2
|
Aqueous peat extract exposes rhizobia to sub-lethal stress which may prime cells for improved desiccation tolerance. Appl Microbiol Biotechnol 2018; 102:7521-7539. [DOI: 10.1007/s00253-018-9086-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Revised: 05/04/2018] [Accepted: 05/08/2018] [Indexed: 01/25/2023]
|
3
|
Liu Y, Jiang X, Guan D, Zhou W, Ma M, Zhao B, Cao F, Li L, Li J. Transcriptional analysis of genes involved in competitive nodulation in Bradyrhizobium diazoefficiens at the presence of soybean root exudates. Sci Rep 2017; 7:10946. [PMID: 28887528 PMCID: PMC5591287 DOI: 10.1038/s41598-017-11372-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Accepted: 08/23/2017] [Indexed: 01/22/2023] Open
Abstract
Nodulation competition is a key factor that limits symbiotic nitrogen fixation between rhizobia and their host legumes. Soybean root exudates (SREs) are thought to act as signals that influence Bradyrhizobium ability to colonize roots and to survive in the rhizosphere, and thus they act as a key determinant of nodulation competitiveness. In order to find the competitiveness-related genes in B. diazoefficiens, the transcriptome of two SREs treated B. diazoefficiens with completely different nodulation abilities (B. diazoefficiens 4534 and B. diazoefficiens 4222) were sequenced and compared. In SREs treated strain 4534 (SREs-4534), 253 unigenes were up-regulated and 204 unigenes were down-regulated. In SREs treated strain 4534 (SREs-4222), the numbers of up- and down-regulated unigenes were 108 and 185, respectively. There were considerable differences between the SREs-4534 and SREs-4222 gene expression profiles. Some differentially expressed genes are associated with a two-component system (i.g., nodW, phyR-σEcfG), bacterial chemotaxis (i.g., cheA, unigene04832), ABC transport proteins (i.g., unigene02212), IAA (indole-3-acetic acid) metabolism (i.g., nthA, nthB), and metabolic fitness (i.g., put.), which may explain the higher nodulation competitiveness of B. diazoefficiens in the rhizosphere. Our results provide a comprehensive transcriptomic resource for SREs treated B. diazoefficiens and will facilitate further studies on competitiveness-related genes in B. diazoefficiens.
Collapse
Affiliation(s)
- Yao Liu
- Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Xin Jiang
- Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
- Laboratory of Quality&Safety Risk Assessment for Microbial Products (Beijing), Ministry of Agriculture, Beijing, 100081, China.
| | - Dawei Guan
- Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Wei Zhou
- Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Mingchao Ma
- Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
- Laboratory of Quality&Safety Risk Assessment for Microbial Products (Beijing), Ministry of Agriculture, Beijing, 100081, China
| | - Baisuo Zhao
- Laboratory of Quality&Safety Risk Assessment for Microbial Products (Beijing), Ministry of Agriculture, Beijing, 100081, China
| | - Fengming Cao
- Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
- Laboratory of Quality&Safety Risk Assessment for Microbial Products (Beijing), Ministry of Agriculture, Beijing, 100081, China
| | - Li Li
- Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Jun Li
- Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
- Laboratory of Quality&Safety Risk Assessment for Microbial Products (Beijing), Ministry of Agriculture, Beijing, 100081, China.
| |
Collapse
|
4
|
Shiro S, Kuranaga C, Yamamoto A, Sameshima-Saito R, Saeki Y. Temperature-Dependent Expression of NodC and Community Structure of Soybean-Nodulating Bradyrhizobia. Microbes Environ 2016; 31:27-32. [PMID: 26877137 PMCID: PMC4791112 DOI: 10.1264/jsme2.me15114] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Accepted: 11/19/2015] [Indexed: 11/30/2022] Open
Abstract
In order to assess the physiological responses of bradyrhizobia and competition for the nodulation of soybean at different temperatures, we investigated the expression of the nodC gene at 20, 25, and 30°C and the abilities of bacteria to nodulate soybean in microcosms at day/night cultivation temperatures of 23/18°C, 28/23°C, and 33/28°C for 16/8 h. We tested five Bradyrhizobium USDA strains: B. diazoefficiens USDA 110(T) and 122, B. japonicum USDA 123, and B. elkanii USDA 31 and 76(T). The expression of nodC was up-regulated by increasing culture temperatures in USDA 110(T), 122, 31, and 76(T), but was down-regulated in USDA 123. The proportions of USDA 110(T) and 122 within the community were the greatest at 28/23°C. The population of USDA 31 increased, whereas that of USDA 123 decreased with increasing cultivation temperatures. On the other hand, infection by USDA 76(T) was not detected, and low numbers of USDA 76(T) nodules confirmed its poor nodulation ability. These results indicate that the competitiveness of and infection by USDA 110(T), 122, 123, and 31 for soybean nodulation depend on cultivation temperatures, and suggest that the temperature dependence of nodC expression affects the bradyrhizobial community structure.
