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Adan IH, Asudi GO, Niassy S, Jalloh AA, Mutua JM, Chidawanyika F, Khamis F, Khan Z, Subramanian S, Dubois T, Mutyambai DM. Comparative microbiome diversity in root-nodules of three Desmodium species used in push-pull cropping system. Front Microbiol 2024; 15:1395811. [PMID: 38966391 PMCID: PMC11222577 DOI: 10.3389/fmicb.2024.1395811] [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: 03/04/2024] [Accepted: 05/28/2024] [Indexed: 07/06/2024] Open
Abstract
Background Desmodium species used as intercrops in push-pull cropping systems are known to repel insect-pests, suppress Striga species weeds, and shift soil microbiome. However, the mechanisms through which Desmodium species impact the soil microbiome, either through its root exudates, changes in soil nutrition, or shading microbes from its nodules into the rhizosphere, are less understood. Here, we investigated the diversity of root-nodule microbial communities of three Desmodium species- Desmodium uncinatum (SLD), Desmodium intortum (GLD), and Desmodium incanum (AID) which are currently used in smallholder maize push-pull technology (PPT). Methods Desmodium species root-nodule samples were collected from selected smallholder farms in western Kenya, and genomic DNA was extracted from the root-nodules. The amplicons underwent paired-end Illumina sequencing to assess bacterial and fungal populations. Results We found no significant differences in composition and relative abundance of bacterial and fungal species within the root-nodules of the three Desmodium species. While a more pronounced shift was observed for fungal community compositions compared to bacteria, no significant differences were observed in the general diversity (evenness and richness) of fungal and bacterial populations among the three Desmodium species. Similarly, beta diversity was not significantly different among the three Desmodium species. The root-nodule microbiome of the three Desmodium species was dominated by Bradyrhizobium and Fusarium species. Nevertheless, there were significant differences in the proportion of marker gene sequences responsible for energy and amino acid biosynthesis among the three Desmodium species, with higher sequence proportions observed in SLD. Conclusion There is no significant difference in the microbial community of the three Desmodium species used in PPT. However, root-nodule microbiome of SLD had significantly higher marker gene sequences responsible for energy and amino acid biosynthesis. Therefore, it is likely that the root-nodules of the three Desmodium species host similar microbiomes and influence soil health, consequently impacting plant growth and agroecosystem functioning.
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Affiliation(s)
- Isack H. Adan
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
- Department of Biochemistry, Microbiology, and Biotechnology, Kenyatta University, Nairobi, Kenya
| | - George Ochieng Asudi
- Department of Biochemistry, Microbiology, and Biotechnology, Kenyatta University, Nairobi, Kenya
| | - Saliou Niassy
- Inter-African Phytosanitary Council of the African Union, Yaoundé, Cameroon
| | - Abdul A. Jalloh
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
- Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
| | | | - Frank Chidawanyika
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
- Department of Zoology and Entomology, University of Free State, Bloemfontein, South Africa
| | - Fathiya Khamis
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
| | - Zeyaur Khan
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
| | | | - Thomas Dubois
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
| | - Daniel Munyao Mutyambai
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
- Department of Life Science, South Eastern Kenya University, Kitui, Kenya
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Dip DP, Sannazzaro AI, Otondo J, Pistorio M, Estrella MJ. Exploring Phosphate Solubilizing Bacterial Communities in Rhizospheres of Native and Exotic Forage Grasses in Alkaline-Sodic Soils of the Flooding Pampa. Curr Microbiol 2024; 81:189. [PMID: 38789812 DOI: 10.1007/s00284-024-03704-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Accepted: 04/16/2024] [Indexed: 05/26/2024]
Abstract
The flooding pampa is one of the most important cattle-raising regions in Argentina. In this region, natural pastures are dominated by low-productivity native grass species, which are the main feed for livestock. In this context, previous studies in the region with the subtropical exotic grass Panicum coloratum highlight it as a promising species to improve pasture productivity. Cultivable phosphate solubilizing bacteria (PSB) communities associated to native (Sporobolus indicus) and exotic (Panicum coloratum) forage grasses adapted to alkaline-sodic soils of the flooding pampa were analyzed. PSB represented 2-14% of cultivable rhizobacteria and Box-PCR fingerprinting revealed a high genetic diversity in both rhizospheres. Taxonomic identification by MALDI-TOF showed that PSB populations of P. coloratum and S. indicus rhizospheres are dominated by the phylum Proteobacteria (92,51% and 96,60% respectively) and to a lesser extent (< 10%), by the phyla Actinobacteria and Firmicutes. At the genus level, both PSB populations were dominated by Enterobacter and Pseudomonas. Siderophore production, nitrogen fixation, and indoleacetic acid production were detected in a variety of PSB genera of both plant species. A higher proportion of siderophore and IAA producers were associated to P. coloratum than S. indicus, probably reflecting a greater dependence of the exotic species on rhizospheric microorganisms to satisfy its nutritional requirements in the soils of the flooding pampa. This work provides a novel knowledge about functional groups of bacteria associated to plants given that there are no previous reports dedicated to the characterization of PSB rhizosphere communities of S indicus and P coloratum. Finally, it should be noted that the collection obtained in this study can be useful for the development of bioinputs that allow reducing the use of chemical fertilizers, providing sustainability to pasture production systems for livestock.
