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Liu C, Deng J. High-throughput sequencing-based analysis of the composition and diversity of the endophytic bacterial community in the roots of Dipsacus asperoides. 3 Biotech 2024; 14:149. [PMID: 38725865 PMCID: PMC11076436 DOI: 10.1007/s13205-024-03986-9] [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: 11/08/2023] [Accepted: 04/03/2024] [Indexed: 05/12/2024] Open
Abstract
This study employed Illumina high-throughput sequencing technology to investigate diversity and community structure of endophytic bacteria in wild D. asperoides growing in three distinct regions. The study analyzed the impact of region on endophytic bacteria, uncovered the core bacterial community, and furnished valuable insights for the screening of endophytic bacteria. This study identified 6,540 amplicon sequence variants (ASVs) coexisting with D. asperoides roots. These ASVs belong to 35 phyla, 84 classes, 204 orders, 365 families, and 708 genera. At the phylum level, the dominant phyla were Proteobacteria and Actinobacteria, while at the genus level, Acidothermus, Acidibacter, Bradyrhizobium, Frankia, and Pseudomonas emerged as the dominant genera. Furthermore, noticeable differences in endophytic bacterial communities were observed between the Yunnan and Guizhou regions. These findings can serve as a reference for the authentication of medicinal materials from various origins and the selection of active strains.
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Affiliation(s)
- Chao Liu
- Orthopedics Department of Hubei No. 3 People’s Hospital of Jianghan University, Wuhan, 430034 China
| | - Jun Deng
- Health Management (Physical Examination) Department of Hubei No. 3 People’s Hospital of Jianghan University, Wuhan, 430034 China
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Hnini M, Aurag J. Prevalence, diversity and applications potential of nodules endophytic bacteria: a systematic review. Front Microbiol 2024; 15:1386742. [PMID: 38812696 PMCID: PMC11133547 DOI: 10.3389/fmicb.2024.1386742] [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: 02/16/2024] [Accepted: 04/29/2024] [Indexed: 05/31/2024] Open
Abstract
Legumes are renowned for their distinctive biological characteristic of forming symbiotic associations with soil bacteria, mostly belonging to the Rhizobiaceae familiy, leading to the establishment of symbiotic root nodules. Within these nodules, rhizobia play a pivotal role in converting atmospheric nitrogen into a plant-assimilable form. However, it has been discerned that root nodules of legumes are not exclusively inhabited by rhizobia; non-rhizobial endophytic bacteria also reside within them, yet their functions remain incompletely elucidated. This comprehensive review synthesizes available data, revealing that Bacillus and Pseudomonas are the most prevalent genera of nodule endophytic bacteria, succeeded by Paenibacillus, Enterobacter, Pantoea, Agrobacterium, and Microbacterium. To date, the bibliographic data available show that Glycine max followed by Vigna radiata, Phaseolus vulgaris and Lens culinaris are the main hosts for nodule endophytic bacteria. Clustering analysis consistently supports the prevalence of Bacillus and Pseudomonas as the most abundant nodule endophytic bacteria, alongside Paenibacillus, Agrobacterium, and Enterobacter. Although non-rhizobial populations within nodules do not induce nodule formation, their presence is associated with various plant growth-promoting properties (PGPs). These properties are known to mediate important mechanisms such as phytostimulation, biofertilization, biocontrol, and stress tolerance, emphasizing the multifaceted roles of nodule endophytes. Importantly, interactions between non-rhizobia and rhizobia within nodules may exert influence on their leguminous host plants. This is particularly shown by co-inoculation of legumes with both types of bacteria, in which synergistic effects on plant growth, yield, and nodulation are often measured. Moreover these effects are pronounced under both stress and non-stress conditions, surpassing the impact of single inoculations with rhizobia alone.