Collapse
Affiliation(s)
- Sokichi Shiro
- Faculty of Life and Environmental Science, Shimane University1060 Nishikawatsu, Matsue, Shimane 690–8504Japan
| | - Chika Kuranaga
- Faculty of Agriculture, University of Miyazaki1–1 Gakuenkibanadai-Nishi, Miyazaki, Miyazaki 889–2192Japan
| | - Akihiro Yamamoto
- Faculty of Agriculture, University of Miyazaki1–1 Gakuenkibanadai-Nishi, Miyazaki, Miyazaki 889–2192Japan
| | - Reiko Sameshima-Saito
- Faculty of Agriculture, Shizuoka University836 Otani, Suruga-ku, Shizuoka, Shizuoka 422–8529Japan
| | - Yuichi Saeki
- Faculty of Agriculture, University of Miyazaki1–1 Gakuenkibanadai-Nishi, Miyazaki, Miyazaki 889–2192Japan
| |
Collapse
|
5
|
Gomes DF, da Silva Batista JS, Rolla AAP, da Silva LP, Bloch C, Galli-Terasawa LV, Hungria M. Proteomic analysis of free-living Bradyrhizobium diazoefficiens: highlighting potential determinants of a successful symbiosis. BMC Genomics 2014; 15:643. [PMID: 25086822 PMCID: PMC4287336 DOI: 10.1186/1471-2164-15-643] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Accepted: 07/25/2014] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Strain CPAC 7 (=SEMIA 5080) was recently reclassified into the new species Bradyrhizobium diazoefficiens; due to its outstanding efficiency in fixing nitrogen, it has been used in commercial inoculants for application to crops of soybean [Glycine max (L.) Merr.] in Brazil and other South American countries. Although the efficiency of B. diazoefficiens inoculant strains is well recognized, few data on their protein expression are available. RESULTS We provided a two-dimensional proteomic reference map of CPAC 7 obtained under free-living conditions, with the successful identification of 115 spots, representing 95 different proteins. The results highlighted the expression of molecular determinants potentially related to symbiosis establishment (e.g. inositol monophosphatase, IMPase), fixation of atmospheric nitrogen (N2) (e.g. NifH) and defenses against stresses (e.g. chaperones). By using bioinformatic tools, it was possible to attribute probable functions to ten hypothetical proteins. For another ten proteins classified as "NO related COG" group, we analyzed by RT-qPCR the relative expression of their coding-genes in response to the nodulation-gene inducer genistein. Six of these genes were up-regulated, including blr0227, which may be related to polyhydroxybutyrate (PHB) biosynthesis and competitiveness for nodulation. CONCLUSIONS The proteomic map contributed to the identification of several proteins of B. diazoefficiens under free-living conditions and our approach-combining bioinformatics and gene-expression assays-resulted in new information about unknown genes that might play important roles in the establishment of the symbiosis with soybean.
Collapse
Affiliation(s)
| | | | | | | | | | | | - Mariangela Hungria
- Embrapa Soja, Embrapa Soja, C,P, 231, 86001-970 Londrina, Paraná, Brazil.
| |
Collapse
|
6
|
da Silva Batista JS, Hungria M. Proteomics reveals differential expression of proteins related to a variety of metabolic pathways by genistein-induced Bradyrhizobium japonicum strains. J Proteomics 2011; 75:1211-9. [PMID: 22119543 DOI: 10.1016/j.jprot.2011.10.032] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2011] [Revised: 10/28/2011] [Accepted: 10/31/2011] [Indexed: 11/19/2022]
Abstract
The rhizobia-legume symbiosis requires a coordinated molecular interaction between the symbionts, initiated by seed and root exudation of several compounds, mainly flavonoids, that trigger the expression of nodulation genes in the bacteria. Since the role of flavonoids seems to be broader than the induction of nodulation genes, we aimed at characterizing genistein-induced proteins of Bradyrhizobium japonicum CPAC 15 (=SEMIA 5079), used in commercial soybean inoculants in Brazil, and of two genetically related strains grown in vitro. Whole-cell proteins were extracted both from induced (1 μM genistein) and from non-induced cultures of the three strains, and separated by two-dimensional electrophoresis. Spot profiles were compared between the two conditions and selected spots were excised and identified by mass spectrometry. Forty-seven proteins were significantly induced by genistein, including several hypothetical proteins, the cytoplasmic flagellar component FliG, periplasmic ABC transporters, a protein related to biosynthesis of exopolysaccharides (ExoN), and proteins involved in redox-state maintenance. Noteworthy was the induction of the PhyR-σ(EcfG) regulon, recently demonstrated to be involved in the symbiotic efficiency of, and general stress response in B. japonicum. Our results confirm that the role of flavonoids, such as genistein, can go far beyond the expression of nodulation-related proteins in B. japonicum.
Collapse
|