Relative importance of the endomycorrhizal and (or) ectomycorrhizal associations in Allocasuarina and Casuarina genera

2003 ◽  
Vol 49 (4) ◽  
pp. 281-287 ◽  
Author(s):  
R Duponnois ◽  
S Diédhiou ◽  
J L Chotte ◽  
M Ourey Sy
Keyword(s):  
Mycorrhizal Fungi ◽  
Glomus Intraradices ◽  
Arbuscular Mycorrhizas ◽  
Point Of View ◽  
Mycorrhizal Symbiosis ◽  
Relative Importance ◽  
Soil System ◽  
Hartig Net ◽  
Axenic Conditions ◽  
And Function

This work was carried out to determine the relative importance of the endomycorrhizal and (or) ectomycorrhizal association in species of Casuarina and Allocasuarina. Under axenic conditions, Pisolithus and Scleroderma isolates formed ectomycorrhizas with a mantle and a Hartig net on Allocasuarina verticillata but failed to form a Hartig net on Casuarina glauca. In a controlled soil system, C. glauca was inoculated with the endomycorrhizal fungus Glomus intraradices Schenck & Smith, and A. verticillata was inoculated with Pisolithus albus IR100 Bougher & Smith and (or) G. intraradices. Both symbionts significantly stimulated growth in both plant species. For A. verticillata, its growth response to ectomycorrhizal inoculation was higher than to endomycorrhizal inoculation. When both symbionts were inoculated, antagonism among the fungal isolates was observed with a higher ectomycorrhizal colonization. These results showed that A. verticillata was ectomycorrhizal dependent, whereas C. glauca was endomycorrhizal dependent. From a practical point of view, this study shows the importance of selecting compatible mycorrhizal fungi for developing successful inoculation programmes. In addition, it would help to further research and determine the effect of ecto- and endo-mycorrhizal symbiosis on the formation and function of N2-fixing actinorhizal nodules.Key words: Casuarinaceae, ectomycorrhizas, arbuscular mycorrhizas, plant growth.

scholarly journals Sodium Chloride Stress Induced Changes in Leaf Osmotic Adjustment of Trifoliate Orange (Poncirus trifoliata) Seedlings Inoculated with Mycorrhizal Fungi

2011 ◽  
Vol 39 (2) ◽  
pp. 64 ◽  
Author(s):  
Ying-Ning ZOU ◽  
Qiang-Sheng WU
Keyword(s):  
Osmotic Adjustment ◽  
Mycorrhizal Fungi ◽  
Plant Biomass ◽  
Arbuscular Mycorrhizal ◽  
Arbuscular Mycorrhizas ◽  
Mycorrhizal Colonization ◽  
Poncirus Trifoliata ◽  
Mycorrhizal Symbiosis ◽  
Trifoliate Orange ◽  
K Concentration

Citrus plants are sensitive to salinity, and thus employing new approaches to alleviate salt damage are necessary. The present study evaluated the effect of two arbuscular mycorrhizal fungi (AMF), Glomus mosseae and G. versiforme, on leaf osmotic adjustment of trifoliate orange (Poncirus trifoliata) seedings exposed to 100 mM NaCl. Salinity significantly inhibited mycorrhizal colonization, plant biomass and leaf relative water content, whereas the reduce of plant biomass was notably alleviated by the mycorrhizal colonization. Mycorrhizal seedlings exhibited significantly lower Na+ and Ca2+ concentrations, whilst also recorded higher K+ concentration and K+/Na+, Ca2+/Na+ and Mg2+/Na+ ratios at both salinity levels. Under salinity stress, mycorrhizal symbiosis markedly decreased sucrose concentrations of leaves and also increased glucose, fructose and proline concentrations of leaves. The results suggest that arbuscular mycorrhizas improved leaf osmotic adjustment responses of the seedlings to salt stress, thus enhancing salt tolerance of mycorrhizal plants.

Partitioning mycorrhizal influence on water relations of Phaseolus vulgaris into soil and plant components

2004 ◽  
Vol 82 (4) ◽  
pp. 503-514 ◽  
Author(s):  
Robert M Augé ◽  
David M Sylvia ◽  
Soon Park ◽  
Brian R Buttery ◽  
Arnold M Saxton ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Water Relations ◽  
Drought Resistance ◽  
Mycorrhizal Fungi ◽  
Glomus Intraradices ◽  
Characteristic Curve ◽  
Arbuscular Mycorrhizal ◽  
Mycorrhizal Symbiosis ◽  
Gigaspora Margarita ◽  
Soil Water Retention

