1
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Graham LA, Hansen T, Yang Y, Sherik M, Ye Q, Soares BP, Kinrade B, Guo S, Davies PL. Adhesin domains responsible for binding bacteria to surfaces they colonize project outwards from companion split domains. Proteins 2024; 92:933-945. [PMID: 38591850 DOI: 10.1002/prot.26689] [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: 01/09/2024] [Revised: 03/07/2024] [Accepted: 03/26/2024] [Indexed: 04/10/2024]
Abstract
Bacterial adhesins attach their hosts to surfaces that the bacteria will colonize. This surface adhesion occurs through specific ligand-binding domains located towards the distal end of the long adhesin molecules. However, recognizing which of the many adhesin domains are structural and which are ligand binding has been difficult up to now. Here we have used the protein structure modeling program AlphaFold2 to predict structures for these giant 0.2- to 1.5-megadalton proteins. Crystal structures previously solved for several adhesin regions are in good agreement with the models. Whereas most adhesin domains are linked in a linear fashion through their N- and C-terminal ends, ligand-binding domains can be recognized by budding out from a companion core domain so that their ligand-binding sites are projected away from the axis of the adhesin for maximal exposure to their targets. These companion domains are "split" in their continuity by projecting the ligand-binding domain outwards. The "split domains" are mostly β-sandwich extender modules, but other domains like a β-solenoid can serve the same function. Bioinformatic analyses of Gram-negative bacterial sequences revealed wide variety ligand-binding domains are used in their Repeats-in-Toxin adhesins. The ligands for many of these domains have yet to be identified but known ligands include various cell-surface glycans, proteins, and even ice. Recognizing the ligands to which the adhesins bind could lead to ways of blocking colonization by bacterial pathogens. Engineering different ligand-binding domains into an adhesin has the potential to change the surfaces to which bacteria bind.
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Affiliation(s)
- Laurie A Graham
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada
| | - Thomas Hansen
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada
| | - Yanzhi Yang
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada
| | - Mustafa Sherik
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada
| | - Qilu Ye
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada
| | - Blake P Soares
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada
| | - Brett Kinrade
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada
| | - Shuaiqi Guo
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, Canada
| | - Peter L Davies
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada
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2
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Maroniche GA, Puente ML, García JE, Mongiardini E, Coniglio A, Nievas S, Labarthe MM, Wisniewski-Dyé F, Rodriguez Cáceres E, Díaz-Zorita M, Cassán F. Phenogenetic profile and agronomic contribution of Azospirillum argentinense Az39 T, a reference strain for the South American inoculant industry. Microbiol Res 2024; 283:127650. [PMID: 38452553 DOI: 10.1016/j.micres.2024.127650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 02/07/2024] [Accepted: 02/12/2024] [Indexed: 03/09/2024]
Abstract
Azospirillum sp. is a plant growth-promoting rhizobacteria largely recognized for its potential to increase the yield of different important crops. In this work, we present a thorough genomic and phenotypic analysis of A. argentinense Az39T to provide new insights into the beneficial mechanisms of this microorganism. Phenotypic analyses revealed the following in vitro abilities: growth at 20-38 °C (optimum, 28 °C), pH 6.0-8.0 (optimum, pH 6.8), and in the presence of 1% (w/v) NaCl; production of variable amounts of PHB as intracellular granules; nitrogen fixation under microaerophilic conditions; IAA synthesis in the presence of L-tryptophan. Through biochemical (API 20NE) and carbon utilization profiling (Biolog) assays, we proved that A. argentinense Az39T is able to use 15 substrates and metabolize 19 different carbon substrates. Lipid composition indicated a predominance of medium and long-chain saturated fatty acids. A total of 6 replicons classified as one main chromosome, three chromids, and two plasmids, according to their tRNA and core essential genes contents, were identified. Az39T genome includes genes associated with multiple plant growth-promoting (PGP) traits such as nitrogen fixation and production of auxins, cytokinin, abscisic acid, ethylene, and polyamines. In addition, Az39T genome harbor genetic elements associated with physiological features that facilitate its survival in the soil and competence for rhizospheric colonization; this includes motility, secretion system, and quorum sensing genetic determinants. A metadata analysis of Az39T agronomic performance in the pampas region, Argentina, demonstrated significant grain yield increases in wheat and maize, proving its potential to provide better growth conditions for dryland cereals. In conclusion, our data provide a detailed insight into the metabolic profile of A. argentinense Az39T, the strain most widely used to formulate non-legume inoculants in Argentina, and allow a better understanding of the mechanisms behind its field performance.
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Affiliation(s)
- G A Maroniche
- Facultad de Ciencias Agrarias, Universidad Nacional de Mar del Plata (UNMdP), CONICET, Balcarce, Buenos Aires, Argentina
| | - M L Puente
- Instituto de Microbiología y Zoología Agrícola, Instituto Nacional de Tecnología Agropecuaria (INTA), Hurlingham, Buenos Aires, Argentina
| | - J E García
- Instituto de Microbiología y Zoología Agrícola, Instituto Nacional de Tecnología Agropecuaria (INTA), Hurlingham, Buenos Aires, Argentina
| | - E Mongiardini
- Instituto de Biotecnología y Biología Molecular, Facultad de Ciencias Exactas, Universidad Nacional de La Plata (UNLP), CONICET, La Plata, Buenos Aires, Argentina
| | - A Coniglio
- Laboratorio de Fisiología Vegetal y de la Interacción Planta-Microorganismo, Instituto de Investigaciones Agrobiotecnológicas (INIAB-CONICET), Universidad Nacional de Río Cuarto (UNRC), Río Cuarto, Córdoba, Argentina
| | - S Nievas
- Laboratorio de Fisiología Vegetal y de la Interacción Planta-Microorganismo, Instituto de Investigaciones Agrobiotecnológicas (INIAB-CONICET), Universidad Nacional de Río Cuarto (UNRC), Río Cuarto, Córdoba, Argentina
| | - M M Labarthe
- Facultad de Ciencias Agrarias, Universidad Nacional de Mar del Plata (UNMdP), CONICET, Balcarce, Buenos Aires, Argentina
| | - F Wisniewski-Dyé
- Universite Claude Bernard Lyon 1, Laboratoire d'Ecologie Microbienne, UMR CNRS 5557, UMR INRAE 1418, VetAgro Sup, Villeurbanne 69622, France
| | | | - M Díaz-Zorita
- Facultad de Agronomía, Universidad Nacional de La Pampa (UNLPam), CONICET, Santa Rosa, La Pampa, Argentina
| | - F Cassán
- Laboratorio de Fisiología Vegetal y de la Interacción Planta-Microorganismo, Instituto de Investigaciones Agrobiotecnológicas (INIAB-CONICET), Universidad Nacional de Río Cuarto (UNRC), Río Cuarto, Córdoba, Argentina.
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3
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Chakraborty S, Venkataraman M, Infante V, Pfleger BF, Ané JM. Scripting a new dialogue between diazotrophs and crops. Trends Microbiol 2024; 32:577-589. [PMID: 37770375 PMCID: PMC10950843 DOI: 10.1016/j.tim.2023.08.007] [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: 05/27/2023] [Revised: 08/14/2023] [Accepted: 08/15/2023] [Indexed: 09/30/2023]
Abstract
Diazotrophs are bacteria and archaea that can reduce atmospheric dinitrogen (N2) into ammonium. Plant-diazotroph interactions have been explored for over a century as a nitrogen (N) source for crops to improve agricultural productivity and sustainability. This scientific quest has generated much information about the molecular mechanisms underlying the function, assembly, and regulation of nitrogenase, ammonium assimilation, and plant-diazotroph interactions. This review presents various approaches to manipulating N fixation activity, ammonium release by diazotrophs, and plant-diazotroph interactions. We discuss the research avenues explored in this area, propose potential future routes, emphasizing engineering at the metabolic level via biorthogonal signaling, and conclude by highlighting the importance of biocontrol measures and public acceptance.
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Affiliation(s)
- Sanhita Chakraborty
- Department of Bacteriology, University of Wisconsin - Madison, Madison, WI, USA
| | - Maya Venkataraman
- Department of Chemical and Biological Engineering, University of Wisconsin - Madison, Madison, WI, USA
| | - Valentina Infante
- Department of Bacteriology, University of Wisconsin - Madison, Madison, WI, USA
| | - Brian F Pfleger
- Department of Chemical and Biological Engineering, University of Wisconsin - Madison, Madison, WI, USA
| | - Jean-Michel Ané
- Department of Bacteriology, University of Wisconsin - Madison, Madison, WI, USA; Department of Agronomy, University of Wisconsin - Madison, Madison, WI, USA.
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4
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Nisha FA, Tagoe JNA, Pease AB, Horne SM, Ugrinov A, Geddes BA, Prüß BM. Plant seedlings of peas, tomatoes, and cucumbers exude compounds that are needed for growth and chemoattraction of Rhizobium leguminosarum bv. viciae 3841 and Azospirillum brasilense Sp7. Can J Microbiol 2024; 70:150-162. [PMID: 38427979 DOI: 10.1139/cjm-2023-0217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/03/2024]
Abstract
This study characterizes seedling exudates of peas, tomatoes, and cucumbers at the level of chemical composition and functionality. A plant experiment confirmed that Rhizobium leguminosarum bv. viciae 3841 enhanced growth of pea shoots, while Azospirillum brasilense Sp7 supported growth of pea, tomato, and cucumber roots. Chemical analysis of exudates after 1 day of seedling incubation in water yielded differences between the exudates of the three plants. Most remarkably, cucumber seedling exudate did not contain detectable sugars. All exudates contained amino acids, nucleobases/nucleosides, and organic acids, among other compounds. Cucumber seedling exudate contained reduced glutathione. Migration on semi solid agar plates containing individual exudate compounds as putative chemoattractants revealed that R. leguminosarum bv. viciae was more selective than A. brasilense, which migrated towards any of the compounds tested. Migration on semi solid agar plates containing 1:1 dilutions of seedling exudate was observed for each of the combinations of bacteria and exudates tested. Likewise, R. leguminosarum bv. viciae and A. brasilense grew on each of the three seedling exudates, though at varying growth rates. We conclude that the seedling exudates of peas, tomatoes, and cucumbers contain everything that is needed for their symbiotic bacteria to migrate and grow on.
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Affiliation(s)
- Fatema A Nisha
- Department of Microbiological Sciences, North Dakota State University, Fargo, ND, USA
| | - Janice N A Tagoe
- Department of Microbiological Sciences, North Dakota State University, Fargo, ND, USA
| | - Amanda B Pease
- Department of Microbiological Sciences, North Dakota State University, Fargo, ND, USA
| | - Shelley M Horne
- Department of Microbiological Sciences, North Dakota State University, Fargo, ND, USA
| | - Angel Ugrinov
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, ND, USA
| | - Barney A Geddes
- Department of Microbiological Sciences, North Dakota State University, Fargo, ND, USA
| | - Birgit M Prüß
- Department of Microbiological Sciences, North Dakota State University, Fargo, ND, USA
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Chen M, Feng S, Lv H, Wang Z, Zeng Y, Shao C, Lin W, Zhang Z. OsCIPK2 mediated rice root microorganisms and metabolites to improve plant nitrogen uptake. BMC PLANT BIOLOGY 2024; 24:285. [PMID: 38627617 PMCID: PMC11020999 DOI: 10.1186/s12870-024-04982-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Accepted: 04/03/2024] [Indexed: 04/19/2024]
Abstract
Crop roots are colonized by large numbers of microorganisms, collectively known as the root-microbiome, which modulate plant growth, development and contribute to elemental nutrient uptake. In conditions of nitrogen limitation, the over-expressed Calcineurin B-like interacting protein kinase 2 (OsCIPK2) gene with root-specific promoter (RC) has been shown to enhance growth and nitrogen uptake in rice. Analysis of root-associated bacteria through high-throughput sequencing revealed that OsCIPK2 has a significant impact on the diversity of the root microbial community under low nitrogen stress. The quantification of nifH gene expression demonstrated a significant enhancement in nitrogen-fixing capabilities in the roots of RC transgenetic rice. Synthetic microbial communities (SynCom) consisting of six nitrogen-fixing bacterial strains were observed to be enriched in the roots of RC, leading to a substantial improvement in rice growth and nitrogen uptake in nitrogen-deficient soils. Forty and twenty-three metabolites exhibiting differential abundance were identified in the roots and rhizosphere soils of RC transgenic rice compared to wild-type (WT) rice. These findings suggest that OSCIPK2 plays a role in restructuring the microbial community in the roots through the regulation of metabolite synthesis and secretion. Further experiments involving the exogenous addition of citric acid revealed that an optimal concentration of this compound facilitated the growth of nitrogen-fixing bacteria and substantially augmented their population in the soil, highlighting the importance of citric acid in promoting nitrogen fixation under conditions of low nitrogen availability. These findings suggest that OsCIPK2 plays a role in enhancing nitrogen uptake by rice plants from the soil by influencing the assembly of root microbial communities, thereby offering valuable insights for enhancing nitrogen utilization in rice cultivation.
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Affiliation(s)
- Mengying Chen
- College of JunCao Science and Ecology, Fujian Agricultural and Forestry University, Fuzhou, Fujian, 350002, China
- Key Laboratory of Crop Ecology and Molecular Physiology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, 350002, China
| | - Shizhong Feng
- Key Laboratory of Crop Ecology and Molecular Physiology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, 350002, China
- Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - He Lv
- College of JunCao Science and Ecology, Fujian Agricultural and Forestry University, Fuzhou, Fujian, 350002, China
- Key Laboratory of Crop Ecology and Molecular Physiology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, 350002, China
| | - Zewen Wang
- College of JunCao Science and Ecology, Fujian Agricultural and Forestry University, Fuzhou, Fujian, 350002, China
- Key Laboratory of Crop Ecology and Molecular Physiology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, 350002, China
| | - Yuhang Zeng
- College of JunCao Science and Ecology, Fujian Agricultural and Forestry University, Fuzhou, Fujian, 350002, China
- Key Laboratory of Crop Ecology and Molecular Physiology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, 350002, China
| | - Caihong Shao
- Soil and Fertilizer & Resources and Environment Institute, Jiangxi Academy of Agricultural Sciences, Nanchang, 330200, China
| | - Wenxiong Lin
- College of JunCao Science and Ecology, Fujian Agricultural and Forestry University, Fuzhou, Fujian, 350002, China
- Key Laboratory of Crop Ecology and Molecular Physiology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, 350002, China
- Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Zhixing Zhang
- College of JunCao Science and Ecology, Fujian Agricultural and Forestry University, Fuzhou, Fujian, 350002, China.
- Key Laboratory of Crop Ecology and Molecular Physiology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, 350002, China.
- Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.
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6
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Liu D, Song X, Hu J, Liu Y, Wang C, Henkin Z. Precipitation affects soil nitrogen fixation by regulating active diazotrophs and nitrate nitrogen in an alpine grassland of Qinghai-Tibetan Plateau. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 919:170648. [PMID: 38336078 DOI: 10.1016/j.scitotenv.2024.170648] [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: 11/26/2023] [Revised: 01/27/2024] [Accepted: 01/31/2024] [Indexed: 02/12/2024]
Abstract
Soil asymbiotic nitrogen (N) fixation provides a critical N source to support plant growth in alpine grasslands, and precipitation change is expected to lead to shifts in soil asymbiotic N fixation. However, large gaps remain in understanding the response of soil asymbiotic N fixation to precipitation gradients. Here we simulated five precipitation gradients (10 % (0.1P), 50 % (0.5P), 70 % (0.7P), 100 % (1.0P) and 150 % (1.5P) of the natural precipitation) in an alpine grassland of Qinghai-Tibetan Plateau and examined the soil nitrogenase activity and N fixation rate for each gradient. Quantitative PCR and high-throughput sequencing were used to measure the abundance and community composition of the soil nifH DNA (total diazotrophs) and nifH RNA reverse transcription (active diazotrophs) gene. Our results showed that the soil diazotrophic abundance, diversity and nifH gene expression rate peaked under the 0.5P. Soil nitrogenase activity and N fixation rate varied in the range 0.032-0.073 nmol·C2H4·g-1·h-1 and 0.008-0.022 nmol·N2·g-1·h-1 respectively, being highest under the 0.5P. The 50 % precipitation reduction enhanced the gene expression rates of Azospirillum and Halorhodospira which were likely responsible for the high N fixation potential. The 0.5P treatment also possessed a larger and more complex active diazotrophic network than the other treatments, which facilitated the resistance of diazotrophic community to environmental stress and thus maintained a high N fixation potential. The active diazotrophic abundance had the largest positive effect on soil N fixation, while nitrate nitrogen had the largest negative effect. Together, our study suggested that appropriate precipitation reduction can enhance soil N fixation through promoting the abundance of the soil active diazotrophs and decreasing soil nitrate nitrogen, and soil active diazotrophs and nitrate nitrogen should be considered in predicting soil N inputs in the alpine grassland of Qinghai-Tibetan Plateau under precipitation change.
