Subterranean structures and mycotrophy of the achlorophyllous Triuris hyalina (Triuridaceae)

1998 ◽  
Vol 76 (12) ◽  
pp. 2011-2019 ◽  
Author(s):  
Stephan Imhof
Keyword(s):  
Arbuscular Mycorrhiza ◽  
Adventitious Roots ◽  
Sustainable Use ◽  
Root Anatomy ◽  
Root Structure ◽  
Outer Cortex ◽  
Short Cell ◽  
External Hyphae ◽  
Xylem Elements ◽  
Inner Cortex

Triuris hyalina Miers, an unusual achlorophyllous plant, was investigated for subterranean morphology, root anatomy, and mycotrophy. Stems with scale leaves extend subterraneously to a depth of 15 cm. Pairs of adventitious roots develop at the scale leaves and clumps of apparently radiating roots, formed by accumulations of side shoot and scale leaf developments, occur. Roots consist of epidermis, short cell exodermis, three distinct layers of cortex parenchyma, endodermis, and an extremely reduced central cylinder with one or two central tracheidal xylem elements. The fungus associated with T. hyalina roots exhibits thick-walled, 6-9 µm thick, aseptate external hyphae. It penetrates the epidermis by developing appressoria and enters the cortex solely through the short cells of the exodermis. In the cortex cells, the aseptate hyphae start to coil. In the outer cortex layer, hyphae are thin, frequently branched, and most densely coiled. In the middle cortex layer they are thicker and less densely coiled, and mostly appear degenerated to clumps of amorphous fungal material. The inner cortex layer rarely becomes colonized. Vesicles occur in the outer and the middle cortex layers. This mycorrhizal pattern is interpreted as an adaption to attain a sustainable use from the endophyte. It is suggested that the mycorrhiza in Triuris hyalina be interpreted as a type of arbuscular mycorrhiza (AM). Implications for systematics and ecology are discussed.Key words: Triuris, Triuridaceae, root structure, anatomy, arbuscular mycorrhiza, myco-heterotrophy.

Subterranean structures and mycorrhiza of the achlorophyllous Burmannia tenella (Burmanniaceae)

1999 ◽  
Vol 77 (5) ◽  
pp. 637-643 ◽  
Author(s):  
Stephan Imhof
Keyword(s):  
Arbuscular Mycorrhiza ◽  
Cross Section ◽  
Morphological Changes ◽  
Root Systems ◽  
Root Anatomy ◽  
Mycorrhizal Dependency ◽  
Anatomical Structures ◽  
Xylem Elements ◽  
Fungal Association ◽  
Form Star

Plants of the myco-heterotrophic Burmannia tenella Benth. form star-shaped root systems consisting of 0.7-2 mm thick, succulent, brittle roots, reaching lengths of up to 3 cm. In cross section the roots consist of an epidermis, about 10 layers of parenchymatous cortex cells, an endodermis with U-shaped secondary cell wall depositions, and a very reduced central cylinder with two to five central xylem elements and two opposite phloem strands, surrounded by a pericycle of relatively large cells. Based on the thick, aseptate, intracellularly coiled hyphae, arbuscules, and the frequent vesicles, the fungal association of B. tenella is considered to be a Paris-type arbuscular mycorrhiza. The morphological and anatomical structures of the root are discussed in the context of the mycorrhizal dependency of B. tenella. In some root samples, a second fungus with septate hyphae colonized the cortex intracellularly. This fungus restricts the spread of the aseptate symbiont without causing morphological changes to the cortex cells.Key words: Burmanniaceae, root morphology, root anatomy, arbuscular mycorrhiza, myco-heterotrophy, neotropical.

