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Lasa AV, Fernández-González AJ, Villadas PJ, Cobo-Díaz JF, Fernández-López M. Bacterial inoculation of Quercus pyrenaica trees alters co-occurrence patterns but not the composition of the rhizosphere bacteriome in wild conditions. Environ Microbiol 2023; 25:1747-1761. [PMID: 37186411 DOI: 10.1111/1462-2920.16388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Accepted: 04/18/2023] [Indexed: 05/17/2023]
Abstract
Quercus pyrenaica is a woody species of high landscape value, however, its forests show an advanced state of degradation in the Iberian Peninsula. Afforestation typically has low success, thus, it is necessary to improve the fitness of oaks plantlets to be transplanted, for instance, by inoculating beneficial microorganisms. In adding microorganisms to ecosystems, there must be balanced efficacy with potential effects on native microbial communities. We addressed changes in diversity, richness, composition and co-occurrence networks of prokaryotic communities in the rhizosphere of inoculated and control trees outplanted to three different sites located in the Sierra Nevada National and Natural Park (Spain). After 18 months in wild conditions, we did not detect changes due to the inoculation in the richness, diversity and structure in none of the sites. However, we observed an increase in the complexity of the co-occurrence networks in two experimental areas. Modularization of the networks changed as a result of the inoculation, although the sense of the change depended on the site. Although it was impossible to unravel the effect of bacterial inoculation, our results highlighted that inoculation alters the association of rhizosphere bacteria without entailing other changes, so networks should be analysed prior to inoculating the plantlets.
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Affiliation(s)
- Ana V Lasa
- Department of Soil and Plant Microbiology, Estación Experimental del Zaidín, CSIC, Granada, Spain
| | | | - Pablo J Villadas
- Department of Soil and Plant Microbiology, Estación Experimental del Zaidín, CSIC, Granada, Spain
| | - José F Cobo-Díaz
- Department of Food Hygiene and Technology, Faculty of Veterinary, Universidad de León, León, Spain
| | - M Fernández-López
- Department of Soil and Plant Microbiology, Estación Experimental del Zaidín, CSIC, Granada, Spain
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Bacteriome dataset from the rhizosphere of trees in a Pinus pinaster and Pinus halepensis dominated forest subjected to drought conditions. Data Brief 2022; 46:108805. [PMID: 36578531 PMCID: PMC9791801 DOI: 10.1016/j.dib.2022.108805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 11/24/2022] [Accepted: 11/29/2022] [Indexed: 12/12/2022] Open
Abstract
The Mediterranean basin is drastically affected by intense and frequent droughts, which jeopardize the diversity and survival of its forest, for example, Pinus pinaster forests. The dynamics of the bacterial communities inhabiting the rhizosphere of Pinus pinaster and other plants from a pine dominated forest under contrasting hydric conditions was monitored. The forest was located in Sierra de Oria (southeast Spain), and it was mainly composed by P. pinaster, P. halepensis, woody shrub species and herbaceous plants. 18 trees visually belonging to P. pinaster located along the perimeter and across the forest were selected for the analysis. All the trees were separated at least 50 m each other. Although all of them belonged to P. pinaster morphologically according to visual identification, the genotyping of the roots confirmed that they corresponded to P. pinaster, P. halepensis, and other plant species different from genus Pinus, although in the last case it was not possible to identify the plant species. At a distance less than 50 cm from the trunk, the litter and topsoil were removed, and the soil closely attached to non-suberified roots (rhizosphere soil) was collected (depth of 5-25 cm). Sampling was carried out in two seasons with contrasting temperature and rainfall patterns: on July 18, 2017 (summer) and April 24, 2018 (spring). After rhizosphere soil DNA and RNA extraction (and cDNA synthesis), a metabarcoding approach was followed by sequencing the V3-V4 hypervariable regions of the 16S rRNA gene and its derived transcripts by Illumina MiSeq platform. Sequencing reads were bioinformatically processed; specifically, they were filtered, trimmed, clustered into ASV (Amplicon Sequence Variants), and taxonomically identified. As a result, a total of 1,123,209 and 1,089,359 quality sequences were obtained from DNA and RNA-derived libraries, which resulted in 5,241 and 5,231 ASVs, respectively. Total communities (DNA) were mainly dominated by phyla Proteobacteria, Acidobacteria, Actinobacteria, Verrucomicrobia and Bacteroidetes in summer and spring, while potentially active populations (RNA libraries) were rich in Proteobacteria, Acidobacteria, Candidate division WPS-1, Actinobacteria and Verrucomicrobia both in summer and spring. On the other hand, DNA libraries were mainly dominated by genera Sphingomonas and acidobacterial groups Gp4 and Gp6, while potentially active bacteria (RNA) were rich in acidobacterial Gp3, Gp4, Gp6 and Phenylobacterium, although their relative abundance depended on the considered season. This dataset can provide valuable information about bacterial candidates which could be used as bioindicators of drought conditions. In addition to shifts in the bacterial relative abundance due to seasonal changes, the ratio RNA-based cDNA:DNA could be calculated as proxy of the potential activity of bacterial taxa. Moreover, these data could aid in developing bioformulations based on microorganisms which could be resistant to desiccation and involved in the drought resistance mechanisms of the host plant.
