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Camuel A, Teulet A, Carcagno M, Haq F, Pacquit V, Gully D, Pervent M, Chaintreuil C, Fardoux J, Horta-Araujo N, Okazaki S, Ratu STN, Gueye F, Zilli J, Nouwen N, Arrighi JF, Luo H, Mergaert P, Deslandes L, Giraud E. Widespread Bradyrhizobium distribution of diverse Type III effectors that trigger legume nodulation in the absence of Nod factor. THE ISME JOURNAL 2023; 17:1416-1429. [PMID: 37355742 PMCID: PMC10432411 DOI: 10.1038/s41396-023-01458-1] [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: 04/24/2023] [Revised: 06/08/2023] [Accepted: 06/13/2023] [Indexed: 06/26/2023]
Abstract
The establishment of the rhizobium-legume symbiosis is generally based on plant perception of Nod factors (NFs) synthesized by the bacteria. However, some Bradyrhizobium strains can nodulate certain legume species, such as Aeschynomene spp. or Glycine max, independently of NFs, and via two different processes that are distinguished by the necessity or not of a type III secretion system (T3SS). ErnA is the first known type III effector (T3E) triggering nodulation in Aeschynomene indica. In this study, a collection of 196 sequenced Bradyrhizobium strains was tested on A. indica. Only strains belonging to the photosynthetic supergroup can develop a NF-T3SS-independent symbiosis, while the ability to use a T3SS-dependent process is found in multiple supergroups. Of these, 14 strains lacking ernA were tested by mutagenesis to identify new T3Es triggering nodulation. We discovered a novel T3E, Sup3, a putative SUMO-protease without similarity to ErnA. Its mutation in Bradyrhizobium strains NAS96.2 and WSM1744 abolishes nodulation and its introduction in an ernA mutant of strain ORS3257 restores nodulation. Moreover, ectopic expression of sup3 in A. indica roots led to the formation of spontaneous nodules. We also report three other new T3Es, Ubi1, Ubi2 and Ubi3, which each contribute to the nodulation capacity of strain LMTR13. These T3Es have no homology to known proteins but share with ErnA three motifs necessary for ErnA activity. Together, our results highlight an unsuspected distribution and diversity of T3Es within the Bradyrhizobium genus that may contribute to their symbiotic efficiency by participating in triggering legume nodulation.
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Affiliation(s)
- Alicia Camuel
- IRD, Laboratoire des Symbioses Tropicales et Méditerranéennes (LSTM), UMR IRD/Institut Agro/INRAE/Université de Montpellier/CIRAD, TA-A82/J- Campus de Baillarguet 34398, Montpellier cedex 5, France
- PHIM Plant Health Institute, Université de Montpellier, IRD, CIRAD, INRAE, Institut Agro, Montpellier, France
| | - Albin Teulet
- IRD, Laboratoire des Symbioses Tropicales et Méditerranéennes (LSTM), UMR IRD/Institut Agro/INRAE/Université de Montpellier/CIRAD, TA-A82/J- Campus de Baillarguet 34398, Montpellier cedex 5, France
- University of Cambridge, Sainsbury Laboratory (SLCU), Cambridge, CB2 1LR, UK
| | - Mélanie Carcagno
- LIPME, Université de Toulouse, INRAE, CNRS, Castanet-Tolosan, France
| | - Fazal Haq
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
| | - Valérie Pacquit
- LIPME, Université de Toulouse, INRAE, CNRS, Castanet-Tolosan, France
| | - Djamel Gully
- IRD, Laboratoire des Symbioses Tropicales et Méditerranéennes (LSTM), UMR IRD/Institut Agro/INRAE/Université de Montpellier/CIRAD, TA-A82/J- Campus de Baillarguet 34398, Montpellier cedex 5, France
- PHIM Plant Health Institute, Université de Montpellier, IRD, CIRAD, INRAE, Institut Agro, Montpellier, France
| | - Marjorie Pervent
- IRD, Laboratoire des Symbioses Tropicales et Méditerranéennes (LSTM), UMR IRD/Institut Agro/INRAE/Université de Montpellier/CIRAD, TA-A82/J- Campus de Baillarguet 34398, Montpellier cedex 5, France
- PHIM Plant Health Institute, Université de Montpellier, IRD, CIRAD, INRAE, Institut Agro, Montpellier, France
| | - Clémence Chaintreuil
- IRD, Laboratoire des Symbioses Tropicales et Méditerranéennes (LSTM), UMR IRD/Institut Agro/INRAE/Université de Montpellier/CIRAD, TA-A82/J- Campus de Baillarguet 34398, Montpellier cedex 5, France
- PHIM Plant Health Institute, Université de Montpellier, IRD, CIRAD, INRAE, Institut Agro, Montpellier, France
| | - Joël Fardoux
- IRD, Laboratoire des Symbioses Tropicales et Méditerranéennes (LSTM), UMR IRD/Institut Agro/INRAE/Université de Montpellier/CIRAD, TA-A82/J- Campus de Baillarguet 34398, Montpellier cedex 5, France
| | - Natasha Horta-Araujo
- IRD, Laboratoire des Symbioses Tropicales et Méditerranéennes (LSTM), UMR IRD/Institut Agro/INRAE/Université de Montpellier/CIRAD, TA-A82/J- Campus de Baillarguet 34398, Montpellier cedex 5, France
- PHIM Plant Health Institute, Université de Montpellier, IRD, CIRAD, INRAE, Institut Agro, Montpellier, France
| | - Shin Okazaki
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, 183-8509, Japan
| | - Safirah Tasa Nerves Ratu
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, 183-8509, Japan
| | - Fatou Gueye
- Carrefour International, Bureau Régional Afrique de l'Ouest, Dakar, Sénégal
| | - Jerri Zilli
- Embrapa Agrobiologia, Bairro Ecologia, Seropedica, Rio de Janeiro, Brazil
| | - Nico Nouwen
- IRD, Laboratoire des Symbioses Tropicales et Méditerranéennes (LSTM), UMR IRD/Institut Agro/INRAE/Université de Montpellier/CIRAD, TA-A82/J- Campus de Baillarguet 34398, Montpellier cedex 5, France
- PHIM Plant Health Institute, Université de Montpellier, IRD, CIRAD, INRAE, Institut Agro, Montpellier, France
| | - Jean-François Arrighi
- IRD, Laboratoire des Symbioses Tropicales et Méditerranéennes (LSTM), UMR IRD/Institut Agro/INRAE/Université de Montpellier/CIRAD, TA-A82/J- Campus de Baillarguet 34398, Montpellier cedex 5, France
- PHIM Plant Health Institute, Université de Montpellier, IRD, CIRAD, INRAE, Institut Agro, Montpellier, France
| | - Haiwei Luo
- School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Peter Mergaert
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
| | - Laurent Deslandes
- LIPME, Université de Toulouse, INRAE, CNRS, Castanet-Tolosan, France
| | - Eric Giraud
- IRD, Laboratoire des Symbioses Tropicales et Méditerranéennes (LSTM), UMR IRD/Institut Agro/INRAE/Université de Montpellier/CIRAD, TA-A82/J- Campus de Baillarguet 34398, Montpellier cedex 5, France.
- PHIM Plant Health Institute, Université de Montpellier, IRD, CIRAD, INRAE, Institut Agro, Montpellier, France.
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Klonowska A, Ardley J, Moulin L, Zandberg J, Patrel D, Gollagher M, Marinova D, Reddy TBK, Varghese N, Huntemann M, Woyke T, Seshadri R, Ivanova N, Kyrpides N, Reeve W. Discovery of a novel filamentous prophage in the genome of the Mimosa pudica microsymbiont Cupriavidus taiwanensis STM 6018. Front Microbiol 2023; 14:1082107. [PMID: 36925474 PMCID: PMC10011098 DOI: 10.3389/fmicb.2023.1082107] [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: 10/27/2022] [Accepted: 01/24/2023] [Indexed: 03/08/2023] Open
Abstract
Integrated virus genomes (prophages) are commonly found in sequenced bacterial genomes but have rarely been described in detail for rhizobial genomes. Cupriavidus taiwanensis STM 6018 is a rhizobial Betaproteobacteria strain that was isolated in 2006 from a root nodule of a Mimosa pudica host in French Guiana, South America. Here we describe features of the genome of STM 6018, focusing on the characterization of two different types of prophages that have been identified in its genome. The draft genome of STM 6018 is 6,553,639 bp, and consists of 80 scaffolds, containing 5,864 protein-coding genes and 61 RNA genes. STM 6018 contains all the nodulation and nitrogen fixation gene clusters common to symbiotic Cupriavidus species; sharing >99.97% bp identity homology to the nod/nif/noeM gene clusters from C. taiwanensis LMG19424T and "Cupriavidus neocalidonicus" STM 6070. The STM 6018 genome contains the genomes of two prophages: one complete Mu-like capsular phage and one filamentous phage, which integrates into a putative dif site. This is the first characterization of a filamentous phage found within the genome of a rhizobial strain. Further examination of sequenced rhizobial genomes identified filamentous prophage sequences in several Beta-rhizobial strains but not in any Alphaproteobacterial rhizobia.
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Affiliation(s)
- Agnieszka Klonowska
- Université de Montpellier, IRD, CIRAD, INRAE, Institut AgroPHIM Plant Health Institute, Montpellier, France
| | - Julie Ardley
- Centre for Crop and Food Innovation, Food Futures Institute, College of Science, Health, Engineering and Education, Murdoch University, Murdoch, WA, Australia
| | - Lionel Moulin
- Université de Montpellier, IRD, CIRAD, INRAE, Institut AgroPHIM Plant Health Institute, Montpellier, France
| | - Jaco Zandberg
- Centre for Crop and Food Innovation, Food Futures Institute, College of Science, Health, Engineering and Education, Murdoch University, Murdoch, WA, Australia
| | - Delphine Patrel
- Université de Montpellier, IRD, CIRAD, INRAE, Institut AgroPHIM Plant Health Institute, Montpellier, France
| | - Margaret Gollagher
- Curtin University Sustainability Policy Institute, Curtin University, Bentley, WA, Australia
| | - Dora Marinova
- Curtin University Sustainability Policy Institute, Curtin University, Bentley, WA, Australia
| | - T B K Reddy
- Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | - Neha Varghese
- Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | - Marcel Huntemann
- Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | - Tanja Woyke
- Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | - Rekha Seshadri
- Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | - Natalia Ivanova
- Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | - Nikos Kyrpides
- Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | - Wayne Reeve
- Centre for Crop and Food Innovation, Food Futures Institute, College of Science, Health, Engineering and Education, Murdoch University, Murdoch, WA, Australia
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Meena M, Nagda A, Mehta T, Yadav G, Sonigra P. Mechanistic basis of the symbiotic signaling pathway between the host and the pathogen. PLANT-MICROBE INTERACTION - RECENT ADVANCES IN MOLECULAR AND BIOCHEMICAL APPROACHES 2023:375-387. [DOI: 10.1016/b978-0-323-91875-6.00001-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
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Yao Y, Zhang X, Huang Z, Li H, Huang J, Corti G, Wu Z, Qin X, Zhang Y, Ye X, Fan H, Jiang L. A field study on the composition, structure, and function of endophytic bacterial community of Robinia pseudoacacia at a composite heavy metals tailing. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 850:157874. [PMID: 35940266 DOI: 10.1016/j.scitotenv.2022.157874] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2022] [Revised: 08/02/2022] [Accepted: 08/02/2022] [Indexed: 05/27/2023]
Abstract
Robinia pseudoacacia (R. pseudoacacia) is a well reported plant species for heavy metal phytoremediation, and it was capable to improve Cd uptake efficiency after inoculated with plant growth promoting endophytes. However, the knowledge on R. pseudoacacia associated endophytes in field condition and the relationship between these microbial communities and heavy metal uptake capacities are still scarce. In this study, the characteristics of heavy metal bioaccumulation and translocation in R. pseudoacacia, and the structure and function of its endophytic bacterial communities were revealed. The results showed that heavy metal pollution made microbes more sensitive to the environment as the diversity (Shannon) of endophyte community decreased but the abundance (Chao) increased. Redundancy analysis (RDA) also showed that heavy metals were the key factor affecting the composition of endophyte. In the co-occurrence network, 27 keystone taxa mainly from Actinobacteria, Proteobacteria and Firmicutes occupied the dominant niches, among which 16 OTUs mainly from lactobacillus, bacteroides, staphylococcus, methylorubrum and bifidobacterium were positively related to bioaccumulation and translocation of Cd, Cu, Pb and Zn. Besides, heavy metal stress enhanced the functional adaptability of endophytic bacteria community. Related predicted genes were enriched in immune response, physiological metabolism pathway and stress-resistant enzyme synthesis. This study showed that heavy metal stress enhanced the structural and functional adaptability of endophyte community and keystone taxa played significant role in improving the efficiency of phytoremediation.
