scholarly journals Temperature stress in arbuscular mycorrhizal fungi: a test for adaptation to soil temperature in three isolates of Funneliformis mosseae from different climates

2012 ◽  
Vol 21 (1) ◽  
pp. 2-11 ◽  
Author(s):  
Mayra E. Gavito ◽  
Concepción Azcón–Aguilar

Climate change may impose stimulations or constraints on the mycorrhizal symbiosis by increasing and fluctuating temperatures. We conducted a study to compare the soil temperature response curves (6, 12, 18, and 24 oC) of three isolates of Funneliformis mosseae from different regions and climates (Finland, Denmark, Spain), to test if the isolates from cold environments were able to grow better at lower temperatures and the isolates from warmer environments grew better at higher temperatures. The results provided clear evidence suggesting no adaptation to soil temperature in these AMF isolates. All isolates showed reduced development and very little external mycelium growth at 6 and 12 oC, and similar increased development with increasing soil temperature.  These results suggest that AMF have a narrow window to develop in cold regions where temperatures below 15 oC prevail.


2021 ◽  
Vol 51 ◽  
pp. e1304
Author(s):  
Yazmín Carreón-Abud ◽  
Mayra E. Gavito

Background: The elements that are toxic to arbuscular mycorrhizal fungi (AMF) and soil microorganisms, and the levels at which they affect them, are poorly known. Objective: To quantify the effects of: 1) aluminum added to the soil (0, 50 and 100 mg kg-1) and 2) inoculation with AMF (two isolates without prior exposure to aluminum, Acaulospora delicata and Gigaspora margarita, the native AMF community of a soil contaminated with Al, and a control without AMF) on the development of AMF mycelium and the hyphosphere-associated microbiota. Methods: A system with two compartments was used, a central compartment in which maize was sown and AMF were inoculated and a side compartment without root passage, where only the external mycelium was exposed to the different concentrations of Al. AMF external mycelium exposed to Al was quantified with the fatty-acid biomar-ker 16:1w5. Results and conclusions: Al concentrations up to 100 mg kg-1, controlling the pH of the soil, did not alter mycelium growth of any of the inoculated HMA either in the soil or in the roots. Aluminum added up to 100 mg kg-1 did not have a direct toxic effect on the growth of AMF mycelium and the hyphosphere-associated microbiota.



2018 ◽  
Author(s):  
Ivan D. Mateus ◽  
Frédéric G. Masclaux ◽  
Consolée Aletti ◽  
Edward C. Rojas ◽  
Romain Savary ◽  
...  

AbstractArbuscular mycorrhizal fungi (AMF) impact plant growth and are a major driver of plant diversity and productivity. We quantified the contribution of intra-specific genetic variability in cassava (Manihot esculenta) and Rhizophagus irregularis to gene reprogramming in symbioses using dual RNA-sequencing. A large number of cassava genes exhibited altered transcriptional responses to the fungus but transcription of most of these plant genes (72%) responded in a different direction or magnitude depending on the plant genotype. Two AMF isolates displayed large differences in their transcription, but the direction and magnitude of the transcriptional responses for a large number of these genes was also strongly influenced by the genotype of the plant host. This indicates that unlike the highly conserved plant genes necessary for the symbiosis establishment, plant and fungal gene transcriptional responses are not conserved and are greatly influenced by plant and fungal genetic differences, even at the within-species level. The transcriptional variability detected allowed us to identify an extensive gene network showing the interplay in plant-fungal reprogramming in the symbiosis. Key genes illustrated that the two organisms jointly program their cytoskeleton organisation during growth of the fungus inside roots. Our study reveals that plant and fungal genetic variation plays a strong role in shaping the genetic reprograming in response to symbiosis, indicating considerable genotype x genotype interactions in the mycorrhizal symbiosis. Such variation needs to be considered in order to understand the molecular mechanisms between AMF and their plant hosts in natural communities.



2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Li Cui ◽  
Feng Guo ◽  
Jialei Zhang ◽  
Sha Yang ◽  
JingJing Meng ◽  
...  