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Siles JA, Hendrickson AJ, Terry N. Coupling of metataxonomics and culturing improves bacterial diversity characterization and identifies a novel Rhizorhapis sp. with metal resistance potential in a multi-contaminated waste sediment. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 322:116132. [PMID: 36067666 DOI: 10.1016/j.jenvman.2022.116132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Revised: 08/26/2022] [Accepted: 08/26/2022] [Indexed: 06/15/2023]
Abstract
Long-term contaminated environments have been recognized as potential hotspots for bacterial discovery in taxonomic and functional terms for bioremediation purposes. Here, bacterial diversity in waste sediment collected from a former industrial dumpsite and contaminated with petroleum hydrocarbon and heavy metals was investigated through the parallel application of culture-independent (16S rRNA gene amplicon sequencing) and -dependent (plate culturing followed by colony picking and identification of isolates by 16S rRNA gene Sanger sequencing) approaches. The bacterial diversities retrieved by both approaches greatly differed. Bacteroidetes and Proteobacteria were dominant in the culture-independent community, while Firmicutes and Actinobacteria were the main culturable groups. Only 2.7% of OTUs (operational taxonomic units) in the culture-independent dataset were cultured. Most of the culturable OTUs were absent or in very low abundances in the culture-independent dataset, revealing that culturing is a useful tool to study the rare bacterial biosphere. One culturable OTUs (comprising only the isolate SPR117) was identified as a potential new species in the genus Rhizorhapis (class Alphaproteobacteria) and was selected for further characterization. Phytopathogenicity tests showed that Rhizorhapis sp. strain SPR117 (ATCC TSD-228) is not pathogenic to lettuce, despite the only described species in this genus, Rhizorhapis suberifaciens, is causal agent of the lettuce corky root disease. The genome of the strain SPR117 was sequenced, assembled in 256 contigs, with a length of 4,419,522 bp and a GC content of 59.9%, and its further annotation revealed the presence of genes related to the resistance to arsenic, copper, iron, and mercury, among other metals. Therefore, the coupling of metataxonomics and culturing is a useful tool to obtain not only an improved description of bacterial communities in contaminated environments, but also to isolate microorganisms with bioremediation potential.
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Affiliation(s)
- José A Siles
- Department of Plant & Microbial Biology, University of California at Berkeley, Berkeley, CA, 94720, USA.
| | - Andrew J Hendrickson
- Department of Plant & Microbial Biology, University of California at Berkeley, Berkeley, CA, 94720, USA
| | - Norman Terry
- Department of Plant & Microbial Biology, University of California at Berkeley, Berkeley, CA, 94720, USA
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Lasa AV, Guevara MÁ, Villadas PJ, Vélez MD, Fernández-González AJ, de María N, López-Hinojosa M, Díaz L, Cervera MT, Fernández-López M. Correlating the above- and belowground genotype of Pinus pinaster trees and rhizosphere bacterial communities under drought conditions. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 832:155007. [PMID: 35381249 DOI: 10.1016/j.scitotenv.2022.155007] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 03/29/2022] [Accepted: 03/30/2022] [Indexed: 06/14/2023]
Abstract
Increasing temperatures along with severe droughts are factors that may jeopardize the survival of the forests in the Mediterranean basin. In this region, Pinus pinaster is a common conifer species, that has been used as a model species in evolutionary studies due to its adaptive response to changing environments. Although its drought tolerance mechanisms are already known, knowledge about the dynamics of its root microbiota is still scarce. We aimed to decipher the structural (bacterial abundance), compositional, functional and associative changes of the P. pinaster rhizosphere bacterial communities in spring and summer, at DNA and RNA level (environmental DNA, live and dead cells, and those synthesizing proteins). A fundamental aspect of root microbiome-based approaches is to guarantee the correct origin of the samples. Thus, we assessed the genotype of host needles and roots from which rhizosphere samples were obtained. For more than 50% of the selected trees, genotype discrepancies were found and in three cases the plant species could not be determined. Rhizosphere bacterial communities were homogeneous with respect to diversity and structural levels regardless of the host genotype in both seasons. Nonetheless, significant changes were seen in the taxonomic profiles depending on the season. Seasonal changes were also evident in the bacterial co-occurrence patterns, both in DNA and RNA libraries. While spring communities switched to more complex networks, summer populations resulted in more compartmentalized networks, suggesting that these communities were facing a disturbance. These results may mirror the future status of bacterial communities in a context of climate change. A keystone hub was ascribed to the genus Phenylobacterium in the functional network calculated for summer. Overall, it is important to validate the origin and identity of plant samples in any plant-microbiota study so that more reliable ecological analyses are performed.