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Affiliation(s)
- Yuxuan Yao
- College of Life Science and Technology, Central South University of Forestry and Technology, 498 South Shaoshan Road, Changsha, Hunan 410004, PR China; State Key Laboratory of Utilization of Woody Oil Resource, Hunan Academy of Forestry, Changsha, Hunan 410004, PR China
| | - Xuan Zhang
- College of Life Science and Technology, Central South University of Forestry and Technology, 498 South Shaoshan Road, Changsha, Hunan 410004, PR China; State Key Laboratory of Utilization of Woody Oil Resource, Hunan Academy of Forestry, Changsha, Hunan 410004, PR China
| | - Zhongliang Huang
- State Key Laboratory of Utilization of Woody Oil Resource, Hunan Academy of Forestry, Changsha, Hunan 410004, PR China
| | - Hui Li
- State Key Laboratory of Utilization of Woody Oil Resource, Hunan Academy of Forestry, Changsha, Hunan 410004, PR China
| | - Jing Huang
- State Key Laboratory of Utilization of Woody Oil Resource, Hunan Academy of Forestry, Changsha, Hunan 410004, PR China
| | - Giuseppe Corti
- Department of Agrarian, Food and Environmental Sciences, Università Politecnica dell Marche, Ancona, Italy
| | - Zijian Wu
- State Key Laboratory of Utilization of Woody Oil Resource, Hunan Academy of Forestry, Changsha, Hunan 410004, PR China
| | - Xiaoli Qin
- State Key Laboratory of Utilization of Woody Oil Resource, Hunan Academy of Forestry, Changsha, Hunan 410004, PR China
| | - Yanru Zhang
- State Key Laboratory of Utilization of Woody Oil Resource, Hunan Academy of Forestry, Changsha, Hunan 410004, PR China
| | - Xinyu Ye
- State Key Laboratory of Utilization of Woody Oil Resource, Hunan Academy of Forestry, Changsha, Hunan 410004, PR China
| | - Huixin Fan
- College of Life Science and Technology, Central South University of Forestry and Technology, 498 South Shaoshan Road, Changsha, Hunan 410004, PR China; State Key Laboratory of Utilization of Woody Oil Resource, Hunan Academy of Forestry, Changsha, Hunan 410004, PR China
| | - Lijuan Jiang
- College of Life Science and Technology, Central South University of Forestry and Technology, 498 South Shaoshan Road, Changsha, Hunan 410004, PR China.
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Jiménez-Guerrero I, Medina C, Vinardell JM, Ollero FJ, López-Baena FJ. The Rhizobial Type 3 Secretion System: The Dr. Jekyll and Mr. Hyde in the Rhizobium–Legume Symbiosis. Int J Mol Sci 2022; 23:ijms231911089. [PMID: 36232385 PMCID: PMC9569860 DOI: 10.3390/ijms231911089] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 09/08/2022] [Accepted: 09/14/2022] [Indexed: 01/14/2023] Open
Abstract
Rhizobia are soil bacteria that can establish a symbiotic association with legumes. As a result, plant nodules are formed on the roots of the host plants where rhizobia differentiate to bacteroids capable of fixing atmospheric nitrogen into ammonia. This ammonia is transferred to the plant in exchange of a carbon source and an appropriate environment for bacterial survival. This process is subjected to a tight regulation with several checkpoints to allow the progression of the infection or its restriction. The type 3 secretion system (T3SS) is a secretory system that injects proteins, called effectors (T3E), directly into the cytoplasm of the host cell, altering host pathways or suppressing host defense responses. This secretion system is not present in all rhizobia but its role in symbiosis is crucial for some symbiotic associations, showing two possible faces as Dr. Jekyll and Mr. Hyde: it can be completely necessary for the formation of nodules, or it can block nodulation in different legume species/cultivars. In this review, we compile all the information currently available about the effects of different rhizobial effectors on plant symbiotic phenotypes. These phenotypes are diverse and highlight the importance of the T3SS in certain rhizobium–legume symbioses.
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Wang T, Balla B, Kovács S, Kereszt A. Varietas Delectat: Exploring Natural Variations in Nitrogen-Fixing Symbiosis Research. FRONTIERS IN PLANT SCIENCE 2022; 13:856187. [PMID: 35481136 PMCID: PMC9037385 DOI: 10.3389/fpls.2022.856187] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Accepted: 03/08/2022] [Indexed: 06/14/2023]
Abstract
The nitrogen-fixing symbiosis between leguminous plants and soil bacteria collectively called rhizobia plays an important role in the global nitrogen cycle and is an essential component of sustainable agriculture. Genetic determinants directing the development and functioning of the interaction have been identified with the help of a very limited number of model plants and bacterial strains. Most of the information obtained from the study of model systems could be validated on crop plants and their partners. The investigation of soybean cultivars and different rhizobia, however, has revealed the existence of ineffective interactions between otherwise effective partners that resemble gene-for-gene interactions described for pathogenic systems. Since then, incompatible interactions between natural isolates of model plants, called ecotypes, and different bacterial partner strains have been reported. Moreover, diverse phenotypes of both bacterial mutants on different host plants and plant mutants with different bacterial strains have been described. Identification of the genetic factors behind the phenotypic differences did already and will reveal novel functions of known genes/proteins, the role of certain proteins in some interactions, and the fine regulation of the steps during nodule development.
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Affiliation(s)
- Ting Wang
- Eötvös Loránd Research Network, Biological Research Centre, Institute of Plant Biology, Szeged, Hungary
- Doctoral School in Biology, University of Szeged, Szeged, Hungary
| | - Benedikta Balla
- Eötvös Loránd Research Network, Biological Research Centre, Institute of Plant Biology, Szeged, Hungary
- Doctoral School in Biology, University of Szeged, Szeged, Hungary
| | - Szilárd Kovács
- Eötvös Loránd Research Network, Biological Research Centre, Institute of Plant Biology, Szeged, Hungary
| | - Attila Kereszt
- Eötvös Loránd Research Network, Biological Research Centre, Institute of Plant Biology, Szeged, Hungary
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Teulet A, Camuel A, Perret X, Giraud E. The Versatile Roles of Type III Secretion Systems in Rhizobia-Legume Symbioses. Annu Rev Microbiol 2022; 76:45-65. [PMID: 35395168 DOI: 10.1146/annurev-micro-041020-032624] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
To suppress plant immunity and promote the intracellular infection required for fixing nitrogen for the benefit of their legume hosts, many rhizobia use type III secretion systems (T3SSs) that deliver effector proteins (T3Es) inside host cells. As reported for interactions between pathogens and host plants, the immune system of legume hosts and the cocktail of T3Es secreted by rhizobia determine the symbiotic outcome. If they remain undetected, T3Es may reduce plant immunity and thus promote infection of legumes by rhizobia. If one or more of the secreted T3Es are recognized by the cognate plant receptors, defense responses are triggered and rhizobial infection may abort. However, some rhizobial T3Es can also circumvent the need for nodulation (Nod) factors to trigger nodule formation. Here we review the multifaceted roles played by rhizobial T3Es during symbiotic interactions with legumes. Expected final online publication date for the Annual Review of Microbiology, Volume 76 is September 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Albin Teulet
- Laboratoire des Symbioses Tropicales et Méditerranéennes (LSTM), IRD, Institut Agro, INRAE, Université de Montpellier, and CIRAD, Montpellier, France;
| | - Alicia Camuel
- Laboratoire des Symbioses Tropicales et Méditerranéennes (LSTM), IRD, Institut Agro, INRAE, Université de Montpellier, and CIRAD, Montpellier, France; .,PHIM Plant Health Institute, IRD, Institut Agro, INRAE, Université de Montpellier, and CIRAD, Montpellier, France
| | - Xavier Perret
- Laboratory of Microbial Genetics, Department of Botany and Plant Biology, University of Geneva, Geneva, Switzerland
| | - Eric Giraud
- Laboratoire des Symbioses Tropicales et Méditerranéennes (LSTM), IRD, Institut Agro, INRAE, Université de Montpellier, and CIRAD, Montpellier, France; .,PHIM Plant Health Institute, IRD, Institut Agro, INRAE, Université de Montpellier, and CIRAD, Montpellier, France
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Response of Tomato-Pseudomonas Pathosystem to Mild Heat Stress. HORTICULTURAE 2022. [DOI: 10.3390/horticulturae8020174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Higher plants suffer from mild heat stress when temperatures increase by 5 °C above optimum growth temperatures. This produces changes at the cellular and metabolic levels, allowing plants to adapt to heat conditions. This study investigated an increase of 5 °C above the optimum growth temperature (26 °C) of tomato plants in the tomato–Pseudomonas syringae pv. tomato pathosystem. A temperature increase above 26 °C affects plant development, the defensive pathways activated against Pseudomonas syringae pv. tomato strain DC3000 (PstDC3000), and the bacterial growth and virulence machinery. The results demonstrated that tomato plants were able to acclimate to mild heat stress, showing no symptoms of damage. Moreover, plants subjected to a 5 °C increase (T31 °C plants) showed higher basal levels of metabolites such as proline and putrescine, which probably act as compatible osmolytes. This demonstrates their importance as key components of thermotolerance. When grown under mild heat stress, plants were less susceptible to PstDC3000 and showed increased accumulation of abscisic acid, jasmonic acid-isoleucine, and spermine. In addition, the temperature increase negatively affected the infectivity of PstDC3000. Inhibition of the genes responsible for quorum sensing establishment and synthesis of flagellin and coronatine was observed in bacteria extracted from T31 °C plants. Analysis of the genes involved in the synthesis of the type III secretion system indicates the important role of this system in bacterial growth under these conditions. As the known resistance mechanisms involved in the defense against PstDC3000 were not activated, the changes in its virulence mechanisms under high temperatures may explain the lower infection observed in the T31 °C plants.