Effects of angiotensin II on regional afferent and efferent arteriole dimensions and the glomerular pole

2000 ◽  
Vol 279 (2) ◽  
pp. R629-R638 ◽  
Author(s):  
Kate M. Denton ◽  
Warwick P. Anderson ◽  
Raja Sinniah
Keyword(s):  
Angiotensin Ii ◽  
Arterial Pressure ◽  
Capillary Pressure ◽  
Ang Ii ◽  
Similar Extent ◽  
Outer Cortex ◽  
Efferent Arteriole ◽  
Vascular Casting ◽  
Cortical Regions ◽  
Inner Cortex

The diversity of renal arteriole diameters in different cortical regions has important consequences for control of glomerular capillary pressure. We examined whether intrarenal angiotensin II (ANG II; 0.1, 1, or 5 ng · kg−1 · min−1) in anesthetized rabbits acts preferentially on pre- or postglomerular vessels using vascular casting. ANG II produced dose-related reductions in afferent and efferent diameters in the outer, mid, and inner cortex, without effecting arterial pressure. Afferent diameter decreased more than efferent in the outer and mid cortex ( P < 0.05) but by a similar extent in juxtamedullary nephrons ( P = 0.58). Calculated efferent resistance increased more than afferent, especially in the outer cortex (127 vs. 24 units; 5 ng · kg−1 · min−1 ANG II). ANG II produced significant dose-related increases in the distance between the arterioles at the entrance to the glomerular pole in all regions. Thus afferent diameter decreased more in response to ANG II, but efferent resistance rose more due to smaller resting luminal dimensions. The results also indicate that glomerular pole dimensions change in response to ANG II.

scholarly journals Quantitation of erythropoietin-producing cells in kidneys of mice by in situ hybridization: correlation with hematocrit, renal erythropoietin mRNA, and serum erythropoietin concentration

Blood ◽  
1989 ◽  
Vol 74 (2) ◽  
pp. 645-651 ◽  
Author(s):  
ST Koury ◽  
MJ Koury ◽  
MC Bondurant ◽  
J Caro ◽  
SE Graber
Keyword(s):  
In Situ Hybridization ◽  
Blood Loss ◽  
Mrna Levels ◽  
Outer Cortex ◽  
Acute Anemia ◽  
Small Clusters ◽  
Inner Cortex ◽  
Silver Grains ◽  
Serum Erythropoietin

Abstract In situ hybridization was used to quantitate the cells that produce erythropoietin (EP) in the renal cortices of mice with varying severities of acute anemia and of mice recovering from severe, acute anemia. The number of EP-producing cells in the renal cortex increased in an exponential manner as hematocrit was decreased. Individual EP- producing cells had very similar densities of silver grains in autoradiograms regardless of whether they were from normal mice or from slightly, moderately or severely anemic animals. With increasingly severe anemia, total renal EP mRNA levels and serum EP concentrations showed increases that correlated with the number of renal EP-producing cells. These results indicate that as mice become more anemic, additional cells are recruited to produce EP rather than the cells already producing EP being stimulated to increase their individual production. In mildly and moderately anemic animals, small clusters of EP-producing cells were found in the inner cortex with large areas of cortex containing no EP-producing cells. In severely anemic mice, EP- producing cells were found throughout the inner cortex with only a very few found scattered in the outer cortex and outer medulla. The data indicate that only a subset of total renal interstitial cells produce EP. During recovery from severe, acute anemia, the numbers of EP- producing cells decreased exponentially as hematocrits rose and correlated with decreases in total renal EP mRNA and serum EP concentrations. These results suggest that following an acute blood loss and during the recovery from a blood loss, the capacity to deliver oxygen, as represented by hematocrit, is the major regulator of EP production.

scholarly journals Root morpho-physiology changes during the habitat transition from soil to canopy of the aroid vine Rhodospatha oblongata

2020 ◽  
Author(s):  
Arinawa Liz Filartiga ◽  
Dulce Mantuano ◽  
Ricardo Cardoso Vieira ◽  
Karen Lucia Gama de Toni ◽  
Gustavo M Vasques ◽  
...  
Keyword(s):  
Chlorophyll Fluorescence ◽  
Water Absorption ◽  
Root Anatomy ◽  
Water Retention Capacity ◽  
Outer Cortex ◽  
Retention Capacity ◽  
Physiological Basis ◽  
Root Region ◽  
Aerial Roots ◽  
Root Types