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Affiliation(s)
| | - Jamal Aurag
- Microbiology and Molecular Biology Team, Center of Plant and Microbial Biotechnology, Biodiversity and Environment, Faculty of Sciences, Mohammed V University in Rabat, Rabat, Morocco
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Feigl V, Medgyes-Horváth A, Kari A, Török Á, Bombolya N, Berkl Z, Farkas É, Fekete-Kertész I. The potential of Hungarian bauxite residue isolates for biotechnological applications. BIOTECHNOLOGY REPORTS (AMSTERDAM, NETHERLANDS) 2024; 41:e00825. [PMID: 38225962 PMCID: PMC10788403 DOI: 10.1016/j.btre.2023.e00825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 12/14/2023] [Accepted: 12/19/2023] [Indexed: 01/17/2024]
Abstract
Bauxite residue (red mud) is considered an extremely alkaline and salty environment for the biota. We present the first attempt to isolate, identify and characterise microbes from Hungarian bauxite residues. Four identified bacterial strains belonged to the Bacilli class, one each to the Actinomycetia, Gammaproteobacteria, and Betaproteobacteria classes, and two to the Alphaproteobacteria class. All three identified fungi strains belonged to the Ascomycota division. Most strains tolerated pH 8-10 and salt content at 5-7% NaCl concentration. Alkalihalobacillus pseudofirmus BRHUB7 and Robertmurraya beringensis BRHUB9 can be considered halophilic and alkalitolerant. Priestia aryabhattai BRHUB2, Penicillium chrysogenum BRHUF1 and Aspergillus sp. BRHUF2 are halo- and alkalitolerant strains. Most strains produced siderophores and extracellular polymeric substances, could mobilise phosphorous, and were cellulose degraders. These strains and their enzymes are possible candidates for biotechnological applications in processes requiring extreme conditions, e.g. bioleaching of critical raw materials and rehabilitation of alkaline waste deposits.
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Affiliation(s)
- Viktória Feigl
- Budapest University of Technology and Economics, Faculty of Chemical Technology and Biotechnology, Department of Applied Biotechnology and Food Science, Műegyetem Rkp 3., Budapest 1111, Hungary
| | - Anna Medgyes-Horváth
- ELTE Eötvös Loránd University, Department of Physics of Complex Systems, Pázmány P. s. 1A, Budapest 1117, Hungary
| | - András Kari
- ELTE Eötvös Loránd University, Department of Microbiology, Pázmány P. s. 1A, Budapest 1117, Hungary
| | - Ádám Török
- Budapest University of Technology and Economics, Faculty of Chemical Technology and Biotechnology, Department of Applied Biotechnology and Food Science, Műegyetem Rkp 3., Budapest 1111, Hungary
| | - Nelli Bombolya
- Budapest University of Technology and Economics, Faculty of Chemical Technology and Biotechnology, Department of Applied Biotechnology and Food Science, Műegyetem Rkp 3., Budapest 1111, Hungary
| | - Zsófia Berkl
- Budapest University of Technology and Economics, Faculty of Chemical Technology and Biotechnology, Department of Applied Biotechnology and Food Science, Műegyetem Rkp 3., Budapest 1111, Hungary
| | - Éva Farkas
- Budapest University of Technology and Economics, Faculty of Chemical Technology and Biotechnology, Department of Applied Biotechnology and Food Science, Műegyetem Rkp 3., Budapest 1111, Hungary
- Norwegian Institute of Bioeconomy Research (NIBIO), Division of Environment and Natural Resources, Department of Biogeochemistry and Soil Quality, Høgskoleveien 7, 1432 Ås, Norway
| | - Ildikó Fekete-Kertész
- Budapest University of Technology and Economics, Faculty of Chemical Technology and Biotechnology, Department of Applied Biotechnology and Food Science, Műegyetem Rkp 3., Budapest 1111, Hungary
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Yuan T, Qazi IH, Li J, Yang P, Yang H, Zhang X, Liu W, Liu J. Analysis of changes in bacterial diversity in healthy and bacterial wilt mulberry samples using metagenomic sequencing and culture-dependent approaches. FRONTIERS IN PLANT SCIENCE 2023; 14:1206691. [PMID: 37680359 PMCID: PMC10481342 DOI: 10.3389/fpls.2023.1206691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2023] [Accepted: 07/21/2023] [Indexed: 09/09/2023]
Abstract
Introduction Mulberry bacterial wilt is a serious destructive soil-borne disease caused by a complex and diverse group of pathogenic bacteria. Given that the bacterial wilt has been reported to cause a serious damage to the yield and quality of mulberry, therefore, elucidation of its main pathogenic groups is essential in improving our understanding of this disease and for the development of its potential control measures. Methods In this study, combined metagenomic sequencing and culture-dependent approaches were used to investigate the microbiome of healthy and bacterial wilt mulberry samples. Results The results showed that the healthy samples had higher bacterial diversity compared to the diseased samples. Meanwhile, the proportion of opportunistic pathogenic and drug-resistant bacterial flora represented by Acinetobacter in the diseased samples was increased, while the proportion of beneficial bacterial flora represented by Proteobacteria was decreased. Ralstonia solanacearum species complex (RSSC), Enterobacter cloacae complex (ECC), Klebsiella pneumoniae, K. quasipneumoniae, K. michiganensis, K. oxytoca, and P. ananatis emerged as the main pathogens of the mulberry bacterial wilt. Discussion In conclusion, this study provides a valuable reference for further focused research on the bacterial wilt of mulberry and other plants.
