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Bhattacharyya A, Mavrodi O, Bhowmik N, Weller D, Thomashow L, Mavrodi D. Bacterial biofilms as an essential component of rhizosphere plant-microbe interactions. METHODS IN MICROBIOLOGY 2023; 53:3-48. [PMID: 38415193 PMCID: PMC10898258 DOI: 10.1016/bs.mim.2023.05.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/29/2024]
Affiliation(s)
- Ankita Bhattacharyya
- School of Biological, Environmental and Earth Sciences, The University of Southern Mississippi, Hattiesburg, MS, United States
| | - Olga Mavrodi
- School of Biological, Environmental and Earth Sciences, The University of Southern Mississippi, Hattiesburg, MS, United States
| | - Niladri Bhowmik
- School of Biological, Environmental and Earth Sciences, The University of Southern Mississippi, Hattiesburg, MS, United States
| | - David Weller
- USDA-ARS Wheat Health, Genetics and Quality Research Unit, Pullman, WA, United States
| | - Linda Thomashow
- USDA-ARS Wheat Health, Genetics and Quality Research Unit, Pullman, WA, United States
| | - Dmitri Mavrodi
- School of Biological, Environmental and Earth Sciences, The University of Southern Mississippi, Hattiesburg, MS, United States
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Huang Q, Liu H, Zhang J, Wang S, Liu F, Li C, Wang G. Production of extracellular amylase contributes to the colonization of Bacillus cereus 0-9 in wheat roots. BMC Microbiol 2022; 22:205. [PMID: 35996113 PMCID: PMC9394064 DOI: 10.1186/s12866-022-02618-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 08/17/2022] [Indexed: 11/26/2022] Open
Abstract
Background Bacteria usually secrete a variety of extracellular enzymes to degrade extracellular macromolecules to meet their nutritional needs and enhance their environmental adaptability. Bacillus cereus 0–9, a biocontrol bacterial strain isolated from wheat roots, has three genes annotated as encoding amylases in the genome, but their functions are unknown, and whether they are involved in the colonization process of the bacterium remains to be further studied. Methods Mutant gene strains and fluorescently tagged strains were constructed by homologous recombination, and amylase protein was expressed in the prokaryotic Escherichia coli BL21(DE3) expression system. The iodine staining method was used to measure the activity of amylase proteins. We further observed the colonization abilities of the test strains in wheat roots through frozen section technology. Results The results showed that there were three amylase-encoding genes, amyC, amyP and amyS, in the B. cereus 0–9 genome. Among the three amylase encoding genes, only amyS produced extracellular amylase whose secretion was related to signal peptide at position 1–27. The AmyS protein encoded by the amyS gene is an α-amylase. The growth of Rhizoctonia cerealis was inhibited 84.7% by B. cereus 0–9, but the biocontrol ability of the ΔamyS strain decreased to 43.8% and that of ΔamyS/amyS was restored when the amyS gene was complemented. Furthermore, the biocontrol ability of the ΔamySec strain was decreased to 46.8%, almost the same as that of the ΔamyS mutant. Due to the deletion of the amyS gene, the colonization capacities of ΔamyS (RFP) and ΔamySec (RFP) in wheat roots decreased, while that of ΔamyS/amyS (RFP) was restored after the amyS gene was complemented, indicating that the amyS gene influences the colonization of B. cereus 0–9 in wheat roots. In addition, the colonization and biocontrol abilities of the mutant were restored after the addition of sugars, such as glucose and maltose. Conclusions B. cereus 0–9 encodes three genes annotated as amylases, amyC, amyP and amyS. Only the deletion of the amyS gene with a signal peptide did not produce extracellular amylase. The AmyS protein encoded by the amyS gene is an α-amylase. Our results indicated that the amyS gene is closely related to the colonization abilities of B. cereus 0–9 in wheat roots and the biocontrol abilities of B. cereus 0–9 to fight against R. cerealis. The extracellular amylase produced by B. cereus 0–9 can hydrolyze starch and use glucose, maltose and other nutrients to meet the needs of bacterial growth. Therefore, it is very possible that the secretion and hydrolytic activities of extracellular amylase can promote the colonization of B. cereus 0–9 in wheat roots and play important roles in the prevention and control of plant diseases. Our results contribute to exploring the mechanisms of microbial colonization in plant roots. Supplementary Information The online version contains supplementary material available at 10.1186/s12866-022-02618-7.
