Functional diversity of external hyphae of AM fungi: Ability to colonise new hosts is influenced by fungal species, distance and soil conditions

2006 ◽  
Vol 32 (3) ◽  
pp. 350-365 ◽  
Author(s):  
E.A. Drew ◽  
R.S. Murray ◽  
S.E. Smith
Keyword(s):  
Functional Diversity ◽  
Am Fungi ◽  
Fungal Species ◽  
Soil Conditions ◽  
External Hyphae ◽  
New Hosts

The rmc locus does not affect plant interactions or defence-related gene expression when tomato (Solanum lycopersicum) is infected with the root fungal parasite, Rhizoctonia

2006 ◽  
Vol 33 (3) ◽  
pp. 289 ◽  
Author(s):  
Ling-Ling Gao ◽  
F. Andrew Smith ◽  
Sally E. Smith
Keyword(s):  
Gene Expression ◽  
Molecular Mechanisms ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Fungal Species ◽  
Plant Interactions ◽  
Related Gene ◽  
Wild Type ◽  
Cell Layers ◽  
Almost All

A tomato mutant with reduced mycorrhizal colonisation, rmc, confers resistance to almost all arbuscular mycorrhizal (AM) fungal species tested, although there is variation in colonisation of different root cell layers by different fungi and one species of AM fungus can colonise this mutant relatively normally. These variations indicate a high degree of specificity in relation to AM colonisation. We explored the possibility of specificity or otherwise in interactions between rmc and three non-AM root-infecting fungi, Rhizoctonia solani anastomosis groups (AG) 4 and AG8, and binucleate Rhizoctonia (BNR). There were no differences between the wild type tomato 76R and rmc in the speed or extent to which these fungi infected roots or caused disease. Infection by R. solani induced high levels of defence-related gene expression in both tomato genotypes relative to non-infected plants. In contrast, with BNR the expression of these genes was not induced or induced to a much lower extent than with R. solani. The expression of defence-related genes with these two non-AM fungi was very similar in the two plant genotypes. It was different from effects observed during colonisation by AM fungi, which enhanced expression of defence-related genes in rmc compared with the wild type tomato. The specificity and molecular mechanisms of rmc in control of AM colonisation are discussed.

scholarly journals Growth model for arbuscular mycorrhizal fungi

2007 ◽  
Vol 5 (24) ◽  
pp. 773-784 ◽  
Author(s):  
A Schnepf ◽  
T Roose ◽  
P Schweiger
Keyword(s):  
Mycorrhizal Fungi ◽  
Trifolium Subterraneum ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Fungal Species ◽  
Foraging Strategies ◽  
Fungal Mycelium ◽  
Hyphal Length ◽  
Solute Uptake ◽  
Acaulospora Laevis

In order to quantify the contribution of arbuscular mycorrhizal (AM) fungi to plant phosphorus nutrition, the development and extent of the external fungal mycelium and its nutrient uptake capacity are of particular importance. We develop and analyse a model of the growth of AM fungi associated with plant roots, suitable for describing mechanistically the effects of the fungi on solute uptake by plants. The model describes the development and distribution of the fungal mycelium in soil in terms of the creation and death of hyphae, tip–tip and tip–hypha anastomosis, and the nature of the root–fungus interface. It is calibrated and corroborated using published experimental data for hyphal length densities at different distances away from root surfaces. A good agreement between measured and simulated values was found for three fungal species with different morphologies: Scutellospora calospora (Nicol. & Gerd.) Walker & Sanders; Glomus sp.; and Acaulospora laevis Gerdemann & Trappe associated with Trifolium subterraneum L. The model and findings are expected to contribute to the quantification of the role of AM fungi in plant mineral nutrition and the interpretation of different foraging strategies among fungal species.

Functional diversity in fungi

1995 ◽  
Vol 73 (S1) ◽  
pp. 50-57 ◽  
Author(s):  
Steven L. Miller
Keyword(s):  
Functional Diversity ◽  
Fungal Diversity ◽  
Rapid Change ◽  
Fungal Species ◽  
Community Diversity ◽  
Taxonomic Information ◽  
Functional Perspective ◽  
Species Succession ◽  
Isolation Techniques ◽  
Resilient Communities

