scholarly journals Symbiont switching and alternative resource acquisition strategies drive mutualism breakdown

2018 ◽  
Author(s):  
Gijsbert DA Werner ◽  
Johannes HC Cornelissen ◽  
William K Cornwell ◽  
Nadejda A Soudzilovskaia ◽  
Jens Kattge ◽  
...  
Keyword(s):  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Resource Acquisition ◽  
Comparative Approach ◽  
Cooperative Interactions ◽  
Evolutionary Innovation ◽  
Acquisition Strategies ◽  
Root Symbionts ◽  
Alternative Resource ◽  
Mutualism Breakdown

AbstractCooperative interactions among species, termed mutualisms, have played a crucial role in the evolution of life on Earth. However, despite key potential benefits to partners, there are many cases where two species cease to cooperate, and mutualisms break down. What factors drive the evolutionary breakdown of mutualism? We examined the pathways towards breakdowns of the mutualism between plants and arbuscular mycorrhizal (AM) fungi. Using a comparative approach, we identify ~25 independent cases of complete mutualism breakdown across global seed plants. We found that breakdown of cooperation was only stable when host plants either: (i) partner with other root symbionts or (ii) evolve alternative resource acquisition strategies. Our results suggest that key mutualistic services are only permanently lost if hosts evolve alternative symbioses or adaptations.Significance StatementCooperative interactions among species – mutualisms – are major sources of evolutionary innovation. However, despite their importance, two species that formerly cooperated sometimes cease their partnership. Why do mutualisms breakdown? We asked this question in the partnership between arbuscular mycorrhizal (AM) fungi and their plant hosts, one of the most ancient mutualisms. We analyse two potential trajectories towards evolutionary breakdown of their cooperation, symbiont switching and mutualism abandonment. We find evidence that plants stop interacting with AM fungi when they switch to other microbial mutualists or when they evolve alternative strategies to extract nutrients from the environment. Our results show vital cooperative interactions can be lost - but only if successful alternatives evolve.

scholarly journals Symbiont switching and alternative resource acquisition strategies drive mutualism breakdown

2018 ◽  
Vol 115 (20) ◽  
pp. 5229-5234 ◽  
Author(s):  
Gijsbert D. A. Werner ◽  
Johannes H. C. Cornelissen ◽  
William K. Cornwell ◽  
Nadejda A. Soudzilovskaia ◽  
Jens Kattge ◽  
...  
Keyword(s):  
Mycorrhizal Fungi ◽  
Arbuscular Mycorrhizal ◽  
Resource Acquisition ◽  
Comparative Approach ◽  
Acquisition Strategies ◽  
Potential Benefits ◽  
Root Symbionts ◽  
Life On Earth ◽  
Alternative Resource ◽  
Mutualism Breakdown

Cooperative interactions among species, termed mutualisms, have played a crucial role in the evolution of life on Earth. However, despite key potential benefits to partners, there are many cases in which two species cease to cooperate and mutualisms break down. What factors drive the evolutionary breakdown of mutualism? We examined the pathways toward breakdowns of the mutualism between plants and arbuscular mycorrhizal fungi. By using a comparative approach, we identify ∼25 independent cases of complete mutualism breakdown across global seed plants. We found that breakdown of cooperation was only stable when host plants (i) partner with other root symbionts or (ii) evolve alternative resource acquisition strategies. Our results suggest that key mutualistic services are only permanently lost if hosts evolve alternative symbioses or adaptations.

scholarly journals Arbuscular Mycorrhizal Fungal Communities in the Soils of Desert Habitats

2021 ◽  
Vol 9 (2) ◽  
pp. 229
Author(s):  
Martti Vasar ◽  
John Davison ◽  
Siim-Kaarel Sepp ◽  
Maarja Öpik ◽  
Mari Moora ◽  
...  
Keyword(s):  
Plant Root ◽  
Significant Proportion ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Illumina Miseq ◽  
Desert Ecosystems ◽  
Fungal Dna ◽  
Root Symbionts ◽  
Arbuscular Mycorrhizal Fungal