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Affiliation(s)
- Qiubin Huang
- Institute of Microbial Engineering, Henan University, Kaifeng, Henan, 475004, People's Republic of China.,School of Life Sciences, Henan University, Kaifeng, Henan, 475004, People's Republic of China
| | - Huiping Liu
- School of Life Sciences, Henan University, Kaifeng, Henan, 475004, People's Republic of China
| | - Juanmei Zhang
- Institute of Microbial Engineering, Henan University, Kaifeng, Henan, 475004, People's Republic of China.,Pharmaceutical College, Henan University, Kaifeng, Henan, 475004, People's Republic of China
| | - Shaowei Wang
- Institute of Microbial Engineering, Henan University, Kaifeng, Henan, 475004, People's Republic of China.,School of Life Sciences, Henan University, Kaifeng, Henan, 475004, People's Republic of China
| | - Fengying Liu
- Institute of Microbial Engineering, Henan University, Kaifeng, Henan, 475004, People's Republic of China.,School of Life Sciences, Henan University, Kaifeng, Henan, 475004, People's Republic of China
| | - Chengdie Li
- School of Life Sciences, Henan University, Kaifeng, Henan, 475004, People's Republic of China
| | - Gang Wang
- Institute of Microbial Engineering, Henan University, Kaifeng, Henan, 475004, People's Republic of China. .,School of Life Sciences, Henan University, Kaifeng, Henan, 475004, People's Republic of China.
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Ai W, Guo T, Lay KD, Ou K, Cai K, Ding Y, Liu J, Cao Y. Isolation of soybean-specific plant growth-promoting rhizobacteria using soybean agglutin and evaluation of their effects to improve soybean growth, yield, and soil nutritional status. Microbiol Res 2022; 261:127076. [PMID: 35636091 DOI: 10.1016/j.micres.2022.127076] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 05/06/2022] [Accepted: 05/16/2022] [Indexed: 11/26/2022]
Abstract
The basic requirements of plant growth-promoting rhizobacteria (PGPR) for field applications are that they have an affinity for the host plant and that they can colonize the rhizosphere. Here, a new technique was established using soybean agglutin (SBA) as a tool to isolate soybean-specific PGPR. Thirty-three PGPR strains with an affinity for soybean were obtained via the screening method with SBA. All 33 isolates were able to produce indole acetic acid and solubilize inorganic phosphate and potassium. Most isolates (93.94%) were able to solubilize organic phosphate and almost half (45.45%) were able to produce siderophores. More than 40% of the isolates exhibited all five plant growth-promoting traits. The isolate Enterobacter sp. strain DN9 was selected for further analyses of its rhizosphere colonization and soybean growth-promoting effects because of its excellent activity in phosphate and potassium solubilization. The luciferase luxAB gene was electrotransformed into DN9, and the labelled DN9 (DN9-L) was able to survive in the soybean rhizosphere and colonize new spaces as the soybean roots elongated. This strain positively affected root system development and soybean seedling growth. In pot and field experiments, the isolates DN9, DW1, and DW13 significantly increased the nutrient contents in rhizosphere soil and soybean leaves. On average, the seed number per plant and the seed weight per plant were increased by 20% and 24% respectively, in plants inoculated with these PGPR strains in the pot experiment. In a field experiment, compared with uninoculated plants, those inoculated with DW1 showed 46.78% higher pod number per plant and 5.23% higher seed oil content; those inoculated with DW13 showed 79.82% higher seed number per plant and 65.10% higher seed weight per plant; and those inoculated with DN9 showed 9.13% higher 100-seed weight. These results show that SBA can be used as a tool to isolate efficient PGPR to enhance soybean production.
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Affiliation(s)
- Wenfeng Ai
- School of Life Sciences, Anhui Agricultural University, Hefei 230036, Anhui, China
| | - Tingting Guo
- School of Life Sciences, Anhui Agricultural University, Hefei 230036, Anhui, China
| | - Khien Duc Lay
- School of Life Sciences, Anhui Agricultural University, Hefei 230036, Anhui, China
| | - Kangmiao Ou
- School of Life Sciences, Anhui Agricultural University, Hefei 230036, Anhui, China
| | - Ke Cai
- School of Life Sciences, Anhui Agricultural University, Hefei 230036, Anhui, China
| | - Yue Ding
- School of Life Sciences, Anhui Agricultural University, Hefei 230036, Anhui, China
| | - Jia Liu
- School of Life Sciences, Anhui Agricultural University, Hefei 230036, Anhui, China
| | - Yuanyuan Cao
- School of Life Sciences, Anhui Agricultural University, Hefei 230036, Anhui, China.