Abstract Background and Aims The aroid vine Rhodospatha oblongata is characterized by a habitat change from terrestrial to canopy, relying on aerial roots at maturity to obtain water and nutrients from the forest soil. We hypothesize that morpho-physiological acclimation occurs in roots as they grow under atmospheric conditions. These changes would guarantee the whole plant survival of aroid vines in the new and potentially stressful habitat of the canopy. Methods Terrestrial and aerial roots were compared on a morpho-physiological basis. Root anatomy, water balance, water absorption capacity via fluorescent tracer, and photochemical activity via chlorophyll fluorescence were measured. Key Results While thin fasciculate roots occur on terrestrial crawling individuals, two clearly distinct aerial roots (anchor and feeder) are produced on canopy individuals, which are both adhered to the host trunk. The color of both aerial roots change during development from red and brownish to striped and green at maturity. Color changes are induced by the replacement of epidermis, exodermis, and outer cortex by an inner layer of lignified cork on the root region exposed to the atmosphere. In the root region that is in contact with the host, covering substitutions do not occur and both exodermis and lignified cork, along with several epidermal hairs, appear. Water retention capacity was higher in green roots than in other root types. Rehydration capacity via water absorption by hairs of aerial roots was confirmed by fluorescence. Chlorophyll fluorescence data indicated low levels of photosynthetic capacity in both root types. Conclusions Plants should evolve strategies to survive stress situations. The transition from soil to canopy imposes abiotic changes and potentially stressful situations to R. oblongata. We conclude that the morpho-physiological changes observed represent an important strategy that permits the maintenance of aroid roots and the survival of R. oblongata in the canopy.

Renal hydrogen ion secretion after release of unilateral ureteral obstruction

1976 ◽  
Vol 231 (4) ◽  
pp. 1233-1239 ◽  
Author(s):  
K Thirakomen ◽  
N Kozlov ◽  
JA Arruda ◽  
NA Kurtzman
Keyword(s):  
Ureteral Obstruction ◽  
Renal Plasma Flow ◽  
Plasma Renin ◽  
Unilateral Ureteral Obstruction ◽  
Outer Cortex ◽  
Urinary Ph ◽  
Contralateral Kidney ◽  
Saline Loading ◽  
K Secretion ◽  
Inner Cortex

The effect of 24 h of unilateral ureteral obstruction on HCO3 reabsroption and urinary acidification was studied in dogs. The postobstructed kidney (EK) had a significantly lower glomerular filtration rate and renal plasma flow than the contralateral kidney (CK). Urinary pH prior to HCO3 loading was significantly higher in the EK as was maximal HCO3 reabsorption. Saline loading depressed HCO3 reabsorption to the same degree in both kidneys. Urinary PCO2, during HCO3 loading, and during phosphate infusion, was significantly lower in the EK than the CK. Fractional Na excretion was significantly higher in the EK than the CK after deoxycorticosterone acetate administration. Na2SO4 administration enhanced acid excretion only in the CK. K excretion was significantly lower in the EK than the CK both during HCO3 loading and Na2SO4 administration. There was redistribution of cortical blood flow from the outer cortex toward the inner cortex in the EK as compared to the CK. There was no difference in plasma renin activity from both renal veins. These data demonstrate enhanced proximal H+ secretion (which is abolished by volume expansion) and impaired distal H+ secretion by the postobstructed kidney. The distal defect is likely an effect of a generalized disorder of distal transport in that both K secretion and steroid-responsive Na reabsorption were impaired in the postobstructed kidney.

scholarly journals Characterization of Adventitious Root Development in Sweetpotato

HortScience ◽  
2009 ◽  
Vol 44 (3) ◽  
pp. 651-655 ◽  
Author(s):  
Arthur Q. Villordon ◽  
Don R. La Bonte ◽  
Nurit Firon ◽  
Yanir Kfir ◽  
Etan Pressman ◽  
...  
Keyword(s):  
Root Development ◽  
Adventitious Root ◽  
Adventitious Roots ◽  
Vascular Cambium ◽  
Storage Root ◽  
Storage Roots ◽  
Adventitious Root Development ◽  
Xylem Elements ◽  
Storage Root Development

