scholarly journals Mycorrhizal symbiosis changes host nitrogen source use

2021 ◽  
Author(s):  
Tiina Savolainen ◽  
Minna-Maarit Kytöviita
Keyword(s):  
Intraspecific Competition ◽  
Mycorrhizal Fungi ◽  
Life Stage ◽  
Plant Competition ◽  
Niche Partitioning ◽  
Plant Performance ◽  
Mycorrhizal Symbiosis ◽  
N Nutrition ◽  
N Source ◽  
Source Use

Abstract Purpose The ecological importance of arbuscular mycorrhizal fungi (AMF) in plant acquisition of inorganic and organic sources of nitrogen (N) is not clear. To improve understanding of the plant N nutrition ecology, we tested the effect of intraspecific competition and AMF in plant N source use in growth and N acquisition. Methods Solidago virgaurea was grown in microcosms in a fully factorial experiment under greenhouse conditions. The factors tested were intraspecific competition between seedlings and adult plants (yes, no), N source (NH4, glycine) and AMF (inoculated with Glomus hoi, not inoculated). Results When grown separately, non-mycorrhizal seedling growth was highest when grown with ammonium, but non-mycorrhizal adults grew best with glycine as the sole N source. Mycorrhizal symbiosis with Glomus hoi evened out this initial niche partitioning in terms of differences in N source use and all mycorrhizal plants grew best with ammonium. Competition shaped plant benefit from mycorrhizal symbiosis depending on the N source. Competition reduced mycorrhizal growth benefit in glycine-grown seedlings, but not in adults. Plant performance did not show uniform relationship with δ15N, but δ15N was affected by life stage, competition and mycorrhiza. Conclusions Plant competition and AMF shape plant N source use. Plant and AMF benefit of the symbiosis depend on the N source.

scholarly journals The Effect of Mycorrhizal Fungi and PGPR on Tree Nutritional Status and Growth in Organic Apple Production

Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1402
Author(s):  
Sebastian Przybyłko ◽  
Wojciech Kowalczyk ◽  
Dariusz Wrona
Keyword(s):  
Nutritional Status ◽  
Mycorrhizal Fungi ◽  
Negative Impact ◽  
Nitrogen Nutrition ◽  
Nutrient Use Efficiency ◽  
Plant Competition ◽  
Fruit Production ◽  
Organic Fertilizers ◽  
Nutrition Status ◽  
Tree Roots

The desire to reduce the negative impact of crops on the environment, as well as the growing concern for consumer health, is increasing interest in organic fruit production. In this context, the development of new environmentally friendly agrotechnical methods which allows for reducing the use of organic fertilizers by improving the nutrient use efficiency and consequently decreasing the leaching of them is a task of a great importance. The main purpose of this study was to evaluate the effect of mycorrhizal arbuscular fungi (AMF) combined with plant-growth-promoting rhizobacteria (PGPR) on growth and nutritional status of apple trees cultivated on a silty-loam, rich in clay minerals and humus soil under organic farming conditions. Thus, a trial was established in an experimental orchard in Wilanów in Central Poland with three cultivars (‘Topaz’, ‘Odra’, and ‘Chopin’) and a promising clone, U 8869. Trees were or were not inoculated with AMF + PGPR within a split-block experimental design with four replicates. According to the results, mycorrhizal frequency obtained in the inoculated tree roots was on average two-fold higher than in the roots of the control plants. After four years of AMF + PGPR inoculation, 24% higher trunk cross-section area (TCSA) was observed, with the nitrogen and magnesium concentrations in leaves increasing, on average, by 7.8% and 64.2%, and phosphorus and potassium content decreasing by 37.2% and 46.5%, respectively. This study shows that using AMF + PGPR inoculum supports tree roots colonization by AMF. As a result, better nitrogen nutrition status is observed that promote vigorous growth of trees and more efficient uptake of magnesium from the bulk soil. On the other hand, lower phosphorus content in inoculated tree leaves might be explained by a dilution effect, and potassium decrease could occur as a result of fungus–plant competition in conditions of this element deficiency in soil.