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Affiliation(s)
- Diana Patricia Dip
- Instituto Tecnológico Chascomús (INTECH), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Universidad Nacional de San Martín (UNSAM), Avenida Intendente Marino, Km 8.2, 7130, Chascomús, Buenos Aires, Argentina
| | - Analía Inés Sannazzaro
- Instituto Tecnológico Chascomús (INTECH), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Universidad Nacional de San Martín (UNSAM), Avenida Intendente Marino, Km 8.2, 7130, Chascomús, Buenos Aires, Argentina
| | - José Otondo
- Instituto Nacional de Tecnología Agropecuaria INTA, EEA Cuenca del Salado, Chascomús, Argentina
| | - Mariano Pistorio
- Instituto de Biotecnología y Biología Molecular (IBBM), Consejo Nacional de Investigaciones Científicas y Técnicas - Universidad Nacional de La Plata (UNLP), La Plata, Buenos Aires, Argentina
| | - María Julia Estrella
- Instituto Tecnológico Chascomús (INTECH), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Universidad Nacional de San Martín (UNSAM), Avenida Intendente Marino, Km 8.2, 7130, Chascomús, Buenos Aires, Argentina.
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Protachevicz AP, Paulitsch F, Klepa MS, Hainosz J, Olchanheski LR, Hungria M, Stefania da Silva Batista J. Pioneering Desmodium spp. are nodulated by natural populations of stress-tolerant alpha- and beta-rhizobia. Braz J Microbiol 2023; 54:3127-3135. [PMID: 37673840 PMCID: PMC10689651 DOI: 10.1007/s42770-023-01113-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Accepted: 08/23/2023] [Indexed: 09/08/2023] Open
Abstract
The rhizobia-Desmodium (Leguminosae, Papilionoideae) symbiosis is generally described by its specificity with alpha-rhizobia, especially with Bradyrhizobium. Our study aimed to isolate rhizobia from root nodules of native D. barbatum, D. incanum, and D. discolor, collected in remnants of the biomes of Atlantic Forest and Cerrado in protected areas of the Paraná State, southern Brazil. Based on the 16S rRNA phylogeny, 18 out of 29 isolates were classified as Alphaproteobacteria (Bradyrhizobium and Allorhizobium/Rhizobium) and 11 as Betaproteobacteria (Paraburkholderia). Phylogeny of the recA gene of the alpha-rhizobia resulted in ten main clades, of which two did not group with any described rhizobial species. In the 16S rRNA phylogeny of the beta-rhizobia, Paraburkholderia strains from the same host and conservation unity occupied the same clade. Phenotypic characterization of representative strains revealed the ability of Desmodium rhizobia to grow under stressful conditions such as high temperature, salinity, low pH conditions, and tolerance of heavy metals and xenobiotic compounds. Contrasting with previous reports, our results revealed that Brazilian native Desmodium can exploit symbiotic interactions with stress-tolerant strains of alpha- and beta-rhizobia. Stress tolerance can highly contribute to the ecological success of Desmodium in this phytogeographic region, possibly relating to its pioneering ability in Brazil. We propose Desmodium as a promising model for studies of plant-rhizobia interactions.
