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.

scholarly journals Mycorrhizal fungi inoculation and phosphorus fertilizer on growth, essential oil production and nutrient uptake in peppermint (Mentha piperita L.)

2012 ◽  
Vol 14 (4) ◽  
pp. 692-699 ◽  
Author(s):  
M.C. Arango ◽  
M.F. Ruscitti ◽  
M.G. Ronco ◽  
J. Beltrano
Keyword(s):  
Essential Oil ◽  
Plant Growth ◽  
Arbuscular Mycorrhizal Fungi ◽  
Mycorrhizal Fungi ◽  
Glomus Intraradices ◽  
Arbuscular Mycorrhizal ◽  
Fungal Species ◽  
Mentha Piperita ◽  
Essential Oil Yield ◽  
Essential Oil Production

This study evaluated the effects of inoculation with the arbuscular mycorrhizal fungi Glomus mosseae, Glomus intraradices A4 and Glomus intraradices B1 and two phosphorus levels (10 and 40 mg kg-1) on root colonization, plant growth, nutrient uptake and essential oil content in Mentha piperita L. The experiment was carried out in a greenhouse, in 4x2 factorial arrangement, in completely randomized design. At sixty days after transplanting, the mycorrhizal plants had significantly higher fresh matter, dry matter and leaf area compared to non-mycorrhizal plants. The inoculation increased P, K and Ca levels in the shoot which were higher under 40 mg P kg-1 of soil. Plants grown with 40 mg P kg-1 soil increased the essential oil yield per plant by about 40-50% compared to those cultivated with 10 mg P kg-1, regardless of the mycorrhizal treatment. Among the studied fungal species, inoculation with G. intraradices A4 and a high level of P significantly increased plant growth and essential oil yield, compared to the other studied mycorrhizal fungal species. In conclusion, inoculation of arbuscular mycorrhizal fungi into peppermint plants is a feasible alternative to increase the essential oil production and reduce the use of fertilizers required to obtain economic production of peppermint under phosphorus-deficient soil condition.

scholarly journals Exogenous Carbon Magnifies Mycorrhizal Effects on Growth Behaviour and Sucrose Metabolism in Trifoliate Orange

2018 ◽  
Vol 46 (2) ◽  
pp. 365-370 ◽  
Author(s):  
Li TIAN ◽  
Yan LI ◽  
Qiang-Sheng WU
Keyword(s):  
Plant Growth ◽  
Root Morphology ◽  
Mycorrhizal Fungi ◽  
Arbuscular Mycorrhizal ◽  
Arbuscular Mycorrhizas ◽  
Sucrose Metabolism ◽  
Poncirus Trifoliata ◽  
Trifoliate Orange ◽  
Positive Effects ◽  
Mycorrhizal Plants

Arbuscular mycorrhizas (AMs) need the carbohydrates from host plants for its growth, whereas it is not clear whether exogenous carbon affects mycorrhizal roles. A two-chambered rootbox was divided into root + hyphae chamber and hyphae chamber (free of roots) by 37-μm nylon mesh, in which trifoliate orange (Poncirus trifoliata) seedlings and Funneliformis mosseae were applied into root + hyphae chamber, and exogenous 40 mmol/L fructose, glucose and sucrose was applied to hyphae chamber. Application of exogenous sugars dramatically elevated root mycorrhizal colonization. Sole arbuscular mycorrhizal fungi (AMF) inoculation significantly promoted plant growth and root morphology than non-AMF treatment. Mycorrhiza-improved plant growth and root modification could be enlarged by exogenous carbon, especially fructose. Exogenous carbon markedly increased root fructose, glucose and sucrose accumulation in mycorrhizal plants, especially sucrose. Exogenous fructose significantly reduced leaf and root sucrose synthase (SS) activity in synthesis direction and increased them in cleavage direction in AMF seedlings. Exogenous glucose and sucrose heavily elevated root SS activity of mycorrhizal seedlings in synthesis and cleavage direction and reduced leaf SS activity in synthesis direction. Leaf acid invertase (AI) and neutral invertase (NI) activities of mycorrhizal seedlings were decreased by exogenous carbon, except sucrose in NI. Exogenous fructose significantly increased root AI and NI activity in mycorrhizal plants. These results implied that mycorrhizal inoculation represented positive effects on plant growth, root morphology, and sucrose metabolism of trifoliate orange, which could be magnified further by exogenous carbon, especially fructose.