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Affiliation(s)
- Dan Liu
- Provincial key laboratory for alpine grassland conservation and utilization on Qinghai-Tibetan Plateau, Institute of Qinghai-Tibetan Plateau Research, Southwest Minzu University, Chengdu 610041, China.
| | - Xiaoyan Song
- Provincial key laboratory for alpine grassland conservation and utilization on Qinghai-Tibetan Plateau, Institute of Qinghai-Tibetan Plateau Research, Southwest Minzu University, Chengdu 610041, China
| | - Jian Hu
- Provincial key laboratory for alpine grassland conservation and utilization on Qinghai-Tibetan Plateau, Institute of Qinghai-Tibetan Plateau Research, Southwest Minzu University, Chengdu 610041, China
| | - Yang Liu
- Provincial key laboratory for alpine grassland conservation and utilization on Qinghai-Tibetan Plateau, Institute of Qinghai-Tibetan Plateau Research, Southwest Minzu University, Chengdu 610041, China
| | - Changting Wang
- Provincial key laboratory for alpine grassland conservation and utilization on Qinghai-Tibetan Plateau, Institute of Qinghai-Tibetan Plateau Research, Southwest Minzu University, Chengdu 610041, China
| | - Zalmen Henkin
- Department of Natural Resources, Newe Ya'ar Research Center, Agricultural Research Organization, Volcani Institute, Israel
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Garciglia-Mercado C, Contreras CA, Choix FJ, de-Bashan LE, Gómez-Anduro GA, Palacios OA. Metabolic and physiological adaptations of microalgal growth-promoting bacterium Azospirillum brasilense growing under biogas atmosphere: a microarray-based transcriptome analysis. Arch Microbiol 2024; 206:173. [PMID: 38492040 DOI: 10.1007/s00203-024-03890-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: 12/19/2023] [Revised: 01/30/2024] [Accepted: 02/08/2024] [Indexed: 03/18/2024]
Abstract
Using microalgal growth-promoting bacteria (MGPB) to improve the cultured microalga metabolism during biotechnological processes is one of the most promising strategies to enhance their benefits. Nonetheless, the culture condition effect used during the biotechnological process on MGPB growth and metabolism is key to ensure the expected positive bacterium growth and metabolism of microalgae. In this sense, the present research study investigated the effect of the synthetic biogas atmosphere (75% CH4-25% CO2) on metabolic and physiological adaptations of the MGPB Azospirillum brasilense by a microarray-based transcriptome approach. A total of 394 A. brasilense differentially expressed genes (DEGs) were found: 201 DEGs (34 upregulated and 167 downregulated) at 24 h and 193 DEGs (140 upregulated and 53 downregulated) under the same conditions at 72 h. The results showed a series of A. brasilense genes regulating processes that could be essential for its adaptation to the early stressful condition generated by biogas. Evidence of energy production is shown by nitrate/nitrite reduction and activation of the hypothetical first steps of hydrogenotrophic methanogenesis; signal molecule modulation is observed: indole-3-acetic acid (IAA), riboflavin, and vitamin B6, activation of Type VI secretion system responding to IAA exposure, as well as polyhydroxybutyrate (PHB) biosynthesis and accumulation. Moreover, an overexpression of ipdC, ribB, and phaC genes, encoding the key enzymes for the production of the signal molecule IAA, vitamin riboflavin, and PHB production of 2, 1.5 and 11 folds, respectively, was observed at the first 24 h of incubation under biogas atmosphere Overall, the ability of A. brasilense to metabolically adapt to a biogas atmosphere is demonstrated, which allows its implementation for generating biogas with high calorific values and the use of renewable energies through microalga biotechnologies.
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Affiliation(s)
| | - Claudia A Contreras
- Facultad de Ciencias Químicas, Universidad Autónoma de Chihuahua, Chihuahua, Mexico
| | - Francisco J Choix
- Facultad de Ciencias Químicas, Universidad Autónoma de Chihuahua, Chihuahua, Mexico
- CONAHCYT-Universidad Autónoma de Chihuahua, Chihuahua, Mexico
| | - Luz E de-Bashan
- The Bashan Institute of Science, Auburn, AL, USA
- Departament of Entomology and Plant Pathology, Auburn University, Auburn, AL, USA
| | | | - Oskar A Palacios
- Facultad de Ciencias Químicas, Universidad Autónoma de Chihuahua, Chihuahua, Mexico.
- The Bashan Institute of Science, Auburn, AL, USA.
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Liang H, Yang L, He X, Wu Q, Chen D, Liu M, Shen P. Rhizosphere Ventilation Effects on Root Development and Bacterial Diversity of Peanut in Compacted Soil. PLANTS (BASEL, SWITZERLAND) 2024; 13:790. [PMID: 38592790 PMCID: PMC10975058 DOI: 10.3390/plants13060790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 02/22/2024] [Accepted: 03/07/2024] [Indexed: 04/11/2024]
Abstract
Soil compaction is one of the crucial factors that restrains the root respiration, energy metabolism and growth of peanut (Arachis hypogaea L.) due to hypoxia, which can be alleviated by ventilation. We therefore carried out a pot experiment with three treatments: no ventilation control (CK), (2) ventilation volumes at 1.2 (T1), and 1.5 (T2) times of the standard ventilation volume (2.02 L/pot). Compared to no-ventilation in compacted soil, ventilation T1 significantly increased total root length, root surface area, root volume and tips at the peanut anthesis stage (62 days after sowing), while T2 showed a negative impact on the above-mentioned root morphological characteristics. At the podding stage (S2, 95 days after sowing), both ventilation treatments improved root morphology, especially under T1. Compared to CK, both ventilation T1 and T2 decreased the activities of enzymes involving the anaerobic respiration, including root lactate dehydrogenase, pyruvate decarboxylase and alcohol dehydrogenase. The activities of antioxidant enzymes of root superoxide dismutase, peroxidase and catalase also decreased at S1, while superoxide dismutase and peroxidase significantly increased under T1 at S2. The ventilation of compacted soil changed soil nitrogen-fixing bacterial communities, with highest bacterial alpha diversity indices under T1. The Pearson correlation analyses indicated a positive relationship between the relative abundance of Bradyrhizobiaceae and root activity, and between unclassified_family of Rhizobiales and the root surface area, while Enterobacteriaceae had a negative impact on the root nodule number. The Pearson correlation test showed that the root surface, tips and activity positively correlated with root superoxide dismutase and peroxidase activities. These results demonstrate that soil ventilation could enhance plant root growth, the diversity and function of soil nitrogen-fixing bacterial communities. The generated results from this present study could serve as important evidence in alleviating soil hypoxia caused by compaction.
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Affiliation(s)
- Haiyan Liang
- Shandong Peanut Research Institute/Key Laboratory of Peanut Biology, Genetics & Breeding, Ministry of Agriculture and Rural Affairs, Shandong Academy of Agricultural Sciences, Qingdao 266100, China; (H.L.); (L.Y.); (Q.W.); (D.C.); (M.L.)
| | - Liyu Yang
- Shandong Peanut Research Institute/Key Laboratory of Peanut Biology, Genetics & Breeding, Ministry of Agriculture and Rural Affairs, Shandong Academy of Agricultural Sciences, Qingdao 266100, China; (H.L.); (L.Y.); (Q.W.); (D.C.); (M.L.)
| | - Xinhua He
- School of Biological Sciences, University of Western Australia, Perth 6009, Australia;
- Department of Land, Air and Water Resources, University of California at Davis, Davis, CA 90616, USA
| | - Qi Wu
- Shandong Peanut Research Institute/Key Laboratory of Peanut Biology, Genetics & Breeding, Ministry of Agriculture and Rural Affairs, Shandong Academy of Agricultural Sciences, Qingdao 266100, China; (H.L.); (L.Y.); (Q.W.); (D.C.); (M.L.)
| | - Dianxu Chen
- Shandong Peanut Research Institute/Key Laboratory of Peanut Biology, Genetics & Breeding, Ministry of Agriculture and Rural Affairs, Shandong Academy of Agricultural Sciences, Qingdao 266100, China; (H.L.); (L.Y.); (Q.W.); (D.C.); (M.L.)
| | - Miao Liu
- Shandong Peanut Research Institute/Key Laboratory of Peanut Biology, Genetics & Breeding, Ministry of Agriculture and Rural Affairs, Shandong Academy of Agricultural Sciences, Qingdao 266100, China; (H.L.); (L.Y.); (Q.W.); (D.C.); (M.L.)
| | - Pu Shen
- Shandong Peanut Research Institute/Key Laboratory of Peanut Biology, Genetics & Breeding, Ministry of Agriculture and Rural Affairs, Shandong Academy of Agricultural Sciences, Qingdao 266100, China; (H.L.); (L.Y.); (Q.W.); (D.C.); (M.L.)
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9
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Sharma P, Pandey R, Chauhan NS. Biofertilizer and biocontrol properties of Stenotrophomonas maltophilia BCM emphasize its potential application for sustainable agriculture. FRONTIERS IN PLANT SCIENCE 2024; 15:1364807. [PMID: 38501138 PMCID: PMC10944936 DOI: 10.3389/fpls.2024.1364807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Accepted: 02/09/2024] [Indexed: 03/20/2024]
Abstract
Introduction Microbial biofertilizers or biocontrol agents are potential sustainable approaches to overcome the limitations of conventional agricultural practice. However, the limited catalog of microbial candidates for diversified crops creates hurdles in successfully implementing sustainable agriculture for increasing global/local populations. The present study aimed to explore the wheat rhizosphere microbiota for microbial strains with a biofertilizer and biocontrol potential. Methods Using a microbial culturing-based approach, 12 unique microbial isolates were identified and screened for biofertilizer/biocontrol potential using genomics and physiological experimentations. Results and discussion Molecular, physiological, and phylogenetic characterization identified Stenotrophomonas maltophilia BCM as a potential microbial candidate for sustainable agriculture. Stenotrophomonas maltophilia BCM was identified as a coccus-shaped gram-negative microbe having optimal growth at 37°C in a partially alkaline environment (pH 8.0) with a proliferation time of ~67 minutes. The stress response physiology of Stenotrophomonas maltophilia BCM indicates its successful survival in dynamic environmental conditions. It significantly increased (P <0.05) the wheat seed germination percentage in the presence of phytopathogens and saline conditions. Genomic characterization decoded the presence of genes involved in plant growth promotion, nutrient assimilation, and antimicrobial activity. Experimental evidence also correlates with genomic insights to explain the potential of Stenotrophomonas maltophilia BCM as a potential biofertilizer and biocontrol agent. With these properties, Stenotrophomonas maltophilia BCM could sustainably promote wheat production to ensure food security for the increasing population, especially in native wheat-consuming areas.
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Affiliation(s)
- Pinki Sharma
- Department of Biochemistry, Maharshi Dayanand University, Haryana, Rohtak, India
| | - Rajesh Pandey
- INtegrative GENomics of HOst-PathogEn (INGEN-HOPE) Laboratory, CSIR-Institute of Genomics and Integrative Biology Council of Scientific and Industrial Research (CSIR-IGIB), Delhi, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Nar Singh Chauhan
- Department of Biochemistry, Maharshi Dayanand University, Haryana, Rohtak, India
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10
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Talwar C, Nagar S, Negi RK. Comparative analyses of gut microbiota reveal ammonia detoxification and nitrogen assimilation in Cyprinus carpio var. specularis. Folia Microbiol (Praha) 2024:10.1007/s12223-024-01151-6. [PMID: 38367166 DOI: 10.1007/s12223-024-01151-6] [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: 08/29/2023] [Accepted: 02/08/2024] [Indexed: 02/19/2024]
Abstract
The complex niche of fish gut is often characterized by the associated microorganisms that have implications in fish gut-health nexus. Although efforts to distinguish the microbial communities have highlighted their disparate structure along the gut length, remarkably little information is available about their distinct structural and functional profiles in different gut compartments in different fish species. Here, we performed comparative taxonomic and predictive functional analyses of the foregut and hindgut microbiota in an omnivorous freshwater fish species, Cyprinus carpio var. specularis, commonly known as mirror carp. Our analyses showed that the hindgut microbiota could be distinguished from foregut based on the abundance of ammonia-oxidizing, denitrifying, and nitrogen-fixing commensals of families such as Rhodospirillaceae, Oxalobacteraceae, Nitrosomonadaceae, and Nitrospiraceae. Functionally, unique metabolic pathways such as degradation of lignin, 2-nitrobenzoate, vanillin, vanillate, and toluene predicted within hindgut also hinted at the ability of hindgut microbiota for assimilation of nitrogen and detoxification of ammonia. The study highlights a major role of hindgut microbiota in assimilating nitrogen, which remains to be one of the limiting nutrients within the gut of mirror carp.
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Affiliation(s)
- Chandni Talwar
- Fish Molecular Biology Laboratory, Department of Zoology, University of Delhi, Delhi, 110007, India
- Department of Pathology & Immunology, Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, 770030, USA
| | - Shekhar Nagar
- Fish Molecular Biology Laboratory, Department of Zoology, University of Delhi, Delhi, 110007, India
- Department of Zoology, Deshbandhu College, Kalkaji, New Delhi, 110019, India
| | - Ram Krishan Negi
- Fish Molecular Biology Laboratory, Department of Zoology, University of Delhi, Delhi, 110007, India.
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11
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Zuo S, Wu D, Du Z, Xu C, Tan Y, Bol R, Wu W. Mitigation of soil N 2O emissions by decomposed straw based on changes in dissolved organic matter and denitrifying bacteria. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 905:167148. [PMID: 37730058 DOI: 10.1016/j.scitotenv.2023.167148] [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: 03/18/2023] [Revised: 08/19/2023] [Accepted: 09/14/2023] [Indexed: 09/22/2023]
Abstract
The return of decomposed straw represents a less explored potential option for reducing N2O emissions. However, the mechanisms underlying the effects of decomposed straw return on soil N2O mitigation are still not fully clear. Therefore, we used a helium atmosphere robotized continuous flow incubation system to compare the soil N2O and N2 emissions from four treatments: CK (control: no straw), WS (wheat straw), IWS (wheat straw decomposed with Irpex lacteus), and PWS (wheat straw decomposed with Phanerochaete chrysosporium). All the treatments have been fertilized with the same amount of KNO3. Furthermore, we also analyzed i) the chemodiversity of soil dissolved organic matter (DOM), ii) the nirS, nirK, and nosZ gene copies and relative abundances of denitrifying bacterial communities (DBCs), and iii) the specific linkages between N2O emissions and DOM and DBC. The results showed that the WS, IWS and PWS treatments increased N2O emissions compared to the CK treatment. However, applying decomposed straw to soil, especially straw treated with P. chrysosporium, effectively decreased the soil N2O and increased N2 emissions compared to WS and IWS. Moreover, the IWS and PWS treatments increased the CHO composition, but they decreased the CHON and CHOS compositions of heteroatomic compounds of DOM compared with the WS and CK treatments. Furthermore, the WS, IWS and PWS treatments all significantly increased the nirS and nosZ gene copies compared with the CK treatment. Additionally, compared with the other treatments, the PWS treatment significantly shaped the DBC and led to a higher relative abundance of Pseudomonas with nirS and nosZ genes. Meanwhile, Network analysis showed that the mitigation of N2O was closely related to particular DOM molecules, and specific DBC taxa. These results highlight the potential for decomposed straw amendments to mitigate of soil N2O emissions not only by changing soil DOM but also mediating the soil DBC.
