scholarly journals Drought Influences Fungal Community Dynamics in the Grapevine Rhizosphere and Root Microbiome

2021 ◽  
Vol 7 (9) ◽  
pp. 686
Author(s):  
María Julia Carbone ◽  
Sandra Alaniz ◽  
Pedro Mondino ◽  
Matías Gelabert ◽  
Ales Eichmeier ◽  
...  

Plant roots support complex microbial communities that can influence nutrition, plant growth, and health. In grapevine, little is known about the impact of abiotic stresses on the belowground microbiome. In this study, we examined the drought-induced shifts in fungal composition in the root endosphere, the rhizosphere and bulk soil by internal transcribed spacer (ITS) high-throughput amplicon sequencing (HTAS). We imposed three irrigation regimes (100%, 50%, and 25% of the field capacity) to one-year old grapevine rootstock plants cv. SO4 when plants had developed 2–3 roots. Root endosphere, rhizosphere, and bulk soil samples were collected 6- and 12-months post-plantation. Drought significantly modified the overall fungal composition of all three compartments, with the root endosphere compartment showing the greatest divergence from well-watered control (100%). The overall response of the fungal microbiota associated with black-foot disease (Dactylonectria and “Cylindrocarpon” genera) and the potential biocontrol agent Trichoderma to drought stress was consistent across compartments, namely that their relative abundances were significantly higher at 50–100% than at 25% irrigation regime. We identified a significant enrichment in several fungal genera such as the arbuscular mycorrhizal fungus Funneliformis during drought at 25% watering regime within the roots. Our results reveal that drought stress, in addition to its well-characterized effects on plant physiology, also results in the restructuring of grapevine root microbial communities, and suggest the possibility that members of the altered grapevine microbiota might contribute to plant survival under extreme environmental conditions.

2021 ◽  
Vol 12 ◽  
Author(s):  
Charles S. Cockell ◽  
Bettina Schaefer ◽  
Cornelia Wuchter ◽  
Marco J. L. Coolen ◽  
Kliti Grice ◽  
...  

We report on the effect of the end-Cretaceous impact event on the present-day deep microbial biosphere at the impact site. IODP-ICDP Expedition 364 drilled into the peak ring of the Chicxulub crater, México, allowing us to investigate the microbial communities within this structure. Increased cell biomass was found in the impact suevite, which was deposited within the first few hours of the Cenozoic, demonstrating that the impact produced a new lithological horizon that caused a long-term improvement in deep subsurface colonization potential. In the biologically impoverished granitic rocks, we observed increased cell abundances at impact-induced geological interfaces, that can be attributed to the nutritionally diverse substrates and/or elevated fluid flow. 16S rRNA gene amplicon sequencing revealed taxonomically distinct microbial communities in each crater lithology. These observations show that the impact caused geological deformation that continues to shape the deep subsurface biosphere at Chicxulub in the present day.


2020 ◽  
Vol 21 (5) ◽  
pp. 1748
Author(s):  
Gabriela Quiroga ◽  
Gorka Erice ◽  
Ricardo Aroca ◽  
Juan Manuel Ruiz-Lozano

Boron (B) is an essential micronutrient for higher plants, having structural roles in primary cell walls, but also other functions in cell division, membrane integrity, pollen germination or metabolism. Both high and low B levels negatively impact crop performance. Thus, plants need to maintain B concentration in their tissues within a narrow range by regulating transport processes. Both active transport and protein-facilitated diffusion through aquaporins have been demonstrated. This study aimed at elucidating the possible involvement of some plant aquaporins, which can potentially transport B and are regulated by the arbuscular mycorrhizal (AM) symbiosis in the plant B homeostasis. Thus, AM and non-AM plants were cultivated under 0, 25 or 100 μM B in the growing medium and subjected or not subjected to drought stress. The accumulation of B in plant tissues and the regulation of plant aquaporins and other B transporters were analyzed. The benefits of AM inoculation on plant growth (especially under drought stress) were similar under the three B concentrations assayed. The tissue B accumulation increased with B availability in the growing medium, especially under drought stress conditions. Several maize aquaporins were regulated under low or high B concentrations, mainly in non-AM plants. However, the general down-regulation of aquaporins and B transporters in AM plants suggests that, when the mycorrhizal fungus is present, other mechanisms contribute to B homeostasis, probably related to the enhancement of water transport, which would concomitantly increase the passive transport of this micronutrient.