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.

scholarly journals Agricultural intensification reduces microbial network complexity and the abundance of keystone taxa in roots

2018 ◽  
Author(s):  
Samiran Banerjee ◽  
Florian Walder ◽  
Lucie Büchi ◽  
Marcel Meyer ◽  
Alain Y. Held ◽  
...  
Keyword(s):  
Organic Farming ◽  
Mycorrhizal Fungi ◽  
Agricultural Intensification ◽  
Soil Phosphorus ◽  
Farming Systems ◽  
Wheat Root ◽  
Plant Performance ◽  
No Till ◽  
The Impact ◽  
Root Microbiota

AbstractRoot-associated microbes play a key role in plant performance and productivity, making them important players in agroecosystems. So far, very few studies have assessed the impact of different farming systems on the root microbiota and it is still unclear whether agricultural intensification influences network complexity of microbial communities. We investigated the impact of conventional, no-till and organic farming on wheat root fungal communities usingPacBio SMRT sequencingon samples collected from 60 farmlands in Switzerland. Organic farming harboured a much more complex fungal network than conventional and no-till farming systems. The abundance of keystone taxa was the highest under organic farming where agricultural intensification was the lowest. The occurrence of keystone taxa was best explained by soil phosphorus levels, bulk density, pH and mycorrhizal colonization. The majority of keystone taxa are known to form arbuscular mycorrhizal associations with plants and belong to the ordersGlomerales,Paraglomerales, andDiversisporales. Supporting this, the abundance of mycorrhizal fungi in roots and soils was also significantly higher under organic farming. To our knowledge, this is the first study to report mycorrhizal keystone taxa for agroecosystems, and we demonstrate that agricultural intensification reduces network complexity and the abundance of keystone taxa in the root microbiota.

scholarly journals Dual RNA-seq reveals large-scale non-conserved genotype x genotype specific genetic reprograming and molecular crosstalk in the mycorrhizal symbiosis

2018 ◽  
Author(s):  
Ivan D. Mateus ◽  
Frédéric G. Masclaux ◽  
Consolée Aletti ◽  
Edward C. Rojas ◽  
Romain Savary ◽  
...  
Keyword(s):  
Mycorrhizal Fungi ◽  
Large Scale ◽  
Molecular Mechanisms ◽  
Arbuscular Mycorrhizal ◽  
Mycorrhizal Symbiosis ◽  
Rna Seq ◽  
Plant Host ◽  
Transcriptional Responses ◽  
Plant Genes ◽  
Fungal Genetic

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.

scholarly journals Divergence in bidirectional plant-soil feedbacks between montane annual and coastal perennial ecotypes of yellow monkeyflower (Mimulus guttatus)

2020 ◽  
Author(s):  
Mariah M. McIntosh ◽  
Lorinda Bullington ◽  
Ylva Lekberg ◽  
Lila Fishman
Keyword(s):  
Mycorrhizal Fungi ◽  
Arbuscular Mycorrhizal ◽  
Plant Performance ◽  
Fungal Communities ◽  
Mechanistic Study ◽  
List Type ◽  
Mimulus Guttatus ◽  
Plant Variation ◽  
Plant Soil ◽  
Soil Origin

SUMMARYUnderstanding the physiological and genetic mechanisms underlying plant variation in interactions with root-associated biota (RAB) requires a micro-evolutionary approach. We use locally adapted montane annual and coastal perennial ecotypes of Mimulus guttatus (yellow monkeyflower) to examine population-scale differences in plant-RAB-soil feedbacks.We characterized fungal communities for the two ecotypes in-situ and used a full-factorial greenhouse experiment to investigate the effects of plant ecotype, RAB source, and soil origin on plant performance and endophytic root fungal communities.The two ecotypes harbored different fungal communities and responsiveness to soil biota was highly context-dependent. Soil origin, RAB source, and plant ecotype all affected the intensity of biotic feedbacks on plant performance. Feedbacks were primarily negative, and we saw little evidence of local adaptation to either soils or RAB. Both RAB source and soil origin significantly shaped fungal communities in roots of experimental plants. Further, the perennial ecotype was more colonized by arbuscular mycorrhizal fungi (AMF) than the montane ecotype, and preferentially recruited home AMF taxa.Our results suggest life history divergence and distinct edaphic habitats shape plant responsiveness to RAB and influence specific associations with potentially mutualistic root endophytic fungi. Our results advance the mechanistic study of intraspecific variation in plant–soil–RAB interactions.

scholarly journals The Mycorrhizal Tragedy of the Commons

2021 ◽  
Author(s):  
Nils Henriksson ◽  
Oskar Franklin ◽  
Lasse Tarvainen ◽  
John Marshall ◽  
Judith Lundberg-Felten ◽  
...  
Keyword(s):  
Mycorrhizal Fungi ◽  
Boreal Forests ◽  
Nitrogen Availability ◽  
Carbon Allocation ◽  
Tragedy Of The Commons ◽  
Nitrogen Immobilization ◽  
Mycorrhizal Symbiosis ◽  
Individual Tree ◽  
Carbon Supply ◽  
The Commons