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Affiliation(s)
- Sasa Zuo
- Beijing Key Laboratory of Biodiversity and Organic Farming, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China; Department of Agricultural Engineering, College of Engineering, China Agricultural University, Beijing 100083, China
| | - Di Wu
- Beijing Key Laboratory of Biodiversity and Organic Farming, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China
| | - Zhangliu Du
- Beijing Key Laboratory of Biodiversity and Organic Farming, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China
| | - Chuncheng Xu
- Department of Agricultural Engineering, College of Engineering, China Agricultural University, Beijing 100083, China
| | - Yuechen Tan
- Beijing Key Laboratory of Wetland Services and Restoration, Institute of Ecological Conservation and Restoration, Chinese Academy of Forestry, Beijing 100091, China
| | - Roland Bol
- Institute of Bio- and Geosciences, Agrosphere (IBG-3), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany; School of Natural Sciences, Environment Centre Wales, Bangor University, Bangor LL57 2UW, UK
| | - Wenliang Wu
- Beijing Key Laboratory of Biodiversity and Organic Farming, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China.
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12
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Wang Y, Huang Y, Zeng Q, Liu D, An S. Biogeographic distribution of autotrophic bacteria was more affected by precipitation than by soil properties in an arid area. Front Microbiol 2023; 14:1303469. [PMID: 38173682 PMCID: PMC10761425 DOI: 10.3389/fmicb.2023.1303469] [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: 09/28/2023] [Accepted: 12/06/2023] [Indexed: 01/05/2024] Open
Abstract
Introduction Autotrophic bacteria play an important role in carbon dioxide fixation and are widespread in terrestrial ecosystems. However, the biogeographic patterns of autotrophic bacteria and the driving factors still remain poorly understood. Methods Herein, we conducted a 391-km north to south transect (mean annual precipitation <600 mm) survey in the Loess Plateau of China, to investigate the biogeographic distributions of autotrophic bacteria (RubisCO cbbL and cbbM genes) and the environmental drivers across different latitude sites with clear vegetational and climatic gradients. Results and discussion The soils in northern region with lower precipitation are dominated by grassland/forest, which is typically separated from the soils in southern region with higher precipitation. The community structure of autotrophic bacterial cbbL and cbbM genes generally differed between the soils in the southern and northern Loess Plateau, suggesting that precipitation and its related land use practices/ecosystem types, rather than local soil properties, are more important in shaping the soil autotrophic microorganisms. The cbbL-containing generalist OTUs were almost equally abundant across the northern and southern Loess Plateau, while the cbbM-containing bacterial taxa were more prevalent in the low precipitation northern region. Such differences indicate differentiate distribution patterns of cbbM- and cbbL-containing bacteria across the north to south transect. Our results suggest that the community composition and the differentiate distributions of soil cbbL- and cbbM-containing bacterial communities depend on precipitation and the related ecosystem types in the north to south transect in the Loess Plateau of China.
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Affiliation(s)
- Ying Wang
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A & F University, Yangling, Shaanxi Province, China
| | - Yimei Huang
- College of Resources and Environment, Northwest A & F University, Yangling, Shaanxi Province, China
| | - Quanchao Zeng
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, China
| | - Dong Liu
- The Germplasm Bank of Wild Species, Yunnan Key Laboratory for Fungal Diversity and Green Development, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
| | - Shaoshan An
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A & F University, Yangling, Shaanxi Province, China
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Zhu YG, Peng J, Chen C, Xiong C, Li S, Ge A, Wang E, Liesack W. Harnessing biological nitrogen fixation in plant leaves. TRENDS IN PLANT SCIENCE 2023; 28:1391-1405. [PMID: 37270352 DOI: 10.1016/j.tplants.2023.05.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 05/11/2023] [Accepted: 05/15/2023] [Indexed: 06/05/2023]
Abstract
The importance of biological nitrogen fixation (BNF) in securing food production for the growing world population with minimal environmental cost has been increasingly acknowledged. Leaf surfaces are one of the biggest microbial habitats on Earth, harboring diverse free-living N2-fixers. These microbes inhabit the epiphytic and endophytic phyllosphere and contribute significantly to plant N supply and growth. Here, we summarize the contribution of phyllosphere-BNF to global N cycling, evaluate the diversity of leaf-associated N2-fixers across plant hosts and ecosystems, illustrate the ecological adaptation of N2-fixers to the phyllosphere, and identify the environmental factors driving BNF. Finally, we discuss potential BNF engineering strategies to improve the nitrogen uptake in plant leaves and thus sustainable food production.
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Affiliation(s)
- Yong-Guan Zhu
- State Key Laboratory of Urban and Regional Ecology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China.
| | - Jingjing Peng
- State Key Laboratory of Nutrient Use and Management, College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, China Agricultural University, Beijing, 100193, China
| | - Cai Chen
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China
| | - Chao Xiong
- College of Urban and Environmental Sciences, Peking University, Beijing, 100871, China
| | - Shule Li
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China
| | - Anhui Ge
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, SIBS, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Ertao Wang
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, SIBS, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Werner Liesack
- Max Planck Institute for Terrestrial Microbiology, Marburg, 35043, Germany
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14
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Liu X, Li P, Wang H, Han LL, Yang K, Wang Y, Jiang Z, Cui L, Kao SJ. Nitrogen fixation and diazotroph diversity in groundwater systems. THE ISME JOURNAL 2023; 17:2023-2034. [PMID: 37715043 PMCID: PMC10579273 DOI: 10.1038/s41396-023-01513-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 09/03/2023] [Accepted: 09/05/2023] [Indexed: 09/17/2023]
Abstract
Biological nitrogen fixation (BNF), the conversion of N2 into bioavailable nitrogen (N), is the main process for replenishing N loss in the biosphere. However, BNF in groundwater systems remains poorly understood. In this study, we examined the activity, abundance, and community composition of diazotrophs in groundwater in the Hetao Plain of Inner Mongolia using 15N tracing methods, reverse transcription qPCR (RT-qPCR), and metagenomic/metatranscriptomic analyses. 15N2 tracing incubation of near in situ groundwater (9.5-585.4 nmol N L-1 h-1) and N2-fixer enrichment and isolates (13.2-1728.4 nmol N g-1 h-1, as directly verified by single-cell resonance Raman spectroscopy), suggested that BNF is a non-negligible source of N in groundwater in this region. The expression of nifH genes ranged from 3.4 × 103 to 1.2 × 106 copies L-1 and was tightly correlated with dissolved oxygen (DO), Fe(II), and NH4+. Diazotrophs in groundwater were chiefly aerobes or facultative anaerobes, dominated by Stutzerimonas, Pseudomonas, Paraburkholderia, Klebsiella, Rhodopseudomonas, Azoarcus, and additional uncultured populations. Active diazotrophs, which prefer reducing conditions, were more metabolically diverse and potentially associated with nitrification, sulfur/arsenic mobilization, Fe(II) transport, and CH4 oxidation. Our results highlight the importance of diazotrophs in subsurface geochemical cycles.
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Affiliation(s)
- Xiaohan Liu
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, 430074, PR China
- Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic Science, School of Environmental Studies, China University of Geosciences, Wuhan, 430074, PR China
| | - Ping Li
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, 430074, PR China.
- Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic Science, School of Environmental Studies, China University of Geosciences, Wuhan, 430074, PR China.
| | - Helin Wang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, 430074, PR China
- Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic Science, School of Environmental Studies, China University of Geosciences, Wuhan, 430074, PR China
| | - Li-Li Han
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, 361102, PR China
| | - Kai Yang
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, PR China
| | - Yanhong Wang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, 430074, PR China
- Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic Science, School of Environmental Studies, China University of Geosciences, Wuhan, 430074, PR China
| | - Zhou Jiang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, 430074, PR China
- Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic Science, School of Environmental Studies, China University of Geosciences, Wuhan, 430074, PR China
| | - Li Cui
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, PR China
| | - Shuh-Ji Kao
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, 361102, PR China
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15
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Aerts JW, Sarbu SM, Brad T, Ehrenfreund P, Westerhoff HV. Microbial Ecosystems in Movile Cave: An Environment of Extreme Life. Life (Basel) 2023; 13:2120. [PMID: 38004260 PMCID: PMC10672346 DOI: 10.3390/life13112120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 10/21/2023] [Accepted: 10/24/2023] [Indexed: 11/26/2023] Open
Abstract
Movile Cave, situated in Romania close to the Black Sea, constitutes a distinct and challenging environment for life. Its partially submerged ecosystem depends on chemolithotrophic processes for its energetics, which are fed by a continuous hypogenic inflow of mesothermal waters rich in reduced chemicals such as hydrogen sulfide and methane. We sampled a variety of cave sublocations over the course of three years. Furthermore, in a microcosm experiment, minerals were incubated in the cave waters for one year. Both endemic cave samples and extracts from the minerals were subjected to 16S rRNA amplicon sequencing. The sequence data show specific community profiles in the different subenvironments, indicating that specialized prokaryotic communities inhabit the different zones in the cave. Already after one year, the different incubated minerals had been colonized by specific microbial communities, indicating that microbes in Movile Cave can adapt in a relatively short timescale to environmental opportunities in terms of energy and nutrients. Life can thrive, diversify and adapt in remote and isolated subterranean environments such as Movile Cave.
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Affiliation(s)
- Joost W. Aerts
- Molecular Cell Biology, A-LIFE, 01-E-57, Faculty of Science, VU University Amsterdam, Van der Boechorstraat 3, 1081 BT Amsterdam, The Netherlands
| | - Serban M. Sarbu
- “Emil Racoviţă” Institute of Speleology, Str. Frumoasă 31, 010986 Bucharest, Romania
- Department of Biological Sciences, California State University, Chico, CA 95929, USA
| | - Traian Brad
- “Emil Racoviţă” Institute of Speleology, Clinicilor 5-7, 400006 Cluj-Napoca, Romania;
| | - Pascale Ehrenfreund
- Laboratory for Astrophysics, Leiden Observatory, Leiden University, 2333 RA Leiden, The Netherlands
- Space Policy Institute, George Washington University, Washington, DC 20052, USA
| | - Hans V. Westerhoff
- Molecular Cell Biology, A-LIFE, 01-E-57, Faculty of Science, VU University Amsterdam, Van der Boechorstraat 3, 1081 BT Amsterdam, The Netherlands
- Synthetic Systems Biology and Nuclear Organization, Swammerdam Institute for Life Sciences, University of Amsterdam, 1098 XH Amsterdam, The Netherlands
- School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PL, UK
- Stellenbosch Institute for Advanced Study, Stellenbosch 7600, South Africa
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16
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Thongsamer T, Vinitnantharat S, Pinisakul A, Werner D. Fixed-bed biofilter for polluted surface water treatment using chitosan impregnated-coconut husk biochar. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 334:122137. [PMID: 37406752 DOI: 10.1016/j.envpol.2023.122137] [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: 02/12/2023] [Revised: 06/25/2023] [Accepted: 07/01/2023] [Indexed: 07/07/2023]
Abstract
Pelletizing biochar enables its use as a biofilter medium for polluted canal water treatment. Coconut husk biochar pellets and their modification with chitosan (CHC) were compared with conventional activated carbon pellets and gravel. The biofilter columns with these media were operated with a hydraulic loading rate of 0.1 m3/m2∙h. CHC showed the highest potential to reduce phosphate and nitrogen, via the adsorption process in the first week of filtration and later enhanced by biodegradation, to achieve removal efficiencies of 61.70 and 54.37% for these two key nutrients, respectively, over five weeks of biofilter operation. The predominant bacteria in the biofilter communities were characterized at the end of the experiments by next generation sequencing and quantitative polymerase chain reaction analysis. The biofilter communities included ammonium oxidizing, nitrite oxidizing, denitrifying, polyphosphate accumulating and denitrifying phosphate-accumulating bacteria that benefit nutrient removal. The CHC biofilter also effectively removed micropollutants, including pharmaceuticals.
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Affiliation(s)
- Thunchanok Thongsamer
- Environmental Technology Program in School of Energy, Environment and Materials, King Mongkut's University of Technology Thonburi, Bangkok, 10140, Thailand
| | - Soydoa Vinitnantharat
- Environmental Technology Program in School of Energy, Environment and Materials, King Mongkut's University of Technology Thonburi, Bangkok, 10140, Thailand; Environmental and Energy Management for Community and Circular Economy Research Group, King Mongkut's University of Technology Thonburi, Bangkok, 10140, Thailand
| | - Anawat Pinisakul
- Chemistry for Green Society and Healthy Research Group, Department of Chemistry, Faculty of Science, King Mongkut's University of Technology Thonburi, Bangkok, 10140, Thailand.
| | - David Werner
- School of Engineering, Newcastle University, Newcastle Upon Tyne, NE1 7RU, United Kingdom
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Zhao H, Sun N, Huang L, Qian R, Lin X, Sun C, Zhu Y. Azospirillum brasilense activates peroxidase-mediated cell wall modification to inhibit root cell elongation. iScience 2023; 26:107144. [PMID: 37534167 PMCID: PMC10391928 DOI: 10.1016/j.isci.2023.107144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 05/24/2023] [Accepted: 06/12/2023] [Indexed: 08/04/2023] Open
Abstract
The molecular mechanism of beneficial bacterium Azospirillum brasilense-mediated root developmental remain elusive. A. brasilense elicited extensively transcriptional changes but inhibited primary root elongation in Arabidopsis. By analyzing root cell type-specific developmental markers, we demonstrated that A. brasilense affected neither overall organization nor cell division of primary root meristem. The cessation of primary root resulted from reduction of cell elongation, which is probably because of bacterially activated peroxidase that will lead to cell wall cross-linking at consuming of H2O2. The activated peroxidase combined with downregulated cell wall loosening enzymes consequently led to cell wall thickness, whereas inhibiting peroxidase restored root growth under A. brasilense inoculation. We further showed that peroxidase activity was probably promoted by cadaverine secreted by A. brasilense. These results suggest that A. brasilense inhibits root elongation by activating peroxidase and inducing cell wall modification in Arabidopsis, in which cadaverine released by A. brasilense is a potential signal compound.
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Affiliation(s)
- Hongcheng Zhao
- MOE Key Laboratory of Environment Remediation and Ecological Health, College of Natural Resource & Environmental Sciences, Zhejiang University, Hangzhou 310058, China
| | - Nan Sun
- MOE Key Laboratory of Environment Remediation and Ecological Health, College of Natural Resource & Environmental Sciences, Zhejiang University, Hangzhou 310058, China
| | - Lin Huang
- MOE Key Laboratory of Environment Remediation and Ecological Health, College of Natural Resource & Environmental Sciences, Zhejiang University, Hangzhou 310058, China
| | - Ruyi Qian
- MOE Key Laboratory of Environment Remediation and Ecological Health, College of Natural Resource & Environmental Sciences, Zhejiang University, Hangzhou 310058, China
| | - Xianyong Lin
- MOE Key Laboratory of Environment Remediation and Ecological Health, College of Natural Resource & Environmental Sciences, Zhejiang University, Hangzhou 310058, China
| | - Chengliang Sun
- MOE Key Laboratory of Environment Remediation and Ecological Health, College of Natural Resource & Environmental Sciences, Zhejiang University, Hangzhou 310058, China
| | - Yongguan Zhu
- MOE Key Laboratory of Environment Remediation and Ecological Health, College of Natural Resource & Environmental Sciences, Zhejiang University, Hangzhou 310058, China
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, PR China
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Dunn MF, Becerra-Rivera VA. The Biosynthesis and Functions of Polyamines in the Interaction of Plant Growth-Promoting Rhizobacteria with Plants. PLANTS (BASEL, SWITZERLAND) 2023; 12:2671. [PMID: 37514285 PMCID: PMC10385936 DOI: 10.3390/plants12142671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 07/12/2023] [Accepted: 07/15/2023] [Indexed: 07/30/2023]
Abstract
Plant growth-promoting rhizobacteria (PGPR) are members of the plant rhizomicrobiome that enhance plant growth and stress resistance by increasing nutrient availability to the plant, producing phytohormones or other secondary metabolites, stimulating plant defense responses against abiotic stresses and pathogens, or fixing nitrogen. The use of PGPR to increase crop yield with minimal environmental impact is a sustainable and readily applicable replacement for a portion of chemical fertilizer and pesticides required for the growth of high-yielding varieties. Increased plant health and productivity have long been gained by applying PGPR as commercial inoculants to crops, although with uneven results. The establishment of plant-PGPR relationships requires the exchange of chemical signals and nutrients between the partners, and polyamines (PAs) are an important class of compounds that act as physiological effectors and signal molecules in plant-microbe interactions. In this review, we focus on the role of PAs in interactions between PGPR and plants. We describe the basic ecology of PGPR and the production and function of PAs in them and the plants with which they interact. We examine the metabolism and the roles of PAs in PGPR and plants individually and during their interaction with one another. Lastly, we describe some directions for future research.