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Affiliation(s)
| | | | | | | | | | | | | | - Jiping Liu
- South China Agriculture University, College of Animal Science, Regional Sericulture Training Center for Asia-Pacific, Guangzhou, Guangdong, China
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Liu F, Yuan ZS, Zeng ZH, Pan H. Effects of high- and low-yield moso bamboo (Phyllostachys edulis) forests on bacterial community structure. Sci Rep 2023; 13:9833. [PMID: 37330578 PMCID: PMC10276864 DOI: 10.1038/s41598-023-36979-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Accepted: 06/13/2023] [Indexed: 06/19/2023] Open
Abstract
To study the characteristics of bacterial community structure in high-yield and low-yield moso bamboo (Phyllostachys edulis) forests, we collected bamboo rhizome, rhizome root, stem, leaf, rhizosphere soil, and non-rhizosphere soil from high- and low-yield forests in Yong'an City and Jiangle County of Fujian Province, China. The genomic DNA of the samples was extracted, sequenced and analyzed. The results show that: the common differences between the high-yield and low-yield P. edulis forest samples in the two regions were mainly in bacterial community compositions in the bamboo rhizome, rhizome root, and soil samples. Differences in the bacterial community compositions in the stem and leaf samples were insignificant. The bacterial species and diversity in rhizome root and rhizosphere soil of high-yield P. edulis forests were less than those of low-yield forests. The relative abundance of Actinobacteria and Acidobacteria in rhizome root samples of high-yield forests was higher than that in low-yield forests. The relative abundance of Rhizobiales and Burkholderiales in bamboo rhizome samples in high-yield forests was higher than that in low-yield forests. The relative abundance of Bradyrhizobium in bamboo rhizome samples in high-yield forests was higher than that in low-yield forests in the two regions. The change of bacterial community composition in P. edulis stems and leaves showed little correlation with high- or low-yields of P. edulis forests. Notably, the bacterial community composition of the rhizome root system was correlated with the high yield of bamboo. This study provides a theoretical basis for using of microbes to enhance the yields of P. edulis forests.
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Affiliation(s)
- Fang Liu
- College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, Fujian, China
| | - Zong-Sheng Yuan
- Institute of Oceanography, Minjiang University, Minhou County, Fuzhou, 350108, Fujian, China.