There is growing appreciation of arbuscular mycorrhizal effects on soil properties and their potential consequences on plant behavior. We examined the possibility that mycorrhizal soil may directly influence plant water relations. Using wild-type and noncolonizing bean mutants planted into soils previously produced using mycorrhizal or nonmycorrhizal sorghum plants, we partitioned mycorrhizal influence on stomatal conductance and drought resistance into soil and root components, testing whether effects of mycorrhizal fungi occurred mostly via mycorrhization of roots, mycorrhization of soil, or both. The mutation itself had no effect on any water relations parameter. Colonization by Gigaspora margarita Gerdemann & Trappe and Glomus intraradices Schenck & Smith had appreciable effects on leaf water potential at the lethal point and on osmotic adjustment, relative to nonmycorrhizal plants of comparable size. Mycorrhizal effects on drought resistance were attributable to an effect on the plant itself rather than to an effect of mycorrhizal soil. Mycorrhizal effects on stomatal conductance were attributable to mycorrhization of both roots and soil, as well as to mycorrhization of roots alone. Surprisingly, merely growing in a mycorrhizal soil resulted in promotion of stomatal conductance of nonmycorrhizal plants in both amply watered and droughted plants. Mycorrhizal effects on droughted plants did not appear to be related to altered soil water retention properties, as Gigaspora margarita and Glomus intraradices altered the soil's moisture characteristic curve only slightly.Key words: arbuscular mycorrhizal symbiosis, bean, drought, Gigaspora margarita, Glomus intraradices, stomatal conductance.

scholarly journals A Phosphate Transporter Gene from the Extra-Radical Mycelium of an Arbuscular Mycorrhizal Fungus Glomus intraradices Is Regulated in Response to Phosphate in the Environment

2001 ◽  
Vol 14 (10) ◽  
pp. 1140-1148 ◽  
Author(s):  
Ignacio E. Maldonado-Mendoza ◽  
Gary R. Dewbre ◽  
Maria J. Harrison
Keyword(s):  
Mycorrhizal Fungi ◽  
Glomus Intraradices ◽  
Arbuscular Mycorrhizal Fungus ◽  
Mycorrhizal Fungus ◽  
Arbuscular Mycorrhizal ◽  
Arbuscular Mycorrhizas ◽  
Phosphate Transporter ◽  
Transporter Gene ◽  
Symbiotic Associations ◽  
Mycorrhizal Association

The majority of vascular flowering plants are able to form symbiotic associations with arbuscular mycorrhizal fungi. These symbioses, termed arbuscular mycorrhizas, are mutually beneficial, and the fungus delivers phosphate to the plant while receiving carbon. In these symbioses, phosphate uptake by the arbuscular mycorrhizal fungus is the first step in the process of phosphate transport to the plant. Previously, we cloned a phosphate transporter gene involved in this process. Here, we analyze the expression and regulation of a phosphate transporter gene (GiPT) in the extra-radical mycelium of the arbuscular mycorrhizal fungus Glomus intraradices during mycorrhizal association with carrot or Medicago truncatula roots. These analyses reveal that GiPT expression is regulated in response to phosphate concentrations in the environment surrounding the extra-radical hyphae and modulated by the overall phosphate status of the mycorrhiza. Phosphate concentrations, typical of those found in the soil solution, result in expression of GiPT. These data imply that G. intraradices can perceive phosphate levels in the external environment but also suggest the presence of an internal phosphate sensing mechanism.

Intraspecific genetic variation in arbuscular mycorrhizal fungi and its consequences for molecular biology, ecology, and development of inoculum

2004 ◽  
Vol 82 (8) ◽  
pp. 1057-1062 ◽  
Author(s):  
Ian R Sanders
Keyword(s):  
Genetic Diversity ◽  
Population Genetics ◽  
Genetic Variation ◽  
Genetic Variability ◽  
Plant Growth ◽  
Mycorrhizal Fungi ◽  
Glomus Intraradices ◽  
Arbuscular Mycorrhizal ◽  
Arbuscular Mycorrhizas ◽  
Coding Regions

