the rectal wall is that expected of a fluid-transporting tissue. The ileum appears to play little or no part in water recycling.

scholarly journals The Effect of Pitressin and Pitocin on Water Balance in Bufo Regularis Reuss

1951 ◽  
Vol 28 (3) ◽  
pp. 374-384
Author(s):  
R. F. EWER
Keyword(s):  
Water Balance ◽  
Water Absorption ◽  
Water Uptake ◽  
Marked Decrease ◽  
Urine Flow ◽  
Diuretic Effect ◽  
Posterior Pituitary ◽  
Antagonistic Action ◽  
Diuretic Action ◽  
Main Factor

1. In Bufo regularis the injection of either pitressin or pitocin is followed by an increase in the rate of water absorption through the skin, together with a marked decrease in urine flow. The response to pitressin is greater than that to pitocin. 2. The effect of pitocin in increasing water uptake can be attributed to the activity of the 5-10% of the pressor fraction which it contains. 3. A mixture of pitressin and pitocin has the same effect on water balance as a corresponding dose of pituitrin. Pitressin alone has a greater anti-diuretic effect than it has when pitocin is added. 4. Taking into account the antagonistic action of pitocin to pitressin it is possible to account for the anti-diuretic action of pitocin in terms of its pressor fraction content. 5. It is concluded that the pressor fraction is the main factor responsible for both the dermal and the renal components of the water-balance effect produced in B. regularis by injection of mammalian posterior pituitary extracts. This conclusion is discussed in relation to the findings of other workers.

Ultrastructure of Plant Leaf Tissue Infected with Mite-Borne Viral-Like Pathogens

1970 ◽  
Vol 28 ◽  
pp. 178-179 ◽  
Author(s):  
O. E. Bradfute ◽  
R. E. Whitmoyer ◽  
L. R. Nault
Keyword(s):  
Triticum Aestivum ◽  
Zea Mays ◽  
Electron Microscope ◽  
Hordeum Vulgare ◽  
Microscope Study ◽  
Electron Microscope Study ◽  
Leaf Tissue ◽  
Leaf Ultrastructure ◽  
Double Membrane ◽  
Aceria Tulipae

A pathogen transmitted by the eriophyid mite, Aceria tulipae, infects a number of Gramineae producing symptoms similar to wheat spot mosaic virus (1). An electron microscope study of leaf ultrastructure from systemically infected Zea mays, Hordeum vulgare, and Triticum aestivum showed the presence of ovoid, double membrane bodies (0.1 - 0.2 microns) in the cytoplasm of parenchyma, phloem and epidermis cells (Fig. 1 ).

Use of TEM in Plant Disease Diagnosis: A Xylem-Limited Bacterium Associated with Diseased ‘Toronto’ Creeping Bentgrass

1981 ◽  
Vol 39 ◽  
pp. 414-415
Author(s):  
Karen K. Baker ◽  
David L. Roberts
Keyword(s):  
Osmium Tetroxide ◽  
Plant Disease ◽  
Leaf Tissue ◽  
Infectious Agent ◽  
Creeping Bentgrass ◽  
Disease Diagnosis ◽  
Unknown Etiology ◽  
Agrostis Palustris ◽  
Putting Greens ◽  
Plant Disease Diagnosis

Plant disease diagnosis is most often accomplished by examination of symptoms and observation or isolation of causal organisms. Occasionally, diseases of unknown etiology occur and are difficult or impossible to accurately diagnose by the usual means. In 1980, such a disease was observed on Agrostis palustris Huds. c.v. Toronto (creeping bentgrass) putting greens at the Butler National Golf Course in Oak Brook, IL.The wilting symptoms of the disease and the irregular nature of its spread through affected areas suggested that an infectious agent was involved. However, normal isolation procedures did not yield any organism known to infect turf grass. TEM was employed in order to aid in the possible diagnosis of the disease.Crown, root and leaf tissue of both infected and symptomless plants were fixed in cold 5% glutaraldehyde in 0.1 M phosphate buffer, post-fixed in buffered 1% osmium tetroxide, dehydrated in ethanol and embedded in a 1:1 mixture of Spurrs and epon-araldite epoxy resins.