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Spatiotemporal Heterogeneity and Intragenus Variability in Rhizobacterial Associations with
Brassica rapa
Growth. mSystems 2022; 7:e0006022. [PMID: 35575562 PMCID: PMC9239066 DOI: 10.1128/msystems.00060-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Microbial communities in the rhizosphere are distinct from those in soils and are influenced by stochastic and deterministic processes during plant development. These communities contain bacteria capable of promoting growth in host plants through various strategies. While some interactions are characterized in mechanistic detail using model systems, others can be inferred from culture-independent methods, such as 16S amplicon sequencing, using machine learning methods that account for this compositional data type. To characterize assembly processes and identify community members associated with plant growth amid the spatiotemporal variability of the rhizosphere, we grew Brassica rapa in a greenhouse time series with amended and reduced microbial treatments. Inoculation with a native soil community increased plant leaf area throughout the time series by up to 28%. Despite identifying spatially and temporally variable amplicon sequence variants (ASVs) in both treatments, inoculated communities were more highly connected and assembled more deterministically overall. Using a generalized linear modeling approach controlling for spatial variability, we identified 43 unique ASVs that were positively or negatively associated with leaf area, biomass, or growth rates across treatments and time stages. ASVs of the genus Flavobacterium dominated rhizosphere communities and showed some of the strongest positive and negative correlations with plant growth. Members of this genus, and growth-associated ASVs more broadly, exhibited variable connectivity in networks independent of growth association (positive or negative). These findings suggest host-rhizobacterial interactions vary temporally at narrow taxonomic scales and present a framework for identifying rhizobacteria that may work independently or in concert to improve agricultural yields. IMPORTANCE The rhizosphere, the zone of soil surrounding plant roots, is a hot spot for microbial activity, hosting bacteria capable of promoting plant growth in ways like increasing nutrient availability or fighting plant pathogens. This microbial system is highly diverse and most bacteria are unculturable, so to identify specific bacteria associated with plant growth, we used culture-independent community DNA sequencing combined with machine learning techniques. We identified 43 specific bacterial sequences associated with the growth of the plant Brassica rapa in different soil microbial treatments and at different stages of plant development. Most associations between bacterial abundances and plant growth were positive, although similar bacterial groups sometimes had different effects on growth. Why this happens will require more research, but overall, this study provides a way to identify native bacteria from plant roots that might be isolated and applied to boost agricultural yields.
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Bacillus velezensis stimulates resident rhizosphere Pseudomonas stutzeri for plant health through metabolic interactions. THE ISME JOURNAL 2022; 16:774-787. [PMID: 34593997 PMCID: PMC8483172 DOI: 10.1038/s41396-021-01125-3] [Citation(s) in RCA: 104] [Impact Index Per Article: 52.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 09/16/2021] [Accepted: 09/20/2021] [Indexed: 02/08/2023]
Abstract
Trophic interactions play a central role in driving microbial community assembly and function. In gut or soil ecosystems, successful inoculants are always facilitated by efficient colonization; however, the metabolite exchanges between inoculants and resident bacteria are rarely studied, particularly in the rhizosphere. Here, we used bioinformatic, genetic, transcriptomic, and metabonomic analyses to uncover syntrophic cooperation between inoculant (Bacillus velezensis SQR9) and plant-beneficial indigenous Pseudomonas stutzeri in the cucumber rhizosphere. We found that the synergistic interaction of these two species is highly environmental dependent, the emergence of syntrophic cooperation was only evident in a static nutrient-rich niche, such as pellicle biofilm in addition to the rhizosphere. Our results identified branched-chain amino acids (BCAAs) biosynthesis pathways are involved in syntrophic cooperation. Genome-scale metabolic modeling and metabolic profiling also demonstrated metabolic facilitation among the bacterial strains. In addition, biofilm matrix components from Bacillus were essential for the interaction. Importantly, the two-species consortium promoted plant growth and helped plants alleviate salt stress. In summary, we propose a mechanism in which synergic interactions between a biocontrol bacterium and a partner species promote plant health.
