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Brito LF, López MG, Straube L, Passaglia LMP, Wendisch VF. Inorganic Phosphate Solubilization by Rhizosphere Bacterium Paenibacillus sonchi: Gene Expression and Physiological Functions. Front Microbiol 2020; 11:588605. [PMID: 33424789 PMCID: PMC7793946 DOI: 10.3389/fmicb.2020.588605] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 11/16/2020] [Indexed: 12/13/2022] Open
Abstract
Due to the importance of phosphorus (P) in agriculture, crop inoculation with phosphate-solubilizing bacteria is a relevant subject of study. Paenibacillus sonchi genomovar Riograndensis SBR5 is a promising candidate for crop inoculation, as it can fix nitrogen and excrete ammonium at a remarkably high rate. However, its trait of phosphate solubilization (PS) has not yet been studied in detail. Here, differential gene expression and functional analyses were performed to characterize PS in this bacterium. SBR5 was cultivated with two distinct P sources: NaH2PO4 as soluble phosphate source (SPi) and hydroxyapatite as insoluble phosphate source (IPi). Total RNA of SBR5 cultivated in those two conditions was isolated and sequenced, and bacterial growth and product formation were monitored. In the IPi medium, the expression of 68 genes was upregulated, whereas 100 genes were downregulated. Among those, genes involved in carbon metabolism, including those coding for subunits of 2-oxoglutarate dehydrogenase, were identified. Quantitation of organic acids showed that the production of tricarboxylic acid cycle-derived organic acids was reduced in IPi condition, whereas acetate and gluconate were overproduced. Increased concentrations of proline, trehalose, and glycine betaine revealed active osmoprotection during growth in IPi. The cultivation with hydroxyapatite also caused the reduction in the motility of SBR5 cells as a response to Pi depletion at the beginning of its growth. SBR5 was able to solubilize hydroxyapatite, which suggests that this organism is a promising phosphate-solubilizing bacterium. Our findings are the initial step in the elucidation of the PS process in P. sonchi SBR5 and will be a valuable groundwork for further studies of this organism as a plant growth-promoting rhizobacterium.
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Affiliation(s)
- Luciana F. Brito
- Genetics of Prokaryotes, Faculty of Biology, Bielefeld University, Bielefeld, Germany
- Center for Biotechnology, Bielefeld University, Bielefeld, Germany
| | - Marina Gil López
- Genetics of Prokaryotes, Faculty of Biology, Bielefeld University, Bielefeld, Germany
- Center for Biotechnology, Bielefeld University, Bielefeld, Germany
| | - Lucas Straube
- Genetics of Prokaryotes, Faculty of Biology, Bielefeld University, Bielefeld, Germany
- Center for Biotechnology, Bielefeld University, Bielefeld, Germany
| | | | - Volker F. Wendisch
- Genetics of Prokaryotes, Faculty of Biology, Bielefeld University, Bielefeld, Germany
- Center for Biotechnology, Bielefeld University, Bielefeld, Germany
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Bharwad K, Rajkumar S. Rewiring the functional complexity between Crc, Hfq and sRNAs to regulate carbon catabolite repression in Pseudomonas. World J Microbiol Biotechnol 2019; 35:140. [DOI: 10.1007/s11274-019-2717-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Accepted: 08/22/2019] [Indexed: 10/26/2022]
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Macedo-Raygoza GM, Valdez-Salas B, Prado FM, Prieto KR, Yamaguchi LF, Kato MJ, Canto-Canché BB, Carrillo-Beltrán M, Di Mascio P, White JF, Beltrán-García MJ. Enterobacter cloacae, an Endophyte That Establishes a Nutrient-Transfer Symbiosis With Banana Plants and Protects Against the Black Sigatoka Pathogen. Front Microbiol 2019; 10:804. [PMID: 31133991 PMCID: PMC6513882 DOI: 10.3389/fmicb.2019.00804] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 03/28/2019] [Indexed: 01/20/2023] Open
Abstract
Banana (Musa spp.) is an important crop worldwide, but black Sigatoka disease caused by the fungus Pseudocercospora fijiensis threatens fruit production. In this work, we examined the potential of the endophytes of banana plants Enterobacter cloacae and Klebsiella pneumoniae, as antagonists of P. fijiensis and support plant growth in nutrient limited soils by N-transfer. The two bacterial isolates were identified by MALDI-TOF mass spectrometry and corroborated by 16S rRNA sequence analysis. Both bacteria were positive for beneficial traits such as N-fixation, indole acetic acid production, phosphate solubilization, negative for 1-aminocyclopropane 1-carboxylic acid deaminase and were antagonistic to P. fijiensis. To measure the effects on plant growth, the two plant bacteria and an E. coli strain (as non-endophyte), were inoculated weekly for 60 days as active cells (AC) and