It has been known for some time that different arbuscular mycorrhizal fungal (AMF) taxa confer differences in plant growth. Although genetic variation within AMF species has been given less attention, it could potentially be an ecologically important source of variation. Ongoing studies on variability in AMF genes within Glomus intraradices indicate that at least for some genes, such as the BiP gene, sequence variability can be high, even in coding regions. This suggests that genetic variation within an AMF may not be selectively neutral. This clearly needs to be investigated in more detail for other coding regions of AMF genomes. Similarly, studies on AMF population genetics indicate high genetic variation in AMF populations, and a considerable amount of variation seen in phenotypes in the population can be attributed to genetic differences among the fungi. The existence of high within-species genetic variation could have important consequences for how investigations on AMF gene expression and function are conducted. Furthermore, studies of within-species genetic variability and how it affects variation in plant growth will help to identify at what level of precision ecological studies should be conducted to identify AMF in plant roots in the field. A population genetic approach to studying AMF genetic variability can also be useful for inoculum development. By knowing the amount of genetic variability in an AMF population, the maximum and minimum numbers of spores that will contain a given amount of genetic diversity can be estimated. This could be particularly useful for developing inoculum with high adaptability to different environments.Key words: arbuscular mycorrhizas, symbiosis, genomics, genetic diversity, population genetics, evolutionary ecology.

Relative amounts of soluble and insoluble forms of phosphorus and other elements in intraradical hyphae and arbuscules of arbuscular mycorrhizas

2007 ◽  
Vol 34 (5) ◽  
pp. 457 ◽  
Author(s):  
Megan H. Ryan ◽  
Margaret E. McCully ◽  
Cheng X. Huang
Keyword(s):  
Mycorrhizal Fungi ◽  
Glomus Intraradices ◽  
Arbuscular Mycorrhizal ◽  
Arbuscular Mycorrhizas ◽  
Host Cells ◽  
Root Cells ◽  
Inorganic P ◽  
Analytical Technique ◽  
Molar Ratios ◽  
Extractable P

Transport of phosphorus (P) into host plants and its release to root cells is an important function of arbuscular mycorrhizal fungi (AMF). However, relatively little is known about the forms and water solubilities of P compounds in specific locations in the intraradical fungal structures. We determined concentrations and solubility of P components in these structures in white clover (Trifolium repens L.). Plants were grown in the field (colonised by indigenous AMF) or in the glasshouse (inoculated with Glomus intraradices). Mycorrhizas were cryo-fixed in liquid nitrogen immediately (control) or after treatments designed to destroy cell membranes and extract solubles. Thirty to 70% of total P in hyphae and 100% in arbuscules was not extracted. The unextracted proportion of P was higher in the inoculated plants suggesting an environmental effect. It is proposed that the large component of non-extractable P in the arbuscules is involved in the tight regulation of inorganic P release to the host cells. In control roots magnesium, potassium and P were present in hyphae in molar ratios 1 : 2 : 4, further evidence that this relationship may be universal for AMF, and that other P-balancing cations are present but undetectable by the analytical technique.

scholarly journals Expression and Function of Organic Anion Transporting Polypeptides in the Human Brain: Physiological and Pharmacological Implications

Pharmaceutics ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 834
Author(s):  
Anima M. Schäfer ◽  
Henriette E. Meyer zu Schwabedissen ◽  
Markus Grube
Keyword(s):  
Organic Anion ◽  
Physiological Role ◽  
Point Of View ◽  
Efflux Transporters ◽  
Organic Anion Transporting Polypeptides ◽  
Current State ◽  
P Glycoprotein ◽  
The Central Nervous System ◽  
And Function ◽  
Uptake Transporters

The central nervous system (CNS) is an important pharmacological target, but it is very effectively protected by the blood–brain barrier (BBB), thereby impairing the efficacy of many potential active compounds as they are unable to cross this barrier. Among others, membranous efflux transporters like P-Glycoprotein are involved in the integrity of this barrier. In addition to these, however, uptake transporters have also been found to selectively uptake certain compounds into the CNS. These transporters are localized in the BBB as well as in neurons or in the choroid plexus. Among them, from a pharmacological point of view, representatives of the organic anion transporting polypeptides (OATPs) are of particular interest, as they mediate the cellular entry of a variety of different pharmaceutical compounds. Thus, OATPs in the BBB potentially offer the possibility of CNS targeting approaches. For these purposes, a profound understanding of the expression and localization of these transporters is crucial. This review therefore summarizes the current state of knowledge of the expression and localization of OATPs in the CNS, gives an overview of their possible physiological role, and outlines their possible pharmacological relevance using selected examples.