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Cardinale M, Viola M, Miceli E, Faddetta T, Puglia AM, Maggini V, Tani C, Firenzuoli F, Schiff S, Bogani P, Fani R, Papini A. The cypsela (achene) of Echinacea purpurea as a diffusion unit of a community of microorganisms. Appl Microbiol Biotechnol 2021; 105:2951-2965. [PMID: 33687502 PMCID: PMC8007504 DOI: 10.1007/s00253-021-11212-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2020] [Revised: 02/15/2021] [Accepted: 02/28/2021] [Indexed: 11/30/2022]
Abstract
Echinacea purpurea is a plant cultivated worldwide for its pharmaceutical properties, mainly related to the stimulation of the immune system in the treatment of respiratory infections. The cypselas (fruits) of E. purpurea were examined in order to investigate the presence, localization and potential function(s) of endophytic microorganisms. Electron and confocal microscopy observations showed that three different components of microorganisms were associated to cypselas of E. purpurea: (i) one endocellular bacterial component in the cotyledons, enclosed within the host membrane; (ii) another more generic bacterial component adhering to the external side of the perianth; and (iii) a fungal component inside the porous layer of the perianth, the woody and porous modified residual of the flower, in the form of numerous hyphae able to cross the wall between adjacent cells. Isolated bacteria were affiliated to the genera Paenibacillus, Pantoea, and Sanguibacter. Plate tests showed a general resistance to six different antibiotics and also to an antimicrobial-producing Rheinheimera sp. test strain. Finally, microbiome-deprived E. purpurea seeds showed a reduced ability to germinate, suggesting an active role of the microbiome in the plant vitality. Our results suggest that the endophytic bacterial community of E. purpurea, previously found in roots and stem/leaves, might be already carried at the seed stage, hosted by the cotyledons. A further microbial fungal component is transported together with the seed in the perianth of the cypsela, whose remarkable structure may be considered as an adaptation for fungal transportation, and could influence the capability of the seed to germinate in the soil.Key Points• The fruit of Echinacea purpurea contains fungi not causing any damage to the plant.• The seed cotyledons contain endocellular bacteria.• Seed/fruit deprived of the microbiome showed a reduced ability to germinate.
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Affiliation(s)
- Massimiliano Cardinale
- Department of Biological and Environmental Sciences and Technologies, University of Salento, P.le Lecce-Monteroni, 73100, Lecce, Italy
- Institute of Applied Microbiology, Research Center for BioSystems, Land Use, and Nutrition (IFZ), Justus-Liebig-University Giessen, Heinrich-Buff-Ring 26-32, 35392, Giessen, Germany
| | - Marian Viola
- Laboratory of Biomorphologies, Department of Biology, University of Florence, Via Madonna del Piano 6, 50019, Sesto Fiorentino, Italy
| | - Elisangela Miceli
- Laboratory of Microbial and Molecular evolution, Department of Biology, University of Florence, Via Madonna del Piano 6, 50019, Sesto Fiorentino, Italy
| | - Teresa Faddetta
- Laboratory of Molecular Microbiology and Biotechnology, STEBICEF Department, University of Palermo, Viale delle Scienze Ed. 16, 90128, Palermo, Italy
| | - Anna Maria Puglia
- Laboratory of Molecular Microbiology and Biotechnology, STEBICEF Department, University of Palermo, Viale delle Scienze Ed. 16, 90128, Palermo, Italy
| | - Valentina Maggini
- Referring Center for Phytotherapy, Tuscany Region, Careggi University Hospital, Largo Brambilla 3, 50134, Florence, Italy
- Department of Experimental and Clinical Medicine, University of Florence, Largo Brambilla 3, 50134, Florence, Italy
| | - Corrado Tani
- Laboratory of Biomorphologies, Department of Biology, University of Florence, Via Madonna del Piano 6, 50019, Sesto Fiorentino, Italy
| | - Fabio Firenzuoli
- Referring Center for Phytotherapy, Tuscany Region, Careggi University Hospital, Largo Brambilla 3, 50134, Florence, Italy
| | - Silvia Schiff
- Laboratory of Biomorphologies, Department of Biology, University of Florence, Via Madonna del Piano 6, 50019, Sesto Fiorentino, Italy
| | - Patrizia Bogani
- Laboratory of Plant Genetics, Department of Biology, University of Florence, Via Madonna del Piano 6, 50019, Sesto Fiorentino, Italy
| | - Renato Fani
- Laboratory of Microbial and Molecular evolution, Department of Biology, University of Florence, Via Madonna del Piano 6, 50019, Sesto Fiorentino, Italy.
| | - Alessio Papini
- Laboratory of Biomorphologies, Department of Biology, University of Florence, Via Madonna del Piano 6, 50019, Sesto Fiorentino, Italy.