The mycorrhizal symbiosis is ubiquitous in boreal forests. Trees and plants provide their fungal partners with photosynthetic carbon in exchange for soil nutrients like nitrogen, which is critical to the growth and survival of the plants. But plant carbon allocation to mycorrhizal symbionts can also fuel nitrogen immobilization, hampering tree growth. Here we present results from field and greenhouse experiments combined with mathematical modelling, showing that mycorrhizal fungi can be simultaneously mutualistic to an individual tree and parasitic to the networked community of trees. Mycorrhizal networks connect multiple plants and fungi, and we show that each tree gains additional nitrogen at the expense of its neighbors by supplying more carbon to the fungi. But this additional carbon supply eventually aggravates nitrogen immobilization in the shared fungal biomass. Individual trees may thus independently benefit from increasing their carbon investment to mycorrhiza, while causing a decline in nitrogen availability for the whole plant community. We illustrate the evolutionary underpinnings of this situation by drawing on the analogous the tragedy of the commons, and explain how rising atmospheric CO2 may lead to greater nitrogen immobilization in the future.

Plant endophytes and arbuscular mycorrhizal fungi alter plant competition

2018 ◽  
Vol 32 (5) ◽  
pp. 1168-1179 ◽  
Author(s):  
Yong Zhou ◽  
Xia Li ◽  
Yuan Gao ◽  
Hui Liu ◽  
Yu‐Bao Gao ◽  
...  
Keyword(s):  
Arbuscular Mycorrhizal Fungi ◽  
Mycorrhizal Fungi ◽  
Plant Competition ◽  
Arbuscular Mycorrhizal

Phylogenomics of orchids and their mycorrhizal fungi : trees, diversity, and the pursuit of symbiosis

2019 ◽  
Author(s):  
◽  
Sarah Unruh
Keyword(s):  
Mycorrhizal Fungi ◽  
Phylogenetic Trees ◽  
High Throughput Sequencing ◽  
Genomic Sequence ◽  
Sequence Data ◽  
Mycorrhizal Symbiosis ◽  
Sequencing Data ◽  
Phylogenetic Structure ◽  
University Of Missouri ◽  
Fungal Symbiosis

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] Phylogenetic trees show us how organisms are related and provide frameworks for studying and testing evolutionary hypotheses. To better understand the evolution of orchids and their mycorrhizal fungi, I used high-throughput sequencing data and bioinformatic analyses, to build phylogenetic hypotheses. In Chapter 2, I used transcriptome sequences to both build a phylogeny of the slipper orchid genera and to confirm the placement of a polyploidy event at the base of the orchid family. Polyploidy is hypothesized to be a strong driver of evolution and a source of unique traits so confirming this event leads us closer to explaining extant orchid diversity. The list of orthologous genes generated from this study will provide a less expensive and more powerful method for researchers examining the evolutionary relationships in Orchidaceae. In Chapter 3, I generated genomic sequence data for 32 fungal isolates that were collected from orchids across North America. I inferred the first multi-locus nuclear phylogenetic tree for these fungal clades. The phylogenetic structure of these fungi will improve the taxonomy of these clades by providing evidence for new species and for revising problematic species designations. A robust taxonomy is necessary for studying the role of fungi in the orchid mycorrhizal symbiosis. In chapter 4 I summarize my work and outline the future directions of my lab at Illinois College including addressing the remaining aims of my Community Sequencing Proposal with the Joint Genome Institute by analyzing the 15 fungal reference genomes I generated during my PhD. Together these chapters are the start of a life-long research project into the evolution and function of the orchid/fungal symbiosis.

scholarly journals Synergy of arbuscular mycorrhizal symbiosis and exogenous Ca2+ benefits peanut (Arachis hypogaea L.) growth through the shared hormone and flavonoid pathway

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Li Cui ◽  
Feng Guo ◽  
Jialei Zhang ◽  
Sha Yang ◽  
JingJing Meng ◽  
...  
Keyword(s):  
Arachis Hypogaea ◽  
Mycorrhizal Fungi ◽  
Differentially Expressed Gene ◽  
Sufficient Conditions ◽  
Arbuscular Mycorrhizal ◽  
Mycorrhizal Symbiosis ◽  
Marker Genes ◽  
Specific Marker ◽  
Flavonoid Pathway ◽  
Am Symbiosis

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.

Sign in / Sign up

Export Citation Format

Share Document