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Affiliation(s)
- Ana V Lasa
- Department of Soil and Plant Microbiology, Estación Experimental del Zaidín, CSIC, Profesor Albareda 1, 18008 Granada, Spain.
| | - M Ángeles Guevara
- Dept. Forest Ecology and Genetics, Centro de Investigación Forestal, INIA-CSIC, Carretera de La Coruña Km 7,5, 28040 Madrid, Spain; Mixed Unit of Forest Genomics and Ecophysiology, INIA/UPM, Spain.
| | - Pablo J Villadas
- Department of Soil and Plant Microbiology, Estación Experimental del Zaidín, CSIC, Profesor Albareda 1, 18008 Granada, Spain.
| | - María Dolores Vélez
- Dept. Forest Ecology and Genetics, Centro de Investigación Forestal, INIA-CSIC, Carretera de La Coruña Km 7,5, 28040 Madrid, Spain; Mixed Unit of Forest Genomics and Ecophysiology, INIA/UPM, Spain.
| | - Antonio J Fernández-González
- Department of Soil and Plant Microbiology, Estación Experimental del Zaidín, CSIC, Profesor Albareda 1, 18008 Granada, Spain.
| | - Nuria de María
- Dept. Forest Ecology and Genetics, Centro de Investigación Forestal, INIA-CSIC, Carretera de La Coruña Km 7,5, 28040 Madrid, Spain; Mixed Unit of Forest Genomics and Ecophysiology, INIA/UPM, Spain.
| | - Miriam López-Hinojosa
- Dept. Forest Ecology and Genetics, Centro de Investigación Forestal, INIA-CSIC, Carretera de La Coruña Km 7,5, 28040 Madrid, Spain; Mixed Unit of Forest Genomics and Ecophysiology, INIA/UPM, Spain
| | - Luis Díaz
- Dept. Forest Ecology and Genetics, Centro de Investigación Forestal, INIA-CSIC, Carretera de La Coruña Km 7,5, 28040 Madrid, Spain; Mixed Unit of Forest Genomics and Ecophysiology, INIA/UPM, Spain.
| | - María Teresa Cervera
- Dept. Forest Ecology and Genetics, Centro de Investigación Forestal, INIA-CSIC, Carretera de La Coruña Km 7,5, 28040 Madrid, Spain; Mixed Unit of Forest Genomics and Ecophysiology, INIA/UPM, Spain.
| | - Manuel Fernández-López
- Department of Soil and Plant Microbiology, Estación Experimental del Zaidín, CSIC, Profesor Albareda 1, 18008 Granada, Spain.
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Persyn A, Mueller A, Goormachtig S. Drops join to make a stream: high-throughput nanoscale cultivation to grasp the lettuce root microbiome. ENVIRONMENTAL MICROBIOLOGY REPORTS 2022; 14:60-69. [PMID: 34797028 DOI: 10.1111/1758-2229.13014] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 10/02/2021] [Indexed: 06/13/2023]
Abstract
Root endospheres house complex and diverse bacterial communities, of which many strains have not been cultivated yet by means of the currently available isolation techniques. The Prospector® (General Automation Lab Technologies, San Carlos, CA, USA), an automated and high-throughput bacterial cultivation system, was applied to analyse the root endomicrobiome of lettuce (Lactuca sativa L.). By using deep sequencing, we compared the results obtained with the Prospector and the traditional solid medium culturing and extinction methods. We found that the species richness did not differ and that the amount of previously uncultured bacteria did not increase, but that the bacterial diversity isolated by the three methods varied. In addition, the tryptic soy broth and King's B media provided a lower, but different, diversity of bacteria than that of Reasoner's 2A (R2A) medium when used within the Prospector system and the number of unique bacterial strains did not weigh up against those isolated with the R2A medium. Thus, to cultivate as broad a variety of bacteria as possible, divergent isolation techniques should be used in parallel. Thanks to its speed and limited manual requirements, the Prospector is a valuable system to enlarge root microbiome culture collections.