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Affiliation(s)
- Michael F Dunn
- Programa de Genómica Funcional de Procariotes, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca 62210, Mexico
| | - Víctor A Becerra-Rivera
- Programa de Genómica Funcional de Procariotes, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca 62210, Mexico
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19
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Housh AB, Noel R, Powell A, Waller S, Wilder SL, Sopko S, Benoit M, Powell G, Schueller MJ, Ferrieri RA. Studies Using Mutant Strains of Azospirillum brasilense Reveal That Atmospheric Nitrogen Fixation and Auxin Production Are Light Dependent Processes. Microorganisms 2023; 11:1727. [PMID: 37512900 PMCID: PMC10383956 DOI: 10.3390/microorganisms11071727] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 06/27/2023] [Accepted: 06/29/2023] [Indexed: 07/30/2023] Open
Abstract
As the use of microbial inoculants in agriculture rises, it becomes important to understand how the environment may influence microbial ability to promote plant growth. This work examines whether there are light dependencies in the biological functions of Azospirillum brasilense, a commercialized prolific grass-root colonizer. Though classically defined as non-phototrophic, A. brasilense possesses photoreceptors that could perceive light conducted through its host's roots. Here, we examined the light dependency of atmospheric biological nitrogen fixation (BNF) and auxin biosynthesis along with supporting processes including ATP biosynthesis, and iron and manganese uptake. Functional mutants of A. brasilense were studied in light and dark environments: HM053 (high BNF and auxin production), ipdC (capable of BNF, deficient in auxin production), and FP10 (capable of auxin production, deficient in BNF). HM053 exhibited the highest rate of nitrogenase activity with the greatest light dependency comparing iterations in light and dark environments. The ipdC mutant showed similar behavior with relatively lower nitrogenase activity observed, while FP10 did not show a light dependency. Auxin biosynthesis showed strong light dependencies in HM053 and FP10 strains, but not for ipdC. Ferrous iron is involved in BNF, and a light dependency was observed for microbial 59Fe2+ uptake in HM053 and ipdC, but not FP10. Surprisingly, a light dependency for 52Mn2+ uptake was only observed in ipdC. Finally, ATP biosynthesis was sensitive to light across all three mutants favoring blue light over red light compared to darkness with observed ATP levels in descending order for HM053 > ipdC > FP10.
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Affiliation(s)
- Alexandra Bauer Housh
- Missouri Research Reactor Center, University of Missouri, Columbia, MO 65211, USA
- Chemistry Department, University of Missouri, Columbia, MO 65211, USA
- Interdisciplinary Plant Group, University of Missouri, Columbia, MO 65211, USA
| | - Randi Noel
- Missouri Research Reactor Center, University of Missouri, Columbia, MO 65211, USA
- Interdisciplinary Plant Group, University of Missouri, Columbia, MO 65211, USA
- Division of Plant Science & Technology, University of Missouri, Columbia, MO 65211, USA
| | - Avery Powell
- Missouri Research Reactor Center, University of Missouri, Columbia, MO 65211, USA
- Interdisciplinary Plant Group, University of Missouri, Columbia, MO 65211, USA
- School of Natural Resources, University of Missouri, Columbia, MO 65211, USA
| | - Spenser Waller
- Missouri Research Reactor Center, University of Missouri, Columbia, MO 65211, USA
- Interdisciplinary Plant Group, University of Missouri, Columbia, MO 65211, USA
- School of Natural Resources, University of Missouri, Columbia, MO 65211, USA
| | - Stacy L Wilder
- Missouri Research Reactor Center, University of Missouri, Columbia, MO 65211, USA
| | - Stephanie Sopko
- Missouri Research Reactor Center, University of Missouri, Columbia, MO 65211, USA
- Department of Biochemistry, University of Missouri, Columbia, MO 65211, USA
| | - Mary Benoit
- Missouri Research Reactor Center, University of Missouri, Columbia, MO 65211, USA
- Division of Plant Science & Technology, University of Missouri, Columbia, MO 65211, USA
| | - Garren Powell
- Missouri Research Reactor Center, University of Missouri, Columbia, MO 65211, USA
- Department of Biochemistry, University of Missouri, Columbia, MO 65211, USA
| | - Michael J Schueller
- Missouri Research Reactor Center, University of Missouri, Columbia, MO 65211, USA
- Chemistry Department, University of Missouri, Columbia, MO 65211, USA
| | - Richard A Ferrieri
- Missouri Research Reactor Center, University of Missouri, Columbia, MO 65211, USA
- Chemistry Department, University of Missouri, Columbia, MO 65211, USA
- Interdisciplinary Plant Group, University of Missouri, Columbia, MO 65211, USA
- Division of Plant Science & Technology, University of Missouri, Columbia, MO 65211, USA
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20
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Adedayo AA, Fadiji AE, Babalola OO. Unraveling the functional genes present in rhizosphere microbiomes of Solanum lycopersicum. PeerJ 2023; 11:e15432. [PMID: 37283894 PMCID: PMC10241170 DOI: 10.7717/peerj.15432] [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: 02/16/2023] [Accepted: 04/26/2023] [Indexed: 06/08/2023] Open
Abstract
The microbiomes living in the rhizosphere soil of the tomato plant contribute immensely to the state of health of the tomato plant alongside improving sustainable agriculture. With the aid of shotgun metagenomics sequencing, we characterized the putative functional genes (plant-growth-promoting and disease-resistant genes) produced by the microbial communities dwelling in the rhizosphere soil of healthy and powdery mildew-diseased tomato plants. The results identified twenty-one (21) plant growth promotion (PGP) genes in the microbiomes inhabiting the healthy rhizosphere (HR) which are more predomiant as compared to diseased rhizosphere (DR) that has nine (9) genes and four (4) genes in bulk soil (BR). Likewise, we identified some disease-resistant genes which include nucleotide binding genes and antimicrobial genes. Our study revealed fifteen (15) genes in HR which made it greater in comparison to DR that has three (3) genes and three (3) genes in bulk soil. Further studies should be conducted by isolating these microorganisms and introduce them to field experiments for cultivation of tomatoes.
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Castillo J, Alom J, Gomez-Arias A, Cebekhulu S, Matu A, Cason E, Valverde A. Bacterial communities shift and influence in an acid mine drainage treatment using barium carbonate disperse alkaline substrate system. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 885:163526. [PMID: 37116802 DOI: 10.1016/j.scitotenv.2023.163526] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 04/09/2023] [Accepted: 04/11/2023] [Indexed: 05/12/2023]
Abstract
Chemical passive treatment systems used to remediate acid mine drainage has been evaluated based mainly on the reactivity of the chemical alkaline reagents, overlooking the activity of the microorganisms that proliferate in these artificial ecosystems. In this study, the bacterial communities of a unique passive treatment system known as BDAS (Barium carbonate Dispersed Alkaline Substrate) were investigated using 16S rRNA gene metagenomic sequencing combined with hydrochemical characterization of the AMD and phenotypic characterization of biogenic precipitates. According to the hydrochemical characterization, the water quality improved as the water progressed through the system, with a drastic increase in the pH (up to alkaline conditions) and total organic carbon, as well as the removal of main contaminants such as Ca2+, SO42-, Fe3+, Al3+, and Mn2+. These environmental changes resulted in an increase in bacterial diversity (richness) after the inlet and in the shift of the bacterial communities from chemoautotrophs (e.g., Ferrovum and Acidiphilum) to chemoheterotrophs (e.g., Brevundimonas and Geobacter). Some of these taxa harbour potential to immobilize metals, aiding in the treatment of the water. One of the mechanisms involved in the immobilization of metals is microbially induced calcium carbonate precipitation, which seems to occur spontaneously in BDAS. The production of biofilm was also observed in most parts of the system, except in the inlet, helping with the removal of metals. However, in the long run, the build-up of biofilm and precipitation of metals could clog (i.e., biofouling) the pores of the matrix, reducing the treatment efficiency. Potential human pathogens (e.g. Legionella) were also detected in BDAS indicating the need for a treatment step at the end of the system to remove pathogenic microorganisms. These findings present a new perspective of the bacterial communities and their effects (both positively and negatively) in a chemical passive treatment system.
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Affiliation(s)
- J Castillo
- Department of Microbiology and Biochemistry, University of the Free State, Bloemfontein, South Africa.
| | - J Alom
- Department of Microbiology and Biochemistry, University of the Free State, Bloemfontein, South Africa
| | - A Gomez-Arias
- Department of Chemistry, University of the Free State, Bloemfontein, South Africa
| | - S Cebekhulu
- Centre for Environmental Management, University of the Free State, Bloemfontein, South Africa
| | - A Matu
- Department of Microbiology and Biochemistry, University of the Free State, Bloemfontein, South Africa
| | - E Cason
- Department of Animal Sciences, University of the Free State, Bloemfontein, South Africa
| | - A Valverde
- Instituto de Recursos Naturales y Agrobiología de Salamanca (IRNASA-CSIC), Consejo Superior de Investigaciones Científicas, Salamanca, Spain
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22
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de Leon V, Orr K, Stelinski LL, Mandadi K, Ibanez-Carrasco F. Inoculation of Tomato With Plant Growth Promoting Rhizobacteria Affects the Tomato-Potato Psyllid-Candidatus Liberibacter Solanacearum Interactions. JOURNAL OF ECONOMIC ENTOMOLOGY 2023; 116:379-388. [PMID: 36723158 DOI: 10.1093/jee/toad006] [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: 09/30/2022] [Indexed: 05/30/2023]
Abstract
The Rio Grande Valley (RGV) in southern Texas is well-suited for vegetable production due to its relatively mild/warm weather conditions in the fall and winter. Consequently, insects inflict year-round, persistent damage to crops in the RGV and regions with similar climate. Bactericera cockerelli (Šulc) (Hemiptera: Triozidae), commonly known as the potato psyllid, is a known vector of Candidatus Liberibacter solanacearum (CLso) (Hyphomicrobiales: Rhizobiaceae), a fastidious phloem-limited bacterium associated to vein-greening in tomatoes and Zebra Chip in potatoes. Vector control is the primary approach of integrated pest management (IPM) strategies that aim to prevent plant diseases in commercial agricultural systems. However, resistance-selective pressures that decrease the effectiveness of chemical control (insecticide) applications over time are of increasing concern. Therefore, we explore an ecological approach to devising alternative IPM methodologies to manage the psyllid-transmitted CLso pathogen to supplement existing chemical products and application schedules without increasing resistance. In this study, our objective was to examine the effects of plant-growth promoting rhizobacteria (PGPR) on host-vector-pathogen interactions. Soil-drench applications of PGPRs to Solanum lycopersicum (Solanales: Solanaceae) seedlings revealed structural and possible physiological changes to the plant host and indirect changes on psyllid behavior: host plants had increased length and biomass of roots and exhibited delayed colonization by CLso, while psyllids displayed changes in parental (F0) psyllid behavior (orientation and oviposition) in response to treated hosts and in the sex ratio of their progeny (F1). Based on our results, we suggest that PGPR may have practical use in commercial tomato production.
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Affiliation(s)
- Victoria de Leon
- Texas A&M AgriLife Research and Extension Center, 2415 East US Highway 83, Weslaco, TX, 78596, USA
| | - Katharine Orr
- Texas A&M AgriLife Research and Extension Center, 2415 East US Highway 83, Weslaco, TX, 78596, USA
| | - Lukasz L Stelinski
- Department of Entomology and Nematology, Citrus Research and Education Center, University of Florida, Lake Alfred, FL, 33850, USA
| | - Kranthi Mandadi
- Texas A&M AgriLife Research and Extension Center, 2415 East US Highway 83, Weslaco, TX, 78596, USA
- Department of Plant Pathology & Microbiology, Texas A&M University, 496 Olsen Boulevard, College Station, TX, 77840, USA
- Institute for Advancing Health Through Agriculture, Texas A&M AgriLife, College Station, TX, USA
| | - Freddy Ibanez-Carrasco
- Texas A&M AgriLife Research and Extension Center, 2415 East US Highway 83, Weslaco, TX, 78596, USA
- Department of Entomology, Texas A&M University, Minnie Bell Heep Center, Suite 412, 2475 TAMU, 370 Olsen Boulevard, College Station, TX, 77843, USA
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23
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Acosta K, Sorrels S, Chrisler W, Huang W, Gilbert S, Brinkman T, Michael TP, Lebeis SL, Lam E. Optimization of Molecular Methods for Detecting Duckweed-Associated Bacteria. PLANTS (BASEL, SWITZERLAND) 2023; 12:872. [PMID: 36840219 PMCID: PMC9965182 DOI: 10.3390/plants12040872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 02/05/2023] [Accepted: 02/08/2023] [Indexed: 06/18/2023]
Abstract
The bacterial colonization dynamics of plants can differ between phylogenetically similar bacterial strains and in the context of complex bacterial communities. Quantitative methods that can resolve closely related bacteria within complex communities can lead to a better understanding of plant-microbe interactions. However, current methods often lack the specificity to differentiate phylogenetically similar bacterial strains. In this study, we describe molecular strategies to study duckweed-associated bacteria. We first systematically optimized a bead-beating protocol to co-isolate nucleic acids simultaneously from duckweed and bacteria. We then developed a generic fingerprinting assay to detect bacteria present in duckweed samples. To detect specific duckweed-bacterium associations, we developed a genomics-based computational pipeline to generate bacterial strain-specific primers. These strain-specific primers differentiated bacterial strains from the same genus and enabled the detection of specific duckweed-bacterium associations present in a community context. Moreover, we used these strain-specific primers to quantify the bacterial colonization of duckweed by normalization to a plant reference gene and revealed differences in colonization levels between strains from the same genus. Lastly, confocal microscopy of inoculated duckweed further supported our PCR results and showed bacterial colonization of the duckweed root-frond interface and root interior. The molecular methods introduced in this work should enable the tracking and quantification of specific plant-microbe associations within plant-microbial communities.
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Affiliation(s)
- Kenneth Acosta
- Department of Plant Biology, Rutgers the State University of New Jersey, New Brunswick, NJ 08901, USA
| | - Shawn Sorrels
- Department of Plant Biology, Rutgers the State University of New Jersey, New Brunswick, NJ 08901, USA
| | - William Chrisler
- Environmental Molecular Sciences Laboratory (EMSL), Pacific Northwest National Laboratory (PNNL), Richland, WA 99354, USA
| | - Weijuan Huang
- Institute of Nanfan & Seed Industry, Guangdong Academy of Sciences, Guangzhou 510316, China
| | - Sarah Gilbert
- Department of Plant Biology, Rutgers the State University of New Jersey, New Brunswick, NJ 08901, USA
| | - Thomas Brinkman
- Department of Plant Biology, Rutgers the State University of New Jersey, New Brunswick, NJ 08901, USA
| | - Todd P. Michael
- The Plant Molecular and Cellular Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Sarah L. Lebeis
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI 48824, USA
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI 48824, USA
- Plant Resilience Institute, Michigan State University, East Lansing, MI 48824, USA
| | - Eric Lam
- Department of Plant Biology, Rutgers the State University of New Jersey, New Brunswick, NJ 08901, USA
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Zhou G, Fan K, Li G, Gao S, Chang D, Liang T, Li S, Liang H, Zhang J, Che Z, Cao W. Synergistic effects of diazotrophs and arbuscular mycorrhizal fungi on soil biological nitrogen fixation after three decades of fertilization. IMETA 2023; 2:e81. [PMID: 38868350 PMCID: PMC10989903 DOI: 10.1002/imt2.81] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 12/19/2022] [Accepted: 01/02/2023] [Indexed: 06/14/2024]
Abstract
Biological nitrogen (N) fixation (BNF) via diazotrophs is an important ecological process for the conversion of atmospheric N to biologically available N. Although soil diazotrophs play a dominant role in BNF and arbuscular mycorrhizal fungi (AMF) serve as helpers to favor BNF, the response of soil BNF and diazotrophic communities to different long-term fertilizations and the role of AMF in diazotrophs-driven BNF are poorly understood. Herein, a 33-year fertilization experiment in a wheat-maize intercropping system was conducted to investigate the changes in soil BNF rates, diazotrophic and AMF communities, and their interactions after long-term representative fertilization (chemical fertilizer, cow manure, wheat straw, and green manure). We found a remarkable increase in soil BNF rates after more than three decades of fertilization compared with nonfertilized soil, and the green manure treatment rendered the highest enhancement. The functionality strengthening was mainly associated with the increase in the absolute abundance of diazotrophs and AMF and the relative abundance of the key ecological cluster of Module #0 (gained from the co-occurrence network of diazotrophic and AMF species) with dominant diazotrophs such as Skermanella and Azospirillum. Furthermore, although the positive correlations between diazotrophs and AMF were reduced under long-term organic fertilization regimes, green manuring could reverse the decline within Module #0, and this had a positive relationship with the BNF rate. This study suggests that long-term fertilization could promote N fixation and select specific groups of N fixers and their helpers in certain areas. Our work provides solid evidence that N fixation and certain groups of diazotrophic and AMF taxa and their interspecies relationship will be largely favored after the fertilized strategy of green manure.
