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Liu Y, Lin Y, Guan N, Song Y, Li Y, Xie X. A Lipopolysaccharide Synthesis Gene rfaD from Mesorhizobium huakuii Is Involved in Nodule Development and Symbiotic Nitrogen Fixation. Microorganisms 2022; 11:microorganisms11010059. [PMID: 36677351 PMCID: PMC9866225 DOI: 10.3390/microorganisms11010059] [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: 11/28/2022] [Revised: 12/21/2022] [Accepted: 12/21/2022] [Indexed: 12/28/2022] Open
Abstract
Rhizobium lipopolysaccharide (LPS) is an important component of the cell wall of gram-negative bacteria and serves as a signal molecule on the surface of rhizobia, participating in the symbiosis during rhizobia-legume interaction. In this study, we constructed a deletion mutant of ADP-L-glycerol-D-mannoheptosyl-6-exoisomerase (rfaD) of Mesorhizobium huakuii 7653R and a functional complementary strain. The results showed that the deletion of rfaD did not affect the free-living growth rate of 7653R, but that it did affect the LPS synthesis and that it increased sensitivity to abiotic stresses. The rfaD promoter-GUS reporter assay showed that the gene was mainly expressed in the infection zone of the mature nodules. The root nodules formation of the rfaD mutant was delayed during symbiosis with the host plant of Astragalus sinicus. The symbiotic phenotype analyses showed that the nodules of A. sinicus lost symbiotic nitrogen fixation ability, when inoculated with the rfaD mutant strain. In conclusion, our results reveal that the 7653R rfaD gene plays a crucial role in the LPS synthesis involved in the symbiotic interaction between rhizobia and A. sinicus. This study also provides new insights into the molecular mechanisms by which the rhizobia regulate their own gene expression and cell wall components enabling nodulation in legumes.
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Affiliation(s)
- Yuan Liu
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Ye Lin
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Ning Guan
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Yuting Song
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Youguo Li
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
- Correspondence: (Y.L.); (X.X.); Tel.: +86-127-8728-1685 (Y.L.); +86-159-1855-2425 (X.X.)
| | - Xianan Xie
- State Key Laboratory of Conservation and Utilization of Subtropical Agro-Bioresources, Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou 510642, China
- Correspondence: (Y.L.); (X.X.); Tel.: +86-127-8728-1685 (Y.L.); +86-159-1855-2425 (X.X.)
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Xiang Q, Wang J, Qin P, Adil B, Xu K, Gu Y, Yu X, Zhao K, Zhang X, Ma M, Chen Q, Chen X, Yan Y. Effect of common bean seed exudates on growth, lipopolysaccharide production, and lipopolysaccharide transport gene expression of Rhizobium anhuiense. Can J Microbiol 2019; 66:186-193. [PMID: 31751146 DOI: 10.1139/cjm-2019-0413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Lipopolysaccharide (LPS) is essential for successful nodulation during the symbiosis of rhizobia and legumes. However, the detailed mechanism of the LPS in this process has not yet been clearly elucidated. In this study, the effects of common bean seed exudates on the growth, lipopolysaccharide production, and lipopolysaccharide transport genes expression (lpt) of Rhizobium anhuiense were investigated. Rhizobium anhuiense exposed to exudates showed changes in LPS electrophoretic profiles and content, whereby the LPS band was wider and the LPS content was higher in R. anhuiense treated with seed exudates. Exudates enhanced cell growth of R. anhuiense in a concentration-dependent manner; R. anhuiense exposed to higher doses of the exudate showed faster growth. Seven lpt genes of R. anhuiense were amplified and sequenced. Sequences of six lpt genes, except for lptE, were the same as those found in previously analyzed R. anhuiense strains, while lptE shared low sequence similarity with other strains. Exposure to the exudates strongly stimulated the expression of all lpt genes. Approximately 6.7- (lptG) to 301-fold (lptE) increases in the transcriptional levels were observed after only 15 min of exposure to exudates. These results indicate that seed exudates affect the LPS by making the cell wall structure more conducive to symbiotic nodulation.