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Aguirre-Noyola JL, Rosenblueth M, Santiago-Martínez MG, Martínez-Romero E. Transcriptomic Responses of Rhizobium phaseoli to Root Exudates Reflect Its Capacity to Colonize Maize and Common Bean in an Intercropping System. Front Microbiol 2021; 12:740818. [PMID: 34777287 PMCID: PMC8581550 DOI: 10.3389/fmicb.2021.740818] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Accepted: 09/22/2021] [Indexed: 12/13/2022] Open
Abstract
Corn and common bean have been cultivated together in Mesoamerica for thousands of years in an intercropping system called "milpa," where the roots are intermingled, favoring the exchange of their microbiota, including symbionts such as rhizobia. In this work, we studied the genomic expression of Rhizobium phaseoli Ch24-10 (by RNA-seq) after a 2-h treatment in the presence of root exudates of maize and bean grown in monoculture and milpa system under hydroponic conditions. In bean exudates, rhizobial genes for nodulation and degradation of aromatic compounds were induced; while in maize, a response of genes for degradation of mucilage and ferulic acid was observed, as well as those for the transport of sugars, dicarboxylic acids and iron. Ch24-10 transcriptomes in milpa resembled those of beans because they both showed high expression of nodulation genes; some genes that were expressed in corn exudates were also induced by the intercropping system, especially those for the degradation of ferulic acid and pectin. Beans grown in milpa system formed nitrogen-fixing nodules similar to monocultured beans; therefore, the presence of maize did not interfere with Rhizobium-bean symbiosis. Genes for the metabolism of sugars and amino acids, flavonoid and phytoalexin tolerance, and a T3SS were expressed in both monocultures and milpa system, which reveals the adaptive capacity of rhizobia to colonize both legumes and cereals. Transcriptional fusions of the putA gene, which participates in proline metabolism, and of a gene encoding a polygalacturonase were used to validate their participation in plant-microbe interactions. We determined the enzymatic activity of carbonic anhydrase whose gene was also overexpressed in response to root exudates.
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Affiliation(s)
- José Luis Aguirre-Noyola
- Programa de Ecología Genómica, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Mónica Rosenblueth
- Programa de Ecología Genómica, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | | | - Esperanza Martínez-Romero
- Programa de Ecología Genómica, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
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Ulrich K, Kube M, Becker R, Schneck V, Ulrich A. Genomic Analysis of the Endophytic Stenotrophomonas Strain 169 Reveals Features Related to Plant-Growth Promotion and Stress Tolerance. Front Microbiol 2021; 12:687463. [PMID: 34220780 PMCID: PMC8245107 DOI: 10.3389/fmicb.2021.687463] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 05/20/2021] [Indexed: 11/15/2022] Open
Abstract
Plant-associated Stenotrophomonas isolates have great potential for plant growth promotion, especially under stress conditions, due to their ability to promote tolerance to abiotic stresses such as salinity or drought. The endophytic strain Stenotrophomonas sp. 169, isolated from a field-grown poplar, increased the growth of inoculated in vitro plants, with a particular effect on root development, and was able to stimulate the rooting of poplar cuttings in the greenhouse. The strain produced high amounts of the plant growth-stimulating hormone auxin under in vitro conditions. The comparison of the 16S rRNA gene sequences and the phylogenetic analysis of the core genomes showed a close relationship to Stenotrophomonas chelatiphaga and a clear separation from Stenotrophomonas maltophilia. Whole genome sequence analysis revealed functional genes potentially associated with attachment and plant colonization, growth promotion, and stress protection. In detail, an extensive set of genes for twitching motility, chemotaxis, flagella biosynthesis, and the ability to form biofilms, which are connected with host plant colonization, could be identified in the genome of strain 169. The production of indole-3-acetic acid and the presence of genes for auxin biosynthesis pathways and the spermidine pathway could explain the ability to promote plant growth. Furthermore, the genome contained genes encoding for features related to the production of different osmoprotective molecules and enzymes mediating the regulation of stress tolerance and the ability of bacteria to quickly adapt to changing environments. Overall, the results of physiological tests and genome analysis demonstrated the capability of endophytic strain 169 to promote plant growth. In contrast to related species, strain 169 can be considered non-pathogenic and suitable for biotechnology applications.
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Affiliation(s)
- Kristina Ulrich
- Johann Heinrich von Thünen Institute, Institute of Forest Genetics, Waldsieversdorf, Germany
| | | | - Regina Becker
- Leibniz Center for Agricultural Landscape Research (ZALF), Müncheberg, Germany
| | - Volker Schneck
- Johann Heinrich von Thünen Institute, Institute of Forest Genetics, Waldsieversdorf, Germany
| | - Andreas Ulrich
- Leibniz Center for Agricultural Landscape Research (ZALF), Müncheberg, Germany
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11
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Huo H, Wang X, Liu Y, Chen J, Wei G. A Nod factor- and type III secretion system-dependent manner for Robinia pseudoacacia to establish symbiosis with Mesorhizobium amorphae CCNWGS0123. TREE PHYSIOLOGY 2021; 41:817-835. [PMID: 33219377 DOI: 10.1093/treephys/tpaa160] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 11/15/2020] [Indexed: 06/11/2023]
Abstract
Under nitrogen-limiting conditions, symbiotic nodulation promotes the growth of legume plants via the fixation of atmospheric nitrogen to ammonia by rhizobia in root nodules. The rhizobial Nod factor (NF) and type III secretion system (T3SS) are two key signaling pathways for establishing the legume-rhizobium symbiosis. However, whether NF signaling is involved in the nodulation of Robinia pseudoacacia and Mesorhizobium amorphae CCNWGS0123, and its symbiotic differences compared with T3SS signaling remain unclear. Therefore, to elucidate the function of NF signaling in nodulation, we mutated nodC in M. amorphae CCNWGS0123, which aborted NF synthesis. Compared with the plants inoculated with the wild type strain, the plants inoculated with the NF-deficient strain exhibited shorter shoots with etiolated leaves. These phenotypic characteristics were similar to those of the plants inoculated with the T3SS-deficient strain, which served as a Nod- (non-effective nodulation) control. The plants inoculated with both the NF- and T3SS-deficient strains formed massive root hair swellings, but no normal infection threads were detected. Sections of the nodules showed that inoculation with the NF- and T3SS-deficient strains induced small, white bumps without any rhizobia inside. Analyzing the accumulation of 6 plant hormones and the expression of 10 plant genes indicated that the NF- and T3SS-deficient strains activated plant defense reactions while suppressing plant symbiotic signaling during the perception and nodulation processes. The requirement for NF signaling appeared to be conserved in two other leguminous trees that can establish symbiosis with M. amorphae CCNWGS0123. In contrast, the function of the T3SS might differ among species, even within the same subfamily (Faboideae). Overall, this work demonstrated that nodulation of R. pseudoacacia and M. amorphae CCNWGS0123 was both NF and T3SS dependent.
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Affiliation(s)
- Haibo Huo
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Science, Northwest A&F University, 3 Taicheng Road, Yangling 712100, Shaanxi, People's Republic of China
| | - Xinye Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Science, Northwest A&F University, 3 Taicheng Road, Yangling 712100, Shaanxi, People's Republic of China
| | - Yao Liu
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Science, Northwest A&F University, 3 Taicheng Road, Yangling 712100, Shaanxi, People's Republic of China
| | - Juan Chen
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water conservation, Northwest A&F University, 26 Xinong Road, Yangling 712100, Shaanxi, People's Republic of China
| | - Gehong Wei
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Science, Northwest A&F University, 3 Taicheng Road, Yangling 712100, Shaanxi, People's Republic of China
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12
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Bernal P, Eberl L, de Jonge R, Lepek VC, Malone JG. Understanding plant-microorganism interactions to envision a future of sustainable agriculture. Environ Microbiol 2021; 23:1809-1811. [PMID: 33754448 DOI: 10.1111/1462-2920.15479] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 03/19/2021] [Indexed: 12/22/2022]
Affiliation(s)
- Patricia Bernal
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Seville, E41012, Spain
| | - Leo Eberl
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Ronnie de Jonge
- Department of Biology, Plant-Microbe Interactions, Utrecht University, Utrecht, 3584 CH, The Netherlands
| | - Viviana C Lepek
- Instituto de Investigaciones Biotecnológicas "Dr. Rodolfo A. Ugalde", Universidad Nacional de San Martín (IIB-UNSAM-CONICET), Buenos Aires, Argentina
| | - Jacob G Malone
- Molecular Microbiology Department, John Innes Centre, Norwich, UK.,School of Biological Sciences, University of East Anglia, Norwich, UK
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13
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Hotinger JA, Pendergrass HA, May AE. Molecular Targets and Strategies for Inhibition of the Bacterial Type III Secretion System (T3SS); Inhibitors Directly Binding to T3SS Components. Biomolecules 2021; 11:biom11020316. [PMID: 33669653 PMCID: PMC7922566 DOI: 10.3390/biom11020316] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 02/16/2021] [Accepted: 02/17/2021] [Indexed: 01/01/2023] Open
Abstract
The type III secretion system (T3SS) is a virulence apparatus used by many Gram-negative pathogenic bacteria to cause infections. Pathogens utilizing a T3SS are responsible for millions of infections yearly. Since many T3SS knockout strains are incapable of causing systemic infection, the T3SS has emerged as an attractive anti-virulence target for therapeutic design. The T3SS is a multiprotein molecular syringe that enables pathogens to inject effector proteins into host cells. These effectors modify host cell mechanisms in a variety of ways beneficial to the pathogen. Due to the T3SS’s complex nature, there are numerous ways in which it can be targeted. This review will be focused on the direct targeting of components of the T3SS, including the needle, translocon, basal body, sorting platform, and effector proteins. Inhibitors will be considered a direct inhibitor if they have a binding partner that is a T3SS component, regardless of the inhibitory effect being structural or functional.
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14
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Luo Y, Liu D, Jiao S, Liu S, Wang X, Shen X, Wei G. Identification of Robinia pseudoacacia target proteins responsive to Mesorhizobium amphore CCNWGS0123 effector protein NopT. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:7347-7363. [PMID: 32865563 DOI: 10.1093/jxb/eraa405] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 08/28/2020] [Indexed: 06/11/2023]
Abstract
Nodulation outer proteins secreted via type 3 secretion systems are involved in the process of symbiosis between legume plants and rhizobia. To study the function of NopT in symbiosis, we mutated nopT in Mesorhizobium amphore CCNWGS0123 (GS0123), which can nodulate black locust (Robinia pseudoacacia). The nopT mutant induced higher levels of jasmonic acid, salicylic acid, and hydrogen peroxide accumulation in the roots of R. pseudoacacia compared with wild-type GS0123. The ΔnopT mutant induced higher disease-resistant gene expression 72 hours post-inoculation (hpi), whereas GS0123 induced higher disease-resistant gene expression earlier, at 36 hpi. Compared with the nopT mutant, GS0123 induced the up-regulation of most genes at 36 hpi and the down-regulation of most genes at 72 hpi. Proteolytically active NopT_GS0123 induced hypersensitive responses when expressed transiently in tobacco leaves (Nicotiana benthamiana). Two NopT_GS0123 targets in R. pseudoacacia were identified, ATP-citrate synthase alpha chain protein 2 and hypersensitive-induced response protein. Their interactions with NopT_GS0123 triggered resistance by the plant immune system. In conclusion, NopT_GS0123 inhibited the host plant immune system and had minimal effect on nodulation in R. pseudoacacia. Our results reveal the underlying molecular mechanism of NopT function in plant-symbiont interactions.