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Affiliation(s)
- Guopeng Zhou
- Key Laboratory of Plant Nutrition and Fertilizer, Ministry of Agriculture and Rural Affairs/Institute of Agricultural Resources and Regional PlanningChinese Academy of Agricultural SciencesBeijingChina
| | - Kunkun Fan
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil ScienceChinese Academy of SciencesNanjingChina
| | - Guilong Li
- Institute of Soil & Fertilizer and Resource & EnvironmentJiangxi Academy of Agricultural SciencesNanchangChina
| | - Songjuan Gao
- College of Resources and Environmental SciencesNanjing Agricultural UniversityNanjingChina
| | - Danna Chang
- Key Laboratory of Plant Nutrition and Fertilizer, Ministry of Agriculture and Rural Affairs/Institute of Agricultural Resources and Regional PlanningChinese Academy of Agricultural SciencesBeijingChina
| | - Ting Liang
- Key Laboratory of Plant Nutrition and Fertilizer, Ministry of Agriculture and Rural Affairs/Institute of Agricultural Resources and Regional PlanningChinese Academy of Agricultural SciencesBeijingChina
| | - Shun Li
- College of Resources and Environmental SciencesNanjing Agricultural UniversityNanjingChina
| | - Hai Liang
- College of Resources and Environmental SciencesNanjing Agricultural UniversityNanjingChina
| | - Jiudong Zhang
- Institute of Soil and Fertilizer and Water‐saving AgricultureGansu Academy of Agriculture ScienceLanzhouChina
| | - Zongxian Che
- Institute of Soil and Fertilizer and Water‐saving AgricultureGansu Academy of Agriculture ScienceLanzhouChina
| | - Weidong Cao
- Key Laboratory of Plant Nutrition and Fertilizer, Ministry of Agriculture and Rural Affairs/Institute of Agricultural Resources and Regional PlanningChinese Academy of Agricultural SciencesBeijingChina
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Hu Y, Chen C, Liu S, Zhou Y, Jia W, Cao Y. Biofilm-induced corrosion inhibition of Q235 carbon steel by anaerobic Bacillus cereus inoculum in simulated cooling water. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:20833-20848. [PMID: 36260227 DOI: 10.1007/s11356-022-23561-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Accepted: 10/07/2022] [Indexed: 06/16/2023]
Abstract
In this study, the corrosion behavior of Q235 carbon steel (CS) under a Bacillus cereus (B. cereus) inoculum in simulated cooling water was evaluated. The weight loss study proved B. cereus inoculum possessed anticorrosion efficiencies of 92.84% and 73.88% for 3-day and 14-day rotation tests, respectively. The electrochemical measurements indicated that the added B. cereus inoculum increased the charge transfer resistance and reduced corrosion current density. B. cereus cells with strong biofilm-forming capacity were able to adhere onto the Q235 CS surface to form compact biofilms and cause biomineralization. Surface characterization analysis demonstrated that the presence of the B. cereus inoculum reduced the amount of Fe2O3 and simultaneously increased the amount of CaCO3 in corrosion products. The corrosion inhibition mechanisms of the B. cereus inoculum involve forming biofilm, generating a biomineralized layer, and consuming dissolved oxygen. Thus, B. cereus inoculum provides a biological strategy for industrial cooling water anticorrosion application.
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Affiliation(s)
- Yanglin Hu
- Hebei Key Lab of Power Plant Flue Gas Multi-Pollutants Control, Department of Environmental Science and Engineering, North China Electric Power University, Baoding, 071003, People's Republic of China
- MOE Key Laboratory of Resources and Environmental Systems Optimization, College of Environmental Science and Engineering, North China Electric Power University, Beijing, 102206, People's Republic of China
| | - Chuanmin Chen
- Hebei Key Lab of Power Plant Flue Gas Multi-Pollutants Control, Department of Environmental Science and Engineering, North China Electric Power University, Baoding, 071003, People's Republic of China.
- MOE Key Laboratory of Resources and Environmental Systems Optimization, College of Environmental Science and Engineering, North China Electric Power University, Beijing, 102206, People's Republic of China.
| | - Songtao Liu
- Hebei Key Lab of Power Plant Flue Gas Multi-Pollutants Control, Department of Environmental Science and Engineering, North China Electric Power University, Baoding, 071003, People's Republic of China
- MOE Key Laboratory of Resources and Environmental Systems Optimization, College of Environmental Science and Engineering, North China Electric Power University, Beijing, 102206, People's Republic of China
| | - Yingran Zhou
- Hebei Key Lab of Power Plant Flue Gas Multi-Pollutants Control, Department of Environmental Science and Engineering, North China Electric Power University, Baoding, 071003, People's Republic of China
- MOE Key Laboratory of Resources and Environmental Systems Optimization, College of Environmental Science and Engineering, North China Electric Power University, Beijing, 102206, People's Republic of China
| | - Wenbo Jia
- Hebei Key Lab of Power Plant Flue Gas Multi-Pollutants Control, Department of Environmental Science and Engineering, North China Electric Power University, Baoding, 071003, People's Republic of China
- MOE Key Laboratory of Resources and Environmental Systems Optimization, College of Environmental Science and Engineering, North China Electric Power University, Beijing, 102206, People's Republic of China
| | - Yue Cao
- Hebei Key Lab of Power Plant Flue Gas Multi-Pollutants Control, Department of Environmental Science and Engineering, North China Electric Power University, Baoding, 071003, People's Republic of China
- MOE Key Laboratory of Resources and Environmental Systems Optimization, College of Environmental Science and Engineering, North China Electric Power University, Beijing, 102206, People's Republic of China
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26
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Yang J, Yu Q, Su W, Wang S, Wang X, Han Q, Li H. Metagenomics reveals that temperature predicts a small proportion of antibiotic resistomes and mobile genetic elements in polluted water. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 317:120793. [PMID: 36462677 DOI: 10.1016/j.envpol.2022.120793] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 11/04/2022] [Accepted: 11/28/2022] [Indexed: 06/17/2023]
Abstract
Climate warming multiplies the threat of antibiotic resistance genes (ARGs) to public health, but whether temperature may predict antibiotic resistomes in water environment remain unknown. Here, by metagenomic sequencing, we investigated the changes of resistome at five different temperature gradients (23, 26, 29, 32, and 35 °C) in polluted water by animal cadaver. Thirty ARG types including 668 subtypes were observed in our samples. Temperature significantly influenced ARG profiles and showed a negative correlation with ARG diversity. The ARG assembly process was dominated by a deterministic process (63.32%-95.08%) but showed a peak pattern with temperature. Notably, temperature may predict approximately 21% of ARGs and 36% of mobile genetic elements (MGEs), while most other ARGs or MGEs were insensitive to temperature. Three types (carbapenem, dicyclomycin, and diaminopyrimidine antibiotic) and 63 subtypes of ARGs that positively correlated with temperature were identified in the polluted water. Notably, we screened 21 subtypes of high-risk ARGs (bacA, mdtA, tetM, etc.) and 22 opportunistic pathogens (Aeromonas, Clostridium, Bacteroides, etc.) and found their positive co-occurrence with temperature, implying these potential biological or genetic pollutants may probably go up under global warming. Our study reveals the predictability of temperature on antibiotic resistance genes, providing a suitable approach to track the fate and spread of ARGs in water environment under climate warming.
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Affiliation(s)
- Jiawei Yang
- School of Public Health, Lanzhou University, Lanzhou, 730000, China
| | - Qiaoling Yu
- State Key Laboratory of Grassland Agro-ecosystems, Center for Grassland Microbiome, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, 730000, China
| | - Wanghong Su
- School of Public Health, Lanzhou University, Lanzhou, 730000, China
| | - Sijie Wang
- School of Public Health, Lanzhou University, Lanzhou, 730000, China
| | - Xiaochen Wang
- School of Public Health, Lanzhou University, Lanzhou, 730000, China
| | - Qian Han
- School of Public Health, Lanzhou University, Lanzhou, 730000, China
| | - Huan Li
- School of Public Health, Lanzhou University, Lanzhou, 730000, China; State Key Laboratory of Grassland Agro-ecosystems, Center for Grassland Microbiome, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, 730000, China.
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27
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Molecular Mechanism and Agricultural Application of the NifA-NifL System for Nitrogen Fixation. Int J Mol Sci 2023; 24:ijms24020907. [PMID: 36674420 PMCID: PMC9866876 DOI: 10.3390/ijms24020907] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 12/27/2022] [Accepted: 12/30/2022] [Indexed: 01/06/2023] Open
Abstract
Nitrogen-fixing bacteria execute biological nitrogen fixation through nitrogenase, converting inert dinitrogen (N2) in the atmosphere into bioavailable nitrogen. Elaborating the molecular mechanisms of orderly and efficient biological nitrogen fixation and applying them to agricultural production can alleviate the "nitrogen problem". Azotobacter vinelandii is a well-established model bacterium for studying nitrogen fixation, utilizing nitrogenase encoded by the nif gene cluster to fix nitrogen. In Azotobacter vinelandii, the NifA-NifL system fine-tunes the nif gene cluster transcription by sensing the redox signals and energy status, then modulating nitrogen fixation. In this manuscript, we investigate the transcriptional regulation mechanism of the nif gene in autogenous nitrogen-fixing bacteria. We discuss how autogenous nitrogen fixation can better be integrated into agriculture, providing preliminary comprehensive data for the study of autogenous nitrogen-fixing regulation.
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Beccaccioli M, Moricca C, Faino L, Reale R, Mineo M, Reverberi M. The Neolithic site "La Marmotta": DNA metabarcoding to identify the microbial deterioration of waterlogged archeological wood. Front Microbiol 2023; 14:1129983. [PMID: 37032892 PMCID: PMC10079079 DOI: 10.3389/fmicb.2023.1129983] [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: 12/22/2022] [Accepted: 03/03/2023] [Indexed: 04/11/2023] Open
Abstract
Introduction The evaluation of biological degradation of waterlogged archeological wood is crucial to choose the conservative and protective treatments to be applied to the wooden material. The waterlogged environmental conditions are characterized by oxygen scarcity, only allowing the growth of adapted microbes capable to degrade the organic wooden material, mainly erosion bacteria and soft-rot fungi. In this work, we characterized and evaluated the biodegradation state and the microbial communities of wooden fragments preserved in storage tanks. These were preserved by waterlogging within the Neolithic village "La Marmotta," currently found under the Bracciano Lake (Lazio, Italy). Methods The waterlogged wood samples were first identified taxonomically with an optical microscope, also allowing an evaluation of their preservation state. The microbial community was then evaluated through the sequencing of Internal Transcribed Spacer sequences for fungi and 16S for bacteria with the Oxford Nanopore Technologies (ONT) MinION platform. Results The identified microbial community appears to be consistent with the waterlogged samples, as many bacteria attributable to the erosion of wood and ligninolytic fungi have been sequenced. Discussion The reported results highlight the first use of targeted metabarcoding by ONT applied to study the biodeterioration of waterlogged archeological wood.
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Affiliation(s)
- Marzia Beccaccioli
- Department of Environmental Biology, “Sapienza” University of Rome, Rome, Italy
- *Correspondence: Marzia Beccaccioli,
| | - Claudia Moricca
- Department of Environmental Biology, “Sapienza” University of Rome, Rome, Italy
| | - Luigi Faino
- Department of Environmental Biology, “Sapienza” University of Rome, Rome, Italy
| | - Rita Reale
- Chemistry Applied to Restoration, A. Galli Academy, Via Petrarca, Como, Italy
| | - Mario Mineo
- Department of Environmental Biology, “Sapienza” University of Rome, Rome, Italy
| | - Massimo Reverberi
- Department of Environmental Biology, “Sapienza” University of Rome, Rome, Italy
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Meena M, Mehta T, Nagda A, Yadav G, Sonigra P. PGPR-mediated synthesis and alteration of different secondary metabolites during plant-microbe interactions. PLANT-MICROBE INTERACTION - RECENT ADVANCES IN MOLECULAR AND BIOCHEMICAL APPROACHES 2023:229-255. [DOI: 10.1016/b978-0-323-91875-6.00002-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
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Patra D, Mandal S. Non-rhizobia are the alternative sustainable solution for growth and development of the nonlegume plants. Biotechnol Genet Eng Rev 2022:1-30. [PMID: 36471635 DOI: 10.1080/02648725.2022.2152623] [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: 08/20/2022] [Accepted: 11/13/2022] [Indexed: 12/12/2022]
Abstract
The major research focus for biological nitrogen fixation (BNF) has mostly been on typical rhizobia with legumes. But the newly identified non-rhizobial bacteria, both individually or in combination could also be an alternative for nitrogen supplementation in both legumes and nonlegume plants. Although about 90% of BNF is derived from a legume - rhizobia symbiosis, the non-legumes specially the cereals lack canonical nitrogen fixation system through root-nodule organogenesis. The non-rhizobia may colonize in the rhizosphere or present in endophytic/associative nature. The non-rhizobia are well known for facilitating plant growth through their potential to alleviate various stresses (salt, drought, and pathogens), acquisition of minerals (P, K, etc.), or by producing phytohormones. Bacterial symbiosis in non-legumes represents by the Gram-positive Frankia having a major contribution in overall fortification of usable nitrogenous material in soil where they are associated with their hosts. This review discusses the recent updates on the diversity and association of the non-rhizobial species and their impact on the growth and productivity of their host plants with particular emphasis on major economically important cereal plants. The future application possibilities of non-rhizobia for soil fertility and plant growth enhancement for sustainable agriculture have been discussed.
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Affiliation(s)
- Dipanwita Patra
- Department of Microbiology, University of Calcutta, Kolkata, India
| | - Sukhendu Mandal
- Department of Microbiology, University of Calcutta, Kolkata, India
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Antoszewski M, Mierek-Adamska A, Dąbrowska GB. The Importance of Microorganisms for Sustainable Agriculture-A Review. Metabolites 2022; 12:1100. [PMID: 36422239 PMCID: PMC9694901 DOI: 10.3390/metabo12111100] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 11/04/2022] [Accepted: 11/08/2022] [Indexed: 08/27/2023] Open
Abstract
In the face of climate change, progressive degradation of the environment, including agricultural land negatively affecting plant growth and development, endangers plant productivity. Seeking efficient and sustainable agricultural techniques to replace agricultural chemicals is one of the most important challenges nowadays. The use of plant growth-promoting microorganisms is among the most promising approaches; however, molecular mechanisms underneath plant-microbe interactions are still poorly understood. In this review, we summarized the knowledge on plant-microbe interactions, highlighting the role of microbial and plant proteins and metabolites in the formation of symbiotic relationships. This review covers rhizosphere and phyllosphere microbiomes, the role of root exudates in plant-microorganism interactions, the functioning of the plant's immune system during the plant-microorganism interactions. We also emphasized the possible role of the stringent response and the evolutionarily conserved mechanism during the established interaction between plants and microorganisms. As a case study, we discussed fungi belonging to the genus Trichoderma. Our review aims to summarize the existing knowledge about plant-microorganism interactions and to highlight molecular pathways that need further investigation.