Diversity has various meanings but generally they reflect the variation in species assemblages within a community. Species establish interpopulation relationships that lead to stable community structure, and stable and resilient communities by definition contain a certain level of diversity. Communities with too great or too little diversity predictably undergo rapid change. Studies of fungal diversity have been limited by taxonomic and logistical difficulties in collecting and defining fungal individuals and species. Succession of fungi on substrates, seasonal fluctuations, inconsistent isolation techniques, and other considerations have also led to problems in assessing fungal species diversity. Although the problem has now been identified it is not likely that significant additions to our taxonomic knowledge will soon be useful in saving rapidly disappearing ecosystems. However, calculations of fungal diversity are not limited to taxonomic information. Several approaches provide measurements of functional diversity in situations where taxonomic information is poorly defined. These include using binary biochemical and physiological descriptors to characterize isolates, evaluating enzymatic capabilities for utilizing particular substrates and extracting DNA or RNA from the soil or other substrate and probing for genes that code for functional enzymes. Such functional approaches can provide timely information on the contribution of fungi to community diversity and toward the establishment of predictors of community stability. This paper reviews the problems in assessing fungal diversity and evaluates potential techniques for determining fungal diversity from a functional perspective. Key words: fungal, microbial diversity, biodiversity, ecology.

scholarly journals Arbuscular mycorrhiza and dark septate endophyte fungal associations of Oryza sativa L. under field condition: colonization features and their occurrence

2019 ◽  
Vol 6 (1) ◽  
pp. 63-70
Author(s):  
Kripamoy Chakraborty ◽  
Subam Banik ◽  
Atithi Debnath ◽  
Aparajita Roy Das ◽  
Ajay Krishna Saha ◽  
...  
Keyword(s):  
Oryza Sativa L ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Fungal Species ◽  
Chemical Fertilizers ◽  
Dark Septate Endophyte ◽  
Root Cortex ◽  
The Third ◽  
Fungal Associations ◽  
Local Farmers

The present study was aimed to study monthly colonization of arbuscular mycorrhizal (AM) and dark septate endophyte (DSE) fungal associations in rice. The presence of mycorrhizal structures in the roots confirms the colonization by AM fungi. The pattern of hyphae and arbuscules denotes Arum type of AM fungal morphology. The presence of dark coloured septate hyphae running frequently on the epidermal layer and in root cortex and the occurrence of microsclerotia marks the colonization by DSE fungi. The co-occurrence of both AM and DSE fungi ensure dual colonization by two distinct fungal groups. There was significant increase in arbuscules, vesicles and hyphal percentages from first to third month in both the samples collected from two sites. In the third month, AM colonization significantly higher in both the sites. DSE colonization percentages do not differ significantly in first to third month. A total of nine AM fungal species were recovered from two sites. This study is an effort to make aware the local farmers about the usefulness of these native AM mycobiota which can be a preferable choice over chemical fertilizers leading to ecofriendly organic farming.

scholarly journals Análisis de poblaciones de micorrizas en maíz (Zea mays) cultivado en suelos ácidos bajo diferentes tratamientos agronómicos

2004 ◽  
Vol 5 (1) ◽  
pp. 31 ◽  
Author(s):  
Ana María Serralde O. ◽  
María Margarita Ramírez G.
Keyword(s):  
Zea Mays ◽  
Organic Matter ◽  
Organic Matter Content ◽  
Acid Soils ◽  
Am Fungi ◽  
Matter Content ◽  
Chicken Manure ◽  
Control Treatment ◽  
Stepwise Multiple Regression ◽  
Soil Conditions

<p>Mediante el seguimiento de cultivos experimentales en suelos ácidos de los Llanos Orientales, durante un periodo de cinco años consecutivos (1997-2001), se evaluaron las poblaciones nativas de hongos micorrícicos arbusculares (MA) asociados con dos variedades de maíz: ICA- Sikuani V-110 y la variedad regional criolla Clavito, analizando su comportamiento bajo distintos tratamientos con abono orgánico (gallinaza), abono verde (Caupí) y testigo sin aplicación de materiales orgánicos, para un total de seis tratamientos. De 7.924 esporas analizadas se aislaron veinticuatro morfotipos identificados morfológica y molecularmente. Se determinó la relación de las condiciones del suelo (pH, los contenidos de materia orgánica, P, K, Al+++ y % saturación Al) con el comportamiento de las poblaciones de MA. Con la aplicación del Análisis de Regresión Múltiple (Stepwise), se obtuvieron coeficientes significativos (P≤ 0.001 y R2 ≥ 83) para todas las variables y se seleccionaron como variables predictivas principales el pH y la materia orgánica del suelo, que presentaron coeficientes significativos para cinco y cuatro de los siete modelos establecidos, respectivamente. La técnica molecular empleada basada en la Reacción en Cadena de la Polimerasa (PCR), con el uso de primers específicos, permitió la identificación confirmatoria de las esporas aisladas de los géneros <em>Glomus, Entrophospora </em>y <em>Gigaspora</em>. Además, mediante el uso de esta metodología se logró identificar la presencia del género <em>Glomus</em>en raíces de maíz altamente colonizadas.</p><p> </p><p><strong>Mycorrhiza populations analysis in corn (<em>Zea mays</em>) cultivated in acid soils under different agronomic treatments</strong></p><p>A study was carried out to evaluate the populations of native arbuscular mycorrhizas (AM) fungi on established crops on acid soils of the Colombian Eastern Plains, for a period of five years (1997-2001). Fungi spores were isolated from the crop-fungi association of two maize cultivars: ICASikuani V-110 and the regional cultivar Clavito. The mycorrhizal behavior was evaluated under six different organic fertilization treatments, which included green manure (cowpea), chicken manure and a control treatment (no application). From a total of 7924 spores, 24 different types of mycorrhiza were characterized using morphological and molecular analysis. The relation between soil conditions (pH, organic matter contents, P, K, Al+++ and % Al saturation) and AM fungi populations was analysed using a Stepwise Multiple Regression model. According to the regression coefficients obtained (P≤ 0.001 y R2 ≥ 0.83), soil pH and organic matter content were the independent variables that explained most of the variation observed in AM populations. The molecular methodology was based on the Polymerase Chain Reaction (PCR) and the use of specific primers allowed to identify spores from <em>Glomus</em>, <em>Entrophospora </em>and <em>Gigaspora</em>. This methodology also provided the identification of fungi from the <em>Glomus </em>genera in highly colonized maize roots.</p>