scholarly journals Nursery and Field Response of Olive Trees Inoculated with Two Arbuscular Mycorrhizal Fungi, Glomus intraradices and Glomus mosseae

2003 ◽  
Vol 128 (5) ◽  
pp. 767-775 ◽  
Author(s):  
Victoria Estaún ◽  
Amelia Camprubí ◽  
Cinta Calvet ◽  
Jorge Pinochet
Keyword(s):  
Plant Growth ◽  
Arbuscular Mycorrhizal Fungi ◽  
Crop Yield ◽  
Plant Development ◽  
Mycorrhizal Fungi ◽  
Glomus Intraradices ◽  
Arbuscular Mycorrhizal ◽  
Crop Productivity ◽  
Orchard Soil ◽  
Olive Trees

This paper reports the effects of inoculation with arbuscular mycorrhizal fungi on early plant development, field establishment, and crop yield of the olive (Olea europaea L.) cultivar Arbequina. The response of olive plants to the fungi Glomus intraradices (Schenck and Smith) and G. mosseae (Nicol.& Gerd.) Gerdemann & Trappe in different potting mixes was studied in two different nursery experiments. Pre-inoculation with selected arbuscular mycorrhizal fungi prior to transplanting in the field improved plant growth and crop yield up to three years after inoculation. G. intraradices was more efficient at promoting plant growth than both G. mosseae and the native endophytes present in the orchard soil. Inoculation at the time of transplanting enhanced early plant growth in all the field situations studied. Diminishing mycorrhizal effects over time resulted from natural colonization of noninoculated seedlings and related to the native arbuscular mycorrhizal (AM) fungal population of the field soil. Early inoculation of olive seedlings enhances early plant development and crop productivity of olive trees.

Arbuscular mycorrhizas enhance plant interception of leached nutrients

2011 ◽  
Vol 38 (3) ◽  
pp. 219 ◽  
Author(s):  
Hamid Reza Asghari ◽  
Timothy Richard Cavagnaro
Keyword(s):  
Plant Growth ◽  
Mycorrhizal Fungi ◽  
Arbuscular Mycorrhizal ◽  
Root Systems ◽  
Arbuscular Mycorrhizas ◽  
Nutrient Depletion ◽  
Mycorrhizal Root ◽  
Growth And Nutrition ◽  
Mycorrhizal Plants ◽  
Plant Available P

Arbuscular mycorrhizal fungi (AMF) can increase plant growth and nutrition. However, their capacity to reduce the leaching of nutrients through the soil profile is less well understood. Here we present results of an experiment in which the effects of forming arbuscular mycorrhizas (AM) on plant growth and nutrition, nutrient depletion from soil, and nutrient leaching, were investigated in microcosms containing the grass Phalaris aquatica L. Mycorrhizal and non-mycorrhizal plants were grown in a mixture of riparian soil and sand under glasshouse conditions. The formation of AM by P. aquatica significantly increased plant growth and nutrient uptake. Lower levels of NO3–, NH4+ and plant available P in both soil and leachate were observed in columns containing mycorrhizal root systems. These differences in nutrient interception were proportionally greater than the increase in root biomass of the mycorrhizal plants, compared with their non-mycorrhizal counterparts. Taken together, these data indicate that mycorrhizal root systems have an important, but previously little considered, role to play reducing the net loss of nutrients via leaching.

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.

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 Microbial Inoculants Modulate Physiological Behaviour Of Troyer Citrange Under Drought Stress

2021 ◽  
Vol 50 (3) ◽  
pp. 467-474
Author(s):  
Prananath Barman ◽  
Sanjay Kumar Singh
Keyword(s):  
Plant Growth ◽  
Mycorrhizal Fungi ◽  
Glomus Intraradices ◽  
Arbuscular Mycorrhizal ◽  
Poncirus Trifoliata ◽  
Plant Growth Promoting Bacteria ◽  
Antioxidant Metabolites ◽  
Plant Growth Promoting ◽  
Scavenging Enzymes ◽  
Troyer Citrange