Ultrastructure and Senescence in an Achloroplastic Mutant of Hordeum vulgare L. cv. Dyan

1992 ◽  
Vol 50 (1) ◽  
pp. 844-845
Author(s):  
R.H.M. Cross ◽  
C.E.J. Botha ◽  
A.K. Cowan ◽  
B.J. Hartley
Keyword(s):  
Cell Wall ◽  
Hordeum Vulgare ◽  
Leaf Tissue ◽  
Ultrastructural Changes ◽  
Hordeum Vulgare L ◽  
Mesophyll Cells ◽  
Lethal Mutant ◽  
Cytoplasmic Matrix ◽  
Close Proximity ◽  
Pinocytotic Vesicles

Senescence is an ordered degenerative process leading to death of individual cells, organs and organisms. The detection of a conditional lethal mutant (achloroplastic) of Hordeum vulgare has enabled us to investigate ultrastructural changes occurring in leaf tissue during foliar senescence.Examination of the tonoplast structure in six and 14 day-old mutant tissue revealed a progressive degeneration and disappearance of the membrane, apparently starting by day six in the vicinity of the mitochondria associated with the degenerating proplastid (Fig. 1.) where neither of the plastid membrane leaflets is evident (arrows, Fig. 1.). At this stage there was evidence that the mitochondrial membranes were undergoing retrogressive changes, coupled with disorganization of cristae (Fig. 2.). Proplastids (P) lack definitive prolamellar bodies. The cytoplasmic matrix is largely agranular, with few endoplasmic reticulum (ER) cisternae or polyribosomal aggregates. Interestingly, large numbers of actively-budding dictysomes, associated with pinocytotic vesicles, were observed in close proximity to the plasmalemma of mesophyll cells (Fig. 3.). By day 14 however, mesophyll cells showed almost complete breakdown of subcellular organelle structure (Fig. 4.), and further evidence for the breakdown of the tonoplast. The final stage of senescence is characterized by the solubilization of the cell wall due to expression and activity of polygalacturonase and/or cellulose. The presence of dictyosomes with associated pinocytotic vesicles formed from the mature face, in close proximity to both the plasmalemma and the cell wall, would appear to support the model proposed by Christopherson for the secretion of cellulase. This pathway of synthesis is typical for secretory glycoproteins.

High-pressure freezing and freeze substitution of plant tissue

1992 ◽  
Vol 50 (1) ◽  
pp. 748-749
Author(s):  
William P. Sharp ◽  
Robert W. Roberson
Keyword(s):  
High Pressure ◽  
Cell Structure ◽  
Leaf Tissue ◽  
Freeze Substitution ◽  
Crystal Formation ◽  
Ice Crystal ◽  
High Pressure Freezing ◽  
Cell Components ◽  
Cold Metal ◽  
Brome Grass

The aim of ultrastructural investigation is to analyze cell architecture and relate a functional role(s) to cell components. It is known that aqueous chemical fixation requires seconds to minutes to penetrate and stabilize cell structure which may result in structural artifacts. The use of ultralow temperatures to fix and prepare specimens, however, leads to a much improved preservation of the cell’s living state. A critical limitation of conventional cryofixation methods (i.e., propane-jet freezing, cold-metal slamming, plunge-freezing) is that only a 10 to 40 μm thick surface layer of cells can be frozen without distorting ice crystal formation. This problem can be allayed by freezing samples under about 2100 bar of hydrostatic pressure which suppresses the formation of ice nuclei and their rate of growth. Thus, 0.6 mm thick samples with a total volume of 1 mm3 can be frozen without ice crystal damage. The purpose of this study is to describe the cellular details and identify potential artifacts in root tissue of barley (Hordeum vulgari L.) and leaf tissue of brome grass (Bromus mollis L.) fixed and prepared by high-pressure freezing (HPF) and freeze substitution (FS) techniques.

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