scholarly journals Successional adaptive strategies revealed by correlating arbuscular mycorrhizal fungal abundance with host plant gene expression

2021 ◽  
Author(s):  
Cheng Gao ◽  
Pierre-Emmanuel Courty ◽  
Nelle Varoquaux ◽  
Benjamin Cole ◽  
Liliam Montoya ◽  
...  
Keyword(s):  
Gene Expression ◽  
Drought Stress ◽  
Host Plant ◽  
Mycorrhizal Fungi ◽  
Arbuscular Mycorrhizal ◽  
Adaptive Strategies ◽  
Future Research ◽  
Differential Correlation ◽  
Fungal Abundance ◽  
Arbuscular Mycorrhizal Fungal

Arbuscular mycorrhizal fungi (AMF), the mutualistic symbionts with most crops, constitute a research system of human-associated fungi whose relative simplicity and synchrony are conducive to experimental ecology. However, little is known about the shifts in adaptive strategies of sorghum associated AMFs where strong AMF succession replaces initially ruderal species with competitive ones and where the strongest plant response to drought is to manage these AMF. First, we hypothesize that, when irrigation is stopped to mimic drought, competitive AMF species should be replaced by AMF species tolerant to drought stress. We then, for the first time, correlate AMF abundance and host plant transcription to test two novel hypotheses about the mechanisms behind the shift from ruderal to competitive AMF. Surprisingly, despite imposing drought stress, we found no stress tolerant AMF. Remarkably, we found strong and differential correlation between the successional shift from ruderal to competitive AMF and sorghum genes whose products (i) produce and release strigolactone signals, (ii) perceive mycorrhizal-lipochitinoligosaccharide (Myc-LCO) signals, (iii) provide plant lipid and sugar to AMF and, (iv) import minerals and water provided by AMF. These novel insights into host gene expression and succession of AMF show adaptive strategies evolved by AMF and their hosts and provide a rationale for selecting AMF to reduce inputs and maximize yield in commercial agriculture. Future research opportunities include testing the specifics and generality of our hypotheses by employing genetically modified host plants, and exploring additional genes underlying the adaptive strategies in natural succession.

scholarly journals Effects of Inoculum Additions in the Presence of a Preestablished Arbuscular Mycorrhizal Fungal Community

2013 ◽  
Vol 79 (20) ◽  
pp. 6507-6515 ◽  
Author(s):  
Martina Janoušková ◽  
Karol Krak ◽  
Cameron Wagg ◽  
Helena Štorchová ◽  
Petra Caklová ◽  
...  
Keyword(s):  
Plant Growth ◽  
Mycorrhizal Fungi ◽  
Positive Response ◽  
Arbuscular Mycorrhizal ◽  
Plant Productivity ◽  
Ecological Aspect ◽  
Trade Off ◽  
Fungal Abundance ◽  
Managed Ecosystems ◽  
Arbuscular Mycorrhizal Fungal

ABSTRACTCommunities of arbuscular mycorrhizal fungi (AMF) are crucial for promoting plant productivity in most terrestrial systems, including anthropogenically managed ecosystems. Application of AMF inocula has therefore become a widespread practice. It is, however, pertinent to understand the mechanisms that govern AMF community composition and their performance in order to design successful manipulations. Here we assess whether the composition and plant growth-promotional effects of a synthetic AMF community can be altered by inoculum additions of the isolates forming the community. This was determined by following the effects of three AMF isolates, each inoculated in two propagule densities into a preestablished AMF community. Fungal abundance in roots and plant growth were evaluated in three sequential harvests. We found a transient positive response in AMF abundance to the intraspecific inoculation only in the competitively weakest isolate. The other two isolates responded negatively to intra- and interspecific inoculations, and in some cases plant growth was also reduced. Our results suggest that increasing the AMF density may lead to increased competition among fungi and a trade-off with their ability to promote plant productivity. This is a key ecological aspect to consider when introducing AMF into soils.

scholarly journals Elucidating the Mechanisms Underlying Enhanced Drought Tolerance in Plants Mediated by Arbuscular Mycorrhizal Fungi

2021 ◽  
Vol 12 ◽  
Author(s):  
Shen Cheng ◽  
Ying-Ning Zou ◽  
Kamil Kuča ◽  
Abeer Hashem ◽  
Elsayed Fathi Abd_Allah ◽  
...  
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Mycorrhizal Fungi ◽  
Host Plants ◽  
Molecular Mechanisms ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Host Cells ◽  
Future Research ◽  
Symbiotic Association