heat-killed cells (HKC) into plant microcosms without nutrients and compared to a water only treatment, and a mineral nutrients solution (MMN) treatment. Bacterial treatments increased growth parameters and prevented accelerated senescence, which was observed for water and mineral nutrients solution (MMN) treatments used as controls. Plants died after the first 20 days of being irrigated with water; irrigation with MMN enabled plants to develop some new leaves, but plants lost weight (−30%) during the same period. Plants treated with bacteria showed good growth, but E. cloacae AC treated plants had significantly greater biomass than the E. cloacae HKC. After 60 days, plants inoculated with E. cloacae AC showed intracellular bacteria within root cells, suggesting that a stable symbiosis was established. To evaluate the transference of organic N from bacteria into the plants, the 3 bacteria were grown with 15NH4Cl or Na15NO3 as the nitrogen source. The 15N transferred from bacteria to plant tissues was measured by pheophytin isotopomer abundance. The relative abundance of the isotopomers m/z 872.57, 873.57, 874.57, 875.57, 876.57 unequivocally demonstrated that plants acquired 15N atoms directly from bacterial cells, using them as a source of N, to support plant growth in restricted nutrient soils. E. cloacae might be a new alternative to promote growth and health of banana crops.
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Affiliation(s)
- Gloria M Macedo-Raygoza
- Engineering Institute, Universidad Autónoma de Baja California, Mexicali, Mexico.,Department of Chemistry, Universidad Autónoma de Guadalajara, Zapopan, Mexico
| | | | - Fernanda M Prado
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, Brazil
| | - Katia R Prieto
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, Brazil.,PPG Ciência Animal, Universidade de Franca, Franca, Brazil
| | - Lydia F Yamaguchi
- Department of Fundamental Chemistry, Institute of Chemistry, Universidade de São Paulo, São Paulo, Brazil
| | - Massuo J Kato
- Department of Fundamental Chemistry, Institute of Chemistry, Universidade de São Paulo, São Paulo, Brazil
| | - Blondy B Canto-Canché
- Biotechnology Unit, Centro de Investigación Científica de Yucatán A.C., Mérida, Mexico
| | | | - Paolo Di Mascio
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, Brazil
| | - James F White
- Department of Plant Biology, School of Environmental and Biological Sciences Rutgers, The State University of New Jersey, New Brunswick, NJ, United States
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Zhang Y, Chen FS, Wu XQ, Luan FG, Zhang LP, Fang XM, Wan SZ, Hu XF, Ye JR. Isolation and characterization of two phosphate-solubilizing fungi from rhizosphere soil of moso bamboo and their functional capacities when exposed to different phosphorus sources and pH environments. PLoS One 2018; 13:e0199625. [PMID: 29995910 PMCID: PMC6040707 DOI: 10.1371/journal.pone.0199625] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 06/03/2018] [Indexed: 11/19/2022] Open
Abstract
Phosphate-solubilizing fungi (PSF) generally enhance available phosphorus (P) released from soil, which contributes to plants' P requirement, especially in P-limiting regions. In this study, two PSF, TalA-JX04 and AspN-JX16, were isolated from the rhizosphere soil of moso bamboo (Phyllostachys edulis) widely distributed in P-deficient areas in China and identified as Talaromyces aurantiacus and Aspergillus neoniger, respectively. The two PSF were cultured in potato dextrose liquid medium with six types of initial pH values ranging from 6.5 to 1.5 to assess acid resistance. Both PSF were incubated in Pikovskaya's liquid media with different pH values containing five recalcitrant P sources, including Ca3(PO4)2, FePO4, CaHPO4, AlPO4, and C6H6Ca6O24P6, to estimate their P-solubilizing capacity. No significant differences were found in the biomass of both fungi grown in media with different initial pH, indicating that these fungi could grow well under acid stress. The P-solubilizing capacity of TalA-JX04 was highest in medium containing CaHPO4, followed by Ca3(PO4)2, FePO4, C6H6Ca6O24P6, and AlPO4 in six types of initial pH treatments, while the recalcitrant P-solubilizing capacity of AspN-JX16 varied with initial pH. Meanwhile, the P-solubilizing capacity of AspN-JX16 was much higher than TalA-JX04. The pH of fermentation broth was negatively correlated with P-solubilizing capacity (p<0.01), suggesting that the fungi promote the dissolution of P sources by secreting organic acids. Our results showed that TalA-JX04 and AspN-JX16 could survive in acidic environments and both fungi had a considerable ability to release soluble P by decomposing recalcitrant P-bearing compounds. The two fungi had potential for application as environment-friendly biofertilizers in subtropical bamboo ecosystem.