Abstract Peanut yield is severely affected by exchangeable calcium ion (Ca2+) deficiency in the soil. Arbuscular mycorrhizal (AM) symbiosis increases the absorption of Ca2+ for host plants. Here, we analyzed the physiological and transcriptional changes in the roots of Arachis hypogaea L. colonized by Funneliformismosseae under Ca2+-deficient and -sufficient conditions. The results showed that exogenous Ca2+ application increased arbuscular mycorrhizal fungi (AMF) colonization, plant dry weight, and Ca content of AM plants. Simultaneously, transcriptome analysis showed that Ca2+ application further induced 74.5% of differentially expressed gene transcripts in roots of AM peanut seedlings. These genes are involved in AM symbiosis development, hormone biosynthesis and signal transduction, and carotenoid and flavonoid biosynthesis. The transcripts of AM-specific marker genes in AM plants with Ca2+ deprivation were further up-regulated by Ca2+ application. Gibberellic acid (GA3) and flavonoid contents were higher in roots of AM- and Ca2+-treated plants, but salicylic acid (SA) and carotenoid contents specifically increased in roots of the AM plants. Thus, these results suggest that the synergy of AM symbiosis and Ca2+ improves plant growth due to the shared GA- and flavonoid-mediated pathway, whereas SA and carotenoid biosynthesis in peanut roots are specific to AM symbiosis.



2012 ◽  
Vol 518-523 ◽  
pp. 5381-5384
Author(s):  
Song Mei Shi ◽  
Bo Tu ◽  
Dai Jun Liu ◽  
Xiao Hong Yang

Physic nut (Jatropha curcas Linn., Euphorbiaceae) is one of the hottest biomass energy plant studied by scientists. This paper first reviewed the symbiosis relationship between physic nut and arbuscular mycorrhizal fungi. The researches have showed that diversity of arbuscular mycorrhizal fungi (AMF) exists around the rhizosphere of physic nut. The AMF hyphae colonize root tips of physic nut to develop arbuscular mycorrhizae. The construction of mycorrhizal symbiosis relationship improves the nutritional absorption, promotes the growth and development of seedlings, and enhance the stress tolerance capacity of physic nut. This paper also displays a prospect for mycorrhizal physic nut research in the future, such as mycorrhizal system, the molecular mechanism for stress resistance and gene engineering. As an important resource of biomass energy, mycorrhizal physic nut has a huge exploitation potential and practical value.



Botany ◽  
2008 ◽  
Vol 86 (9) ◽  
pp. 1009-1019 ◽  
Author(s):  
Maria Manjarrez ◽  
F. Andrew Smith ◽  
Petra Marschner ◽  
Sally E. Smith

For the first time, the phenotypes formed in the reduced mycorrhizal colonization (rmc) Solanum lycopersicum  L. (tomato) mutant with different arbuscular mycorrhizal (AM) fungi were used to explore the potential of different fungal structures to support development of external fungal mycelium and spores. The life cycle of AM fungi with rmc was followed for up to 24 weeks. Results showed that production of external mycelium was slight and transitory for those fungi that did not penetrate the roots of rmc (Pen–) ( Glomus intraradices DAOM181602 and Glomus etunicatum ). For fungi that penetrated the root epidermis and hypodermis (Coi–, Glomus coronatum and Scutellospora calospora ) the mycelium produced varied in size, but was always smaller than with the wild-type 76R. Spores were formed by these fungi with 76R but not with rmc. The only fungus forming a Myc+ phenotype with rmc, G. intraradices WFVAM23, produced as much mycelium with rmc as with 76R. We observed lipid accumulation in hyphae and vesicles in both plant genotypes with this fungus. Mature spores were formed with 76R. However, with rmc, spores remained small and (presumably) immature for up to 24 weeks. We conclude that significant carbon transfer from plant to fungus can occur in Coi– interactions with rmc in which no cortical colonization occurs. We speculate that both carbon transfer and root signals are required for mature spores to be produced.



2013 ◽  
Vol 281 ◽  
pp. 664-669
Author(s):  
En Wu ◽  
Guo Rong Xin ◽  
Kazuo Sugawara

With the aggravation of volcanic ash Andosol acidification, artificial forage grass Dactylis glomerata L. gradual degradation, replaced by weed plant Anthoxanthum odoratum L., but the mechanism is unclear. In order to reveal the mechanism, this study used Andosol soil as matrix, explored the effects of arbuscular mycorrhizal fungi on D. glomerata and A. odoratum at different pH gradients in acidic Andosol by glasshouse experiment. The results show that the mycorrhizal colonization of D. glomerata strongly affected by soil pH, but the A. odoratum was not yet. The mycorrhizal symbiosis led to a positive effect on growth and P uptake of D. glomerata and A. odoratum. Consider to invasion and expansion of A. odoratum in severity acidic pasture is origin of this specificity on arbuscular mycorrhizal symbiosis in acidic soil other than D. glomerata.