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Affiliation(s)
- Antoine Persyn
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
- Center for Plant Systems Biology, VIB, 9052 Ghent, Belgium
| | - André Mueller
- General Automation Lab Technologies (GALT), San Carlos, CA, 94070, USA
| | - Sofie Goormachtig
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
- Center for Plant Systems Biology, VIB, 9052 Ghent, Belgium
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Runte GC, Smith AH, Moeller HV, Bogar LM. Spheres of Influence: Host Tree Proximity and Soil Chemistry Shape rRNA, but Not DNA, Communities of Symbiotic and Free-Living Soil Fungi in a Mixed Hardwood-Conifer Forest. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.641732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Host and symbiont diversity are inextricably linked across partnerships and ecosystems, with degree of partner reliance governing the strength of this correlation. In many forest soils, symbiotic ectomycorrhizal fungi coexist and compete with free-living saprotrophic fungi, with the outcomes of these interactions shaping resource availability and competitive outcomes for the trees aboveground. Traditional approaches to characterizing these communities rely on DNA sequencing of a ribosomal precursor RNA gene (the internal transcribed spacer region), but directly sequencing the precursor rRNA may provide a more functionally relevant perspective on the potentially active fungal communities. Here, we map ectomycorrhizal and saprotrophic soil fungal communities through a mixed hardwood-conifer forest to assess how above- and belowground diversity linkages compare across these differently adapted guilds. Using highly spatially resolved transects (sampled every 2 m) and well-mapped stands of varying host tree diversity, we sought to understand the relative influence of symbiosis versus environment in predicting fungal diversity measures. Canopy species in this forest included two oaks (Quercus agrifolia and Quercus douglasii) and one pine (Pinus sabiniana). At the scale of our study, spatial turnover in rRNA-based communities was much more predictable from measurable environmental attributes than DNA-based communities. And while turnover of ectomycorrhizal fungi and saprotrophs were predictable by the presence and abundance of different canopy species, they both responded strongly to soil nutrient characteristics, namely pH and nitrogen availability, highlighting the niche overlap of these coexisting guilds and the strong influence of aboveground plants on belowground fungal communities.
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Choudhary P, Singh BN, Chakdar H, Saxena AK. DNA barcoding of phytopathogens for disease diagnostics and bio-surveillance. World J Microbiol Biotechnol 2021; 37:54. [PMID: 33604719 DOI: 10.1007/s11274-021-03019-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 02/08/2021] [Indexed: 11/29/2022]
Abstract
DNA barcoding has proven to be a versatile tool for plant disease diagnostics in the genomics era. As the mass parallel and next generation sequencing techniques gained importance, the role of specific barcodes came under immense scrutiny. Identification and accurate classification of phytopathogens need a universal approach which has been the main application area of the concept of barcode. The present review entails a detailed description of the present status of barcode application in plant disease diagnostics. A case study on the application of Internal Transcribed Spacer (ITS) as barcode for Aspergillus and Fusarium spp. sheds light on the requirement of other potential candidates as barcodes for accurate identification. The challenges faced while barcoding novel pathogens have also been discussed with a comprehensive outline of integrating more recent technologies like meta-barcoding and genome skimming for detecting plant pathogens.
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Affiliation(s)
- Prassan Choudhary
- ICAR-National Bureau of Agriculturally Important Microorganisms (NBAIM), Kushmaur, Maunath Bhanjan, Uttar Pradesh, 275103, India
| | - Bansh Narayan Singh
- ICAR-National Bureau of Agriculturally Important Microorganisms (NBAIM), Kushmaur, Maunath Bhanjan, Uttar Pradesh, 275103, India
| | - Hillol Chakdar
- ICAR-National Bureau of Agriculturally Important Microorganisms (NBAIM), Kushmaur, Maunath Bhanjan, Uttar Pradesh, 275103, India.