Foods ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1247
Author(s):  
Emiel Van Reckem ◽  
Christina Charmpi ◽  
David Van der Veken ◽  
Wim Borremans ◽  
Luc De Vuyst ◽  
...  

Insight into the microbial species diversity of fermented meats is not only paramount to gain control over quality development, but also to better understand the link with processing technology and geographical origin. To study the composition of the microbial communities, the use of culture-independent methods is increasingly popular but often still suffers from drawbacks, such as a limited taxonomic resolution. This study aimed to apply a previously developed high-throughput amplicon sequencing (HTS) method targeting the 16S rRNA and tuf genes to characterize the bacterial communities in European fermented meats in greater detail. The data obtained broadened the view on the microbial communities that were associated with the various products examined, revealing the presence of previously underreported subdominant species. Moreover, the composition of these communities could be linked to the specificities of individual products, in particular pH, salt content, and geographical origin. In contrast, no clear links were found between the volatile organic compound profiles of the different products and the country of origin, distinct processing conditions, or microbial communities. Future application of the HTS method offers the potential to further unravel complex microbial communities in fermented meats, as well as to assess the impact of different processing conditions on microbial consortia.


2008 ◽  
Vol 20 (1) ◽  
pp. 29-37 ◽  
Author(s):  
José Beltrano ◽  
Marta G. Ronco

The aim of this paper was to investigate the contribution of the arbuscular mycorrhizal fungus Glomus claroideum to drought stress tolerance in wheat plants grown under controlled conditions in a growth chamber, and subjected to moderate or severe water stress and rewatering. Water stress tolerance was determined through total dry weight, leaf relative water content, leakage of solutes and leaf chlorophyll and protein concentrations in mycorrhizal and non-mycorrhizal wheat plants. Total dry weight and leaf chlorophyll concentrations were significantly higher in mycorrhizal plants after moderate or severe water stress treatments compared with non-mycorrhizal ones. Electrolyte leakage was significantly lower in water-stressed inoculated plants. Compared to non-inoculated plants, leaf relative water content and total protein concentration of inoculated individuals increased only under severe water stress. When irrigation was re-established, mycorrhizal plants increased their total dry weight and leaf chlorophyll concentration, and recovered cell membrane permeability in leaves compared with non-mycorrhizal plants. In conclusion, root colonization by G. claroideum could be an adequate strategy to alleviate the deleterious effects of drought stress and retard the senescence syndrome in wheat.


Plant Disease ◽  
2006 ◽  
Vol 90 (12) ◽  
pp. 1481-1484 ◽  
Author(s):  
Elsa Petit ◽  
Walter Douglas Gubler

We examined the influence of an arbuscular-mycorrhizal fungus, Glomus intraradices (INVAM CA 501), on black foot disease caused by the fungus Cylindrocarpon macrodidymum on Vitis rupestris cv. St. George under controlled conditions. Mycorrhizal or nonmycorrhizal grape rootings were inoculated with the pathogen. Eight months following inoculation with the pathogen, we evaluated disease severity, vine growth, and mycorrhizal colonization. Mycorrhizal plants developed significantly less leaf and root symptoms than nonmycorrhizal plants (P = 0.04 and P < 0.0001, respectively). Only nonmycorrhizal grape rootings inoculated with the pathogen had significantly less dry root and leaf weights compared with the noninoculated control (P = 0.0021 and P = 0.0017, respectively). Mycorrhizal colonization was high (48.3% for the noninfected control and 54.5% for plants infected with C. macrodidymum) and not significantly affected by inoculation with C. macrodidymum (P = 0.2256). Thus, V. rupestris preinoculated with G. intraradices were less susceptible to black foot disease than nonmycorrhizal plants. Results from this study suggest that preplant applications of G. intraradices may help prevent black foot disease in the nursery and in the vineyard.


2020 ◽  
Author(s):  
Oskar Modin ◽  
Raquel Liebana ◽  
Soroush Saheb-Alam ◽  
Britt-Marie Wilén ◽  
Carolina Suarez ◽  
...  