Plants are often subjected to various environmental stresses during their life cycle, among which drought stress is perhaps the most significant abiotic stress limiting plant growth and development. Arbuscular mycorrhizal (AM) fungi, a group of beneficial soil fungi, can enhance the adaptability and tolerance of their host plants to drought stress after infecting plant roots and establishing a symbiotic association with their host plant. Therefore, AM fungi represent an eco-friendly strategy in sustainable agricultural systems. There is still a need, however, to better understand the complex mechanisms underlying AM fungi-mediated enhancement of plant drought tolerance to ensure their effective use. AM fungi establish well-developed, extraradical hyphae on root surfaces, and function in water absorption and the uptake and transfer of nutrients into host cells. Thus, they participate in the physiology of host plants through the function of specific genes encoded in their genome. AM fungi also modulate morphological adaptations and various physiological processes in host plants, that help to mitigate drought-induced injury and enhance drought tolerance. Several AM-specific host genes have been identified and reported to be responsible for conferring enhanced drought tolerance. This review provides an overview of the effect of drought stress on the diversity and activity of AM fungi, the symbiotic relationship that exists between AM fungi and host plants under drought stress conditions, elucidates the morphological, physiological, and molecular mechanisms underlying AM fungi-mediated enhanced drought tolerance in plants, and provides an outlook for future research.

scholarly journals Physiological and biochemical responses of soybean plants inoculated with Arbuscular mycorrhizal fungi and Bradyrhizobium under drought stress

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Mohamed S. Sheteiwy ◽  
Dina Fathi Ismail Ali ◽  
You-Cai Xiong ◽  
Marian Brestic ◽  
Milan Skalicky ◽  
...  
Keyword(s):  
Drought Stress ◽  
Arbuscular Mycorrhizal Fungi ◽  
Secondary Metabolism ◽  
Mycorrhizal Fungi ◽  
Plant Biomass ◽  
Arbuscular Mycorrhizal ◽  
Growth And Yield ◽  
Relative Expression ◽  
Reverse Trend ◽  
Soybean Plants

Abstract Background The present study aims to study the effects of biofertilizers potential of Arbuscular Mycorrhizal Fungi (AMF) and Bradyrhizobium japonicum (B. japonicum) strains on yield and growth of drought stressed soybean (Giza 111) plants at early pod stage (50 days from sowing, R3) and seed development stage (90 days from sowing, R5). Results Highest plant biomass, leaf chlorophyll content, nodulation, and grain yield were observed in the unstressed plants as compared with water stressed-plants at R3 and R5 stages. At soil rhizosphere level, AMF and B. japonicum treatments improved bacterial counts and the activities of the enzymes (dehydrogenase and phosphatase) under well-watered and drought stress conditions. Irrespective of the drought effects, AMF and B. japonicum treatments improved the growth and yield of soybean under both drought (restrained irrigation) and adequately-watered conditions as compared with untreated plants. The current study revealed that AMF and B. japonicum improved catalase (CAT) and peroxidase (POD) in the seeds, and a reverse trend was observed in case of malonaldehyde (MDA) and proline under drought stress. The relative expression of the CAT and POD genes was up-regulated by the application of biofertilizers treatments under drought stress condition. Interestingly a reverse trend was observed in the case of the relative expression of the genes involved in the proline metabolism such as P5CS, P5CR, PDH, and P5CDH under the same conditions. The present study suggests that biofertilizers diminished the inhibitory effect of drought stress on cell development and resulted in a shorter time for DNA accumulation and the cycle of cell division. There were notable changes in the activities of enzymes involved in the secondary metabolism and expression levels of GmSPS1, GmSuSy, and GmC-INV in the plants treated with biofertilizers and exposed to the drought stress at both R3 and R5 stages. These changes in the activities of secondary metabolism and their transcriptional levels caused by biofertilizers may contribute to increasing soybean tolerance to drought stress. Conclusions The results of this study suggest that application of biofertilizers to soybean plants is a promising approach to alleviate drought stress effects on growth performance of soybean plants. The integrated application of biofertilizers may help to obtain improved resilience of the agro ecosystems to adverse impacts of climate change and help to improve soil fertility and plant growth under drought stress.

scholarly journals Micro-Landscape Dependent Changes in Arbuscular Mycorrhizal Fungal Community Structure