Deserts cover a significant proportion of the Earth’s surface and continue to expand as a consequence of climate change. Mutualistic arbuscular mycorrhizal (AM) fungi are functionally important plant root symbionts, and may be particularly important in drought stressed systems such as deserts. Here we provide a first molecular characterization of the AM fungi occurring in several desert ecosystems worldwide. We sequenced AM fungal DNA from soil samples collected from deserts in six different regions of the globe using the primer pair WANDA-AML2 with Illumina MiSeq. We recorded altogether 50 AM fungal phylotypes. Glomeraceae was the most common family, while Claroideoglomeraceae, Diversisporaceae and Acaulosporaceae were represented with lower frequency and abundance. The most diverse site, with 35 virtual taxa (VT), was in the Israeli Negev desert. Sites representing harsh conditions yielded relatively few reads and low richness estimates, for example, a Saudi Arabian desert site where only three Diversispora VT were recorded. The AM fungal taxa recorded in the desert soils are mostly geographically and ecologically widespread. However, in four sites out of six, communities comprised more desert-affiliated taxa (according to the MaarjAM database) than expected at random. AM fungal VT present in samples were phylogenetically clustered compared with the global taxon pool, suggesting that nonrandom assembly processes, notably habitat filtering, may have shaped desert fungal assemblages.

scholarly journals Use of the Signature Fatty Acid 16:1ω5 as a Tool to Determine the Distribution of Arbuscular Mycorrhizal Fungi in Soil

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Christopher Ngosong ◽  
Elke Gabriel ◽  
Liliane Ruess
Keyword(s):  
Fatty Acid ◽  
Mycorrhizal Fungi ◽  
Plant Root ◽  
Background Level ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Biomass Estimation ◽  
Lipid Fatty Acid ◽  
Neutral Lipid Fatty Acid ◽  
Root Symbionts

Biomass estimation of arbuscular mycorrhiza (AM) fungi, widespread plant root symbionts, commonly employs lipid biomarkers, predominantly the fatty acid 16:1ω5. We briefly reviewed the application of this signature fatty acid, followed by a case study comparing biochemical markers with microscopic techniques in an arable soil following a change to AM non-host plants after 27 years of continuous host crops, that is, two successive cropping seasons with wheat followed by amaranth. After switching to the non-host amaranth, spore biomass estimated by the neutral lipid fatty acid (NLFA) 16:1ω5 decreased to almost nil, whereas microscopic spore counts decreased by about 50% only. In contrast, AM hyphal biomass assessed by the phospholipid (PLFA) 16:1ω5 was greater under amaranth than wheat. The application of PLFA 16:1ω5 as biomarker was hampered by background level derived from bacteria, and further enhanced by its incorporation from degrading spores used as microbial resource. Meanwhile, biochemical and morphological assessments showed negative correlation for spores and none for hyphal biomass. In conclusion, the NLFA 16:1ω5 appears to be a feasible indicator for AM fungi of the Glomales group in the complex field soils, whereas the use of PLFA 16:1ω5 for hyphae is unsuitable and should be restricted to controlled laboratory studies.

scholarly journals Photosynthetic Traits and Nitrogen Uptake in Crops: Which Is the Role of Arbuscular Mycorrhizal Fungi?