| | - Zhi-Hao Zeng
- College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, Fujian, China
| | - Hui Pan
- Institute of Oceanography, Minjiang University, Minhou County, Fuzhou, 350108, Fujian, China
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Evaluation of inorganic phosphate solubilizing efficiency and multiple plant growth promoting properties of endophytic bacteria isolated from root nodules Erythrina brucei. BMC Microbiol 2022; 22:276. [PMCID: PMC9675159 DOI: 10.1186/s12866-022-02688-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Accepted: 11/02/2022] [Indexed: 11/21/2022] Open
Abstract
Background In soils, phosphorous (P) mostly exists in fixed/insoluble form and unavailable for plants use in soil solution, hence it is in scarcity. P is fixed in the form of aluminium, iron and manganese phosphates in acidic soils and calcium phosphate in alkaline soils. Phosphate solubilizing bacteria, the ecological engineers play a pivotal role in the mobilization of fixed forms of P by using different mechanisms. The objectives of this study were to evaluate inorganic phosphate solubilizing efficiency and other multiple plant growth promoting traits of Erythrina brucei root nodule endophytic bacteria and to investigate effects of the selected endophytic bacteria on the growth of wheat plant under phosphorous deficient sand culture at greenhouse conditions. Results Among a total of 304 passenger endophytic bacteria, 119 (39%) exhibited tricalcium phosphate (TCP) solubilization; however, none of them were formed clear halos on solid medium supplemented with aluminum phosphate (Al-P) or iron phosphate (Fe–P). Among 119 isolates, 40% exhibited IAA production. The selected nine potential isolates also exhibited potentials of IAA, HCN, NH3 and/or hydrolytic enzymes production. All the selected isolates were potential solubilizers of the three inorganic phosphates (Al-P, Fe–P and TCP) included in liquid medium. The highest values of solubilized TCP were recorded by isolates AU4 and RG6 (A. soli), 108.96 mg L−1 and 107.48 mg L−1, respectively at sampling day3 and 120.36 mg L−1 and 112.82 mg L−1, respectively at day 6. The highest values of solubilized Al-P and Fe–P were recorded by isolate RG6, 102.14 mg L−1 and 96.07 mg L−1, respectively at sampling days 3 and 6, respectively. The highest IAA, 313.61 µg mL−1 was recorded by isolate DM17 (Bacillus thuringiensis). Inoculation of wheat with AU4, RG6 and RG5 (Acinetobacter soli) increased shoot length by 11, 17.4 and 14.6%, respectively compared to the negative control. Similarly, 76.9, 69.2 and 53.8% increment in shoot dry weight is recorded by inoculation with RG6, AU4 and RG5, respectively. These nine potential endophytic isolates are identified to Gluconobacter cerinus (4), Acinetobacter soli (3), Achromobacter xylosoxidans (1) and Bacillus thuringiensis (1). Conclusion AU4, RG6 and RG5 can be potential bio-inoculants candidates as low cost agricultural inputs in acidic and/or alkaline soils for sustainable crop production. Supplementary Information The online version contains supplementary material available at 10.1186/s12866-022-02688-7.
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Broccanello C, Ravi S, Deb S, Bolton M, Secor G, Richards C, Maretto L, Lucia MCD, Bertoldo G, Orsini E, Ronquillo-López MG, Concheri G, Campagna G, Squartini A, Stevanato P. Bacterial endophytes as indicators of susceptibility to Cercospora Leaf Spot (CLS) disease in Beta vulgaris L. Sci Rep 2022; 12:10719. [PMID: 35739218 PMCID: PMC9226160 DOI: 10.1038/s41598-022-14769-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 06/13/2022] [Indexed: 12/03/2022] Open
Abstract
The fungus Cercospora beticola causes Cercospora Leaf Spot (CLS) of sugar beet (Beta vulgaris L.). Despite the global importance of this disease, durable resistance to CLS has still not been obtained. Therefore, the breeding of tolerant hybrids is a major goal for the sugar beet sector. Although recent studies have suggested that the leaf microbiome composition can offer useful predictors to assist plant breeders, this is an untapped resource in sugar beet breeding efforts. Using Ion GeneStudio S5 technology to sequence amplicons from seven 16S rRNA hypervariable regions, the most recurring endophytes discriminating CLS-symptomatic and symptomless sea beets (Beta vulgaris L.ssp. maritima) were identified. This allowed the design of taxon-specific primer pairs to quantify the abundance of the most representative endophytic species in large naturally occurring populations of sea beet and subsequently in sugar beet breeding genotypes under either CLS symptomless or infection stages using qPCR. Among the screened bacterial genera, Methylobacterium and Mucilaginibacter were found to be significantly (p < 0.05) more abundant in symptomatic sea beets with respect to symptomless. In cultivated sugar beet material under CLS infection, the comparison between resistant and susceptible genotypes confirmed that the susceptible genotypes hosted higher contents of the above-mentioned bacterial genera. These results suggest that the abundance of these species can be correlated with increased sensitivity to CLS disease. This evidence can further prompt novel protocols to assist plant breeding of sugar beet in the pursuit of improved pathogen resistance.