| | - Anil Kumar Saxena
- ICAR-National Bureau of Agriculturally Important Microorganisms (NBAIM), Kushmaur, Maunath Bhanjan, Uttar Pradesh, 275103, India
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Barra Caracciolo A, Grenni P, Garbini GL, Rolando L, Campanale C, Aimola G, Fernandez-Lopez M, Fernandez-Gonzalez AJ, Villadas PJ, Ancona V. Characterization of the Belowground Microbial Community in a Poplar-Phytoremediation Strategy of a Multi-Contaminated Soil. Front Microbiol 2020; 11:2073. [PMID: 32983051 PMCID: PMC7477336 DOI: 10.3389/fmicb.2020.02073] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 08/06/2020] [Indexed: 11/25/2022] Open
Abstract
Due to their widespread use in industrial applications in recent decades, Polychlorobiphenyls (PCBs) and heavy metals (HMs) are the most common soil contaminants worldwide, posing a risk for both ecosystems and human health. In this study, a poplar-assisted bioremediation strategy has been applied for more than 4 years to a historically contaminated area (PCBs and HMs) in Southern Italy using the Monviso poplar clone. This clone was effective in promoting a decrease in all contaminants and an increase in soil quality in terms of organic carbon and microbial abundance. Moreover, a significant shift in the structure and predicted function of the belowground microbial community was also observed when analyzing both DNA and cDNA sequencing data. In fact, an increase in bacterial genera belonging to Proteobacteria able to degrade PCBs and resist HMs was observed. Moreover, the functional profiling of the microbial community predicted by PICRUSt2 made it possible to identify several genes associated with PCB transformation (e.g., bphAa, bphAb, bphB, bphC), response to HM oxidative stress (e.g., catalase, superoxide reductase, peroxidase) and HM uptake and expulsion (e.g., ABC transporters). This work demonstrated the effectiveness of the poplar clone Monviso in stimulating the natural belowground microbial community to remove contaminants and improve the overall soil quality. It is a practical example of a nature based solution involving synergic interactions between plants and the belowground microbial community.
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Affiliation(s)
| | - Paola Grenni
- National Research Council, Water Research Institute, Montelibretti (Rome), Italy
| | - Gian Luigi Garbini
- National Research Council, Water Research Institute, Montelibretti (Rome), Italy
| | - Ludovica Rolando
- National Research Council, Water Research Institute, Montelibretti (Rome), Italy.,Department of Ecological and Biological Sciences, University of Tuscia, Viterbo, Italy
| | | | - Giorgia Aimola
- National Research Council, Water Research Institute, Bari, Italy
| | - Manuel Fernandez-Lopez
- Consejo Superior de Investigaciones Científicas (CSIC), Zaidin Experimental Station, Granada, Spain
| | | | - Pablo José Villadas
- Consejo Superior de Investigaciones Científicas (CSIC), Zaidin Experimental Station, Granada, Spain
| | - Valeria Ancona
- National Research Council, Water Research Institute, Bari, Italy
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Fernández-González AJ, Cardoni M, Gómez-Lama Cabanás C, Valverde-Corredor A, Villadas PJ, Fernández-López M, Mercado-Blanco J. Linking belowground microbial network changes to different tolerance level towards Verticillium wilt of olive. MICROBIOME 2020; 8:11. [PMID: 32007096 PMCID: PMC6995654 DOI: 10.1186/s40168-020-0787-2] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 01/13/2020] [Indexed: 05/28/2023]
Abstract
BACKGROUND Verticillium wilt of olive (VWO) is caused by the soilborne fungal pathogen Verticillium dahliae. One of the best VWO management measures is the use of tolerant/resistant olive cultivars. Knowledge on the olive-associated microbiome and its potential relationship with tolerance to biotic constraints is almost null. The aims of this work are (1) to describe the structure, functionality, and co-occurrence interactions of the belowground (root endosphere and rhizosphere) microbial communities of two olive cultivars qualified as tolerant (Frantoio) and susceptible (Picual) to VWO, and (2) to assess whether these communities contribute to their differential disease susceptibility level. RESULTS Minor differences in alpha and beta diversities of root-associated microbiota were detected between olive cultivars regardless of whether they were inoculated or not with the defoliating pathotype of V. dahliae. Nevertheless, significant differences were found in taxonomic composition of non-inoculated plants' communities, "Frantoio" showing a higher abundance of beneficial genera in contrast to "Picual" that exhibited major abundance of potential deleterious genera. Upon inoculation with V. dahliae, significant changes at taxonomic level were found mostly in Picual plants. Relevant topological alterations were observed in microbial communities' co-occurrence interactions after inoculation, both at structural and functional level, and in the positive/negative edges ratio. In the root endosphere, Frantoio communities switched to highly connected and low modularized networks, while Picual communities showed a sharply different behavior. In the rhizosphere, V. dahliae only irrupted in the microbial networks of Picual plants. CONCLUSIONS The belowground microbial communities of the two olive cultivars are very similar and pathogen introduction did not provoke significant alterations in their structure and functionality. However, notable differences were found in their networks in response to the inoculation. This phenomenon was more evident in the root endosphere communities. Thus, a correlation between modifications in the microbial networks of this microhabitat and susceptibility/tolerance to a soilborne pathogen was found. Moreover, V. dahliae irruption in the Picual microbial networks suggests a stronger impact on the belowground microbial communities of this cultivar upon inoculation. Our results suggest that changes in the co-occurrence interactions may explain, at least partially, the differential VWO susceptibility of the tested olive cultivars. Video abstract.