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Affiliation(s)
- Yantao Luo
- State Key Laboratory of Crop Stress Biology in Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A & F University, Yangling, Shaanxi, China
| | - Dongying Liu
- State Key Laboratory of Crop Stress Biology in Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A & F University, Yangling, Shaanxi, China
| | - Shuo Jiao
- State Key Laboratory of Crop Stress Biology in Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A & F University, Yangling, Shaanxi, China
| | - Shuang Liu
- State Key Laboratory of Crop Stress Biology in Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A & F University, Yangling, Shaanxi, China
| | - Xinye Wang
- Department of Liquor Making Engineering, Moutai College, Renhuai, China
| | - Xihui Shen
- State Key Laboratory of Crop Stress Biology in Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A & F University, Yangling, Shaanxi, China
| | - Gehong Wei
- State Key Laboratory of Crop Stress Biology in Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A & F University, Yangling, Shaanxi, China
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15
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Wang L, Lin H, Dong Y, Li B, He Y. Effects of endophytes inoculation on rhizosphere and endosphere microecology of Indian mustard (Brassica juncea) grown in vanadium-contaminated soil and its enhancement on phytoremediation. CHEMOSPHERE 2020; 240:124891. [PMID: 31574442 DOI: 10.1016/j.chemosphere.2019.124891] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 09/02/2019] [Accepted: 09/16/2019] [Indexed: 06/10/2023]
Abstract
We investigated the effects of endophytes inoculation on ecological factors such as root morphology, rhizosphere soil properties, heavy metal speciation, and rhizosphere and endophytic bacterial communities and their role on phytoremediation. Indian mustards were grown for two months in V-contaminated soil with three treatments (control, inoculation with Serratia PRE01 or Arthrobacter PRE05). Inoculation with PRE01 and PRE05 increased organic matter content by 6.94% and 4.6% respectively and significantly increased bioavailability of heavy metals in rhizosphere soils. Despite the endophyte inocula failed to flourish as stable endophytes, they significantly affected the specific composition and diversity of endophytic bacterial communities in roots, with no significant effect on rhizosphere bacterial communities. The test strains could greatly increase plant growth promotion-related biomarkers in the endosphere, especially those associated with Pseudomonas and Microbacterium genera. PICRUSt analysis predicted high relative abundances of functional genes related to environmental information processing especially in the endophytic microbiota. More biomass production (12.0%-17.4%) and total metals uptake (24.2%-32.0%) were acquired in inoculated treatments. We conclude that endophyte PRE01 or PRE05 inoculation could effectively enhance phytoremediation of V-contaminated soil by improving the rhizosphere and endosphere microecology without causing any ecological damage.
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Affiliation(s)
- Liang Wang
- Department of Environmental Engineering, University of Science and Technology Beijing, 10083, China
| | - Hai Lin
- Department of Environmental Engineering, University of Science and Technology Beijing, 10083, China; Beijing Key Laboratory on Resource-oriented Treatment of Industrial Pollutants, 10083, China.
| | - Yingbo Dong
- Department of Environmental Engineering, University of Science and Technology Beijing, 10083, China; Beijing Key Laboratory on Resource-oriented Treatment of Industrial Pollutants, 10083, China.
| | - Bing Li
- Department of Environmental Engineering, University of Science and Technology Beijing, 10083, China; Beijing Key Laboratory on Resource-oriented Treatment of Industrial Pollutants, 10083, China
| | - Yinhai He
- Department of Environmental Engineering, University of Science and Technology Beijing, 10083, China; Beijing Key Laboratory on Resource-oriented Treatment of Industrial Pollutants, 10083, China
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16
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Piromyou P, Songwattana P, Teamtisong K, Tittabutr P, Boonkerd N, Tantasawat PA, Giraud E, Göttfert M, Teaumroong N. Mutualistic co-evolution of T3SSs during the establishment of symbiotic relationships between Vigna radiata and Bradyrhizobia. Microbiologyopen 2019; 8:e00781. [PMID: 30628192 PMCID: PMC6612562 DOI: 10.1002/mbo3.781] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 11/04/2018] [Accepted: 11/06/2018] [Indexed: 02/06/2023] Open
Abstract
This study supports the idea that the evolution of type III secretion system (T3SS) is one of the factors that controls Vigna radiata-bradyrhizobia symbiosis. Based on phylogenetic tree data and gene arrangements, it seems that the T3SSs of the Thai bradyrhizobial strains SUTN9-2, DOA1, and DOA9 and the Senegalese strain ORS3257 may share the same origin. Therefore, strains SUTN9-2, DOA1, DOA9, and ORS3257 may have evolved their T3SSs independently from other bradyrhizobia, depending on biological and/or geological events. For functional analyses, the rhcJ genes of ORS3257, SUTN9-2, DOA9, and USDA110 were disrupted. These mutations had cultivar-specific effects on nodulation properties. The T3SSs of ORS3257 and DOA9 showed negative effects on V. radiata nodulation, while the T3SS of SUTN9-2 showed no effect on V. radiata symbiosis. In the roots of V. radiata CN72, the expression levels of the PR1 gene after inoculation with ORS3257 and DOA9 were significantly higher than those after inoculation with ORS3257 ΩT3SS, DOA9 ΩT3SS, and SUTN9-2. The T3Es from ORS3257 and DOA9 could trigger PR1 expression, which ultimately leads to abort nodulation. In contrast, the T3E from SUTN9-2 reduced PR1 expression. It seems that the mutualistic relationship between SUTN9-2 and V. radiata may have led to the selection of the most well-adapted combination of T3SS and symbiotic bradyrhizobial genotype.
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Affiliation(s)
- Pongdet Piromyou
- School of Biotechnology, Institute of Agricultural TechnologySuranaree University of TechnologyNakhon RatchasimaThailand
| | - Pongpan Songwattana
- School of Biotechnology, Institute of Agricultural TechnologySuranaree University of TechnologyNakhon RatchasimaThailand
| | - Kamonluck Teamtisong
- The Center for Scientific and Technological EquipmentSuranaree University of TechnologyNakhon RatchasimaThailand
| | - Panlada Tittabutr
- School of Biotechnology, Institute of Agricultural TechnologySuranaree University of TechnologyNakhon RatchasimaThailand
| | - Nantakorn Boonkerd
- School of Biotechnology, Institute of Agricultural TechnologySuranaree University of TechnologyNakhon RatchasimaThailand
| | - Piyada Alisha Tantasawat
- School of Crop Production Technology, Institute of Agricultural TechnologySuranaree University of TechnologyNakhon RatchasimaThailand
| | - Eric Giraud
- IRD, Laboratory of Tropical and Mediterranean SymbiosesUMR IRD/SupAgro/INRA/UM2/CIRAD, Campus International de BaillarguetMontpellierFrance
| | | | - Neung Teaumroong
- School of Biotechnology, Institute of Agricultural TechnologySuranaree University of TechnologyNakhon RatchasimaThailand
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17
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Repurposing Macromolecule Delivery Tools for Plant Genetic Modification in the Era of Precision Genome Engineering. Methods Mol Biol 2019; 1864:3-18. [PMID: 30415325 DOI: 10.1007/978-1-4939-8778-8_1] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Efficient delivery of macromolecules into plant cells and tissues is important for both basic research and biotechnology product applications. In transgenic research, the goal is to deliver DNA molecules into regenerable cells and stably integrate them into the genome. Over the past 40 years, many macromolecule delivery methods have been studied. To generate transgenic plants, particle bombardment and Agrobacterium-mediated transformation are the methods of choice for DNA delivery. The rapid advance of genome editing technologies has generated new requirements on large biomolecule delivery and at the same time reinvigorated the development of new transformation technologies. Many of the gene delivery options that have been studied before are now being repurposed for delivering genome editing machinery for various applications. This article reviews the major progress in the development of tools for large biomolecule delivery into plant cells in the new era of precision genome engineering.
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18
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Lorite MJ, Estrella MJ, Escaray FJ, Sannazzaro A, Videira e Castro IM, Monza J, Sanjuán J, León-Barrios M. The Rhizobia- Lotus Symbioses: Deeply Specific and Widely Diverse. Front Microbiol 2018; 9:2055. [PMID: 30258414 PMCID: PMC6144797 DOI: 10.3389/fmicb.2018.02055] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 08/13/2018] [Indexed: 11/13/2022] Open
Abstract
The symbiosis between Lotus and rhizobia has been long considered very specific and only two bacterial species were recognized as the microsymbionts of Lotus: Mesorhizobium loti was considered the typical rhizobia for the L. corniculatus complex, whereas Bradyrhizobium sp. (Lotus) was the symbiont for L. uliginosus and related species. As discussed in this review, this situation has dramatically changed during the last 15 years, with the characterization of nodule bacteria from worldwide geographical locations and from previously unexplored Lotus spp. Current data support that the Lotus rhizobia are dispersed amongst nearly 20 species in five genera (Mesorhizobium, Bradyrhizobium, Rhizobium, Ensifer, and Aminobacter). As a consequence, M. loti could be regarded an infrequent symbiont of Lotus, and several plant-bacteria compatibility groups can be envisaged. Despite the great progress achieved with the model L. japonicus in understanding the establishment and functionality of the symbiosis, the genetic and biochemical bases governing the stringent host-bacteria compatibility pairships within the genus Lotus await to be uncovered. Several Lotus spp. are grown for forage, and inoculation with rhizobia is a common practice in various countries. However, the great diversity of the Lotus rhizobia is likely squandered, as only few bacterial strains are used as inoculants for Lotus pastures in very different geographical locations, with a great variety of edaphic and climatic conditions. The agroecological potential of the genus Lotus can not be fully harnessed without acknowledging the great diversity of rhizobia-Lotus interactions, along with a better understanding of the specific plant and bacterial requirements for optimal symbiotic nitrogen fixation under increasingly constrained environmental conditions.