Abstract Background: High-throughput amplicon sequencing of marker genes, such as the 16S rRNA gene in Bacteria and Archaea, provides a wealth of information about the composition of microbial communities. To quantify differences between samples and draw conclusions about factors affecting community assembly, dissimilarity indices are typically used. However, results are subject to several biases and data interpretation can be challenging. The Jaccard and Bray-Curtis indices, which are often used to quantify taxonomic dissimilarity, are not necessarily the most logical choices. Instead, we argue that Hill-based indices, which make it possible to systematically investigate the impact of relative abundance on dissimilarity, should be used for robust analysis of data. In combination with a null model, mechanisms of microbial community assembly can be analyzed. Here, we also introduce a new software, qdiv, which enables rapid calculations of Hill-based dissimilarity indices in combination with null models.Results: Using amplicon sequencing data from two experimental systems, aerobic granular sludge (AGS) reactors and microbial fuel cells (MFC), we show that the choice of dissimilarity index can have considerable impact on results and conclusions. High dissimilarity between replicates because of random sampling effects make incidence-based indices less suited for identifying differences between groups of samples. Determining a consensus table based on count tables generated with different bioinformatic pipelines reduced the number of low-abundant, potentially spurious amplicon sequence variants (ASVs) in the data sets, which led to lower dissimilarity between replicates. Analysis with a combination of Hill-based indices and a null model allowed us to show that different ecological mechanisms acted on different fractions of the microbial communities in the experimental systems.Conclusions: Hill-based indices provide a rational framework for analysis of dissimilarity between microbial community samples. In combination with a null model, the effects of deterministic and stochastic community assembly factors on taxa of different relative abundances can be systematically investigated. Calculations of Hill-based dissimilarity indices in combination with a null model can be done in qdiv, which is freely available as a Python package (https://github.com/omvatten/qdiv). In qdiv, a consensus table can also be determined from several count tables generated with different bioinformatic pipelines.


2021 ◽  
Author(s):  
Ying Zhang ◽  
Yang Huo ◽  
Zhiruo Zhang ◽  
Suiyi Zhu ◽  
Wei Fan ◽  
...  

Abstract We conducted physicochemical parameters analysis, 16S rRNA amplicon sequencing and real-time quantitative polymerase chain reaction to explore the impact of human inputs on the bacterioplankton communities within a tributary of the largest river flowing through a megacity in northeast China. Agriculture largely accounted for the alteration of diversity and functions of the microbial communities. Furthermore, nutrients were significantly declined at the reservoir outlet, and WWTP effluent discharge caused changes in the river microbial community. NH3-N and NO3--N were the main environmental factors that drive the shift of the bacteria community, and rare taxa played a more important role in the response to environmental changes compared with the abundant ones. The occurrence of the human-specific fecal indicator was mostly derived from agriculture, and its increase in relative abundance was observed in the effluent. Thus, our study provides guidance for ecological assessment and management of rivers by revealing the response pattern of river bacterioplankton to multiple types of anthropogenic stressors.


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


2019 ◽  
Author(s):  
Sven P. Tobias-Hünefeldt ◽  
Stephen R. Wing ◽  
Nadjejda Espinel-Velasco ◽  
Federico Baltar ◽  
Sergio E. Morales

SummarySystems with strong horizontal and vertical gradients, such as fjords, are useful models for studying environmental forcing. Here we examine microbial (prokaryotic and eukaryotic) community changes associated with the surface low salinity layer (LSL) and underlying seawater in multiple fjords in Fiordland National Park (New Zealand). High rainfall (1200-8000 mm annually) and linked runoff from native forested catchments results in surface LSLs with high tannin concentrations within each fjord. These gradients are expected to drive changes in microbial communities. We used amplicon sequencing (16S and 18S) to assess the impact of these gradients on microbial communities and identified depth linked changes in diversity and community structure. With increasing depth we observed significant increases in Proteobacteria (15%) and SAR (37%), decreases in Opisthokonta (35%), and transiently increased Bacteroidetes (3% increase from 0 to 40 m, decreasing by 8% at 200 m). Community structure differences were observed along a transect from inner to outer regions, specifically 25% mean relative abundance decreases in Opisthokonta and Bacteroidetes, and increases in SAR (25%) and Proteobacteria (>5%) at the surface, indicating changes based on distance from the ocean. This provides the first in-depth view into the ecological drivers of microbial communities within New Zealand fjords.


Sign in / Sign up

Export Citation Format

Share Document