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Affiliation(s)
- Quanju Xiang
- College of Resource, Sichuan Agricultural University, Chengdu, Sichuan 611130, P.R. China
| | - Jie Wang
- College of Resource, Sichuan Agricultural University, Chengdu, Sichuan 611130, P.R. China
| | - Peng Qin
- College of Resource, Sichuan Agricultural University, Chengdu, Sichuan 611130, P.R. China
| | - Bilal Adil
- College of Resource, Sichuan Agricultural University, Chengdu, Sichuan 611130, P.R. China
| | - Kaiwei Xu
- College of Resource, Sichuan Agricultural University, Chengdu, Sichuan 611130, P.R. China
| | - Yunfu Gu
- College of Resource, Sichuan Agricultural University, Chengdu, Sichuan 611130, P.R. China
| | - Xiumei Yu
- College of Resource, Sichuan Agricultural University, Chengdu, Sichuan 611130, P.R. China
| | - Ke Zhao
- College of Resource, Sichuan Agricultural University, Chengdu, Sichuan 611130, P.R. China
| | - Xiaoping Zhang
- College of Resource, Sichuan Agricultural University, Chengdu, Sichuan 611130, P.R. China
| | - Menggen Ma
- College of Resource, Sichuan Agricultural University, Chengdu, Sichuan 611130, P.R. China
| | - Qiang Chen
- College of Resource, Sichuan Agricultural University, Chengdu, Sichuan 611130, P.R. China
| | - Xiaoqiong Chen
- Rice Research Institute of Sichuan Agricultural University, Chengdu, Sichuan 611130, P.R. China
| | - Yanhong Yan
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, Sichuan 611130, P.R. China
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Selection of reference genes for measuring the expression of aiiO in Ochrobactrum quorumnocens A44 using RT-qPCR. Sci Rep 2019; 9:13129. [PMID: 31511547 PMCID: PMC6739375 DOI: 10.1038/s41598-019-49474-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 08/22/2019] [Indexed: 11/09/2022] Open
Abstract
Reverse transcription quantitative PCR (RT-qPCR), a method of choice for quantification of gene expression changes, requires stably expressed reference genes for normalization of data. So far, no reference genes were established for the Alphaproteobacteria of the genus Ochrobactrum. Here, we determined reference genes for gene expression studies in O. quorumnocens A44. Strain A44 was cultured under 10 different conditions and the stability of expression of 11 candidate genes was evaluated using geNorm, NormFinder and BestKeeper. Most stably expressed genes were found to be rho, gyrB and rpoD. Our results can facilitate the choice of reference genes in the related Ochrobactrum strains. O. quorumnocens A44 is able to inactivate a broad spectrum of N-acyl homoserine lactones (AHLs) - the quorum sensing molecules of many Gram-negative bacteria. This activity is attributed to AiiO hydrolase, yet it remains unclear whether AHLs are the primary substrate of this enzyme. Using the established RT-qPCR setup, we found that the expression of the aiiO gene upon exposure to two AHLs, C6-HLS and 3OC12-HSL, does not change above the 1-fold significance threshold. The implications of this finding are discussed in the light of the role of quorum sensing-interfering enzymes in the host strains.