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Affiliation(s)
- María J. Lorite
- Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, Granada, Spain
| | - María J. Estrella
- Instituto Tecnológico de Chascomús, IIB-INTECH, UNSAM-CONICET, Chascomús, Argentina
| | - Francisco J. Escaray
- Instituto Tecnológico de Chascomús, IIB-INTECH, UNSAM-CONICET, Chascomús, Argentina
| | - Analía Sannazzaro
- Instituto Tecnológico de Chascomús, IIB-INTECH, UNSAM-CONICET, Chascomús, Argentina
| | | | - Jorge Monza
- Facultad de Agronomia, Universidad de la República, Montevideo, Uruguay
| | - Juan Sanjuán
- Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, Granada, Spain
| | - Milagros León-Barrios
- Departamento de Bioquímica, Microbiología, Biología Celular y Genética, Universidad de la Laguna, Santa Cruz de Tenerife, Spain
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19
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Sugawara M, Takahashi S, Umehara Y, Iwano H, Tsurumaru H, Odake H, Suzuki Y, Kondo H, Konno Y, Yamakawa T, Sato S, Mitsui H, Minamisawa K. Variation in bradyrhizobial NopP effector determines symbiotic incompatibility with Rj2-soybeans via effector-triggered immunity. Nat Commun 2018; 9:3139. [PMID: 30087346 PMCID: PMC6081438 DOI: 10.1038/s41467-018-05663-x] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 07/12/2018] [Indexed: 12/31/2022] Open
Abstract
Genotype-specific incompatibility in legume-rhizobium symbiosis has been suggested to be controlled by effector-triggered immunity underlying pathogenic host-bacteria interactions. However, the rhizobial determinant interacting with the host resistance protein (e.g., Rj2) and the molecular mechanism of symbiotic incompatibility remain unclear. Using natural mutants of Bradyrhizobium diazoefficiens USDA 122, we identified a type III-secretory protein NopP as the determinant of symbiotic incompatibility with Rj2-soybean. The analysis of nopP mutations and variants in a culture collection reveal that three amino acid residues (R60, R67, and H173) in NopP are required for Rj2-mediated incompatibility. Complementation of rj2-soybean by the Rj2 allele confers the incompatibility induced by USDA 122-type NopP. In response to incompatible strains, Rj2-soybean plants activate defense marker gene PR-2 and suppress infection thread number at 2 days after inoculation. These results suggest that Rj2-soybeans monitor the specific variants of NopP and reject bradyrhizobial infection via effector-triggered immunity mediated by Rj2 protein.
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Affiliation(s)
- Masayuki Sugawara
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi, 980-8577, Japan.
| | - Satoko Takahashi
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi, 980-8577, Japan
| | - Yosuke Umehara
- Institute of Agrobiological Sciences, National Agriculture and Food Research Organization, 2-1-2 Kannondai, Tsukuba, Ibaraki, 305-8602, Japan
| | - Hiroya Iwano
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi, 980-8577, Japan
| | - Hirohito Tsurumaru
- Faculty of Agriculture, Kagoshima University, 1-21-24 Korimoto, Kagoshima, 890-0065, Japan
| | - Haruka Odake
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi, 980-8577, Japan
| | - Yuta Suzuki
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi, 980-8577, Japan
| | - Hitoshi Kondo
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi, 980-8577, Japan
| | - Yuki Konno
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi, 980-8577, Japan
| | - Takeo Yamakawa
- Faculty of Agriculture, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka, 812-8581, Japan
| | - Shusei Sato
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi, 980-8577, Japan
| | - Hisayuki Mitsui
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi, 980-8577, Japan
| | - Kiwamu Minamisawa
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi, 980-8577, Japan
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Fan M, Xiao X, Guo Y, Zhang J, Wang E, Chen W, Lin Y, Wei G. Enhanced phytoremdiation of Robinia pseudoacacia in heavy metal-contaminated soils with rhizobia and the associated bacterial community structure and function. CHEMOSPHERE 2018; 197:729-740. [PMID: 29407837 DOI: 10.1016/j.chemosphere.2018.01.102] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 01/20/2018] [Accepted: 01/22/2018] [Indexed: 05/05/2023]
Abstract
Heavy metals can cause serious contamination of soils, especially in mining regions. A detailed understanding of the effects of heavy metals on plants and root-associated microbial communities could help to improve phytoremediation systems. In this study, black locust (Robinia pseudoacacia) seedlings with or without rhizobial inoculation were planted in soils contaminated with different levels of heavy metals. Bacterial communities in rhizosphere and bulk soil samples were analyzed using 16S rRNA gene sequencing on the Illumina MiSeq platform and shotgun metagenome sequencing on the Illumina HiSeq platform. Soil bacterial communities varied significantly depending on the level of soil contamination, and planting also had some influence. Although inoculation of Mesorhizobium loti HZ76 (a natural microsymbiont of R. pseudoacacia) was a relatively minor factor, it did influence the soil bacterial community. Under the selective pressure, plant growth promotion-related biomarkers in the rhizosphere increased after inoculation compared with non-inoculated controls, especially those associated with Mesorhizobium, Variovorax, Streptomyces, and Rhodococcus genera. Genes encoding ATP-binding cassette transporters were up-regulated in the rhizosphere after inoculation compared with genes related to sulfur/nitrogen metabolism. These results provide insight into soil bacterial communities and their functions in the R. pseudoacacia rhizosphere in response to rhizobial inoculation and heavy metal contamination. This knowledge may prove useful for improving phytoremediation of metal-contaminated soils.
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Affiliation(s)
- Miaochun Fan
- State Key Laboratory of Crop Stress Biology in Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, PR China
| | - Xiao Xiao
- State Key Laboratory of Crop Stress Biology in Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, PR China
| | - Yanqing Guo
- State Key Laboratory of Crop Stress Biology in Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, PR China
| | - Jun Zhang
- State Key Laboratory of Crop Stress Biology in Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, PR China
| | - Entao Wang
- Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, 11340, México D.F., Mexico
| | - Weimin Chen
- State Key Laboratory of Crop Stress Biology in Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, PR China
| | - Yanbing Lin
- State Key Laboratory of Crop Stress Biology in Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, PR China.
| | - Gehong Wei
- State Key Laboratory of Crop Stress Biology in Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, PR China.
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Songwattana P, Noisangiam R, Teamtisong K, Prakamhang J, Teulet A, Tittabutr P, Piromyou P, Boonkerd N, Giraud E, Teaumroong N. Type 3 Secretion System (T3SS) of Bradyrhizobium sp. DOA9 and Its Roles in Legume Symbiosis and Rice Endophytic Association. Front Microbiol 2017; 8:1810. [PMID: 28979252 PMCID: PMC5611442 DOI: 10.3389/fmicb.2017.01810] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Accepted: 09/05/2017] [Indexed: 11/15/2022] Open
Abstract
The Bradyrhizobium sp. DOA9 strain isolated from a paddy field has the ability to nodulate a wide spectrum of legumes. Unlike other bradyrhizobia, this strain has a symbiotic plasmid harboring nod, nif, and type 3 secretion system (T3SS) genes. This T3SS cluster contains all the genes necessary for the formation of the secretory apparatus and the transcriptional activator (TtsI), which is preceded by a nod-box motif. An in silico search predicted 14 effectors putatively translocated by this T3SS machinery. In this study, we explored the role of the T3SS in the symbiotic performance of DOA9 by evaluating the ability of a T3SS mutant (ΩrhcN) to nodulate legumes belonging to Dalbergioid, Millettioid, and Genistoid tribes. Among the nine species tested, four (Arachis hypogea, Vigna radiata, Crotalaria juncea, and Macroptilium atropurpureum) responded positively to the rhcN mutation (ranging from suppression of plant defense reactions, an increase in the number of nodules and a dramatic improvement in nodule development and infection), one (Stylosanthes hamata) responded negatively (fewer nodules and less nitrogen fixation) and four species (Aeschynomene americana, Aeschynomene afraspera, Indigofera tinctoria, and Desmodium tortuosum) displayed no phenotype. We also tested the role of the T3SS in the ability of the DOA9 strain to endophytically colonize rice roots, but detected no effect of the T3SS mutation, in contrast to what was previously reported in the Bradyrhizobium SUTN9-2 strain. Taken together, these data indicate that DOA9 contains a functional T3SS that interferes with the ability of the strain to interact symbiotically with legumes but not with rice.
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Affiliation(s)
- Pongpan Songwattana
- School of Biotechnology, Institute of Agricultural Technology, Suranaree University of TechnologyNakhon Ratchasima, Thailand
| | - Rujirek Noisangiam
- National Bureau of Agricultural Commodity and Food Standards, Ministry of Agriculture and CooperativesBangkok, Thailand
| | - Kamonluck Teamtisong
- The Center for Scientific and Technological Equipment, Suranaree University of TechnologyNakhon Ratchasima, Thailand
| | - Janpen Prakamhang
- Department of Applied Biology, Faculty of Sciences and Liberal Arts, Rajamangala University of Technology IsanNakhon Ratchasima, Thailand
| | - Albin Teulet
- Institut de Recherche pour le Développement, LSTM, UMR IRD/SupAgro/INRA/Univ. Montpellier/CIRADMontpellier, France
| | - Panlada Tittabutr
- School of Biotechnology, Institute of Agricultural Technology, Suranaree University of TechnologyNakhon Ratchasima, Thailand
| | - Pongdet Piromyou
- School of Biotechnology, Institute of Agricultural Technology, Suranaree University of TechnologyNakhon Ratchasima, Thailand
| | - Nantakorn Boonkerd
- School of Biotechnology, Institute of Agricultural Technology, Suranaree University of TechnologyNakhon Ratchasima, Thailand
| | - Eric Giraud
- Institut de Recherche pour le Développement, LSTM, UMR IRD/SupAgro/INRA/Univ. Montpellier/CIRADMontpellier, France
| | - Neung Teaumroong
- School of Biotechnology, Institute of Agricultural Technology, Suranaree University of TechnologyNakhon Ratchasima, Thailand
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Abstract
Beneficial microbes such as rhizobia possess effector proteins that are secreted into the host cytoplasm where they modulate host-signaling pathways. Among these effectors, type 3 secreted effectors (T3Es) of rhizobia play roles in promoting nitrogen-fixing nodule symbiosis, suppressing host defenses and directly activating symbiosis-related processes. Rhizobia use the same strategy as pathogenic bacteria to suppress host defenses such as targeting the MAPK cascade. In addition, rhizobial T3E can promote root nodule symbiosis by directly activating Nod factor signaling, which bypasses Nod factor perception. The various strategies employed by beneficial microbes to promote infection and maintain viability in the host are therefore crucial for plant endosymbiosis.
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Affiliation(s)
- Hiroki Miwa
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwaicho, Fuchu, Tokyo 183-8509, Japan
| | - Shin Okazaki
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwaicho, Fuchu, Tokyo 183-8509, Japan.