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Affiliation(s)
- Yang Zhang
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forest, Nanjing Forestry University, Nanjing, Jiangsu, China
- 2011 Collaborative Innovation Center of Jiangxi Typical Trees Cultivation and Utilization, College of Forestry, Jiangxi Agricultural University, Nanchang, Jiangxi, China
| | - Fu-Sheng Chen
- 2011 Collaborative Innovation Center of Jiangxi Typical Trees Cultivation and Utilization, College of Forestry, Jiangxi Agricultural University, Nanchang, Jiangxi, China
| | - Xiao-Qin Wu
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forest, Nanjing Forestry University, Nanjing, Jiangsu, China
| | - Feng-Gang Luan
- 2011 Collaborative Innovation Center of Jiangxi Typical Trees Cultivation and Utilization, College of Forestry, Jiangxi Agricultural University, Nanchang, Jiangxi, China
| | - Lin-Ping Zhang
- 2011 Collaborative Innovation Center of Jiangxi Typical Trees Cultivation and Utilization, College of Forestry, Jiangxi Agricultural University, Nanchang, Jiangxi, China
| | - Xiang-Min Fang
- 2011 Collaborative Innovation Center of Jiangxi Typical Trees Cultivation and Utilization, College of Forestry, Jiangxi Agricultural University, Nanchang, Jiangxi, China
| | - Song-Ze Wan
- 2011 Collaborative Innovation Center of Jiangxi Typical Trees Cultivation and Utilization, College of Forestry, Jiangxi Agricultural University, Nanchang, Jiangxi, China
| | - Xiao-Fei Hu
- Management School of Nanchang University, Nanchang, China
| | - Jian-Ren Ye
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forest, Nanjing Forestry University, Nanjing, Jiangsu, China
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Iyer B, Rajput MS, Rajkumar S. Effect of succinate on phosphate solubilization in nitrogen fixing bacteria harbouring chick pea and their effect on plant growth. Microbiol Res 2017. [PMID: 28647122 DOI: 10.1016/j.micres.2017.05.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Diverse nitrogen fixing bacteria harbouring chick pea rhizosphere and root nodules were tested for multiple plant growth promoting traits like tricalcium phosphate (TCP) and rock phosphate (RP) solubilization, production of ammonia, indole 3-acetic acid, chitinase, phytase and alkaline phosphatase. Isolates belonged to diverse genus like Enterobacter, Acinetobacter, Erwinia, Pseudomonas, Rhizobium, Sinorhizobium, Ensifer, Klebsiella, etc. Most isolates solubilized TCP and RP along with the lowering of media pH, indicating acidification to be the chief mechanism behind this solubilization. However, lowering of media pH and P release decreased by 32-100% when media was supplemented with succinate, a major component of plant root exudates indicating succinate mediated repression of P solubilization. Maximum TCP and RP solubilization with P release of 850μg/mL and 2088μg/mL was obtained with lowering of media pH up to 2.8 and 3.3 for isolate E43 and PSB1 respectively. This pH drop changed to 4.4 and 4.8 with 80% and 87% decrease in P solubilization in the presence of succinate. Maximum 246μg/mL indole 3-acetic acid production in Lh3, 44.8U/mL chitinase activity in MB3, 11.3U/mL phytase activity in I91 and 9.4U/mL alkaline phosphatase activity in SM1 were also obtained. Most isolates showed multiple PGP traits which resulted in significant plant growth promotion of chick pea plants. Present study shows repression of P solubilization by succinate for various bacterial groups which might be one of the reasons why phosphate solubilizing bacteria which perform well in vitro often fail in vivo. Studying this repression mechanism might be critical in understanding the in vivo efficacy.
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Affiliation(s)
- Bhagya Iyer
- Institute of Science, Nirma University, Ahmedabad, Gujarat, India
| | - Mahendrapal Singh Rajput
- Institute of Science, Nirma University, Ahmedabad, Gujarat, India; Department of Microbiology, Faculty of Science, Marwadi University, Rajkot, Gujarat, India
| | - Shalini Rajkumar
- Institute of Science, Nirma University, Ahmedabad, Gujarat, India.
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