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Affiliation(s)
| | - Agnieszka Mierek-Adamska
- Department of Genetics, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University, Lwowska 1, 87-100 Toruń, Poland
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Singh VS, Dubey BK, Rai S, Singh SP, Tripathi AK. Engineering D-glucose utilization in Azospirillum brasilense Sp7 promotes rice root colonization. Appl Microbiol Biotechnol 2022; 106:7891-7903. [DOI: 10.1007/s00253-022-12250-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 10/07/2022] [Accepted: 10/12/2022] [Indexed: 11/08/2022]
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Huang D, Xu R, Sun X, Li Y, Xiao E, Xu Z, Wang Q, Gao P, Yang Z, Lin H, Sun W. Effects of perfluorooctanoic acid (PFOA) on activated sludge microbial community under aerobic and anaerobic conditions. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:63379-63392. [PMID: 35459989 DOI: 10.1007/s11356-022-18841-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2021] [Accepted: 01/20/2022] [Indexed: 06/14/2023]
Abstract
Per- and polyfluoroalkyl substances (PFASs) have received increasing attention due to their widespread presence in diverse environments including wastewater treatment plants (WWTPs) and their potential adverse health effects. Perfluorooctanoic acid (PFOA) is one of the most detected forms of PFASs in WWTPs. However, there is still a paucity of knowledge about the effect of PFASs on microorganisms of the key component of WWTP, activated sludge. In this study, lab-scale microcosm experiments were established to evaluate the influences of PFOA on activated sludge microbes under aerobic and anaerobic conditions. The diversity, structure, and microbe-microbe interaction of microbial community were determined by 16S rRNA gene amplicon sequencing and co-occurrence network analysis. After 90 days of exposure to PFOA, activated sludge microbial richness decreased under both aerobic and anaerobic conditions. Specifically, under aerobic condition, Rhodopseudomonas (mean relative abundance 3.6%), Flavobacterium (2.4%), and Ignavibacterium (6.6%) were enriched in PFOA-spiked activated sludge compared with that in the unspiked sludge (2.6%, 0.1%, and 1.9%, respectively). By contrast, after 90 days of exposure to PFOA, Eubacterium (2.1%), Hyphomicrobium (1.8%), and Methyloversatilis (1.2%) were enriched under anaerobic condition, and more abundant than that in the control sludge (0.4%, 1.5%, and 0.6%, respectively). These genera were the potential PFOA-resistant members. In addition, Azospirillum and Sporomusa were the most connected taxa in PFOA-aerobic and PFOA-anaerobic networks, respectively. Prediction of the functional gene showed that PFOA inhibited some gene expression of sludge microbes, such as transcription, amino acid transport and metabolism, and energy production and conversion. In summary, continued exposure to PFOA induced substantial shifts of the sludge bacterial diversity and composition under both aerobic and anaerobic conditions.
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Affiliation(s)
- Duanyi Huang
- College of Environmental Science and Engineering, Hunan University, Changsha, 410082, People's Republic of China
- Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, People's Republic of China
| | - Rui Xu
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-Environmental Pollution Control and Management, Institute of Eco-Environmental and Soil Sciences, Guangdong Academy of Sciences, 808 Tianyuan Road, Guangzhou, 510650, China
| | - Xiaoxu Sun
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-Environmental Pollution Control and Management, Institute of Eco-Environmental and Soil Sciences, Guangdong Academy of Sciences, 808 Tianyuan Road, Guangzhou, 510650, China
| | - Yongbin Li
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-Environmental Pollution Control and Management, Institute of Eco-Environmental and Soil Sciences, Guangdong Academy of Sciences, 808 Tianyuan Road, Guangzhou, 510650, China
| | - Enzong Xiao
- Key Laboratory of Water Quality and Conservation in the Pearl River Delta, Ministry of Education, School of Environmental Science and Engineering, Guangzhou University, Guangzhou, 510006, China
| | - Zhimin Xu
- College of Resources and Environment, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China
| | - Qi Wang
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-Environmental Pollution Control and Management, Institute of Eco-Environmental and Soil Sciences, Guangdong Academy of Sciences, 808 Tianyuan Road, Guangzhou, 510650, China
| | - Pin Gao
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-Environmental Pollution Control and Management, Institute of Eco-Environmental and Soil Sciences, Guangdong Academy of Sciences, 808 Tianyuan Road, Guangzhou, 510650, China
| | - Zhaohui Yang
- College of Environmental Science and Engineering, Hunan University, Changsha, 410082, People's Republic of China.
- Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, People's Republic of China.
| | - Hanzhi Lin
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-Environmental Pollution Control and Management, Institute of Eco-Environmental and Soil Sciences, Guangdong Academy of Sciences, 808 Tianyuan Road, Guangzhou, 510650, China.
| | - Weimin Sun
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-Environmental Pollution Control and Management, Institute of Eco-Environmental and Soil Sciences, Guangdong Academy of Sciences, 808 Tianyuan Road, Guangzhou, 510650, China.
- School of Environment, Henan Normal University, Xinxiang, China.
- Key Laboratory of Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Xinxiang, China.
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Guo X, Wang M, Kang H, Zhou Y, Han F. Distribution, Polymorphism and Function Characteristics of the GST-Encoding Fhb7 in Triticeae. PLANTS 2022; 11:plants11162074. [PMID: 36015378 PMCID: PMC9416630 DOI: 10.3390/plants11162074] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 07/26/2022] [Accepted: 08/05/2022] [Indexed: 11/16/2022]
Abstract
Encoding a glutathione S-transferase (GST) and conferring resistance to Fusarium head blight (FHB), Fhb7 was successfully isolated from the newly assembled Thinopyrum elongatum genome by researchers, with blasting searches revealing that Thinopyrum gained Fhb7 through horizontal gene transfer from an endophytic Epichloë species. On the contrary, our molecular evidence reveals that the homologs of Fhb7 are distributed commonly in Triticeae. Other than Thinopyrum, the Fhb7 homologs were also detected in four other genera, Elymus, Leymus, Roegneria and Pseudoroegneria, respectively. Sequence comparisons revealed that the protein sequences were at least 94% identical across all of the Fhb7 homologs in Triticeae plants, which in turn suggested that the horizontal gene transfer of the Fhb7 might have occurred before Triticeae differentiation instead of Thinopyrum. The multiple Fhb7 homologs detected in some Triticeae accessions and wheat-Thinopyrum derivatives might be attributed to the alloploid nature and gene duplication during evolution. In addition, we discovered that some wheat-Thinopyrum derivatives carrying the Fhb7 homologs had a completely different reaction to Fusarium head blight, which made us question the ability of the GST-encoding Fhb7 to resist FHB.
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Affiliation(s)
- Xianrui Guo
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing 100101, China
| | - Mian Wang
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Houyang Kang
- Triticeae Research Institute, Sichuan Agricultural University, Chengdu 611130, China
| | - Yonghong Zhou
- Triticeae Research Institute, Sichuan Agricultural University, Chengdu 611130, China
| | - Fangpu Han
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Correspondence:
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Yan J, Han X, Lu X, Chen X, Zou W. Land use indirectly affects the cycling of multiple nutrients by altering the diazotrophic community in black soil. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2022; 102:3788-3795. [PMID: 34921680 DOI: 10.1002/jsfa.11727] [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: 06/23/2021] [Revised: 12/10/2021] [Accepted: 12/18/2021] [Indexed: 06/14/2023]
Abstract
BACKGROUND Diazotrophic bacteria, as one of most important group of soil microorganisms, play critical roles in multiple ecosystem functions (i.e., multifunctionality). However, little information is available about the diazotrophic community in driving soil nutrient cycling and multifunctionality at different depths with distinct vegetation in the black soil region of northeastern China. To learn the interactions among land use, cycling of multiple nutrients and the diazotrophic community, we performed this study in grassland (GL), forested land and a cropland (CL) in soils at depths of 0-15 cm and 15-35 cm. RESULTS The highest nifH gene abundances were found in the CL treatment, while the highest diazotrophic species richness and diversity were detected in the GL in both soil layers. The nifH gene abundance was directly/positively correlated with soil bulk density and negatively correlated with land use and soil depth. The index of multiple nutrient cycling was directly/negatively affected by soil depth and indirectly/positively affected by land use. Land use directly/negatively affected soil pH and thus indirectly affected the diazotrophic community composition and the nutrient cycling index. The diversity and community composition of the diazotrophs together accounted for 95% of the differences in the multiple nutrient cycling index. CONCLUSION Soil diazotrophic communities undertake important roles in maintaining nutrient cycling and soil multifunctionality at depths of 0-15 cm and 15-35 cm layers with different land uses of the black soil region of China. © 2021 Society of Chemical Industry.
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Affiliation(s)
- Jun Yan
- Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin, China
| | - Xiaozeng Han
- Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin, China
| | - Xinchun Lu
- Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin, China
| | - Xu Chen
- Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin, China
| | - Wenxiu Zou
- Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin, China
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Abstract
The population ecology of microbial communities is still poorly understood and their notorious instability makes them impossible to control. Much of the instability is caused by the stochastic assembly of microorganisms, especially in highly diverse microbiomes where structural and hence functional changes occur rapidly due to the short generation time of their members. Usually, to maintain organismic proportions in communities, their niches are deterministically reinforced, but stochasticity strongly counteracts this. Based on metacommunity theory, a looped mass transfer was developed that uses the rescue effect to stabilize communities. This study fills a long-standing gap and enables continuous and proportionally equal growth of community members using an unprecedented operational design that addresses an acute need in the healthcare and biotechnology industries. Building and changing a microbiome at will and maintaining it over hundreds of generations has so far proven challenging. Despite best efforts, complex microbiomes appear to be susceptible to large stochastic fluctuations. Current capabilities to assemble and control stable complex microbiomes are limited. Here, we propose a looped mass transfer design that stabilizes microbiomes over long periods of time. Five local microbiomes were continuously grown in parallel for over 114 generations and connected by a loop to a regional pool. Mass transfer rates were altered and microbiome dynamics were monitored using quantitative high-throughput flow cytometry and taxonomic sequencing of whole communities and sorted subcommunities. Increased mass transfer rates reduced local and temporal variation in microbiome assembly, did not affect functions, and overcame stochasticity, with all microbiomes exhibiting high constancy and increasing resistance. Mass transfer synchronized the structures of the five local microbiomes and nestedness of certain cell types was eminent. Mass transfer increased cell number and thus decreased net growth rates μ′. Subsets of cells that did not show net growth μ′SCx were rescued by the regional pool R and thus remained part of the microbiome. The loop in mass transfer ensured the survival of cells that would otherwise go extinct, even if they did not grow in all local microbiomes or grew more slowly than the actual dilution rate D would allow. The rescue effect, known from metacommunity theory, was the main stabilizing mechanism leading to synchrony and survival of subcommunities, despite differences in cell physiological properties, including growth rates.
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Bao L, Sun B, Wei Y, Xu N, Zhang S, Gu L, Bai Z. Grape Cultivar Features Differentiate the Grape Rhizosphere Microbiota. PLANTS (BASEL, SWITZERLAND) 2022; 11:1111. [PMID: 35567111 PMCID: PMC9102929 DOI: 10.3390/plants11091111] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/19/2022] [Revised: 04/10/2022] [Accepted: 04/13/2022] [Indexed: 06/15/2023]
Abstract
Rhizosphere microflora are key determinants that contribute to plant growth and productivity, which are involved in improving the uptake of nutrients, regulation of plants' metabolisms and activation of plants' responses against both biotic and abiotic stresses. However, the structure and diversity of the grape rhizosphere microbiota remains poorly described. To gain a detailed understanding of the assembly of rhizosphere microbiota, we investigated the rhizosphere microbiota of nine grape varieties in northern China by high-throughput sequencing. We found that the richness and diversity of bacterial and fungal community networking in the root compartments were significantly influenced by the grape variety. The bacterial linear discriminant analysis showed that Pseudomonas and Rhizobium, which were considered as potential plant-growth-promoting bacteria, were more enriched in Pinot noir, and Nitrosospira was enriched in Gem. The fungal linear discriminant analysis showed that Fusarium was more enriched in Longan, Sporormiella was more enriched in Merlot, Gibberella and Pseudallescheria were more enriched in Gem and Mortierella was more abundant in Cabernet Sauvignon. The 16S rRNA functional prediction indicated that no significance differentiates among the grape varieties. Understanding the rhizosphere soil microbial diversity characteristics of different grape varieties could provide the basis for exploring microbial associations and maintaining the health of grapes.
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Affiliation(s)
- Lijun Bao
- Key Laboratory for Heavy Metal Pollution Control and Reutilization, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055, China; (L.B.); (N.X.)
- Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environment Sciences, Chinese Academy of Sciences, Beijing 100085, China; (B.S.); (Y.W.); (Z.B.)
| | - Bo Sun
- Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environment Sciences, Chinese Academy of Sciences, Beijing 100085, China; (B.S.); (Y.W.); (Z.B.)
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yingxue Wei
- Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environment Sciences, Chinese Academy of Sciences, Beijing 100085, China; (B.S.); (Y.W.); (Z.B.)
| | - Nan Xu
- Key Laboratory for Heavy Metal Pollution Control and Reutilization, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055, China; (L.B.); (N.X.)
| | - Shiwei Zhang
- Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environment Sciences, Chinese Academy of Sciences, Beijing 100085, China; (B.S.); (Y.W.); (Z.B.)
| | - Likun Gu
- College of Resources and Environment, Henan University of Engingeering, Zhengzhou 451191, China
| | - Zhihui Bai
- Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environment Sciences, Chinese Academy of Sciences, Beijing 100085, China; (B.S.); (Y.W.); (Z.B.)
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
- Xiongan Institute of Innovation, Xiongan New Area Baoding 071000, China
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β-Lactam Resistance in Azospirillum baldaniorum Sp245 Is Mediated by Lytic Transglycosylase and β-Lactamase and Regulated by a Cascade of RpoE7→RpoH3 Sigma Factors. J Bacteriol 2022; 204:e0001022. [PMID: 35352964 DOI: 10.1128/jb.00010-22] [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] [Indexed: 02/05/2023] Open
Abstract
Bacterial resistance to β-lactam antibiotics is often mediated by β-lactamases and lytic transglycosylases. Azospirillum baldaniorum Sp245 is a plant-growth-promoting rhizobacterium that shows high levels of resistance to ampicillin. Investigating the molecular basis of ampicillin resistance and its regulation in A. baldaniorum Sp245, we found that a gene encoding lytic transglycosylase (Ltg1) is organized divergently from a gene encoding an extracytoplasmic function (ECF) σ factor (RpoE7) in its genome. Inactivation of rpoE7 in A. baldaniorum Sp245 led to increased ability to form cell-cell aggregates and produce exopolysaccharides and biofilm, suggesting that rpoE7 might contribute to antibiotic resistance. Inactivation of ltg1 in A. baldaniorum Sp245, however, adversely affected its growth, indicating a requirement of Ltg1 for optimal growth. The expression of rpoE7, as well that of as ltg1, was positively regulated by RpoE7, and overexpression of RpoE7 conferred ampicillin sensitivity to both the rpoE7::km mutant and its parent. In addition, RpoE7 negatively regulated the expression of a gene encoding a β-lactamase (bla1). Out of the 5 paralogs of RpoH encoded in the genome of A. baldaniorum Sp245, RpoH3 played major roles in conferring ampicillin sensitivity and in the downregulation of bla1. The expression of rpoH3 was positively regulated by RpoE7. Collectively, these observations reveal a novel regulatory cascade of RpoE7-RpoH3 σ factors that negatively regulates ampicillin resistance in A. baldaniorum Sp245 by controlling the expression of a β-lactamase and a lytic transglycosylase. In the absence of a cognate anti-sigma factor, addressing how the activity of RpoE7 is regulated by β-lactams will unravel new mechanisms of regulation of β-lactam resistance in bacteria. IMPORTANCE Antimicrobial resistance is a global health problem that requires a better understanding of the mechanisms that bacteria use to resist antibiotics. Bacteria inhabiting the plant rhizosphere are a potential source of antibiotic resistance, but their mechanisms controlling antibiotic resistance are poorly understood. A. baldaniorum Sp245 is a rhizobacterium that is known for its characteristic resistance to ampicillin. Here, we show that an AmpC-type β-lactamase and a lytic transglycosylase mediate resistance to ampicillin in A. baldaniorum Sp245. While the gene encoding lytic transglycosylase is positively regulated by an ECF σ-factor (RpoE7), a cascade of RpoE7 and RpoH3 σ factors negatively regulates the expression of β-lactamase. This is the first evidence showing involvement of a regulatory cascade of σ factors in the regulation of ampicillin resistance in a rhizobacterium.