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Affiliation(s)
- Ana Paolla Protachevicz
- Departamento de Biologia Estrutural, Molecular E Genética, Universidade Estadual de Ponta Grossa, C.P. 6001, Ponta Grossa, PR, 84030-900, Brazil
| | - Fabiane Paulitsch
- Departamento de Biologia Estrutural, Molecular E Genética, Universidade Estadual de Ponta Grossa, C.P. 6001, Ponta Grossa, PR, 84030-900, Brazil
| | | | - Jessica Hainosz
- Departamento de Biologia Estrutural, Molecular E Genética, Universidade Estadual de Ponta Grossa, C.P. 6001, Ponta Grossa, PR, 84030-900, Brazil
| | - Luiz Ricardo Olchanheski
- Departamento de Biologia Estrutural, Molecular E Genética, Universidade Estadual de Ponta Grossa, C.P. 6001, Ponta Grossa, PR, 84030-900, Brazil
| | | | - Jesiane Stefania da Silva Batista
- Departamento de Biologia Estrutural, Molecular E Genética, Universidade Estadual de Ponta Grossa, C.P. 6001, Ponta Grossa, PR, 84030-900, Brazil.
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Zuber NE, Fornasero LV, Erdozain Bagolín SA, Lozano MJ, Sanjuán J, Del Papa MF, Lagares A. Diversity, Genomics and Symbiotic Characteristics of Sinorhizobia That Nodulate Desmanthus spp. in Northwest Argentina. BIOLOGY 2023; 12:958. [PMID: 37508388 PMCID: PMC10376216 DOI: 10.3390/biology12070958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2023] [Revised: 06/26/2023] [Accepted: 06/27/2023] [Indexed: 07/30/2023]
Abstract
Desmanthus spp. are legumes with the ability to associate with diverse α-proteobacteria-a microsymbiont-in order to establish nitrogen-fixing root nodules. A previous investigation from our laboratory revealed that the main bacteria associated with Desmanthus paspalaceus in symbiosis in central Argentina (Province of Santa Fe) were quite diverse and belonged to the genera Rhizobium and Mesorhizobium. To achieve a more extensive view of the local microsymbionts associated with Desmanthus spp., we sampled three different sites in Jujuy and Salta, in northwest Argentina. Matrix-assisted Laser-Desorption-Ionization Time-of-Flight mass spectrometry (MALDI-TOF) typing, 16S-rDNA analysis, and genome sequencing demonstrated that the dominant root-nodule microsymbionts belonged to the genus Sinorhizobium, with some sequenced genomes related to Sinorhizobium mexicanum, Sinorhizobium chiapanecum, and Sinorhizobium psoraleae. An analysis of nodA and nodC markers indicated that, in some of the isolates, horizontal gene transfer appeared to be responsible for the lack of congruence between the phylogenies of the chromosome and of the symbiotic region. These results revealed diverse evolutionary strategies for reaching the current Desmanthus-microsymbiont diversity. What is remarkable beside their observed genetic diversity is that the tolerance profiles of these isolates to abiotic stresses (temperature, salt concentration, pH) were quite coincident with the separation of the sinorhizobia according to place of origin, suggesting possible ecoedaphic adaptations. This observation, together with the higher aerial dry-weight matter that some isolates generated in Desmanthus virgatus cv. Marc when compared to the biomass generated by the commercial strain Sinorhizobium terangae CB3126, distinguish the collected sinorhizobia as constituting valuable germplasm for evaluation in local fields to select for more efficient symbiotic pairs.