A study was undertaken with Troyer citrange (Citrus sinensis × Poncirus trifoliata), the rootstock of citrus, to elucidate the interaction effects of arbuscular mycorrhizal fungi and plant-growth-promoting bacteria on plant physiology under both ample watered and water stress conditions. The result exhibited significant influence of Glomus intraradices and phosphorus solubilising bacteria (PSB) (mixture of Bacillus subtilis and B. megatherium) on plant growth due to root-fungus-bacteria interaction leading to reduced accumulation of reactive oxygen species, production of antioxidant metabolites, higher anti-scavenging enzymes and higher acquisition of plant nutrients, besides enhancing rhizosphere microbial activity. Thus, Troyer citrange could be co-inoculated with G. intraradices and PSB during propagation for healthy growth of the seedlings thereby pre-ponding the budding and subsequent establishment of composite plants under field conditions. Bangladesh J. Bot. 50(3): 467-474, 2021 (September)

scholarly journals Density dependence and interspecific interactions between arbuscular mycorrhizal fungi mediated plant growth, glomalin production, and sporulation

2007 ◽  
Vol 85 (1) ◽  
pp. 63-75 ◽  
Author(s):  
Helen A. Violi ◽  
Kathleen K. Treseder ◽  
John A. Menge ◽  
Sara F. Wright ◽  
Carol J. Lovatt
Keyword(s):  
Plant Growth ◽  
Arbuscular Mycorrhizal Fungi ◽  
Mycorrhizal Fungi ◽  
Glomus Intraradices ◽  
Negative Impact ◽  
Interspecific Interactions ◽  
Arbuscular Mycorrhizal ◽  
Persea Americana ◽  
Available Phosphorus ◽  
Functional Differences

Functional differences between the arbuscular mycorrhizal fungi Glomus intraradices Schenk and Smith and Scutellospora heterogama Nicolson and Gerdemann as they affect Persea americana Mill. growth, glomalin, and fungal sporulation were examined by varying the composition and relative density of the two fungi over a gradient of available phosphorus (P). The plant benefit provided by these mycorrhizal fungi together was not a simple sum of the benefits provided by each fungus in monoculture at its respective density. Glomus intraradices and S. heterogama interacted to reduce plant growth rates and uptake of P, zinc (Zn), and iron (Fe) relative to plants inoculated with G. intraradices alone. Thus, for plant growth and nutrition, no evidence for functional complementarity was detected. Instead, interspecific interactions between mycorrhizal fungi resulted in a negative feedback on plants. Under high available P, fungal functional differences were reduced, whereas the overall difference between mycorrhizal and nonmycorrhizal plants was greatest. Overall, S. heterogama produced more glomalin than did G. intraradices. In a mixture, sporulation of the inferior mutualist, S. heterogama, was lower than that of the superior mutualist, G. intraradices, but interspecific fungal interactions increased the sporulation of both fungi. Despite the negative impact of interspecific interactions on plants, supporting multiple arbuscular mycorrhizal fungi was of greater benefit than being nonmycorrhizal.

scholarly journals Plant Growth-Promoting Microorganisms in Coffee Production: From Isolation to Field Application

Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1531
Author(s):  
Narcisa Urgiles-Gómez ◽  
María Eugenia Avila-Salem ◽  
Paúl Loján ◽  
Max Encalada ◽  
Leslye Hurtado ◽  
...  
Keyword(s):  
Plant Growth ◽  
Mycorrhizal Fungi ◽  
Arbuscular Mycorrhizal ◽  
Plant Growth Promoting Rhizobacteria ◽  
Agroforestry Systems ◽  
Field Application ◽  
Coffee Production ◽  
Coffee Agroforestry ◽  
Plant Growth Promoting ◽  
Growth Promoting

Coffee is an important, high-value crop because its roasted beans are used to produce popular beverages that are consumed worldwide. Coffee plantations exist in over 70 countries and constitute the main economic activity of approximately 125 million people. Currently, there is global concern regarding the excessive use of agrochemicals and pesticides in agriculture, including coffee crops. This situation has motivated researchers, administrators, and farmers to seek ecologically friendly alternatives to decrease the use of synthetic fertilizers and pesticides. In the last decades, multiple studies of the rhizosphere, at the chemical, physical and biological levels, have improved our understanding of the importance of beneficial microorganisms to plant health and growth. This review aims to summarize the state of the use of plant growth-promoting microorganisms (PGPM) in coffee production, where the most extensively studied microorganisms are beneficial plant growth-promoting rhizobacteria (PGPR) and arbuscular mycorrhizal fungi (AMF). This review also contains information on PGPM, in regard to plantations at different latitudes, isolation techniques, mass multiplication, formulation methods, and the application of PGPM in nurseries, monoculture, and coffee agroforestry systems. Finally, this review focuses on relevant research performed during the last decade that can help us improve sustainable coffee production.

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