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Renoud S, Vacheron J, Abrouk D, Prigent-Combaret C, Legendre L, Muller D, Moënne-Loccoz Y. Field Site-Specific Effects of an Azospirillum Seed Inoculant on Key Microbial Functional Groups in the Rhizosphere. Front Microbiol 2022; 12:760512. [PMID: 35154023 PMCID: PMC8825484 DOI: 10.3389/fmicb.2021.760512] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 12/03/2021] [Indexed: 01/05/2023] Open
Abstract
The beneficial effects of plant growth–promoting Rhizobacteria (PGPR) entail several interaction mechanisms with the plant or with other root-associated microorganisms. These microbial functions are carried out by multiple taxa within functional groups and contribute to rhizosphere functioning. It is likely that the inoculation of additional PGPR cells will modify the ecology of these functional groups. We also hypothesized that the inoculation effects on functional groups are site specific, similarly as the PGPR phytostimulation effects themselves. To test this, we assessed in the rhizosphere of field-grown maize the effect of seed inoculation with the phytostimulatory PGPR Azospirillum lipoferum CRT1 on the size and/or diversity of selected microbial functional groups important for plant growth, using quantitative polymerase chain reaction and/or Illumina MiSeq metabarcoding. The functional groups included bacteria able to fix nitrogen (a key nutrient for plant growth), producers of 1-aminocyclopropane-1-carboxylate (ACC) deaminase (which modulate ethylene metabolism in plant and stimulate root growth), and producers of 2,4-diacetylphloroglucinol (an auxinic signal enhancing root branching). To test the hypothesis that such ecological effects were site-specific, the functional groups were monitored at three different field sites, with four sampling times over two consecutive years. Despite poor inoculant survival, inoculation enhanced maize growth. It also increased the size of functional groups in the three field sites, at the maize six-leaf and flowering stages for diazotrophs and only at flowering stage for ACC deaminase and 2,4-diacetylphloroglucinol producers. Sequencing done in the second year revealed that inoculation modified the composition of diazotrophs (and of the total bacterial community) and to a lesser extent of ACC deaminase producers. This study revealed an ecological impact that was field specific (even though a few taxa were impacted in all fields) and of unexpected magnitude with the phytostimulatory Azospirillum inoculant, when considering microbial functional groups. Further methodological developments are needed to monitor additional functional groups important for soil functioning and plant growth under optimal or stress conditions.
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Affiliation(s)
- Sébastien Renoud
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, INRAe, VetAgro Sup, UMR 5557 Ecologie Microbienne, Villeurbanne, France
| | - Jordan Vacheron
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, INRAe, VetAgro Sup, UMR 5557 Ecologie Microbienne, Villeurbanne, France
| | - Danis Abrouk
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, INRAe, VetAgro Sup, UMR 5557 Ecologie Microbienne, Villeurbanne, France
| | - Claire Prigent-Combaret
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, INRAe, VetAgro Sup, UMR 5557 Ecologie Microbienne, Villeurbanne, France
| | - Laurent Legendre
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, INRAe, VetAgro Sup, UMR 5557 Ecologie Microbienne, Villeurbanne, France.,Univ Lyon, Université de St Etienne, St Etienne, France
| | - Daniel Muller
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, INRAe, VetAgro Sup, UMR 5557 Ecologie Microbienne, Villeurbanne, France
| | - Yvan Moënne-Loccoz
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, INRAe, VetAgro Sup, UMR 5557 Ecologie Microbienne, Villeurbanne, France
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Zhang X, Tong J, Dong M, Akhtar K, He B. Isolation, identification and characterization of nitrogen fixing endophytic bacteria and their effects on cassava production. PeerJ 2022; 10:e12677. [PMID: 35127278 PMCID: PMC8796710 DOI: 10.7717/peerj.12677] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Accepted: 12/02/2021] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Cassava (Manibot esculenta Crantz) is one of the most important among tuber crops. The amount of nitrogen fertilizer used for cassava production is relatively high (400 kg ha-1), but there are few studies on biological nitrogen fixation in this crop. Therefore, it is particularly important to study whether cassava and microorganisms have the associated nitrogen-fixing and other promoting effects of endophytic bacteria. METHODS We screened 10 endophytic bacteria using the nitrogen-free culture method from the roots of seven cassava cultivars, and the nitrogenase activity of the A02 strain was the highest 95.81 nmol mL-1 h-1. The A02 strain was confirmed as Microbacteriaceae, Curtobacterium using 16S rRNA sequence alignment. The biological and morphological characteristics of strain A02 were further analyzed. RESULTS The experimental results showed that the biomass of roots, stems, and leaves of cassava inoculated with A02 increased by 17.6%, 12.6%, and 10.3%, respectively, compared to that of the control (without A02 inoculation). These results were not only related to the secretion of auxin (IAA) and solubilization of phosphate but also in the promotion of biological nitrogen fixation of cassava leaves by strain A02. Moreover, the highest 95.81 nmol mL-1h-1 of nitrogenase activity was reported in strain A02, and thus more nitrogen fixation was observed in strain A02. In conclusion, A02 is a newly discovered endophytic nitrogen-fixing bacteria in cassava that can be further used in the research of biological bacterial fertilizers.
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Affiliation(s)
- Xiao Zhang
- College of Agriculture, Guangxi University, Guangxi, Nanning, China
| | - Juanjuan Tong
- College of Agriculture, Guangxi University, Guangxi, Nanning, China
| | - Mengmeng Dong
- College of Agriculture, Guangxi University, Guangxi, Nanning, China
| | - Kashif Akhtar
- College of Life Science and Technology, Guangxi University, Guangxi, Nanning, China
| | - Bing He
- College of Agriculture, Guangxi University, Guangxi, Nanning, China
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Hosseini A, Hosseini M, Schausberger P. Plant Growth-Promoting Rhizobacteria Enhance Defense of Strawberry Plants Against Spider Mites. FRONTIERS IN PLANT SCIENCE 2022; 12:783578. [PMID: 35069641 PMCID: PMC8770953 DOI: 10.3389/fpls.2021.783578] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Accepted: 12/08/2021] [Indexed: 06/02/2023]
Abstract
Plants mediate interactions between below- and above-ground microbial and animal communities. Microbial communities of the rhizosphere commonly include mutualistic symbionts such as mycorrhizal fungi, rhizobia and free-living plant growth-promoting rhizobacteria (PGPR) that may influence plant growth and/or its defense system against aboveground pathogens and herbivores. Here, we scrutinized the effects of three PGPR, Azotobacter chroococcum, Azospirillum brasilense, and Pseudomonas brassicacearum, on life history and population dynamics of two-spotted spider mites, Tetranychus urticae, feeding on aboveground tissue of strawberry plants, and examined associated plant growth and physiology parameters. Our experiments suggest that these three species of free-living rhizobacteria strengthen the constitutive, and/or induce the direct, anti-herbivore defense system of strawberry plants. All three bacterial species exerted adverse effects on life history and population dynamics of T. urticae and positive effects on flowering and physiology of whole strawberry plants. Spider mites, in each life stage and in total, needed longer time to develop on PGPR-treated plants and had lower immature survival rates than those fed on chemically fertilized and untreated plants. Reduced age-specific fecundity, longer developmental time and lower age-specific survival rates of mites feeding on rhizobacteria treated plants reduced their intrinsic rate of increase as compared to mites feeding on chemically fertilized and control plants. The mean abundance was lower in spider mite populations feeding on PGPR-treated strawberries than in those feeding on chemically fertilized and untreated plants. We argue that the three studied PGPR systemically strengthened and/or induced resistance in above-ground plant parts and enhanced the level of biochemical anti-herbivore defense. This was probably achieved by inducing or upregulating the production of secondary plant metabolites, such as phenolics, flavonoids and anthocyanins, which were previously shown to be involved in induced systemic resistance of strawberry plants. Overall, our study emphasizes that PGPR treatment can be a favorable strawberry plant cultivation measure because providing essential nutrients needed for proper plant growth and at the same time decreasing the life history performance and population growth of the notorious herbivorous pest T. urticae.
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Affiliation(s)
- Afsane Hosseini
- Department of Plant Protection, College of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Mojtaba Hosseini
- Department of Plant Protection, College of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Peter Schausberger
- Department of Behavioral and Cognitive Biology, University of Vienna, Vienna, Austria
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Jing X, Liu X, Zhang Z, Wang X, Rensing C, Zhou S. Anode respiration-dependent biological nitrogen fixation by Geobacter sulfurreducens. WATER RESEARCH 2022; 208:117860. [PMID: 34798422 DOI: 10.1016/j.watres.2021.117860] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 10/04/2021] [Accepted: 11/08/2021] [Indexed: 06/13/2023]
Abstract
The present nitrogen fixation industry is usually energy-intensive and environmentally detrimental. Therefore, it is appealing to find alternatives. Here, we achieved both a synchronized biological nitrogen fixation and electric energy production by using Geobacter sulfurreducens in a microbial electrochemical system. The results showed that G. sulfurreducens was able to fix nitrogen depending on anode respiration, producing a maximum current density of 0.17 ± 0.015 mA cm-2 and a nitrogen-fixing activity of ca. 0.78 μmol C2H4 mg protein-1 h-1, thereby achieving a net total nitrogen-fixing rate of ca. 5.6 mg L-1 day-1. Specifically, nitrogen fixation did not impair coulombic efficiency. Transcriptomic and metabolic analyses demonstrated that anode respiration provided sufficient energy to drive nitrogen fixation, and in turn nitrogen fixation promoted anode respiration of the cell by increasing acetate catabolism but reducing acetate anabolism. Furthermore, we showed that G. sulfurreducens could be supplied in a bioelectrochemical system for N-deficient wastewater treatment to relieve N-deficiency stress contributing to the formation of an electroactive biofilm, thereby simultaneously achieving nitrogen fixation, current generation and dissoluble organic carbon removal. Our study revealed a synergistic effect between biological nitrogen fixation and current generation by G. sulfurreducens, providing a green nitrogen fixation alternative through shifting the nitrogen fixation field from energy consumption to energy production and having implications for N-deficient wastewater treatment.
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Affiliation(s)
- Xianyue Jing
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, China
| | - Xing Liu
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, China.
| | - Zhishuai Zhang
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, China
| | - Xin Wang
- MOE Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, China
| | - Christopher Rensing
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, China
| | - Shungui Zhou
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, China.
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Duan YQ, Zhou XK, Habib N, Gao SQ, Dong LM, Liu XF, Shi YM, Li WJ, Du G. Azospirillum tabaci sp. nov., a bacterium isolated from rhizosphere soil of Nicotiana tabacum L. Arch Microbiol 2021; 204:80. [PMID: 34954806 DOI: 10.1007/s00203-021-02688-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 10/31/2021] [Accepted: 11/02/2021] [Indexed: 10/19/2022]
Abstract
Strain W712T was isolated from rhizosphere soil of Nicotiana tabacum L. collected from Kunming, south-west China. Cells were Gram-staining negative, aerobic, motile and rod shaped. The isolate grew at 20-45 °C (optimum 30 °C), pH 6.0-8.0 (optimum pH 7.0) and in the presence of up to 3.0% (w/v) NaCl (optimum 1%, w/v). Ubiquinone-10 was the only respiratory quinone type. Polar lipids contained diphosphatidylglycerol, phosphatidylmehtylethanolamine, phosphatidylglycerol, phosphatidylcholine and an unidentified aminolipid. The major fatty acids were detected as summed feature 8 (C18:1 ω7c or C18:1 ω6c), summed feature 3 (C16:1 ω7c or C16:1 ω6c) and C18:1 2OH. The genomic DNA G + C content was 68.7%. The ANI values were 94.3%, 93.3% and 93.6% between Azospirillum baldaniorum Sp245T, Azospirillum brasilense ATCC 49958T, Azospirillum formosense CC-Nfb-7T and strain W712T, respectively, which were lower than the prokaryotic species delineation threshold of 95.0-96.0%. The digital DNA-DNA hybridization values between A. baldaniorum Sp245T, A. brasilense ATCC 49958T, A. formosense CC-Nfb-7T and strain W712T indicated that the candidate represents a novel genomic species. According to the phenotypic and genotypic characteristics, we propose that strain W712T warrants the assignment to a novel species, for which the name Azospirillum tabaci sp. nov. (type strain W712T = CGMCC 1.18567T = KCTC 82186T) is proposed.
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Affiliation(s)
- Yan-Qing Duan
- China Tobacco Yunnan Industrial Co. Ltd., Kunming, 650231, People's Republic of China
| | - Xing-Kui Zhou
- China Tobacco Yunnan Industrial Co. Ltd., Kunming, 650231, People's Republic of China
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming, 650091, People's Republic of China
| | - Neeli Habib
- Department of Microbiology, Shaheed Benazir Bhutto Women University, Peshawar, 25000, KPK, Pakistan
| | - Shi-Qiang Gao
- China Tobacco Yunnan Industrial Co. Ltd., Kunming, 650231, People's Republic of China
| | - Li-Min Dong
- China Tobacco Yunnan Industrial Co. Ltd., Kunming, 650231, People's Republic of China
| | - Xiao-Fei Liu
- Institute of International Rivers and Eco-Security, Yunnan University, Kunming, 650091, People's Republic of China
| | - Yang-Mei Shi
- China Tobacco Yunnan Industrial Co. Ltd., Kunming, 650231, People's Republic of China
| | - Wen-Jun Li
- State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, People's Republic of China.
| | - Gang Du
- School of Life Sciences, Yunnan Minzu University, Kunming, 650031, People's Republic of China.
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Gushgari-Doyle S, Schicklberger M, Li YV, Walker R, Chakraborty R. Plant Growth Promotion Diversity in Switchgrass-Colonizing, Diazotrophic Endophytes. Front Microbiol 2021; 12:730440. [PMID: 34867848 PMCID: PMC8633415 DOI: 10.3389/fmicb.2021.730440] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 10/15/2021] [Indexed: 11/24/2022] Open
Abstract
Endophytic nitrogen-fixing (diazotrophic) bacteria are essential members of the microbiome of switchgrass (Panicum virgatum), considered to be an important commodity crop in bioenergy production. While endophytic diazotrophs are known to provide fixed atmospheric nitrogen to their host plant, there are many other plant growth-promoting (PGP) capabilities of these organisms to be demonstrated. The diversity of PGP traits across different taxa of switchgrass-colonizing endophytes is understudied, yet critical for understanding endophytic function and improving cultivation methods of important commodity crops. Here, we present the isolation and characterization of three diazotrophic endophytes: Azospirillum agricola R1C, Klebsiella variicola F10Cl, and Raoultella terrigena R1Gly. Strains R1C and F10Cl were isolated from switchgrass and strain R1Gly, while isolated from tobacco, is demonstrated herein to colonize switchgrass. Each strain exhibited highly diverse genomic and phenotypic PGP capabilities. Strain F10Cl and R1Gly demonstrated the highest functional similarity, suggesting that, while endophyte community structure may vary widely based on host species, differences in functional diversity are not a clearly delineated. The results of this study advance our understanding of diazotrophic endophyte diversity, which will allow us to design robust strategies to improve cultivation methods of many economically important commodity crops.