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Affiliation(s)
- Nicolás Emilio Zuber
- IBBM-Instituto de Biotecnología y Biología Molecular, CONICET, CCT-La Plata, Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Calles 47 y 115, La Plata 1900, Argentina
- Facultad de Ciencias Agrarias, Universidad Nacional del Litoral, Esperanza 3080, Argentina
| | | | - Sofía Agostina Erdozain Bagolín
- IBBM-Instituto de Biotecnología y Biología Molecular, CONICET, CCT-La Plata, Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Calles 47 y 115, La Plata 1900, Argentina
| | - Mauricio Javier Lozano
- IBBM-Instituto de Biotecnología y Biología Molecular, CONICET, CCT-La Plata, Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Calles 47 y 115, La Plata 1900, Argentina
| | - Juan Sanjuán
- Departamento de Microbiología del Suelo y la Planta, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas (CSIC), E-18008 Granada, Spain
| | - María Florencia Del Papa
- IBBM-Instituto de Biotecnología y Biología Molecular, CONICET, CCT-La Plata, Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Calles 47 y 115, La Plata 1900, Argentina
| | - Antonio Lagares
- IBBM-Instituto de Biotecnología y Biología Molecular, CONICET, CCT-La Plata, Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Calles 47 y 115, La Plata 1900, Argentina
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de Azevedo EB, Pagel R, Maggio LP, Chiapinotto DM, Conterato IF, Schneider AA, Schaedler CE, de David DB. Germination, overcoming seed dormancy and endozoochory dispersal by cattle of native species from natural grassland. AUSTRAL ECOL 2023. [DOI: 10.1111/aec.13303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/12/2023]
Affiliation(s)
- Eduardo Bohrer de Azevedo
- Federal University of Santa Maria (UFSM) Santa Maria Brazil
- Federal University of Pampa (UNIPAMPA) Itaqui Brazil
| | - Reimar Pagel
- Federal University of Pampa (UNIPAMPA) Itaqui Brazil
| | | | - Diego Martins Chiapinotto
- Federal University of Pampa (UNIPAMPA) Itaqui Brazil
- Federal University of Pelotas (UFPel) Pelotas Brazil
| | | | | | - Carlos Eduardo Schaedler
- Federal University of Pampa (UNIPAMPA) Itaqui Brazil
- Sul‐Rio‐Grandense Federal Institute (IFSul) Bagé Brazil
| | - Diego Bitencourt de David
- Federal University of Pampa (UNIPAMPA) Itaqui Brazil
- Department of Diagnosis and Agricultural Research (DDPA) São Gabriel Brazil
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Evolutionary origin and ecological implication of a unique nif island in free-living Bradyrhizobium lineages. THE ISME JOURNAL 2021; 15:3195-3206. [PMID: 33990706 PMCID: PMC8528876 DOI: 10.1038/s41396-021-01002-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 04/21/2021] [Accepted: 04/28/2021] [Indexed: 02/03/2023]
Abstract
The alphaproteobacterial genus Bradyrhizobium has been best known as N2-fixing members that nodulate legumes, supported by the nif and nod gene clusters. Recent environmental surveys show that Bradyrhizobium represents one of the most abundant free-living bacterial lineages in the world's soils. However, our understanding of Bradyrhizobium comes largely from symbiotic members, biasing the current knowledge of their ecology and evolution. Here, we report the genomes of 88 Bradyrhizobium strains derived from diverse soil samples, including both nif-carrying and non-nif-carrying free-living (nod free) members. Phylogenomic analyses of these and 252 publicly available Bradyrhizobium genomes indicate that nif-carrying free-living members independently evolved from symbiotic ancestors (carrying both nif and nod) multiple times. Intriguingly, the nif phylogeny shows that the vast majority of nif-carrying free-living members comprise an independent cluster, indicating that horizontal gene transfer promotes nif expansion among the free-living Bradyrhizobium. Comparative genomics analysis identifies that the nif genes found in free-living Bradyrhizobium are located on a unique genomic island of ~50 kb equipped with genes potentially involved in coping with oxygen tension. We further analyze amplicon sequencing data to show that Bradyrhizobium members presumably carrying this nif island are widespread in a variety of environments. Given the dominance of Bradyrhizobium in world's soils, our findings have implications for global nitrogen cycles and agricultural research.
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7
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Toniutti MA, Albicoro FJ, Castellani LG, López García SL, Fornasero LV, Zuber NE, Vera LM, Vacca C, Cafiero JH, Winkler A, Kalinowski J, Lagares A, Torres Tejerizo GA, Del Papa MF. Genome sequence of Bradyrhizobium yuanmingense strain P10 130, a highly efficient nitrogen-fixing bacterium that could be used for Desmodium incanum inoculation. Gene 2020; 768:145267. [PMID: 33122079 DOI: 10.1016/j.gene.2020.145267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Revised: 08/08/2020] [Accepted: 10/20/2020] [Indexed: 10/23/2022]
Abstract
Strain P10 130, an isolated Bradyrhizobium strain from Argentina which promotes the growth of the leguminous plant Desmodium incanum by different mechanisms was previously selected as the best candidate for D. incanum inoculation based on broader selective criteria. A close relationship between this strain and B. yuanmingense was determined by MALDI BioTyper identification and 16S rRNA gene phylogenetic analysis. This study aimed to analyse the genome sequence of B. yuanmingense P10 130 in order to deepen our knowledge regarding its plant growth-promoting traits and to establish its phylogenetic relationship with other species of Bradyrhizobium genus. The genome size of strain P10 130 was estimated to be 7.54 Mb that consisted of 65 contigs. Genome Average Nucleotide Identity (ANI) analysis revealed that B. yuanmingense CCBAU 10071 T was the closest strain to P10 130 with ca. 96% identity. Further analysis of the genome of B. yuanmingense P10 130 identified 20 nod/nol/NOE, 14 nif/18 fix, 5 nap/5 nor genes, which may be potentially involved in nodulation, nitrogen fixation, and denitrification process respectively. Genome sequence of B. yuanmingense P10 130 is a valuable source of information to continue the research of its potential industrial production as a biofertilizer of D. incanum.