Adventitious roots of ‘Beauregard’ and ‘Georgia Jet’ sweetpotato were observed and anatomically characterized over a period of 60 days of storage root development. The majority of ‘Beauregard’ and ‘Georgia Jet’ adventitious roots sampled at 5 to 7 days after transplanting (DAT) possessed anatomical features (five or more protoxylem elements) associated with storage root development. The majority of ‘Beauregard’ (86%) and ‘Georgia Jet’ (89%) storage roots sampled at 60 to 65 DAT were traced directly to adventitious roots extant at 5 to 7 DAT. The two varieties, however, differed in the timing in which regular and anomalous cambia were formed. Regular vascular cambium development, i.e., initiation and completion, was observed in both varieties at 19 to 21 DAT. Formation of complete regular vascular cambium was negligible for ‘Beauregard’ (4%) in comparison with ‘Georgia Jet’ (32%) at 26 to 28 DAT. However, anomalous cambia development adjacent to xylem elements was greater in ‘Beauregard’ (30%) in comparison with ‘Georgia Jet’ (13%). Nearly 40% to 50% of samples in both varieties showed extensive lignification in the stele region. At 32 to 35 DAT, 62% to 70% of the adventitious roots for both varieties had either been initiated (developed anomalous cambium) or were lignified. The remaining adventitious roots showed intermediate stages of vascular cambium development. The adventitious root count increased up to 19 to 21 DAT and then remained constant up to 32 to 35 DAT. These accumulated results suggest that the initial stages of adventitious root development are critical in determining storage root set in sweetpotato.

scholarly journals Quantitation of erythropoietin-producing cells in kidneys of mice by in situ hybridization: correlation with hematocrit, renal erythropoietin mRNA, and serum erythropoietin concentration

Blood ◽  
1989 ◽  
Vol 74 (2) ◽  
pp. 645-651 ◽  
Author(s):  
ST Koury ◽  
MJ Koury ◽  
MC Bondurant ◽  
J Caro ◽  
SE Graber
Keyword(s):  
In Situ Hybridization ◽  
Blood Loss ◽  
Mrna Levels ◽  
Outer Cortex ◽  
Acute Anemia ◽  
Small Clusters ◽  
Inner Cortex ◽  
Silver Grains ◽  
Serum Erythropoietin

In situ hybridization was used to quantitate the cells that produce erythropoietin (EP) in the renal cortices of mice with varying severities of acute anemia and of mice recovering from severe, acute anemia. The number of EP-producing cells in the renal cortex increased in an exponential manner as hematocrit was decreased. Individual EP- producing cells had very similar densities of silver grains in autoradiograms regardless of whether they were from normal mice or from slightly, moderately or severely anemic animals. With increasingly severe anemia, total renal EP mRNA levels and serum EP concentrations showed increases that correlated with the number of renal EP-producing cells. These results indicate that as mice become more anemic, additional cells are recruited to produce EP rather than the cells already producing EP being stimulated to increase their individual production. In mildly and moderately anemic animals, small clusters of EP-producing cells were found in the inner cortex with large areas of cortex containing no EP-producing cells. In severely anemic mice, EP- producing cells were found throughout the inner cortex with only a very few found scattered in the outer cortex and outer medulla. The data indicate that only a subset of total renal interstitial cells produce EP. During recovery from severe, acute anemia, the numbers of EP- producing cells decreased exponentially as hematocrits rose and correlated with decreases in total renal EP mRNA and serum EP concentrations. These results suggest that following an acute blood loss and during the recovery from a blood loss, the capacity to deliver oxygen, as represented by hematocrit, is the major regulator of EP production.

scholarly journals Adaptive morphoanatomy and ecophysiology of Billbergia euphemiae, a hemiepiphyte Bromeliaceae

Rodriguésia ◽  
2019 ◽  
Vol 70 ◽  
Author(s):  
Bianca Butter Zorger ◽  
Hiulana Pereira Arrivabene ◽  
Camilla Rozindo Dias Milanez
Keyword(s):  
Water Retention ◽  
Abaxial Surface ◽  
Outer Cortex ◽  
Selective Pressures ◽  
Cortex Cell ◽  
Storage Parenchyma ◽  
Cell Layers ◽  
Length Width ◽  
Lower Height ◽  
Inner Cortex