Plants ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1105
Author(s):  
Raffaella Balestrini ◽  
Cecilia Brunetti ◽  
Walter Chitarra ◽  
Luca Nerva
Keyword(s):  
Mycorrhizal Fungi ◽  
Extreme Temperature ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Fruit Trees ◽  
Growth Stress ◽  
Nitrogen Acquisition ◽  
Positive Effects ◽  
Root Symbionts ◽  
Photosynthetic Traits

Arbuscular mycorrhizal (AM) fungi are root symbionts that provide mineral nutrients to the host plant in exchange for carbon compounds. AM fungi positively affect several aspects of plant life, improving nutrition and leading to a better growth, stress tolerance, and disease resistance and they interact with most crop plants such as cereals, horticultural species, and fruit trees. For this reason, they receive expanding attention for the potential use in sustainable and climate-smart agriculture context. Although several positive effects have been reported on photosynthetic traits in host plants, showing improved performances under abiotic stresses such as drought, salinity and extreme temperature, the involved mechanisms are still to be fully discovered. In this review, some controversy aspects related to AM symbiosis and photosynthesis performances will be discussed, with a specific focus on nitrogen acquisition-mediated by AM fungi.

scholarly journals Glomus intraradices (N.C. Schenck & G.S. Sm.) C. Walker & A. Schuessle enhances nutrients uptake, chlorophyll and essential oil contents and composition in Anethum graveolens L.

2018 ◽  
Vol 111 (2) ◽  
pp. 303
Author(s):  
Weria WEISANY
Keyword(s):  
Chlorophyll Content ◽  
Glomus Intraradices ◽  
Plant Biomass ◽  
Plant Root ◽  
Block Design ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Anethum Graveolens ◽  
Nutrients Uptake ◽  
Root Symbionts

<p class="Normale1">Arbuscular mycorrhizal (AM) fungi are plant-root symbionts whose application in agriculture has been proven its efficiency. However, their application in medicinal plants and their impact on accumulation of essential oils (EO) is still limited. In order to investigate the effect of AM fungi (<em>Glomus intraradices </em>N.C. Schenck &amp; G.S. Sm.) C. Walker &amp; A. Schuessle) on nutrients uptake, biomass production, yield components, chlorophyll content, and EO content and composition in dill (<em>Anethum graveolens</em> L.), a field experiment was conducted as randomized complete block design with three replications. This medicinal plant was grown under AM fungi colonization and non-colonization treatments. Plant inoculation by mycorrhiza increased aerial tissues P and Fe concentrations. However, K, Ca, and Zn concentrations were not affected by AM colonization. The plants inoculated with AM significantly increased plant biomass, chlorophyll content, and EO content by 363 g m<sup>−2</sup>, 11.83 SPAD and 0.683 % in comparison with non-inoculated plants, respectively. Changes in EO composition were found in AM-colonized dill plants. The contents of myristicin, dill-ether and N-dihydrocarvone increased in EO obtained from AM-colonized plants, while AM colonization resulted in a lesser content of α-pinene, α-phellandrene, limonene, and β-phellandrene.</p>

scholarly journals Fungicides With Contrasting Mode of Action Differentially Affect Hyphal Healing Mechanism in Gigaspora sp. and Rhizophagus irregularis

2021 ◽  
Vol 12 ◽  
Author(s):  
Victor Hugo Rodriguez-Morelos ◽  
Maryline Calonne-Salmon ◽  
Vincent Bremhorst ◽  
Mónica Garcés-Ruiz ◽  
Stéphane Declerck
Keyword(s):  
Fungal Pathogens ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Rhizophagus Irregularis ◽  
High Concentration ◽  
Bright Field ◽  
Conventional Agriculture ◽  
Root Symbionts ◽  
The Impact

Fungicides are widely used in conventional agriculture to control fungal diseases, but may also affect non-target microorganisms such as arbuscular mycorrhizal (AM) fungi. These root symbionts develop extended mycelial networks within the soil via mechanisms such as anastomosis that indistinctly concerns intact and damaged hyphae, the latter being named hyphal healing mechanism (HHM). The HHM differs between Glomeraceae and Gigasporaceae. However, the effects of fungicides on this mechanism in unknown. Here, the impact of azoxystrobin, pencycuron, flutolanil, and fenpropimorph at 0.02 and 2 mg L–1 were tested in vitro on the HHM of Gigaspora sp. MUCL 52331 and Rhizophagus irregularis MUCL 41833, and repair events visualized carefully under a dissecting bright-field light microscope. Azoxystrobin was the more detrimental for both AM fungi at 2 mg L–1, while fenpropimorph impacted only R. irregularis (stimulating at low and inhibiting at high concentration). Conversely, flutolanil and pencycuron did not impact any of the two AM fungi. The mechanisms involved remains to be elucidated, but perturbation in the still-to-be firmly demonstrated spitzenkörper or in sterols content as well as a process of hormesis are possible avenues that deserve to be explored in view of a rationale management of chemicals to control fungal pathogens without harming the beneficial AM fungi.