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Affiliation(s)
| | - Francisco Javier Albicoro
- IBBM - Instituto de Biotecnología y Biología Molecular, CONICET - Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Calles 47 y 115 (1900) La Plata, Argentina
| | - Lucas Gabriel Castellani
- IBBM - Instituto de Biotecnología y Biología Molecular, CONICET - Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Calles 47 y 115 (1900) La Plata, Argentina
| | - Silvina Laura López García
- IBBM - Instituto de Biotecnología y Biología Molecular, CONICET - Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Calles 47 y 115 (1900) La Plata, Argentina
| | | | - Nicolás Emilio Zuber
- IBBM - Instituto de Biotecnología y Biología Molecular, CONICET - Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Calles 47 y 115 (1900) La Plata, Argentina
| | - Leda Mailén Vera
- IBBM - Instituto de Biotecnología y Biología Molecular, CONICET - Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Calles 47 y 115 (1900) La Plata, Argentina
| | - Carolina Vacca
- IBBM - Instituto de Biotecnología y Biología Molecular, CONICET - Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Calles 47 y 115 (1900) La Plata, Argentina
| | - Juan Hilario Cafiero
- IBBM - Instituto de Biotecnología y Biología Molecular, CONICET - Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Calles 47 y 115 (1900) La Plata, Argentina
| | - Anika Winkler
- CeBiTec - Centrum für Biotechnologie, Universität Bielefeld, Bielefeld, Germany
| | - Jörn Kalinowski
- CeBiTec - Centrum für Biotechnologie, Universität Bielefeld, Bielefeld, Germany
| | - Antonio Lagares
- IBBM - Instituto de Biotecnología y Biología Molecular, CONICET - Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Calles 47 y 115 (1900) La Plata, Argentina
| | - Gonzalo Arturo Torres Tejerizo
- IBBM - Instituto de Biotecnología y Biología Molecular, CONICET - Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Calles 47 y 115 (1900) La Plata, Argentina.
| | - María Florencia Del Papa
- IBBM - Instituto de Biotecnología y Biología Molecular, CONICET - Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Calles 47 y 115 (1900) La Plata, Argentina.
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Zhou Z, Yu M, Ding G, Gao G, He Y, Wang G. Effects of Hedysarum leguminous plants on soil bacterial communities in the Mu Us Desert, northwest China. Ecol Evol 2020; 10:11423-11439. [PMID: 33144975 PMCID: PMC7593153 DOI: 10.1002/ece3.6779] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 08/16/2020] [Accepted: 08/18/2020] [Indexed: 11/19/2022] Open
Abstract
This study assessed the influence of rhizocompartment types (i.e., root, rhizosphere soil, root-zone soil, and intershrub bulk soil) on the diversity of soil microbial communities under desert leguminous plant shrubs. Moreover, the influence and variations of soil physicochemical factors in interactions among leguminous plants, soil, and microbes were investigated. Both 16S rRNA high-throughput genome sequencing and conventional soil physicochemical index determination were used to characterize both the bacterial diversity and soil physicochemical properties in the rhizocompartments of two Hedysarum species (Hedysarum mongolicum and Hedysarum scoparium) in the Mu Us Desert of China. All nutrient indices (except total phosphorus and available phosphorus) in rhizosphere soil were uniformly higher than those in both root-zone soil and intershrub bulk soil (p < .05). The bacterial community diversity in the root, undershrub soil (i.e., rhizosphere and root zone), and intershrub bulk soil also showed significant differences (p < .05). The bacterial community in the root is mainly composed of Proteobacteria, Actinobacteria, Bacteroidetes, Tenericutes, and Chloroflexi, among which bacteria of the Proteobacteria genus are dominant. Root endophyte and rhizosphere soil microbiomes were mainly influenced by soil nutrients, while bacterial communities in root-zone soil and intershrub bulk soil were mainly influenced by soil pH and NH4 +-N. The rhizocompartment types of desert leguminous plants impose a significant influence on the diversity of soil microbial communities. According to these findings, nitrogen-fixing rhizobia can co-exist with nonsymbiotic endophytes in the roots of desert leguminous plants. Moreover, plants have a hierarchical filtering and enriching effect on beneficial microbes in soil via rhizocompartments. Soil physicochemical factors have a significant influence on both the structure and composition of microbial communities in various rhizocompartments, which is derived from the interactions among leguminous plants, soil, and microbes.