2021 ◽  
Vol 11 (11) ◽  
pp. 5297
Author(s):  
Stavros D. Veresoglou ◽  
Leonie Grünfeld ◽  
Magkdi Mola
Keyword(s):  
Community Structure ◽  
Mycorrhizal Fungi ◽  
Root Colonization ◽  
Environmental Parameters ◽  
Arbuscular Mycorrhizal ◽  
Fungal Community Structure ◽  
High Connectivity ◽  
Spatio Temporal ◽  
Arbuscular Mycorrhizal Fungal ◽  
Colonization Rates

The roots of most plants host diverse assemblages of arbuscular mycorrhizal fungi (AMF), which benefit the plant hosts in diverse ways. Even though we understand that such AMF assemblages are non-random, we do not fully appreciate whether and how environmental settings can make them more or less predictable in time and space. Here we present results from three controlled experiments, where we manipulated two environmental parameters, habitat connectance and habitat quality, to address the degree to which plant roots in archipelagos of high connectivity and invariable habitats are colonized with (i) less diverse and (ii) easier to predict AMF assemblages. We observed no differences in diversity across our manipulations. We show, however, that mixing habitats and varying connectivity render AMF assemblages less predictable, which we could only detect within and not between our experimental units. We also demonstrate that none of our manipulations favoured any specific AMF taxa. We present here evidence that the community structure of AMF is less responsive to spatio-temporal manipulations than root colonization rates which is a facet of the symbiosis which we currently poorly understand.

Evaluation of commercial composts and potting mixes and their ability to support arbuscular mycorrhizal fungi with maize (Zea mays) as host plant

2021 ◽  
Vol 134 ◽  
pp. 187-196
Author(s):  
M.J. Salomon ◽  
S.J. Watts-Williams ◽  
M.J. McLaughlin ◽  
C.J. Brien ◽  
N. Jewell ◽  
...  
Keyword(s):  
Zea Mays ◽  
Arbuscular Mycorrhizal Fungi ◽  
Host Plant ◽  
Mycorrhizal Fungi ◽  
Arbuscular Mycorrhizal

scholarly journals The Phosphate Inhibition Paradigm: Host and Fungal Genotypes Determine Arbuscular Mycorrhizal Fungal Colonization and Responsiveness to Inoculation in Cassava With Increasing Phosphorus Supply

2021 ◽  
Vol 12 ◽  
Author(s):  
Ricardo Alexander Peña Venegas ◽  
Soon-Jae Lee ◽  
Moses Thuita ◽  
Deusdedit Peter Mlay ◽  
Cargele Masso ◽  
...  
Keyword(s):  
Mycorrhizal Fungi ◽  
Arbuscular Mycorrhizal ◽  
Field Trials ◽  
P Uptake ◽  
Fungal Colonization ◽  
P Availability ◽  
Terrestrial Plants ◽  
Soil Microbial ◽  
Arbuscular Mycorrhizal Fungal ◽  
P Supply

A vast majority of terrestrial plants are dependent on arbuscular mycorrhizal fungi (AMF) for their nutrient acquisition. AMF act as an extension of the root system helping phosphate uptake. In agriculture, harnessing the symbiosis can potentially increase plant growth. Application of the AMF Rhizophagus irregularis has been demonstrated to increase the yields of various crops. However, there is a paradigm that AMF colonization of roots, as well as the plant benefits afforded by inoculation with AMF, decreases with increasing phosphorus (P) supply in the soil. The paradigm suggests that when fertilized with sufficient P, inoculation of crops would not be beneficial. However, the majority of experiments demonstrating the paradigm were conducted in sterile conditions without a background AMF or soil microbial community. Interestingly, intraspecific variation in R. irregularis can greatly alter the yield of cassava even at a full application of the recommended P dose. Cassava is a globally important crop, feeding 800 million people worldwide, and a crop that is highly dependent on AMF for P uptake. In this study, field trials were conducted at three locations in Kenya and Tanzania using different AMF and cassava varieties under different P fertilization levels to test if the paradigm occurs in tropical field conditions. We found that AMF colonization and inoculation responsiveness of cassava does not always decrease with an increased P supply as expected by the paradigm. The obtained results demonstrate that maximizing the inoculation responsiveness of cassava is not necessarily only in conditions of low P availability, but that this is dependent on cassava and fungal genotypes. Thus, the modeling of plant symbiosis with AMF under different P levels in nature should be considered with caution.

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