scholarly journals Arbuscular Mycorrhizal (AM) Fungi as a Tool for Sustainable Agricultural System

2020 ◽  
Author(s):  
Kavita Chahal ◽  
Vaishali Gupta ◽  
Naveen Kumar Verma ◽  
Anand Chaurasia ◽  
Babita Rana
Keyword(s):  
Abiotic Stresses ◽  
Arbuscular Mycorrhizae ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Crop Productivity ◽  
Growth And Yield ◽  
Agricultural System ◽  
Vesicular Arbuscular ◽  
Root Symbionts

A sustainable agriculture is a type of agriculture that focuses on producing long-term crops and livestock without having any adverse effect on the environment. However, agricultural malpractices like excessive use of chemical fertilizers and pesticides, as well as climate change have aggravated the effects of biotic and abiotic stresses on crop productivity. These led to the degradation of ecosystem, leaving bad impacts on the soil qualities and water body environment. As an alternative to the rising agricultural energy, the use of Vesicular– Arbuscular Mycorrhizae (AM) may be a better option. Being natural root symbionts, AM provide essential inorganic nutrients to host plants, thereby improving its growth and yield even under stressed conditions. AM fungi can also potentially strengthen the adaptability of a plant to the changing environment, as a bio-fertilizer. The chapter provides a comprehensive up-to-date knowledge on AM fungi as a tool for sustainable agricultural system. Thus, further research focusing on the AM -mediated promotion of crop quality and productivity is needed.

scholarly journals Tracking of Zinc Ferrite Nanoparticle Effects on Pea (Pisum sativum L.) Plant Growth, Pigments, Mineral Content and Arbuscular Mycorrhizal Colonization

Plants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 583
Author(s):  
Reda E. Abdelhameed ◽  
Nagwa I. Abu-Elsaad ◽  
Arafat Abdel Hamed Abdel Latef ◽  
Rabab A. Metwally
Keyword(s):  
Pisum Sativum ◽  
Plant Growth ◽  
Zinc Ferrite ◽  
Crop Improvement ◽  
Nanocrystalline Structure ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Transmission Electron ◽  
Agricultural Applications ◽  
The Impact

Important gaps in knowledge remain regarding the potential of nanoparticles (NPs) for plants, particularly the existence of helpful microorganisms, for instance, arbuscular mycorrhizal (AM) fungi present in the soil. Hence, more profound studies are required to distinguish the impact of NPs on plant growth inoculated with AM fungi and their role in NP uptake to develop smart nanotechnology implementations in crop improvement. Zinc ferrite (ZnFe2O4) NPs are prepared via the citrate technique and defined by X-ray diffraction (XRD) as well as transmission electron microscopy for several physical properties. The analysis of the XRD pattern confirmed the creation of a nanocrystalline structure with a crystallite size equal to 25.4 nm. The effects of ZnFe2O4 NP on AM fungi, growth and pigment content as well as nutrient uptake of pea (Pisum sativum) plants were assessed. ZnFe2O4 NP application caused a slight decrease in root colonization. However, its application showed an augmentation of 74.36% and 91.89% in AM pea plant shoots and roots’ fresh weights, respectively, compared to the control. Moreover, the synthesized ZnFe2O4 NP uptake by plant roots and their contents were enhanced by AM fungi. These findings suggest the safe use of ZnFe2O4 NPs in nano-agricultural applications for plant development with AM fungi.