Arsenic transformation and volatilization by arbuscular mycorrhizal symbiosis under axenic conditions

2021 ◽  
Vol 413 ◽  
pp. 125390
Author(s):  
Jinglong Li ◽  
Baodong Chen ◽  
Xin Zhang ◽  
Zhipeng Hao ◽  
Xuemeng Zhang ◽  
...  
Keyword(s):  
Arbuscular Mycorrhizal ◽  
Arbuscular Mycorrhizal Symbiosis ◽  
Mycorrhizal Symbiosis ◽  
Arsenic Transformation ◽  
Axenic Conditions

Age and Perceptions of Usability on Telephone Menu Systems

2002 ◽  
Vol 46 (2) ◽  
pp. 175-179 ◽  
Author(s):  
Christopher Reynolds ◽  
Sara J. Czaja ◽  
Joseph Sharit
Keyword(s):  
Older Adults ◽  
Real World ◽  
Community Dwelling ◽  
Relative Importance ◽  
Menu System ◽  
And Function ◽  
Sample Set

The objectives of this study were to determine if older adults encounter difficulty using real-world telephone menu system applications and to gather data on the usability features of these systems. Six real-world telephone menu systems, which varied in complexity and function, were examined. The sample included 32 community dwelling adults ranging in age from 18–80 years. Participants interacted with the menu systems to perform a sample set of tasks. They were also asked to rate the usability features of the system in terms of their goodness and their relative importance. The data indicated that in addition to taking longer, the older adults tended to have more difficulty performing the tasks. The findings also indicated that memorability was an important usability feature, and that the ratings of overall usability and overall satisfaction were significantly worse for the older adults.

THE CRITICALLY ILL CHILD: SICKLE CELL DISEASE CRISES AND THEIR MANAGEMENT

PEDIATRICS ◽  
1971 ◽  
Vol 48 (4) ◽  
pp. 629-635
Author(s):  
Howard A. Pearson ◽  
Louis K. Diamond
Keyword(s):  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Mutant Gene ◽  
Point Of View ◽  
Clinical Aspects ◽  
Cell Disease ◽  
Form And Function ◽  
Heterozygous Form ◽  
The Many ◽  
And Function

This brief review, being limited in scope to the recognition and management of the life-threatening and painful crises in infants and children with sickle-cell disease, has not even touched on the intriguing mystery of the molecular basis for the sickling phenomenon–how one amino-acid substitution (gene controlled) in the beta chain sequence of 146 amino acids can cause such serious disruption in form and function; or how this mutation occurred in the first place and why it has persisted in contrast to the rapid disappearance of many other deleterious mutants. Nor has there been even mention of the many milder symptoms, signs, and complications due to the presence of Hb. S., either in the homozygous (disease-producing) state or heterozygous form when found in combination with other hereditary hemoglobin defects. The accumulated knowledge about this mutant gene, its biochemical effects, and geographic distribution is enormous. From a fundamental scientific standpoint, sickle cell disease is one of the best understood of human afflictions. However, from a practical point of view treatment of the patient himself is often only symptomatic and palliative. Nevertheless, prompt and effective therapy of the myriad manifestations of sickle cell disease can effectively reduce morbidity and mortality. The pediatrician who cares for black children in his practice should be familiar with the cardinal diagnostic and clinical aspects of sickle cell disease and its crises.

Deciphering the Chitin Code in Plant Symbiosis, Defense, and Microbial Networks

2021 ◽  
Vol 75 (1) ◽  
pp. 583-607
Author(s):  
Devanshi Khokhani ◽  
Cristobal Carrera Carriel ◽  
Shivangi Vayla ◽  
Thomas B. Irving ◽  
Christina Stonoha-Arther ◽  
...  
Keyword(s):  
Mycorrhizal Fungi ◽  
Growth And Development ◽  
Fungal Growth ◽  
Mycorrhizal Symbiosis ◽  
Signal Molecules ◽  
Symbiotic Relationship ◽  
Beneficial Microbes ◽  
Symbiotic Interactions ◽  
Microbe Interactions ◽  
Structural Polymer

Chitin is a structural polymer in many eukaryotes. Many organisms can degrade chitin to defend against chitinous pathogens or use chitin oligomers as food. Beneficial microorganisms like nitrogen-fixing symbiotic rhizobia and mycorrhizal fungi produce chitin-based signal molecules called lipo-chitooligosaccharides (LCOs) and short chitin oligomers to initiate a symbiotic relationship with their compatible hosts and exchange nutrients. A recent study revealed that a broad range of fungi produce LCOs and chitooligosaccharides (COs), suggesting that these signaling molecules are not limited to beneficial microbes. The fungal LCOs also affect fungal growth and development, indicating that the roles of LCOs beyond symbiosis and LCO production may predate mycorrhizal symbiosis. This review describes the diverse structures of chitin; their perception by eukaryotes and prokaryotes; and their roles in symbiotic interactions, defense, and microbe-microbe interactions. We also discuss potential strategies of fungi to synthesize LCOs and their roles in fungi with different lifestyles.

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