2021 ◽  
pp. 339-355
Author(s):  
Michel Ruiz Sánchez ◽  
Juan Adriano Cabrera Rodríguez ◽  
José M. Del'Anico Rodríguez ◽  
Yaumara Muñoz Hernández ◽  
Ricardo Aroca Álvarez ◽  
...  

Introduction. The water deficit negatively affects rice plants and limits their productivity. Arbuscular mycorrhizal symbiosis has been shown to improve rice productivity in drought conditions. Objective. To propose a new categorization for the state of water stress of rice plants inoculated (AM) or not with arbuscular mycorrhizal fungi (nonAM) and exposed to water deficit (D) during the vegetative phase. Materials and methods. The experiment was carried out under controlled greenhouse conditions during the years 2009 and 2010 at the Zaidín Experimental Station, Granada, Spain. The rice transplantation was carried out fourteen days after germination to pots with a 5 cm water sheet and at 30, 40, or 50 days after transplantation (DAT) they were subjected to water deficit during a period of 15 days, at which time the water sheet was restored. The control treatment was maintained throughout the cycle under flood conditions (ww). Evaluations were performed at 45, 55, 65 DAT and after recovery at 122 DAT. The harvest was carried out at 147 DAT. Results. The reduction in water supply demonstrated water stress in the plants, manifested by the decrease in the water potential of the leaves. Arbuscular mycorrhizal symbiosis always favored the water status of the plant. Four categories of water status of plants were proposed taking into account water potentials and agricultural yield: no stress (≥-0.67 MPa); light stress (<-0.67 to -1.20 MPa); moderate stress (<-1.20 to -1.60 MPa), and severe stress (<-1.60 MPa). Conclusion. The categorization of stress due to the water deficit is a tool of high scientific value for the specific case of rice, since this plant has the capacity to adapt to tolerate the presence of a sheet of water throughout its biological cycle and is highly susceptible to water deficit.



Author(s):  
Poonam Jaiswal ◽  
Suresh Singh Rajpurohit

Mycorrhizal symbiosis occurs between arbuscular mycorrhizal fungi and most of the vascular plants and is a highly evolved mutually beneficial relationship occurring within the rhizosphere of the vascular plants. The host plants are directly conferred benefits to the growth and development due to this symbiotic association. Their function ranges from stress alleviation to bioremediation in polluted soils besides their importance in the restoration of degraded wastelands. In this investigation colonization percentage and spore density of VAM fungi were studied in industrial waste dump sites and soil having natural vegetation. Industrial waste dump sites are characteristically dominated by Glomus. Mycorrhizal association and spore formation potential of AMF was significantly lowered in soil disturbed due to industrial waste dumping.



2017 ◽  
Author(s):  
M. Rosario Ramirez-Flores ◽  
Ruben Rellan-Alvarez ◽  
Barbara Wozniak ◽  
Mesfin-Nigussie Gebreselassie ◽  
Iver Jakobsen ◽  
...  

AbstractArbuscular mycorrhizal symbiosis is an ancient interaction between plants and fungi of the phylum Glomeromycota. In exchange for photosynthetically fixed carbon, the fungus provides the plant host with greater access to soil nutrients via an extensive network of root-external hyphae. Here, to determine the impact of the symbiosis on the host ionome, the concentration of nineteen elements was determined in the roots and leaves of a panel of thirty maize varieties, grown under phosphorus limiting conditions, with, or without, inoculation with the fungus Funneliformis mosseae. Although the most recognized benefit of the symbiosis to the host plant is greater access to soil phosphorus, the concentration of a number of other elements responded significantly to inoculation across the panel as a whole. In addition, variety-specific effects indicated the importance of plant genotype to the response. Clusters of elements were identified that varied in a coordinated manner across genotypes, and that were maintained between non-inoculated and inoculated plants.AbbreviationsNCnon-colonizedMmycorrhizalSDWshoot dry weightICP-MSinductively coupled plasma mass spectrometryPCprincipal component



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