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Affiliation(s)
- Chiara Broccanello
- Department of Agronomy, Food, Natural Resources, Animals and Environment, University of Padua, Viale Dell'Università, Legnaro, PD, Italy
| | - Samathmika Ravi
- Department of Agronomy, Food, Natural Resources, Animals and Environment, University of Padua, Viale Dell'Università, Legnaro, PD, Italy
| | - Saptarathi Deb
- Department of Agronomy, Food, Natural Resources, Animals and Environment, University of Padua, Viale Dell'Università, Legnaro, PD, Italy
| | - Melvin Bolton
- Northern Crop Science Laboratory, U.S. Dept. Agriculture, Fargo, ND, USA
| | - Gary Secor
- Plant Pathology Department, North Dakota State University, Fargo, ND, USA
| | | | - Laura Maretto
- Department of Agronomy, Food, Natural Resources, Animals and Environment, University of Padua, Viale Dell'Università, Legnaro, PD, Italy
| | - Maria Cristina Della Lucia
- Department of Agronomy, Food, Natural Resources, Animals and Environment, University of Padua, Viale Dell'Università, Legnaro, PD, Italy
| | - Giovanni Bertoldo
- Department of Agronomy, Food, Natural Resources, Animals and Environment, University of Padua, Viale Dell'Università, Legnaro, PD, Italy
| | - Elena Orsini
- Strube Research GmbH & Co. KG, Söllingen, Germany
| | | | - Giuseppe Concheri
- Department of Agronomy, Food, Natural Resources, Animals and Environment, University of Padua, Viale Dell'Università, Legnaro, PD, Italy
| | | | - Andrea Squartini
- Department of Agronomy, Food, Natural Resources, Animals and Environment, University of Padua, Viale Dell'Università, Legnaro, PD, Italy
| | - Piergiorgio Stevanato
- Department of Agronomy, Food, Natural Resources, Animals and Environment, University of Padua, Viale Dell'Università, Legnaro, PD, Italy.
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Proteome and Physiological Characterization of Halotolerant Nodule Endophytes: The Case of Rahnella aquatilis and Serratia plymuthica. Microorganisms 2022; 10:microorganisms10050890. [PMID: 35630335 PMCID: PMC9143289 DOI: 10.3390/microorganisms10050890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 04/22/2022] [Accepted: 04/22/2022] [Indexed: 02/06/2023] Open
Abstract
Bacterial endophytes were isolated from nodules of pea and fava bean. The strains were identified and characterized for plant beneficial activities (phosphate solubilization, synthesis of indole acetic acid and siderophores) and salt tolerance. Based on these data, four strains of Rahnella aquatilis and three strains of Serratia plymuthica were selected. To shed light on the mechanisms underlying salt tolerance, the proteome of the two most performant strains (Ra4 and Sp2) grown in the presence or not of salt was characterized. The number of proteins expressed by the endophytes was higher in the presence of salt. The modulated proteome consisted of 302 (100 up-regulated, 202 down-regulated) and 323 (206 up-regulated, 117 down-regulated) proteins in Ra4 and Sp2, respectively. Overall, proteins involved in abiotic stress responses were up-regulated, while those involved in metabolism and flagellum structure were down-regulated. The main up-regulated proteins in Sp2 were thiol: disulfide interchange protein DsbA, required for the sulfur binding formation in periplasmic proteins, while in Ra4 corresponded to the soluble fraction of ABC transporters, having a role in compatible solute uptake. Our results demonstrated a conserved response to salt stress in the two taxonomically related species.