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Malinich EA, Bauer CE. The plant growth promoting bacterium Azospirillum brasilense is vertically transmitted in Phaseolus vulgaris (common bean). Symbiosis 2018. [DOI: 10.1007/s13199-018-0539-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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López-Baena FJ, Ruiz-Sainz JE, Rodríguez-Carvajal MA, Vinardell JM. Bacterial Molecular Signals in the Sinorhizobium fredii-Soybean Symbiosis. Int J Mol Sci 2016; 17:E755. [PMID: 27213334 PMCID: PMC4881576 DOI: 10.3390/ijms17050755] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Revised: 05/04/2016] [Accepted: 05/05/2016] [Indexed: 12/20/2022] Open
Abstract
Sinorhizobium (Ensifer) fredii (S. fredii) is a rhizobial species exhibiting a remarkably broad nodulation host-range. Thus, S. fredii is able to effectively nodulate dozens of different legumes, including plants forming determinate nodules, such as the important crops soybean and cowpea, and plants forming indeterminate nodules, such as Glycyrrhiza uralensis and pigeon-pea. This capacity of adaptation to different symbioses makes the study of the molecular signals produced by S. fredii strains of increasing interest since it allows the analysis of their symbiotic role in different types of nodule. In this review, we analyze in depth different S. fredii molecules that act as signals in symbiosis, including nodulation factors, different surface polysaccharides (exopolysaccharides, lipopolysaccharides, cyclic glucans, and K-antigen capsular polysaccharides), and effectors delivered to the interior of the host cells through a symbiotic type 3 secretion system.
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Affiliation(s)
- Francisco J López-Baena
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Avenida de Reina Mercedes, 6, 41012 Sevilla, Spain.
| | - José E Ruiz-Sainz
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Avenida de Reina Mercedes, 6, 41012 Sevilla, Spain.
| | - Miguel A Rodríguez-Carvajal
- Departamento de Química Orgánica, Facultad de Química, Universidad de Sevilla, Profesor García González, 1, 41012 Sevilla, Spain.
| | - José M Vinardell
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Avenida de Reina Mercedes, 6, 41012 Sevilla, Spain.
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Margaret I, Lucas MM, Acosta-Jurado S, Buendía-Clavería AM, Fedorova E, Hidalgo Á, Rodríguez-Carvajal MA, Rodriguez-Navarro DN, Ruiz-Sainz JE, Vinardell JM. The Sinorhizobium fredii HH103 lipopolysaccharide is not only relevant at early soybean nodulation stages but also for symbiosome stability in mature nodules. PLoS One 2013; 8:e74717. [PMID: 24098345 PMCID: PMC3788101 DOI: 10.1371/journal.pone.0074717] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Accepted: 08/04/2013] [Indexed: 11/25/2022] Open
Abstract
In this work we have characterised the Sinorhizobium fredii HH103 greA lpsB lpsCDE genetic region and analysed for the first time the symbiotic performance of Sinorhizobium fredii lps mutants on soybean. The organization of the S. fredii HH103 greA, lpsB, and lpsCDE genes was equal to that of Sinorhizobium meliloti 1021. S. fredii HH103 greA, lpsB, and lpsE mutant derivatives produced altered LPS profiles that were characteristic of the gene mutated. In addition, S. fredii HH103 greA mutants showed a reduction in bacterial mobility and an increase of auto-agglutination in liquid cultures. RT-PCR and qPCR experiments demonstrated that the HH103 greA gene has a positive effect on the transcription of lpsB. Soybean plants inoculated with HH103 greA, lpsB or lpsE mutants formed numerous ineffective pseudonodules and showed severe symptoms of nitrogen starvation. However, HH103 greA and lps mutants were also able to induce the formation of a reduced number of soybean nodules of normal external morphology, allowing the possibility of studying the importance of bacterial LPS in later stages of the S. fredii HH103-soybean symbiosis. The infected cells of these nodules showed signs of early termination of symbiosis and lytical clearance of bacteroids. These cells also had very thick walls and accumulation of phenolic-like compounds, pointing to induced defense reactions. Our results show the importance of bacterial LPS in later stages of the S. fredii HH103-soybean symbiosis and their role in preventing host cell defense reactions. S. fredii HH103 lpsB mutants also showed reduced nodulation with Vigna unguiculata, although the symbiotic impairment was less pronounced than in soybean.
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Affiliation(s)
- Isabel Margaret
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla. Sevilla, Spain
| | | | | | | | | | - Ángeles Hidalgo
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla. Sevilla, Spain
| | | | | | - José E. Ruiz-Sainz
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla. Sevilla, Spain
| | - José M. Vinardell
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla. Sevilla, Spain
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