scholarly journals Arbuscular mycorrhizal symbiosis facilitates apricot seedling (Prunus sibirica L.) growth and photosynthesis in northwest China

2021 ◽  
Author(s):  
Yinli Bi ◽  
Linlin Xie ◽  
Zhigang Wang ◽  
Kun Wang ◽  
Wenwen Liu ◽  
...  
Keyword(s):  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Northwest China ◽  
Shaanxi Province ◽  
Mycorrhizal Symbiosis ◽  
Seedling Physiology ◽  
Grassland Ecosystems ◽  
Time Period ◽  
Seedling Biomass ◽  
Experimental Treatments

AbstractArbuscular mycorrhizal (AM) fungi can successfully enhance photosynthesis (Pn) and plants growth in agricultural or grassland ecosystems. However, how the symbionts affect species restoration in sunlight-intensive areas remains largely unexplored. Therefore, this study’s objective was to assess the effect of AM fungi on apricot seedling physiology, within a specific time period, in northwest China. In 2010, an experimental field was established in Shaanxi Province, northwest China. The experimental treatments included two AM fungi inoculation levels (0 or 100 g of AM fungal inoculum per seedling), three shade levels (1900, 1100, and 550 µmol m−2 s−1), and three ages (1, 3, and 5 years) of transplantation. We examined growth, Pn, and morphological indicators of apricot (Prunus sibirica L.) seedling performances in 2011, 2013, and 2015. The colonization rate in mycorrhizal seedlings with similar amounts of shade is higher than the corresponding controls. The mycorrhizal seedling biomass is significantly higher than the corresponding non-mycorrhizal seedling biomass. Generally, Pn, stomatal conductance (Gs), transpiration rate (Tr), and water use efficiency are also significantly higher in the mycorrhizal seedlings. Moreover, mycorrhizal seedlings with light shade (LS) have the highest Pn. WUE is increased in non-mycorrhizal seedlings because of the reduction in Tr, while Tr is increased in mycorrhizal seedlings with shade. There is a significant increase in the N, P, and K fractions detected in roots compared with shoots. This means that LS had apparent benefits for mycorrhizal seedlings. Our results also indicate that AM fungi, combined with LS, exert a positive effect on apricot behavior.

scholarly journals Extraction of short chain chitooligosaccharides from fungal biomass and their use as promoters of arbuscular mycorrhizal symbiosis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Andrea Crosino ◽  
Elisa Moscato ◽  
Marco Blangetti ◽  
Gennaro Carotenuto ◽  
Federica Spina ◽  
...  
Keyword(s):  
Fungal Biomass ◽  
Large Scale ◽  
Low Cost ◽  
Trichoderma Viride ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Production Costs ◽  
Short Chain ◽  
Mycorrhizal Symbiosis ◽  
Major Interest

AbstractShort chain chitooligosaccharides (COs) are chitin derivative molecules involved in plant-fungus signaling during arbuscular mycorrhizal (AM) interactions. In host plants, COs activate a symbiotic signalling pathway that regulates AM-related gene expression. Furthermore, exogenous CO application was shown to promote AM establishment, with a major interest for agricultural applications of AM fungi as biofertilizers. Currently, the main source of commercial COs is from the shrimp processing industry, but purification costs and environmental concerns limit the convenience of this approach. In an attempt to find a low cost and low impact alternative, this work aimed to isolate, characterize and test the bioactivity of COs from selected strains of phylogenetically distant filamentous fungi: Pleurotus ostreatus, Cunninghamella bertholletiae and Trichoderma viride. Our optimized protocol successfully isolated short chain COs from lyophilized fungal biomass. Fungal COs were more acetylated and displayed a higher biological activity compared to shrimp-derived COs, a feature that—alongside low production costs—opens promising perspectives for the large scale use of COs in agriculture.

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