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Affiliation(s)
- Sara Gushgari-Doyle
- Climate and Ecosystem Sciences, Earth and Environmental Sciences Area, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | - Marcus Schicklberger
- Climate and Ecosystem Sciences, Earth and Environmental Sciences Area, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | - Yifan V Li
- Climate and Ecosystem Sciences, Earth and Environmental Sciences Area, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | - Robert Walker
- Climate and Ecosystem Sciences, Earth and Environmental Sciences Area, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | - Romy Chakraborty
- Climate and Ecosystem Sciences, Earth and Environmental Sciences Area, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
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Phylosymbiosis in the Rhizosphere Microbiome Extends to Nitrogen Cycle Functional Potential. Microorganisms 2021; 9:microorganisms9122476. [PMID: 34946078 PMCID: PMC8709245 DOI: 10.3390/microorganisms9122476] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 11/18/2021] [Accepted: 11/22/2021] [Indexed: 12/04/2022] Open
Abstract
Most plants rely on specialized root-associated microbes to obtain essential nitrogen (N), yet not much is known about the evolutionary history of the rhizosphere–plant interaction. We conducted a common garden experiment to investigate the plant root–rhizosphere microbiome association using chloridoid grasses sampled from around the world and grown from seed in a greenhouse. We sought to test whether plants that are more closely related phylogenetically have more similar root bacterial microbiomes than plants that are more distantly related. Using metagenome sequencing, we found that there is a conserved core and a variable rhizosphere bacterial microbiome across the chloridoid grasses. Additionally, phylogenetic distance among the host plant species was correlated with bacterial community composition, suggesting the plant hosts prefer specific bacterial lineages. The functional potential for N utilization across microbiomes fluctuated extensively and mirrored variation in the microbial community composition across host plants. Variation in the bacterial potential for N fixation was strongly affected by the host plants’ phylogeny, whereas variation in N recycling, nitrification, and denitrification was unaffected. This study highlights the evolutionary linkage between the N fixation traits of the microbial community and the plant host and suggests that not all functional traits are equally important for plant–microbe associations.
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46
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Yu GH, Kuzyakov Y, Luo Y, Goodman BA, Kappler A, Liu FF, Sun FS. Molybdenum Bioavailability and Asymbiotic Nitrogen Fixation in Soils are Raised by Iron (Oxyhydr)oxide-Mediated Free Radical Production. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:14979-14989. [PMID: 34677955 DOI: 10.1021/acs.est.1c04240] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Nitrogen (N) fixation in soils is closely linked to microbially mediated molybdenum (Mo) cycling. Therefore, elucidating the mechanisms and factors that affect Mo bioavailability is crucial for understanding N fixation. Here, we demonstrate that long-term (26 years) manure fertilization increased microbial diversity and content of short-range ordered iron (oxyhydr)oxides that raised Mo bioavailability (by 2.8 times) and storage (by ∼30%) and increased the abundance of nifH genes (by ∼14%) and nitrogenase activity (by ∼60%). Nanosized iron (oxyhydr)oxides (ferrihydrite, goethite, and hematite nanoparticles) play a dual role in soil Mo cycling: (i) in concert with microorganisms, they raise Mo bioavailability by catalyzing hydroxyl radical (HO•) production via the Fenton reactions and (ii) they increase Mo retention by association with the nanosized iron (oxyhydr)oxides. In summary, long-term manure fertilization raised the stock and bioavailability of Mo (and probably also of other micronutrients) by increasing iron (oxyhydr)oxide reactivity and intensified asymbiotic N fixation through an increased abundance of nifH genes and nitrogenase activity. This work provides a strategy for increasing biological N fixation in agricultural ecosystems.
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Affiliation(s)
- Guang-Hui Yu
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin Key Laboratory of Earth Critical Zone Science and Sustainable Development in Bohai Rim, Tianjin University, Tianjin 300072, China
| | - Yakov Kuzyakov
- Department of Soil Science of Temperate Ecosystems, Department of Agricultural Soil Science, University of Göttingen, Göttingen 37073, Germany
- Agro-Technological Institute, RUDN University, Moscow 117198, Russia
| | - Yu Luo
- Institute of Soil and Water Resources and Environmental Science, Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Zhejiang University, Hangzhou 310058, China
| | - Bernard A Goodman
- College of Physical Science and Technology, Guangxi University, Nanning 530004, China
| | - Andreas Kappler
- Geomicrobiology, Center for Applied Geosciences, University of Tübingen, Tübingen 72076, Germany
- Cluster of Excellence: EXC 2124: Controlling Microbes to Fight Infections, Tübingen 72076, Germany
| | - Fei-Fei Liu
- College of Resources & Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Fu-Sheng Sun
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin Key Laboratory of Earth Critical Zone Science and Sustainable Development in Bohai Rim, Tianjin University, Tianjin 300072, China
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Huang D, Bai X, Wang Q, Xu Q. Validation and optimization of key biochar properties through iron modification for improving the methane oxidation capacity of landfill cover soil. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 793:148551. [PMID: 34174617 DOI: 10.1016/j.scitotenv.2021.148551] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 06/02/2021] [Accepted: 06/15/2021] [Indexed: 06/13/2023]
Abstract
Knowledge of various BC properties in stimulating the methane (CH4) oxidation capacity of landfill cover soil (LCS) is still limited, restricting the optimization of BC performance. To validate key BC properties and seek a feasible way for enhancing BC performance, this study prepared BCs with distinctly varying characteristics through iron (Fe) modification. Then, batch incubation experiments under different CH4 and oxygen concentrations were conducted. Pore volume, cation exchange capacity (CEC), and surface area of BC collectively accounted for 78.5% of the variances in the microbial community structures, with pore volume being the most important factor. These correlated well with the differences in the CH4 oxidation capacities among the different BC-amended LCS. At a low ratio of 15% (v/v) in LCS, BCs' pH not affected their performance but homogeneity could be a limiting factor. Fe modification proved a promising approach to more efficiently improve the three key BC properties (especially pore volume) and thus optimize BC performance than increasing pyrolysis temperature did. Fe-modified BCs encouraged a bacterial consortium (methanotroph, methylotrophs, and nitrogen-fixing bacteria) in the soil with significantly improved CH4 oxidation capacities by up to 26%-74% compared to that of pristine BC.
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Affiliation(s)
- Dandan Huang
- Shenzhen Engineering Laboratory for Eco-efficient Recycled Materials, School of Environment and Energy, Peking University Shenzhen Graduate School, University Town, Xili, Nanshan District, Shenzhen 518055, PR China
| | - Xinyue Bai
- Shenzhen Engineering Laboratory for Eco-efficient Recycled Materials, School of Environment and Energy, Peking University Shenzhen Graduate School, University Town, Xili, Nanshan District, Shenzhen 518055, PR China
| | - Qian Wang
- Shenzhen Engineering Laboratory for Eco-efficient Recycled Materials, School of Environment and Energy, Peking University Shenzhen Graduate School, University Town, Xili, Nanshan District, Shenzhen 518055, PR China
| | - Qiyong Xu
- Shenzhen Engineering Laboratory for Eco-efficient Recycled Materials, School of Environment and Energy, Peking University Shenzhen Graduate School, University Town, Xili, Nanshan District, Shenzhen 518055, PR China.
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Rodrigues GL, Matteoli FP, Gazara RK, Rodrigues PSL, Dos Santos ST, Alves AF, Pedrosa-Silva F, Oliveira-Pinheiro I, Canedo-Alvarenga D, Olivares FL, Venancio TM. Characterization of cellular, biochemical and genomic features of the diazotrophic plant growth-promoting bacterium Azospirillum sp. UENF-412522, a novel member of the Azospirillum genus. Microbiol Res 2021; 254:126896. [PMID: 34715447 DOI: 10.1016/j.micres.2021.126896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 08/11/2021] [Accepted: 10/14/2021] [Indexed: 11/19/2022]
Abstract
Given their remarkable beneficial effects on plant growth, several Azospirillum isolates currently integrate the formulations of various commercial inoculants. Our research group isolated a new strain, Azospirillum sp. UENF-412522, from passion fruit rhizoplane. This isolate uses carbon sources that are partially distinct from closely-related Azospirillum isolates. Scanning electron microscopy analysis and population counts demonstrate the ability of Azospirillum sp. UENF-412522 to colonize the surface of passion fruit roots. In vitro assays demonstrate the ability of Azospirillum sp. UENF-412522 to fix atmospheric nitrogen, to solubilize phosphate and to produce indole-acetic acid. Passion fruit plantlets inoculated with Azospirillum sp. UENF-41255 showed increased shoot and root fresh matter by 13,8% and 88,6% respectively, as well as root dry matter by 61,4%, further highlighting its biotechnological potential for agriculture. We sequenced the genome of Azospirillum sp. UENF-412522 to investigate the genetic basis of its plant-growth promotion properties. We identified the key nif genes for nitrogen fixation, the complete PQQ operon for phosphate solubilization, the acdS gene that alleviates ethylene effects on plant growth, and the napCAB operon, which produces nitrite under anoxic conditions. We also found several genes conferring resistance to common soil antibiotics, which are critical for Azospirillum sp. UENF-412522 survival in the rhizosphere. Finally, we also assessed the Azospirillum pangenome and highlighted key genes involved in plant growth promotion. A phylogenetic reconstruction of the genus was also conducted. Our results support Azospirillum sp. UENF-412522 as a good candidate for bioinoculant formulations focused on plant growth promotion in sustainable systems.
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Affiliation(s)
- Gustavo L Rodrigues
- Laboratório de Química e Função de Proteínas e Peptídeos, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF), Brazil
| | - Filipe P Matteoli
- Laboratório de Química e Função de Proteínas e Peptídeos, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF), Brazil
| | - Rajesh K Gazara
- Laboratório de Química e Função de Proteínas e Peptídeos, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF), Brazil
| | | | - Samuel T Dos Santos
- Núcleo de Desenvolvimento de Insumos Biológicos para a Agricultura (NUDIBA), UENF, Brazil
| | - Alice F Alves
- Núcleo de Desenvolvimento de Insumos Biológicos para a Agricultura (NUDIBA), UENF, Brazil; Laboratório de Biologia Celular e Tecidual, Centro de Biociências e Biotecnologia, UENF, Brazil
| | - Francisnei Pedrosa-Silva
- Laboratório de Química e Função de Proteínas e Peptídeos, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF), Brazil
| | - Isabella Oliveira-Pinheiro
- Laboratório de Química e Função de Proteínas e Peptídeos, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF), Brazil
| | - Daniella Canedo-Alvarenga
- Laboratório de Química e Função de Proteínas e Peptídeos, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF), Brazil
| | - Fabio L Olivares
- Núcleo de Desenvolvimento de Insumos Biológicos para a Agricultura (NUDIBA), UENF, Brazil; Laboratório de Biologia Celular e Tecidual, Centro de Biociências e Biotecnologia, UENF, Brazil.
| | - Thiago M Venancio
- Laboratório de Química e Função de Proteínas e Peptídeos, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF), Brazil.
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Schagen M, Bosch J, Johnson J, Duker R, Lebre P, Potts AJ, Cowan DA. The soil microbiomics of intact, degraded and partially-restored semi-arid succulent thicket (Albany Subtropical Thicket). PeerJ 2021; 9:e12176. [PMID: 34707927 PMCID: PMC8501999 DOI: 10.7717/peerj.12176] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Accepted: 08/29/2021] [Indexed: 01/04/2023] Open
Abstract
This study examines the soil bacterial diversity in the Portulacaria afra-dominated succulent thicket vegetation of the Albany Subtropical Thicket biome; this biome is endemic to South Africa. The aim of the study was to compare the soil microbiomes between intact and degraded zones in the succulent thicket and identify environmental factors which could explain the community compositions. Bacterial diversity, using 16S amplicon sequencing, and soil physicochemistry were compared across three zones: intact (undisturbed and vegetated), degraded (near complete removal of vegetation due to browsing) and restored (a previously degraded area which was replanted approximately 11 years before sampling). Amplicon Sequence Variant (ASV) richness was similar across the three zones, however, the bacterial community composition and soil physicochemistry differed across the intact and degraded zones. We identified, via correlation, the potential drivers of microbial community composition as soil density, pH and the ratio of Ca to Mg. The restored zone was intermediate between the intact and degraded zones. The differences in the microbial communities appeared to be driven by the presence of plants, with plant-associated taxa more common in the intact zone. The dominant taxa in the degraded zone were cosmopolitan organisms, that have been reported globally in a wide variety of habitats. This study provides baseline information on the changes of the soil bacterial community of a spatially restricted and threatened biome. It also provides a starting point for further studies on community composition and function concerning the restoration of degraded succulent thicket ecosystems.
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Affiliation(s)
- Micaela Schagen
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, Gauteng, South Africa
| | - Jason Bosch
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, Gauteng, South Africa
| | - Jenny Johnson
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, Gauteng, South Africa
| | - Robbert Duker
- Botany Department, South Campus, Nelson Mandela University, Port Elizabeth, Eastern Cape, South Africa
| | - Pedro Lebre
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, Gauteng, South Africa
| | - Alastair J Potts
- Botany Department, South Campus, Nelson Mandela University, Port Elizabeth, Eastern Cape, South Africa
| | - Don A Cowan
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, Gauteng, South Africa
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Sui X, Wang X, Liu T, Ye Q, Wu B, Hu G, Yang S, He M, Peng N. Endogenous CRISPR-assisted microhomology-mediated end joining enables rapid genome editing in Zymomonas mobilis. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:208. [PMID: 34689795 PMCID: PMC8543907 DOI: 10.1186/s13068-021-02056-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Accepted: 10/13/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND Zymomonas mobilis is a natural ethanologen with many desirable characteristics, making it an ideal platform for future biorefineries. Recently, an endogenous CRISPR-based genome editing tool has been developed for this species. However, a simple and high-efficient genome editing method is still required. RESULTS We developed a novel gene deletion tool based on the endogenous subtype I-F CRISPR-Cas system and the microhomology-mediated end joining (MMEJ) pathway. This tool only requires a self-interference plasmid carrying the mini-CRISPR (Repeat-Spacer-Repeat) expression cassette, where the spacer matches the target DNA. Transformation of the self-interference plasmid leads to target DNA damage and subsequently triggers the endogenous MMEJ pathway to repair the damaged DNA, leaving deletions normally smaller than 500 bp. Importantly, the MMEJ repair efficiency was increased by introducing mutations at the second repeat of the mini-CRISPR cassette expressing the guide RNA. Several genes have been successfully deleted via this method, and the phenotype of a σ28 deletion mutant generated in this study was characterized. Moreover, large fragment deletions were obtained by transformation of the self-interference plasmids expressing two guide RNAs in tandem. CONCLUSIONS Here, we report the establishment of an efficient gene deletion tool based on the endogenous subtype I-F CRISPR-Cas system and the MMEJ pathway in Zymomonas mobilis. We achieved single gene deletion and large-fragment knockout using this tool. In addition, we further promoted the editing efficiency by modifying the guide RNA expression cassette and selecting lower GC% target sites. Our study has provided an effective method for genetic manipulation in Z. mobilis.
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Affiliation(s)
- Xin Sui
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, Hubei, People's Republic of China
| | - Xiaojie Wang
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, Hubei, People's Republic of China
| | - Tao Liu
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, Hubei, People's Republic of China
| | - Qing Ye
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, Hubei, People's Republic of China
| | - Bo Wu
- Key Laboratory of Development and Application of Rural Renewable Energy (Ministry of Agriculture), Biomass Energy Technology Research Centre, Biogas Institute of Ministry of Agriculture, Chengdu, 610041, Sichuan, People's Republic of China
| | - Guoquan Hu
- Key Laboratory of Development and Application of Rural Renewable Energy (Ministry of Agriculture), Biomass Energy Technology Research Centre, Biogas Institute of Ministry of Agriculture, Chengdu, 610041, Sichuan, People's Republic of China
| | - Shihui Yang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Engineering Research Center for Bio-Enzyme Catalysis, Environmental Microbial Technology Center of Hubei Province, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, School of Life Sciences, Hubei University, Wuhan, 430062, People's Republic of China
| | - Mingxiong He
- Key Laboratory of Development and Application of Rural Renewable Energy (Ministry of Agriculture), Biomass Energy Technology Research Centre, Biogas Institute of Ministry of Agriculture, Chengdu, 610041, Sichuan, People's Republic of China.
| | - Nan Peng
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, Hubei, People's Republic of China.
- Key Laboratory of Development and Application of Rural Renewable Energy (Ministry of Agriculture), Biomass Energy Technology Research Centre, Biogas Institute of Ministry of Agriculture, Chengdu, 610041, Sichuan, People's Republic of China.
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