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Vázquez-Rosas-Landa M, Ponce-Soto GY, Eguiarte LE, Souza V. Comparative genomics of free-living Gammaproteobacteria: pathogenesis-related genes or interaction-related genes? Pathog Dis 2017; 75:3861975. [DOI: 10.1093/femspd/ftx059] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 06/02/2017] [Indexed: 12/25/2022] Open
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Hu Y, Huang H, Cheng X, Shu X, White AP, Stavrinides J, Köster W, Zhu G, Zhao Z, Wang Y. A global survey of bacterial type III secretion systems and their effectors. Environ Microbiol 2017; 19:3879-3895. [DOI: 10.1111/1462-2920.13755] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 04/04/2017] [Indexed: 11/27/2022]
Affiliation(s)
- Yueming Hu
- Department of Cell Biology and Genetics, School of Basic Medical Sciences; Shenzhen University Health Science Center; Shenzhen 518060 P.R. China
| | - He Huang
- MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology; Chinese Academy of Medical Sciences & Peking Union Medical College; Beijing China
| | - Xi Cheng
- Department of Cell Biology and Genetics, School of Basic Medical Sciences; Shenzhen University Health Science Center; Shenzhen 518060 P.R. China
| | - Xingsheng Shu
- Department of Cell Biology and Genetics, School of Basic Medical Sciences; Shenzhen University Health Science Center; Shenzhen 518060 P.R. China
| | - Aaron P. White
- Vaccine and Infectious Disease Organization; University of Saskatchewan; Saskatoon SK Canada
| | | | - Wolfgang Köster
- Vaccine and Infectious Disease Organization; University of Saskatchewan; Saskatoon SK Canada
| | - Guoqiang Zhu
- College of Veterinary Medicine; Yangzhou University; Yangzhou China
| | - Zhendong Zhao
- MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology; Chinese Academy of Medical Sciences & Peking Union Medical College; Beijing China
| | - Yejun Wang
- Department of Cell Biology and Genetics, School of Basic Medical Sciences; Shenzhen University Health Science Center; Shenzhen 518060 P.R. China
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Nelson MS, Chun CL, Sadowsky MJ. Type IV Effector Proteins Involved in the Medicago-Sinorhizobium Symbiosis. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2017; 30:28-34. [PMID: 27918247 DOI: 10.1094/mpmi-10-16-0211-r] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
In this study, we investigated genetic elements of the type IV secretion system (T4SS) found in Sinorhizobium spp. and the role they play in symbiosis. Sinorhizobium meliloti and S. medicae each contain a putative T4SS similar to that used by Agrobacterium tumefaciens during pathogenesis. The Cre reporter assay for translocation system was used to validate potential effector proteins. Both S. meliloti and S. medicae contained the effector protein TfeA, which was translocated into the host plant. Sequence analysis revealed the presence of a nod box involved in transcriptional activation of symbiosis-related genes, upstream of the transcriptional regulator (virG) in the Sinorhizobium T4SS. Replicate quantitative reverse transcription-polymerase chain reaction analyses indicated that luteolin, released by roots and seeds of Medicago truncatula, upregulated transcription of tfeA and virG. Mutations in the T4SS apparatus or tfeA alone resulted in reduced numbers of nodules formed on M. truncatula genotypes. In addition, S. meliloti KH46c, which contains a deletion in the T4SS, was less competitive for nodule formation when coinoculated with an equal number of cells of the wild-type strain. To our knowledge, TfeA is the first T4SS effector protein identified in Sinorhizobium spp. Our results indicate that Sinorhizobium i) uses a T4SS during initiation of symbiosis with Medicago spp., and ii) alters Medicago cells in planta during symbiosis. This study also offers additional bioinformatic evidence that several different rhizobial species may use the T4SS in symbiosis with other legumes.
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Affiliation(s)
| | | | - Michael J Sadowsky
- 1 Biotechnology Institute
- 3 Department of Soil Water & Climate, University of Minnesota, St. Paul, MN, U.S.A
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YopJ Family Effectors Promote Bacterial Infection through a Unique Acetyltransferase Activity. Microbiol Mol Biol Rev 2016; 80:1011-1027. [PMID: 27784797 DOI: 10.1128/mmbr.00032-16] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Gram-negative bacterial pathogens rely on the type III secretion system to inject virulence proteins into host cells. These type III secreted "effector" proteins directly manipulate cellular processes to cause disease. Although the effector repertoires in different bacterial species are highly variable, the Yersinia outer protein J (YopJ) effector family is unique in that its members are produced by diverse animal and plant pathogens as well as a nonpathogenic microsymbiont. All YopJ family effectors share a conserved catalytic triad that is identical to that of the C55 family of cysteine proteases. However, an accumulating body of evidence demonstrates that many YopJ effectors modify their target proteins in hosts by acetylating specific serine, threonine, and/or lysine residues. This unique acetyltransferase activity allows the YopJ family effectors to affect the function and/or stability of their targets, thereby dampening innate immunity. Here, we summarize the current understanding of this prevalent and evolutionarily conserved type III effector family by describing their enzymatic activities and virulence functions in animals and plants. In particular, the molecular mechanisms by which representative YopJ family effectors subvert host immunity through posttranslational modification of their target proteins are discussed.
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Inheritance of Pantoea type III secretion systems through both vertical and horizontal transfer. Mol Genet Genomics 2015; 290:2075-88. [DOI: 10.1007/s00438-015-1062-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Accepted: 05/03/2015] [Indexed: 11/26/2022]
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Tkacz A, Poole P. Role of root microbiota in plant productivity. JOURNAL OF EXPERIMENTAL BOTANY 2015; 66:2167-75. [PMID: 25908654 PMCID: PMC4986727 DOI: 10.1093/jxb/erv157] [Citation(s) in RCA: 96] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Revised: 03/09/2015] [Accepted: 03/12/2015] [Indexed: 05/19/2023]
Abstract
The growing human population requires increasing amounts of food, but modern agriculture has limited possibilities for increasing yields. New crop varieties may be bred to have increased yields and be more resistant to environmental stress and pests. However, they still require fertilization to supplement essential nutrients that are normally limited in the soil. Soil microorganisms present an opportunity to reduce the requirement for inorganic fertilization in agriculture. Microorganisms, due to their enormous genetic pool, are also a potential source of biochemical reactions that recycle essential nutrients for plant growth. Microbes that associate with plants can be considered to be part of the plant's pan-genome. Therefore, it is essential for us to understand microbial community structure and their 'metagenome' and how it is influenced by different soil types and crop varieties. In the future we may be able to modify and better utilize the soil microbiota potential for promoting plant growth.
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Affiliation(s)
- Andrzej Tkacz
- Department of Plant Sciences, University of Oxford, South Parks Road, Oxford OX1 3RB, UK
| | - Philip Poole
- Department of Plant Sciences, University of Oxford, South Parks Road, Oxford OX1 3RB, UK
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Mercante V, Duarte CM, Sánchez CM, Zalguizuri A, Caetano-Anollés G, Lepek VC. The absence of protein Y4yS affects negatively the abundance of T3SS Mesorhizobium loti secretin, RhcC2, in bacterial membranes. FRONTIERS IN PLANT SCIENCE 2015; 6:12. [PMID: 25688250 PMCID: PMC4311626 DOI: 10.3389/fpls.2015.00012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Accepted: 01/06/2015] [Indexed: 06/04/2023]
Abstract
Mesorhizobium loti MAFF303099 has a functional type III secretion system (T3SS) that is involved in the determination of nodulation competitiveness on Lotus. The M. loti T3SS cluster contains gene y4yS (mlr8765) that codes for a protein of unknown function (Y4yS). A mutation in the y4yS gene favors the M. loti symbiotic competitive ability on Lotus tenuis cv. Esmeralda and affects negatively the secretion of proteins through T3SS. Here we localize Y4yS in the bacterial membrane using a translational reporter peptide fusion. In silico analysis indicated that this protein presents a tetratricopeptide repeat (TPR) domain, a signal peptide and a canonical lipobox LGCC in the N-terminal sequence. These features that are shared with proteins required for the formation of the secretin complex in type IV secretion systems and in the Tad system, together with its localization, suggest that the y4yS-encoded protein is required for the formation of the M. loti T3SS secretin (RhcC2) complex. Remarkably, analysis of RhcC2 in the wild-type and M. loti y4yS mutant strains indicated that the absence of Y4yS affects negatively the accumulation of normal levels of RhcC2 in the membrane.
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Affiliation(s)
- Virginia Mercante
- Instituto de Investigaciones Biotecnológicas “Dr. Rodolfo A. Ugalde,” Universidad Nacional de San MartínBuenos Aires, Argentina
| | - Cecilia M. Duarte
- Instituto de Investigaciones Biotecnológicas “Dr. Rodolfo A. Ugalde,” Universidad Nacional de San MartínBuenos Aires, Argentina
| | - Cintia M. Sánchez
- Instituto de Investigaciones Biotecnológicas “Dr. Rodolfo A. Ugalde,” Universidad Nacional de San MartínBuenos Aires, Argentina
| | - Andrés Zalguizuri
- Instituto de Investigaciones Biotecnológicas “Dr. Rodolfo A. Ugalde,” Universidad Nacional de San MartínBuenos Aires, Argentina
| | - Gustavo Caetano-Anollés
- Evolutionary Bioinformatics Laboratory, Department of Crop Sciences, University of IllinoisUrbana-Champaign, USA
| | - Viviana C. Lepek
- Instituto de Investigaciones Biotecnológicas “Dr. Rodolfo A. Ugalde,” Universidad Nacional de San MartínBuenos Aires, Argentina
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Limpens E, van Zeijl A, Geurts R. Lipochitooligosaccharides modulate plant host immunity to enable endosymbioses. ANNUAL REVIEW OF PHYTOPATHOLOGY 2015; 53:311-34. [PMID: 26047562 DOI: 10.1146/annurev-phyto-080614-120149] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Symbiotic nitrogen-fixing rhizobium bacteria and arbuscular mycorrhizal fungi use lipochitooligosaccharide (LCO) signals to communicate with potential host plants. Upon a compatible match, an intimate relation is established during which the microsymbiont is allowed to enter root (-derived) cells. Plants perceive microbial LCO molecules by specific LysM-domain-containing receptor-like kinases. These do not only activate a common symbiosis signaling pathway that is shared in both symbioses but also modulate innate immune responses. Recent studies revealed that symbiotic LCO receptors are closely related to chitin innate immune receptors, and some of these receptors even function in symbiosis as well as immunity. This raises questions about how plants manage to translate structurally very similar microbial signals into different outputs. Here, we describe the current view on chitin and LCO perception in innate immunity and endosymbiosis and question how LCOs might modulate the immune system. Furthermore, we discuss what it takes to become an endosymbiont.
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Affiliation(s)
- Erik Limpens
- Laboratory of Molecular Biology, Department of Plant Science, Wageningen University, 6708PB Wageningen, The Netherlands;
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Saeki K, Ronson CW. Genome Sequence and Gene Functions in Mesorhizobium loti and Relatives. ACTA ACUST UNITED AC 2014. [DOI: 10.1007/978-3-662-44270-8_5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Diepold A, Wagner S. Assembly of the bacterial type III secretion machinery. FEMS Microbiol Rev 2014; 38:802-22. [PMID: 24484471 DOI: 10.1111/1574-6976.12061] [Citation(s) in RCA: 113] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2013] [Revised: 01/02/2014] [Accepted: 01/13/2014] [Indexed: 11/29/2022] Open
Abstract
Many bacteria that live in contact with eukaryotic hosts, whether as symbionts or as pathogens, have evolved mechanisms that manipulate host cell behaviour to their benefit. One such mechanism, the type III secretion system, is employed by Gram-negative bacterial species to inject effector proteins into host cells. This function is reflected by the overall shape of the machinery, which resembles a molecular syringe. Despite the simplicity of the concept, the type III secretion system is one of the most complex known bacterial nanomachines, incorporating one to more than hundred copies of up to twenty different proteins into a multi-MDa transmembrane complex. The structural core of the system is the so-called needle complex that spans the bacterial cell envelope as a tripartite ring system and culminates in a needle protruding from the bacterial cell surface. Substrate targeting and translocation are accomplished by an export machinery consisting of various inner membrane embedded and cytoplasmic components. The formation of such a multimembrane-spanning machinery is an intricate task that requires precise orchestration. This review gives an overview of recent findings on the assembly of type III secretion machines, discusses quality control and recycling of the system and proposes an integrated assembly model.