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Mucilaginibacter sp. Strain Metal(loid) and Antibiotic Resistance Isolated from Estuarine Soil Contaminated Mine Tailing from the Fundão Dam. Genes (Basel) 2022; 13:genes13020174. [PMID: 35205220 PMCID: PMC8871858 DOI: 10.3390/genes13020174] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 01/05/2022] [Accepted: 01/14/2022] [Indexed: 12/30/2022] Open
Abstract
In 2015 a mine dam with Mn-Fe-rich tailings collapsed releasing million tons of sediments over an estuary, in the Southwest of Brazil. The tailings have a high concentration of metals that contaminated soil until the present day. The high contaminant concentrations possibly caused a selection for microorganisms able to strive in such harsh conditions. Here, we isolated metal(loid) and anti-biotic resistance bacteria from the contaminated estuarine soil. After 16S rDNA sequencing to identify the strains, we selected the Mucilaginibacter sp. strain for a whole-genome sequence due to the bioprospective potential of the genus and the high resistance profile. We obtained a complete genome and a genome-guided characterization. Our finding suggests that the 21p strain is possibly a new species of the genus. The species presented genes for resistance for metals (i.e., As, Zn, Co, Cd, and Mn) beyond resistance and cross-resistance for antibiotics (i.e., quinolone, aminoglycoside, β-lactamase, sulphonamide, tetracycline). The Mucilaginibacter sp. 21p description as new species should be further explored, as their extracellular polymeric substances and the potential of this strain as bioremediation and as a growth promoter in high met-al(loid) contaminated soil.
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Youseif SH, Abd El-Megeed FH, Abdelaal AS, Ageez A, Martínez-Romero E. Plant-microbe-microbe interactions influence the faba bean nodule colonization by diverse endophytic bacteria. FEMS Microbiol Ecol 2021; 97:6381688. [PMID: 34610117 DOI: 10.1093/femsec/fiab138] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 09/30/2021] [Indexed: 11/14/2022] Open
Abstract
Legume root nodules harbor rhizobia and other non-nodulating endophytes known as nodule-associated bacteria (NAB) whose role in the legume symbiosis is still unknown. We analysed the genetic diversity of 34 NAB isolates obtained from the root nodules of faba bean grown under various soil conditions in Egypt using 16S rRNA and concatenated sequences of three housekeeping genes. All isolates were identified as members of the family Enterobacteriaceae belonging to the genera Klebsiella, Enterobacter and Raoultella. We identified nine enterobacterial genospecies, most of which have not been previously reported as NAB. All isolated strains harbored nifH gene sequences and most of them possessed plant growth-promoting (PGP) traits. Upon co-inoculation with an N2 fixing rhizobium (Rlv NGB-FR128), two strains (Enterobacter sichanensis NGB-FR97 and Klebsiella variicola NGB-FR116) significantly increased nodulation, growth and N-uptake of faba bean plants over the single treatments or the uninoculated control. The presence of these enterobacteria in nodules was significantly affected by the host plant genotype, symbiotic rhizobium genotype and endophyte genotype, indicating that the nodule colonization process is regulated by plant-microbe-microbe interactions. This study emphasizes the importance of nodule-associated enterobacteria and suggests their potential role in improving the effectiveness of rhizobial inoculants.