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Affiliation(s)
- Ziyuan Zhou
- Yanchi Research StationSchool of Soil and Water ConservationBeijing Forestry UniversityBeijingChina
- Key Laboratory of State Forestry Administration on Soil and Water ConservationBeijing Forestry UniversityBeijingChina
| | - Minghan Yu
- Yanchi Research StationSchool of Soil and Water ConservationBeijing Forestry UniversityBeijingChina
- Key Laboratory of State Forestry Administration on Soil and Water ConservationBeijing Forestry UniversityBeijingChina
| | - Guodong Ding
- Yanchi Research StationSchool of Soil and Water ConservationBeijing Forestry UniversityBeijingChina
- Key Laboratory of State Forestry Administration on Soil and Water ConservationBeijing Forestry UniversityBeijingChina
| | - Guanglei Gao
- Yanchi Research StationSchool of Soil and Water ConservationBeijing Forestry UniversityBeijingChina
- Key Laboratory of State Forestry Administration on Soil and Water ConservationBeijing Forestry UniversityBeijingChina
| | - Yingying He
- Yanchi Research StationSchool of Soil and Water ConservationBeijing Forestry UniversityBeijingChina
- Key Laboratory of State Forestry Administration on Soil and Water ConservationBeijing Forestry UniversityBeijingChina
| | - Genzhu Wang
- Key Laboratory of State Forestry Administration on Soil and Water ConservationBeijing Forestry UniversityBeijingChina
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Agaras BC, Iriarte A, Valverde CF. Genomic insights into the broad antifungal activity, plant-probiotic properties, and their regulation, in Pseudomonas donghuensis strain SVBP6. PLoS One 2018. [PMID: 29538430 PMCID: PMC5851621 DOI: 10.1371/journal.pone.0194088] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Plant-growth promotion has been linked to the Pseudomonas genus since the beginning of this research field. In this work, we mined the genome of an Argentinean isolate of the recently described species P. donghuensis. Strain SVBP6, isolated from bulk soil of an agricultural plot, showed a broad antifungal activity and several other plant-probiotic activities. As this species has been recently described, and it seems like some plant-growth promoting (PGP) traits do not belong to the classical pseudomonads toolbox, we decide to explore the SVBP6 genome via an bioinformatic approach. Genome inspection confirmed our previous in vitro results about genes involved in several probiotic activities. Other genetic traits possibly involved in survival of SVBP6 in highly competitive environments, such as rhizospheres, were found. Tn5 mutagenesis revealed that the antifungal activity against the soil pathogen Macrophomina phaseolina was dependent on a functional gacS gene, from the regulatory cascade Gac-Rsm, but it was not due to volatile compounds. Altogether, our genomic analyses and in vitro tests allowed the phylogenetic assignment and provided the first insights into probiotic properties of the first P. donghuensis isolate from the Americas.
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Affiliation(s)
- Betina Cecilia Agaras
- Laboratorio de Bioquímica, Microbiología e Interacciones Biológicas en el Suelo, Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Bernal, Buenos Aires, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Andrés Iriarte
- Laboratorio de Biología Computacional, Departamento de Desarrollo Biotecnológico, Instituto de Higiene, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Claudio Fabián Valverde
- Laboratorio de Bioquímica, Microbiología e Interacciones Biológicas en el Suelo, Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Bernal, Buenos Aires, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
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