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Cortese IJ, Castrillo ML, Onetto AL, Bich GÁ, Zapata PD, Laczeski ME. De novo genome assembly of Bacillus altitudinis 19RS3 and Bacillus altitudinis T5S-T4, two plant growth-promoting bacteria isolated from Ilex paraguariensis St. Hil. (yerba mate). PLoS One 2021; 16:e0248274. [PMID: 33705487 PMCID: PMC7954119 DOI: 10.1371/journal.pone.0248274] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 02/23/2021] [Indexed: 11/18/2022] Open
Abstract
Plant growth-promoting bacteria (PGPB) are a heterogeneous group of bacteria that can exert beneficial effects on plant growth directly or indirectly by different mechanisms. PGPB-based inoculant formulation has been used to replace chemical fertilizers and pesticides. In our previous studies, two endophytic endospore-forming bacteria identified as Bacillus altitudinis were isolated from roots of Ilex paraguariensis St. Hil. seedlings and selected for their plant growth-promoting (PGP) properties shown in vitro and in vivo. The purposes of this work were to assemble the genomes of B. altitudinis 19RS3 and T5S-T4, using different assemblers available for Windows and Linux and to select the best assembly for each strain. Both genomes were also automatically annotated to detect PGP genes and compare sequences with other genomes reported. Library construction and draft genome sequencing were performed by Macrogen services. Raw reads were filtered using the Trimmomatic tool. Genomes were assembled using SPAdes, ABySS, Velvet, and SOAPdenovo2 assemblers for Linux, and Geneious and CLC Genomics Workbench assemblers for Windows. Assembly evaluation was done by the QUAST tool. The parameters evaluated were the number of contigs ≥ 500 bp and ≥ 1000 bp, the length of the longest contig, and the N50 value. For genome annotation PROKKA, RAST, and KAAS tools were used. The best assembly for both genomes was obtained using Velvet. The B. altitudinis 19RS3 genome was assembled into 15 contigs with an N50 value of 1,943,801 bp. The B. altitudinis T5S-T4 genome was assembled into 24 contigs with an N50 of 344,151 bp. Both genomes comprise several genes related to PGP mechanisms, such as those for nitrogen fixation, iron metabolism, phosphate metabolism, and auxin biosynthesis. The results obtained offer the basis for a better understanding of B. altitudinis 19RS3 and T5S-T4 and make them promissory for bioinoculant development.
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Affiliation(s)
- Iliana Julieta Cortese
- Laboratorio de Biotecnología Molecular, Instituto de Biotecnología
Misiones “Dra. María Ebe Reca” (InBioMis), CONICET, Facultad de Ciencias
Exactas, Químicas y Naturales/FCEQyN, Universidad Nacional de Misiones/UNaM,
Posadas, Misiones, Argentina
| | - María Lorena Castrillo
- Laboratorio de Biotecnología Molecular, Instituto de Biotecnología
Misiones “Dra. María Ebe Reca” (InBioMis), CONICET, Facultad de Ciencias
Exactas, Químicas y Naturales/FCEQyN, Universidad Nacional de Misiones/UNaM,
Posadas, Misiones, Argentina
| | - Andrea Liliana Onetto
- Laboratorio de Biotecnología Molecular, Instituto de Biotecnología
Misiones “Dra. María Ebe Reca” (InBioMis), CONICET, Facultad de Ciencias
Exactas, Químicas y Naturales/FCEQyN, Universidad Nacional de Misiones/UNaM,
Posadas, Misiones, Argentina
| | - Gustavo Ángel Bich
- Laboratorio de Biotecnología Molecular, Instituto de Biotecnología
Misiones “Dra. María Ebe Reca” (InBioMis), CONICET, Facultad de Ciencias
Exactas, Químicas y Naturales/FCEQyN, Universidad Nacional de Misiones/UNaM,
Posadas, Misiones, Argentina
| | - Pedro Darío Zapata
- Laboratorio de Biotecnología Molecular, Instituto de Biotecnología
Misiones “Dra. María Ebe Reca” (InBioMis), CONICET, Facultad de Ciencias
Exactas, Químicas y Naturales/FCEQyN, Universidad Nacional de Misiones/UNaM,
Posadas, Misiones, Argentina
| | - Margarita Ester Laczeski
- Laboratorio de Biotecnología Molecular, Instituto de Biotecnología
Misiones “Dra. María Ebe Reca” (InBioMis), CONICET, Facultad de Ciencias
Exactas, Químicas y Naturales/FCEQyN, Universidad Nacional de Misiones/UNaM,
Posadas, Misiones, Argentina
- Cátedra de Bacteriología, Dpto. de Microbiología, Facultad de Ciencias
Exactas, Químicas y Naturales/FCEQyN, Universidad Nacional de Misiones/UNaM,
Posadas, Misiones, Argentina
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