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Affiliation(s)
- Antonio J. Fernández-González
- Departamento de Microbiología del Suelo y Sistemas Simbióticos, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas (CSIC), Calle Profesor Albareda 1, 18008 Granada, Spain
| | - Martina Cardoni
- Departamento de Protección de Cultivos, Instituto de Agricultura Sostenible, CSIC, Campus ‘Alameda del Obispo’ s/n, Avd. Menéndez Pidal s/n, 14004 Córdoba, Spain
| | - Carmen Gómez-Lama Cabanás
- Departamento de Protección de Cultivos, Instituto de Agricultura Sostenible, CSIC, Campus ‘Alameda del Obispo’ s/n, Avd. Menéndez Pidal s/n, 14004 Córdoba, Spain
| | - Antonio Valverde-Corredor
- Departamento de Protección de Cultivos, Instituto de Agricultura Sostenible, CSIC, Campus ‘Alameda del Obispo’ s/n, Avd. Menéndez Pidal s/n, 14004 Córdoba, Spain
| | - Pablo J. Villadas
- Departamento de Microbiología del Suelo y Sistemas Simbióticos, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas (CSIC), Calle Profesor Albareda 1, 18008 Granada, Spain
| | - Manuel Fernández-López
- Departamento de Microbiología del Suelo y Sistemas Simbióticos, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas (CSIC), Calle Profesor Albareda 1, 18008 Granada, Spain
| | - Jesús Mercado-Blanco
- Departamento de Protección de Cultivos, Instituto de Agricultura Sostenible, CSIC, Campus ‘Alameda del Obispo’ s/n, Avd. Menéndez Pidal s/n, 14004 Córdoba, Spain
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Bacteria from the endosphere and rhizosphere of Quercus spp. use mainly cell wall-associated enzymes to decompose organic matter. PLoS One 2019; 14:e0214422. [PMID: 30908541 PMCID: PMC6433265 DOI: 10.1371/journal.pone.0214422] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 03/12/2019] [Indexed: 01/12/2023] Open
Abstract
Due to the ability of soil bacteria to solubilize minerals, fix N2 and mobilize nutrients entrapped in the organic matter, their role in nutrient turnover and plant fitness is of high relevance in forest ecosystems. Although several authors have already studied the organic matter decomposing enzymes produced by soil and plant root-interacting bacteria, most of the works did not account for the activity of cell wall-attached enzymes. Therefore, the enzyme deployment strategy of three bacterial collections (genera Luteibacter, Pseudomonas and Arthrobacter) associated with Quercus spp. roots was investigated by exploring both cell-bound and freely-released hydrolytic enzymes. We also studied the potential of these bacterial collections to produce enzymes involved in the transformation of plant and fungal biomass. Remarkably, the cell-associated enzymes accounted for the vast majority of the total activity detected among Luteibacter strains, suggesting that they could have developed a strategy to maintain the decomposition products in their vicinity, and therefore to reduce the diffusional losses of the products. The spectrum of the enzymes synthesized and the titres of activity were diverse among the three bacterial genera. While cellulolytic and hemicellulolytic enzymes were rather common among Luteibacter and Pseudomonas strains and less detected in Arthrobacter collection, the activity of lipase was widespread among all the tested strains. Our results indicate that a large fraction of the extracellular enzymatic activity is due to cell wall-attached enzymes for some bacteria, and that Quercus spp. root bacteria could contribute at different levels to carbon (C), phosphorus (P) and nitrogen (N) cycles.
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