Abstract Habitats under distinct selective pressures exert adaptative pressures that can lead individuals of the same species to present different life strategies for their survival. The aim of this study was to analyse morphoanatomical and physiological traits for identification of adaptive ecological strategies related to both terrestrial and epiphytic life phases of Billbergia euphemiae. It was verified that B. euphemiae showed lower height, as well smaller length, width and foliar area in epiphytic phase than in terrestrial phase. Concerning to foliar anatomy, the thicknesses of leaf and water-storage parenchyma were higher in terrestrial phase, as densities of stomata and scales on the abaxial surface were higher in epiphytic phase. About the contents of photosynthetic pigments, only chlorophyll a/b ratio showed differences between life phases. In both habits, plants exhibited roots with absorption hair. In epiphytic phase, roots exhibited higher velamen thickness, smaller outer cortex, higher number of inner cortex cell layers and higher number of protoxylem poles. Thus, B. euphemiae individuals in epiphytic exhibited lots of traits related to water retention, once these plants are not into the ground. Besides, the plasticity observed may contribute for survival of this group in habitats submitted to modifications (e.g., climate change and other variations caused by human interference).

Anatomy of the Legume Nodule Cortex: Species Survey of Suberisation and Intercellular Glycoprotein

1996 ◽  
Vol 23 (2) ◽  
pp. 211 ◽  
Author(s):  
SM Brown ◽  
KB Walsh
Keyword(s):  
Oxygen Diffusion ◽  
Lucifer Yellow ◽  
Vascular Bundles ◽  
Outer Cortex ◽  
Lucifer Yellow Ch ◽  
Primitive Feature ◽  
Determinate Nodule ◽  
The Common ◽  
Apoplastic Barrier ◽  
Inner Cortex

Nodules of 29 species from 23 legume genera were examined for suberisation and glycoprotein deposits. Extensive suberisation of the nodule outer cortex to form a peridem was considered a primitive feature, common to non-legume and caesalpinioid nodules. The periderm was less extensive in nodules of Mimosoideae and Papilionoideae. Vascular bundles within the nodule were always surrounded by a vascular endodermis, defined by the presence of suberin on radial walls. Suberisation of the tangential walls of this endodermis was considered to be a primitive feature (present in all species examined of Caesalpinioideae and Mimosoideae, and in 10 out of 21 Papilionoideae) which may limit solute import to and export from the nodule. Glycoprotein was observed in the apoplast of the cortex in the three papilionoid species examined, but was absent in the caesalpinioid species examined. The common endodermis was recognised as an advanced feature, present only in certain species of the subfamily Papilionoideae (5 of 7, and 11 of 15 species of indeterminate and determinate nodule growth respectively). A membrane impermeant dye (lucifer yellow-CH), supplied in the rhizosphere under a mild vacuum, was observed to infiltrate through the cortex and into the infected zone in caesalpinioid nodules, and as far as the inner cortex in mimosoid and papilionoid nodules. Thus the common endodermis does not serve as an apoplastic barrier, and is unlikely to serve as a significant oxygen 'diffusion barrier'.

HISTOLOGY OF ANOMALOUS GROWTH AND ADVENTITIOUS ROOTS ASSOCIATED WITH MAINSTEM GIRDLING BY THREECORNERED ALFALFA HOPPER, SPISSISTILUS FESTINUS (SAY) (HOMOPTERA: MEMBRACIDAE) ON SOYBEAN1

1988 ◽  
Vol 23 (4) ◽  
pp. 333-341 ◽  
Author(s):  
M. P. Johnson ◽  
A. J. Mueller ◽  
W. M. Harris ◽  
K. S. Kim
Keyword(s):  
Glycine Max ◽  
Adventitious Roots ◽  
Tissue Structure ◽  
Vascular Bundles ◽  
Root Structure ◽  
Secondary Phloem ◽  
Parenchyma Cells ◽  
Glycine Max L ◽  
Spissistilus Festinus ◽  
Anomalous Growth

Cell and tissue structure of undamaged soybean, Glycine max (L.) Merrill, stems were compared with those from the swollen area immediately above (&lt; 1 cm) threecornered alfalfa hopper, Spissistilus festinus (Say), girdles. Examination of epoxy - resin embedded transverse sections from the swollen stems revealed growth that differed significantly from the normal dicot structure. The anomalous growth consisted of vascular bundles scattered in the secondary phloem surrounded by parenchyma cells. Examination of Paraplast® embedded transverse and longitudinal sections of adventitious root - like growths arising from or above the swollen hypocotyl area revealed normal root structure.

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