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Affiliation(s)
- Andreas Diepold
- Department of Biochemistry, University of Oxford, Oxford, UK
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Tampakaki AP. Commonalities and differences of T3SSs in rhizobia and plant pathogenic bacteria. FRONTIERS IN PLANT SCIENCE 2014; 5:114. [PMID: 24723933 PMCID: PMC3973906 DOI: 10.3389/fpls.2014.00114] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Accepted: 03/11/2014] [Indexed: 05/19/2023]
Abstract
Plant pathogenic bacteria and rhizobia infect higher plants albeit the interactions with their hosts are principally distinct and lead to completely different phenotypic outcomes, either pathogenic or mutualistic, respectively. Bacterial protein delivery to plant host plays an essential role in determining the phenotypic outcome of plant-bacteria interactions. The involvement of type III secretion systems (T3SSs) in mediating animal- and plant-pathogen interactions was discovered in the mid-80's and is now recognized as a multiprotein nanomachine dedicated to trans-kingdom movement of effector proteins. The discovery of T3SS in bacteria with symbiotic lifestyles broadened its role beyond virulence. In most T3SS-positive bacterial pathogens, virulence is largely dependent on functional T3SSs, while in rhizobia the system is dispensable for nodulation and can affect positively or negatively the mutualistic associations with their hosts. This review focuses on recent comparative genome analyses in plant pathogens and rhizobia that uncovered similarities and variations among T3SSs in their genetic organization, regulatory networks and type III secreted proteins and discusses the evolutionary adaptations of T3SSs and type III secreted proteins that might account for the distinguishable phenotypes and host range characteristics of plant pathogens and symbionts.
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Affiliation(s)
- Anastasia P. Tampakaki
- *Correspondence: Anastasia P. Tampakaki, Laboratory of General and Agricultural Microbiology, Department of Crop Science, Agricultural University of Athens, Iera Odos 75, Votanikos, 11855, Athens, Greece e-mail:
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Phylogenetic evidence of the transfer of nodZ and nolL genes from Bradyrhizobium to other rhizobia. Mol Phylogenet Evol 2013; 67:626-30. [DOI: 10.1016/j.ympev.2013.03.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Revised: 02/27/2013] [Accepted: 03/04/2013] [Indexed: 11/18/2022]
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Kimbrel JA, Thomas WJ, Jiang Y, Creason AL, Thireault CA, Sachs JL, Chang JH. Mutualistic co-evolution of type III effector genes in Sinorhizobium fredii and Bradyrhizobium japonicum. PLoS Pathog 2013; 9:e1003204. [PMID: 23468637 PMCID: PMC3585131 DOI: 10.1371/journal.ppat.1003204] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2012] [Accepted: 01/08/2013] [Indexed: 12/16/2022] Open
Abstract
Two diametric paradigms have been proposed to model the molecular co-evolution of microbial mutualists and their eukaryotic hosts. In one, mutualist and host exhibit an antagonistic arms race and each partner evolves rapidly to maximize their own fitness from the interaction at potential expense of the other. In the opposing model, conflicts between mutualist and host are largely resolved and the interaction is characterized by evolutionary stasis. We tested these opposing frameworks in two lineages of mutualistic rhizobia, Sinorhizobium fredii and Bradyrhizobium japonicum. To examine genes demonstrably important for host-interactions we coupled the mining of genome sequences to a comprehensive functional screen for type III effector genes, which are necessary for many Gram-negative pathogens to infect their hosts. We demonstrate that the rhizobial type III effector genes exhibit a surprisingly high degree of conservation in content and sequence that is in contrast to those of a well characterized plant pathogenic species. This type III effector gene conservation is particularly striking in the context of the relatively high genome-wide diversity of rhizobia. The evolution of rhizobial type III effectors is inconsistent with the molecular arms race paradigm. Instead, our results reveal that these loci are relatively static in rhizobial lineages and suggest that fitness conflicts between rhizobia mutualists and their host plants have been largely resolved.
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Affiliation(s)
- Jeffrey A. Kimbrel
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon, United States of America
- Molecular and Cellular Biology Program, Oregon State University, Corvallis, Oregon, United States of America
| | - William J. Thomas
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon, United States of America
- Molecular and Cellular Biology Program, Oregon State University, Corvallis, Oregon, United States of America
| | - Yuan Jiang
- Department of Statistics, Oregon State University, Corvallis, Oregon, United States of America
- Center for Genome Research and Biocomputing, Oregon State University, Corvallis, Oregon, United States of America
| | - Allison L. Creason
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon, United States of America
- Molecular and Cellular Biology Program, Oregon State University, Corvallis, Oregon, United States of America
| | - Caitlin A. Thireault
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon, United States of America
| | - Joel L. Sachs
- Department of Biology, University of California-Riverside, Riverside, California, United States of America
| | - Jeff H. Chang
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon, United States of America
- Molecular and Cellular Biology Program, Oregon State University, Corvallis, Oregon, United States of America
- Center for Genome Research and Biocomputing, Oregon State University, Corvallis, Oregon, United States of America
- * E-mail:
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Abby SS, Rocha EPC. The non-flagellar type III secretion system evolved from the bacterial flagellum and diversified into host-cell adapted systems. PLoS Genet 2012; 8:e1002983. [PMID: 23028376 PMCID: PMC3459982 DOI: 10.1371/journal.pgen.1002983] [Citation(s) in RCA: 200] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2012] [Accepted: 08/09/2012] [Indexed: 12/20/2022] Open
Abstract
Type 3 secretion systems (T3SSs) are essential components of two complex bacterial machineries: the flagellum, which drives cell motility, and the non-flagellar T3SS (NF-T3SS), which delivers effectors into eukaryotic cells. Yet the origin, specialization, and diversification of these machineries remained unclear. We developed computational tools to identify homologous components of the two systems and to discriminate between them. Our analysis of >1,000 genomes identified 921 T3SSs, including 222 NF-T3SSs. Phylogenomic and comparative analyses of these systems argue that the NF-T3SS arose from an exaptation of the flagellum, i.e. the recruitment of part of the flagellum structure for the evolution of the new protein delivery function. This reconstructed chronology of the exaptation process proceeded in at least two steps. An intermediate ancestral form of NF-T3SS, whose descendants still exist in Myxococcales, lacked elements that are essential for motility and included a subset of NF-T3SS features. We argue that this ancestral version was involved in protein translocation. A second major step in the evolution of NF-T3SSs occurred via recruitment of secretins to the NF-T3SS, an event that occurred at least three times from different systems. In rhizobiales, a partial homologous gene replacement of the secretin resulted in two genes of complementary function. Acquisition of a secretin was followed by the rapid adaptation of the resulting NF-T3SSs to multiple, distinct eukaryotic cell envelopes where they became key in parasitic and mutualistic associations between prokaryotes and eukaryotes. Our work elucidates major steps of the evolutionary scenario leading to extant NF-T3SSs. It demonstrates how molecular evolution can convert one complex molecular machine into a second, equally complex machine by successive deletions, innovations, and recruitment from other molecular systems.
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Affiliation(s)
- Sophie S Abby
- Département Génomes et Génétique, Institut Pasteur, Microbial Evolutionary Genomics, Paris, France.
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Gazi AD, Sarris PF, Fadouloglou VE, Charova SN, Mathioudakis N, Panopoulos NJ, Kokkinidis M. Phylogenetic analysis of a gene cluster encoding an additional, rhizobial-like type III secretion system that is narrowly distributed among Pseudomonas syringae strains. BMC Microbiol 2012; 12:188. [PMID: 22937899 PMCID: PMC3574062 DOI: 10.1186/1471-2180-12-188] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2012] [Accepted: 08/21/2012] [Indexed: 11/30/2022] Open
Abstract
Background The central role of Type III secretion systems (T3SS) in bacteria-plant interactions is well established, yet unexpected findings are being uncovered through bacterial genome sequencing. Some Pseudomonas syringae strains possess an uncharacterized cluster of genes encoding putative components of a second T3SS (T3SS-2) in addition to the well characterized Hrc1 T3SS which is associated with disease lesions in host plants and with the triggering of hypersensitive response in non-host plants. The aim of this study is to perform an in silico analysis of T3SS-2, and to compare it with other known T3SSs. Results Based on phylogenetic analysis and gene organization comparisons, the T3SS-2 cluster of the P. syringae pv. phaseolicola strain is grouped with a second T3SS found in the pNGR234b plasmid of Rhizobium sp. These additional T3SS gene clusters define a subgroup within the Rhizobium T3SS family. Although, T3SS-2 is not distributed as widely as the Hrc1 T3SS in P. syringae strains, it was found to be constitutively expressed in P. syringae pv phaseolicola through RT-PCR experiments. Conclusions The relatedness of the P. syringae T3SS-2 to a second T3SS from the pNGR234b plasmid of Rhizobium sp., member of subgroup II of the rhizobial T3SS family, indicates common ancestry and/or possible horizontal transfer events between these species. Functional analysis and genome sequencing of more rhizobia and P. syringae pathovars may shed light into why these bacteria maintain a second T3SS gene cluster in their genome.
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Affiliation(s)
- Anastasia D Gazi
- Department of Biology, University of Crete, Vasilika Vouton, P,O, Box 2208, Heraklion, Crete GR 71409, Greece
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López-Guerrero MG, Ormeño-Orrillo E, Acosta JL, Mendoza-Vargas A, Rogel MA, Ramírez MA, Rosenblueth M, Martínez-Romero J, Martínez-Romero E. Rhizobial extrachromosomal replicon variability, stability and expression in natural niches. Plasmid 2012; 68:149-58. [PMID: 22813963 DOI: 10.1016/j.plasmid.2012.07.002] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Revised: 06/28/2012] [Accepted: 07/06/2012] [Indexed: 12/25/2022]
Abstract
In bacteria, niche adaptation may be determined by mobile extrachromosomal elements. A remarkable characteristic of Rhizobium and Ensifer (Sinorhizobium) but also of Agrobacterium species is that almost half of the genome is contained in several large extrachromosomal replicons (ERs). They encode a plethora of functions, some of them required for bacterial survival, niche adaptation, plasmid transfer or stability. In spite of this, plasmid loss is common in rhizobia upon subculturing. Rhizobial gene-expression studies in plant rhizospheres with novel results from transcriptomic analysis of Rhizobium phaseoli in maize and Phaseolus vulgaris roots highlight the role of ERs in natural niches and allowed the identification of common extrachromosomal genes expressed in association with plant rootlets and the replicons involved.
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Schmidt MA, Balsanelli E, Faoro H, Cruz LM, Wassem R, de Baura VA, Weiss V, Yates MG, Madeira HMF, Pereira-Ferrari L, Fungaro MHP, de Paula FM, Pereira LFP, Vieira LGE, Olivares FL, Pedrosa FO, de Souza EM, Monteiro RA. The type III secretion system is necessary for the development of a pathogenic and endophytic interaction between Herbaspirillum rubrisubalbicans and Poaceae. BMC Microbiol 2012; 12:98. [PMID: 22672506 PMCID: PMC3487950 DOI: 10.1186/1471-2180-12-98] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Accepted: 04/24/2012] [Indexed: 11/17/2022] Open
Abstract
Background Herbaspirillum rubrisubalbicans was first identified as a bacterial plant pathogen, causing the mottled stripe disease in sugarcane. H. rubrisubalbicans can also associate with various plants of economic interest in a non pathogenic manner. Results A 21 kb DNA region of the H. rubrisubalbicans genome contains a cluster of 26 hrp/hrc genes encoding for the type three secretion system (T3SS) proteins. To investigate the contribution of T3SS to the plant-bacterial interaction process we generated mutant strains of H. rubrisubalbicans M1 carrying a Tn5 insertion in both the hrcN and hrpE genes. H. rubrisulbalbicans hrpE and hrcN mutant strains of the T3SS system failed to cause the mottled stripe disease in the sugarcane susceptible variety B-4362. These mutant strains also did not produce lesions on Vigna unguiculata leaves. Oryza sativa and Zea mays colonization experiments showed that mutations in hrpE and hrcN genes reduced the capacity of H. rubrisulbalbicans to colonize these plants, suggesting that hrpE and hrcN genes are involved in the endophytic colonization. Conclusions Our results indicate that the T3SS of H. rubrisubalbicans is necessary for the development of the mottled stripe disease and endophytic colonization of rice.