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Affiliation(s)
- Sameh H Youseif
- Department of Microbial Genetic Resources, National Gene Bank, Agricultural Research Center (ARC), Giza 12619, Egypt
| | - Fayrouz H Abd El-Megeed
- Department of Microbial Genetic Resources, National Gene Bank, Agricultural Research Center (ARC), Giza 12619, Egypt
| | - Ali S Abdelaal
- Department of Genetics, Faculty of Agriculture, Damietta University, Damietta 34517, Egypt
| | - Amr Ageez
- Agricultural Genetic Engineering Research Institute, Agricultural Research Center (ARC), Giza 12619, Egypt.,Faculty of Biotechnology, MSA University, 6th of October City 12451, Egypt
| | - Esperanza Martínez-Romero
- Programa de Ecología Genómica, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62210, Mexico
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Fasusi OA, Amoo AE, Babalola OO. Characterization of plant growth-promoting rhizobacterial isolates associated with food plants in South Africa. Antonie van Leeuwenhoek 2021; 114:1683-1708. [PMID: 34387781 PMCID: PMC8448681 DOI: 10.1007/s10482-021-01633-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Accepted: 07/25/2021] [Indexed: 11/30/2022]
Abstract
The region around the plant root referred to as the rhizosphere, is the zone where various microbial activity occurs. It performs crucial functions such as increasing the uptake of nutrients for plant development and preventing plant against plant pathogens. Keeping in mind the beneficial role performed by rhizospheric microorganisms, rhizobacterial species were isolated from the maize and soybean plant's rhizosphere. The isolated microorganisms were evaluated for their biochemical characteristics, plant growth-promoting potentials, tolerance to different environmental conditions, and their antifungal activity against Fusarium graminearum, a fungal pathogen that infects maize. The rhizobacterial isolates with multiple plant growth-promoting potentials were identified as Bacillus spp (80.77%), Rhodocyclaceae bacterium (3.85%), Enterococcus spp (3.85%). Massilia spp (3.85%. and Pseudomonas (7.69%) species based on their 16S rRNA molecular characterization. The bacterial isolates possessed antifungal activities against Fusarium graminearum, promote maize and soybeans seed under laboratory conditions, and exhibited different levels of tolerance to pH, temperature, salt, and heavy metal. Based on this, the whole genome sequencing of Bacillus sp. OA1, Pseudomonas rhizosphaerea OA2, and Pseudomonas sp. OA3 was performed using Miseq Illumina system to determine the functional genes and secondary metabolites responsible for their plant growth-promoting potential Thus, the result of this research revealed that the selected bacterial isolates possess plant growth-promoting potentials that can make them a potential candidate to be employed as microbial inoculants for protecting plants against phytopathogens, environmental stress and increasing plant growth and productivity.
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Affiliation(s)
- Oluwaseun Adeyinka Fasusi
- Food Security and Safety Niche, Faculty of Natural and Agricultural Science, North-West University, Private Mail Bag X2046, Mmabatho, 2735, South Africa
| | - Adenike Eunice Amoo
- Food Security and Safety Niche, Faculty of Natural and Agricultural Science, North-West University, Private Mail Bag X2046, Mmabatho, 2735, South Africa
| | - Olubukola Oluranti Babalola
- Food Security and Safety Niche, Faculty of Natural and Agricultural Science, North-West University, Private Mail Bag X2046, Mmabatho, 2735, South Africa.
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Knežević M, Berić T, Buntić A, Delić D, Nikolić I, Stanković S, Stajković-Srbinović O. Potential of root nodule nonrhizobial endophytic bacteria for growth promotion of Lotus corniculatus L. and Dactylis glomerata L. J Appl Microbiol 2021; 131:2929-2940. [PMID: 34003543 DOI: 10.1111/jam.15152] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 05/11/2021] [Accepted: 05/11/2021] [Indexed: 11/29/2022]
Abstract
AIMS This research aimed to isolate and characterize nonrhizobial endophytic bacteria from root nodules of Medicago sativa L. and Lotus corniculatus L. with plant growth-promoting characteristics and to test its activity in a pot experiment with acid soil. METHODS AND RESULTS Out of 44 nonrhizobial isolates, the majority exhibited indole-3-acetic acid (IAA) production; 29 produced siderophores, few isolates performed phosphate solubilization and/or produced lytic enzymes, while 30% of isolates showed notable antifungal activity. The most promising strains were identified as members of Bacillus, Pseudomonas and Serratia genera, based on 16S rRNA. Bacillus megaterium DZK1BH exhibited the overall best attributes for plant growth promotion and positively influenced the growth of L. corniculatus and Dactylis glomerata. CONCLUSIONS Root nodule endophytic B. megaterium DZK1BH could potentially be used as a biofertilizer for growing L. corniculatus L. and D. glomerata L. in acid soils, while Bacillus mojavensis L3 is a candidate for further antifungal potential investigation. SIGNIFICANCE OF IMPACT OF THE STUDY The use of root nodule endophytic bacteria with PGP traits may find its future application in organic agriculture, as their utilization could decrease the use of chemical fertilizers and pesticides and simultaneously promote plant growth, especially in soils with low production quality.