Effects of Funneliformis mosseae on the utilization of organic phosphorus in Camellia oleifera Abel

2021 ◽  
pp. 1-9
Author(s):  
Fei Wu ◽  
Zhengyun Li ◽  
Yulan Lin ◽  
Linping Zhang
Keyword(s):  
Acid Phosphatase ◽  
Am Fungi ◽  
Dry Mass ◽  
Camellia Oleifera ◽  
Organic P ◽  
Phosphatase Activities ◽  
Funneliformis Mosseae ◽  
External Hyphae ◽  
P Application ◽  
Mycorrhizal Plants

Arbuscular mycorrhizal (AM) fungi play an important role in the acquisition of phosphorus (P) by plants. The external hyphae of AM fungi function as an extension of plant roots and may downregulate related functions in the roots. It is not clear whether the ability of AM fungi to mineralize organic P affects root phosphatase activities. A pot experiment was conducted to investigate the effect of Funneliformis mosseae on soil organic P mineralization under phytate application and to explore root phosphatase activities, P uptake, and growth in Camellia oleifera Abel. The plants and their growth substrates were harvested 4 and 8 months after planting. The results showed that organic P application had no effect on the total dry mass of nonmycorrhizal plants, but differences in dry mass under P application were observed in mycorrhizal plants in both harvests. Inoculation with F. mosseae increased soil acid phosphatase, phytase, and alkaline phosphatase activities and reduced the soil organic P content. Mycorrhizal plants had higher root activity, shoot and root P contents and root acid phosphatase and phytase activities than nonmycorrhizal plants irrespective of organic P application. In conclusion, AM fungi enhanced the mineralization of soil organic P and positively affect root phosphatase activities.

scholarly journals Fungal Lipid Accumulation and Development of Mycelial Structures by Two Arbuscular Mycorrhizal Fungi

2003 ◽  
Vol 69 (11) ◽  
pp. 6762-6767 ◽  
Author(s):  
Ingrid M. van Aarle ◽  
Pål Axel Olsson
Keyword(s):  
Fatty Acid ◽  
Mycorrhizal Fungi ◽  
Glomus Intraradices ◽  
Neutral Lipids ◽  
Phospholipid Fatty Acid ◽  
Plantago Lanceolata ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Fungal Species ◽  
Opposite Pattern

ABSTRACT We monitored the development of intraradical and extraradical mycelia of the arbuscular mycorrhizal (AM) fungi Scutellospora calospora and Glomus intraradices when colonizing Plantago lanceolata. The occurrence of arbuscules (branched hyphal structures) and vesicles (lipid storage organs) was compared with the amounts of signature fatty acids. The fatty acid 16:1ω5 was used as a signature for both AM fungal phospholipids (membrane constituents) and neutral lipids (energy storage) in roots (intraradical mycelium) and in soil (extraradical mycelium). The formation of arbuscules and the accumulation of AM fungal phospholipids in intraradical mycelium followed each other closely in both fungal species. In contrast, the neutral lipids of G. intraradices increased continuously in the intraradical mycelium, while vesicle occurrence decreased after initial rapid root colonization by the fungus. S. calospora does not form vesicles and accumulated more neutral lipids in extraradical than in intraradical mycelium, while the opposite pattern was found for G. intraradices. G. intraradices allocated more of its lipids to storage than did S. calospora. Thus, within a species, the fatty acid 16:1ω5 is a good indicator for AM fungal development. The phospholipid fatty acid 16:1ω5 is especially suitable for indicating the frequency of arbuscules in the symbiosis. We propose that the ratio of neutral lipids to phospholipids is more important than is the presence of vesicles in determining the storage status of AM fungi.

Sign in / Sign up

Export Citation Format

Share Document