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Affiliation(s)
- M Knežević
- Department of Microbiology, Institute of Soil Science, Belgrade, Serbia
| | - T Berić
- Faculty of Biology, University of Belgrade, Belgrade, Serbia
| | - A Buntić
- Department of Microbiology, Institute of Soil Science, Belgrade, Serbia
| | - D Delić
- Department of Microbiology, Institute of Soil Science, Belgrade, Serbia
| | - I Nikolić
- Faculty of Biology, University of Belgrade, Belgrade, Serbia
| | - S Stanković
- Faculty of Biology, University of Belgrade, Belgrade, Serbia
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Yang Y, Liu L, Singh RP, Meng C, Ma S, Jing C, Li Y, Zhang C. Nodule and Root Zone Microbiota of Salt-Tolerant Wild Soybean in Coastal Sand and Saline-Alkali Soil. Front Microbiol 2020; 11:2178. [PMID: 33071999 PMCID: PMC7536311 DOI: 10.3389/fmicb.2020.523142] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Accepted: 08/17/2020] [Indexed: 11/13/2022] Open
Abstract
Soil salinization limits crop growth and yield in agro-ecosystems worldwide by reducing soil health and altering the structure of microbial communities. Salt-tolerant plant growth-promoting rhizobacteria (PGPR) alleviate plant salinity stress. Wild soybean (Glycine soja Sieb. and Zucc.) is unique in agricultural ecosystems owing to its ability to grow in saline-alkali soils and fix atmospheric nitrogen via symbiotic interactions with diverse soil microbes. However, this rhizosphere microbiome and the nodule endosymbionts have not been investigated to identify PGPR. In this study, we investigated the structural and functional rhizosphere microbial communities in saline-alkali soil from the Yellow River Delta and coastal soil in China, as well as wild soybean root nodule endosymbionts. To reveal the composition of the microbial ecosystem, we performed 16S rRNA and nifH gene amplicon sequencing on root nodules and root zones under different environmental conditions. In addition, we used culture-independent methods to examine the root bacterial microbiome of wild soybean. For functional characterization of individual members of the microbiome and their impact on plant growth, we inoculated isolates from the root microbiome with wild soybean and observed nodulation. Sinorhizobium/Ensifer accounted for 97% of the root nodule microbiome, with other enriched members belonging to the phyla Actinobacteria, Bacteroidetes, Chloroflexi, Acidobacteria, and Gemmatimonadetes; the genera Sphingomonas, Microbacterium, Arthrobacter, Nocardioides, Streptomyces, Flavobacterium, Flavisolibacter, and Pseudomonas; and the family Enterobacteriaceae. Compared to saline-alkali soil from the Yellow River Delta, coastal soil was highly enriched for soybean nodules and displayed significant differences in the abundance and diversity of β-proteobacteria, δ-proteobacteria, Actinobacteria, and Bacteroidetes. Overall, the wild soybean root nodule microbiome was dominated by nutrient-providing Sinorhizobium/Ensifer and was enriched for bacterial genera that may provide salt resistance. Thus, this reductionist experimental approach provides an avenue for future systematic and functional studies of the plant root microbiome.
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Affiliation(s)
- Yingjie Yang
- Marine Agriculture Research Center, Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, China
| | - Lei Liu
- Bureau of Agriculture and Rural Affairs of Laoshan District, Qingdao, China
| | - Raghvendra Pratap Singh
- Department of Research and Development, Biotechnology, Uttaranchal University, Dehradun, India
| | - Chen Meng
- Marine Agriculture Research Center, Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, China
| | - Siqi Ma
- Marine Agriculture Research Center, Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, China
| | - Changliang Jing
- Marine Agriculture Research Center, Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, China
| | - Yiqiang Li
- Marine Agriculture Research Center, Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, China
| | - Chengsheng Zhang
- Marine Agriculture Research Center, Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, China
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