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Affiliation(s)
- Maria Augusta Schmidt
- Department of Biochemistry and Molecular Biology, Universidade Federal do Paraná, Curitiba, Brazil
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T3DB: an integrated database for bacterial type III secretion system. BMC Bioinformatics 2012; 13:66. [PMID: 22545727 PMCID: PMC3424820 DOI: 10.1186/1471-2105-13-66] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2011] [Accepted: 04/30/2012] [Indexed: 01/04/2023] Open
Abstract
Background Type III Secretion System (T3SS), which plays important roles in pathogenesis or symbiosis, is widely expressed in a variety of gram negative bacteria. However, lack of unique nomenclature for T3SS genes has hindered T3SS related research. It is necessary to set up a knowledgebase integrating T3SS-related research data to facilitate the communication between different research groups interested in different bacteria. Description A T3SS-related Database (T3DB) was developed. T3DB serves as an integrated platform for sequence collection, function annotation, and ortholog classification for T3SS related apparatus, effector, chaperone and regulatory genes. The collection of T3SS-containing bacteria, T3SS-related genes, function annotation, and the ortholog information were all manually curated from literature. BPBAac, a highly efficient T3SS effector prediction tool, was also implemented. Conclusions T3DB is the first systematic platform integrating well-annotated T3SS-related gene and protein information to facilitate T3SS and bacterial pathogenecity related research. The newly constructed T3 ortholog clusters may faciliate effective communication between different research groups and will promote de novo discoveries. Besides, the manually-curated high-quality effector and chaperone data are useful for feature analysis and evolutionary studies of these important proteins.
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Draft genome sequence of plant growth-promoting rhizobium Mesorhizobium amorphae, isolated from zinc-lead mine tailings. J Bacteriol 2012; 194:736-7. [PMID: 22247533 DOI: 10.1128/jb.06475-11] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Here, we describe the draft genome sequence of Mesorhizobium amorphae strain CCNWGS0123, isolated from nodules of Robinia pseudoacacia growing on zinc-lead mine tailings. A large number of metal(loid) resistance genes, as well as genes reported to promote plant growth, were identified, presenting a great future potential for aiding phytoremediation in metal(loid)-contaminated soil.
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Fotiadis CT, Dimou M, Georgakopoulos DG, Katinakis P, Tampakaki AP. Functional characterization of NopT1 and NopT2, two type III effectors of Bradyrhizobium japonicum. FEMS Microbiol Lett 2012; 327:66-77. [PMID: 22112296 DOI: 10.1111/j.1574-6968.2011.02466.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2011] [Revised: 11/08/2011] [Accepted: 11/15/2011] [Indexed: 12/16/2023] Open
Abstract
NopT1 and NopT2, putative type III effectors from the plant symbiotic bacterium Bradyrhizobium japonicum, are predicted to belong to a family of YopT/AvrPphB effectors, which are cysteine proteases. In the present study, we showed that both NopT1 and NopT2 indeed possess cysteine protease activity. When overexpressed in Escherichia coli, both NopT1 and NopT2 undergo autoproteolytic processing which is largely abolished in the presence of E-64, a papain family-specific inhibitor. Mutations of NopT1 disrupting either the catalytic triad or the putative autoproteolytic site reduce or markedly abolish the protease activity. Autocleavage likely occurs between residues K48 and M49, though another potential cleavage site is also possible. NopT1 also elicitis HR-like cell death when transiently expressed in tobacco plants and its cysteine protease activity is essential for this ability. In contrast, no macroscopic symptoms were observed for NopT2. Furthermore, mutational analysis provided evidence that NopT1 may undergo acylation inside plant cells and that this would be required for its capacity to elicit HR-like cell death in tobacco.
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Affiliation(s)
- Christos T Fotiadis
- Laboratory of General and Agricultural Microbiology, Department of Agricultural Biotechnology, Agricultural University of Athens, Athens, Greece
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Zamioudis C, Pieterse CMJ. Modulation of host immunity by beneficial microbes. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2012; 25:139-50. [PMID: 21995763 DOI: 10.1094/mpmi-06-11-0179] [Citation(s) in RCA: 400] [Impact Index Per Article: 33.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
In nature, plants abundantly form beneficial associations with soilborne microbes that are important for plant survival and, as such, affect plant biodiversity and ecosystem functioning. Classical examples of symbiotic microbes are mycorrhizal fungi that aid in the uptake of water and minerals, and Rhizobium bacteria that fix atmospheric nitrogen for the plant. Several other types of beneficial soilborne microbes, such as plant-growth-promoting rhizobacteria and fungi with biological control activity, can stimulate plant growth by directly suppressing deleterious soilborne pathogens or by priming aboveground plant parts for enhanced defense against foliar pathogens or insect herbivores. The establishment of beneficial associations requires mutual recognition and substantial coordination of plant and microbial responses. A growing body of evidence suggests that beneficial microbes are initially recognized as potential invaders, after which an immune response is triggered, whereas, at later stages of the interaction, mutualists are able to short-circuit plant defense responses to enable successful colonization of host roots. Here, we review our current understanding of how symbiotic and nonsymbiotic beneficial soil microbes modulate the plant immune system and discuss the role of local and systemic defense responses in establishing the delicate balance between the two partners.
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Lewis JD, Lee A, Ma W, Zhou H, Guttman DS, Desveaux D. The YopJ superfamily in plant-associated bacteria. MOLECULAR PLANT PATHOLOGY 2011; 12:928-37. [PMID: 21726386 PMCID: PMC6640427 DOI: 10.1111/j.1364-3703.2011.00719.x] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Bacterial pathogens employ the type III secretion system to secrete and translocate effector proteins into their hosts. The primary function of these effector proteins is believed to be the suppression of host defence responses or innate immunity. However, some effector proteins may be recognized by the host and consequently trigger a targeted immune response. The YopJ/HopZ/AvrRxv family of bacterial effector proteins is a widely distributed and evolutionarily diverse family, found in both animal and plant pathogens, as well as plant symbionts. How can an effector family effectively promote the virulence of pathogens on hosts from two separate kingdoms? Our understanding of the evolutionary relationships among the YopJ superfamily members provides an excellent opportunity to address this question and to investigate the functions and virulence strategies of a diverse type III effector family in animal and plant hosts. In this work, we briefly review the literature on YopJ, the archetypal member from Yersinia pestis, and discuss members of the superfamily in species of Pseudomonas, Xanthomonas, Ralstonia and Rhizobium. We review the molecular and cellular functions, if known, of the YopJ homologues in plants, and highlight the diversity of responses in different plant species, with a particular focus on the Pseudomonas syringae HopZ family. The YopJ superfamily provides an excellent foundation for the study of effector diversification in the context of wide-ranging, co-evolutionary interactions.
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Affiliation(s)
- Jennifer D Lewis
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
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Zhao B, Dahlbeck D, Krasileva KV, Fong RW, Staskawicz BJ. Computational and biochemical analysis of the Xanthomonas effector AvrBs2 and its role in the modulation of Xanthomonas type three effector delivery. PLoS Pathog 2011; 7:e1002408. [PMID: 22144898 PMCID: PMC3228805 DOI: 10.1371/journal.ppat.1002408] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2011] [Accepted: 10/14/2011] [Indexed: 01/06/2023] Open
Abstract
Effectors of the bacterial type III secretion system provide invaluable molecular probes to elucidate the molecular mechanisms of plant immunity and pathogen virulence. In this report, we focus on the AvrBs2 effector protein from the bacterial pathogen Xanthomonas euvesicatoria (Xe), the causal agent of bacterial spot disease of tomato and pepper. Employing homology-based structural analysis, we generate a three-dimensional structural model for the AvrBs2 protein and identify catalytic sites in its putative glycerolphosphodiesterase domain (GDE). We demonstrate that the identified catalytic region of AvrBs2 was able to functionally replace the GDE catalytic site of the bacterial glycerophosphodiesterase BhGlpQ cloned from Borrelia hermsii and is required for AvrBs2 virulence. Mutations in the GDE catalytic domain did not disrupt the recognition of AvrBs2 by the cognate plant resistance gene Bs2. In addition, AvrBs2 activation of Bs2 suppressed subsequent delivery of other Xanthomonas type III effectors into the host plant cells. Investigation of the mechanism underlying this modulation of the type III secretion system may offer new strategies to generate broad-spectrum resistance to bacterial pathogens. The bacterial pathogen Xanthomonas euvesicatoria (Xe) is the causal agent of bacterial leaf spot disease of pepper and tomato. This pathogen is capable of delivering more than 28 effector proteins to plant cells via the type three secretion and translocation system (TTSS). The AvrBs2 protein is a TTSS effector of Xe with a significant virulence contribution that depends on a conserved glycerolphosphodiesterase (GDE) domain. Additionally, activation of the resistance protein Bs2 by AvrBs2 modulates the TTSS of Xe and suppresses the subsequent delivery of TTSS effectors.
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Affiliation(s)
- Bingyu Zhao
- Department of Plant and Microbial Biology, University of California, Berkeley, California, United States of America
- Department of Horticulture, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America
| | - Douglas Dahlbeck
- Department of Plant and Microbial Biology, University of California, Berkeley, California, United States of America
| | - Ksenia V. Krasileva
- Department of Plant and Microbial Biology, University of California, Berkeley, California, United States of America
| | - Richard W. Fong
- Department of Plant and Microbial Biology, University of California, Berkeley, California, United States of America
| | - Brian J. Staskawicz
- Department of Plant and Microbial Biology, University of California, Berkeley, California, United States of America
- * E-mail:
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Margaret I, Becker A, Blom J, Bonilla I, Goesmann A, Göttfert M, Lloret J, Mittard-Runte V, Rückert C, Ruiz-Sainz JE, Vinardell JM, Weidner S. Symbiotic properties and first analyses of the genomic sequence of the fast growing model strain Sinorhizobium fredii HH103 nodulating soybean. J Biotechnol 2011; 155:11-9. [PMID: 21458507 DOI: 10.1016/j.jbiotec.2011.03.016] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2010] [Revised: 03/11/2011] [Accepted: 03/22/2011] [Indexed: 10/18/2022]
Abstract
Glycine max (soybean) plants can be nodulated by fast-growing rhizobial strains of the genus Sinorhizobium as well as by slow-growing strains clustered in the genus Bradyrhizobium. Fast-growing rhizobia strains with different soybean cultivar specificities have been isolated from Chinese soils and from other geographical regions. Most of these strains have been clustered into the species Sinorhizobium fredii. The S. fredii strain HH103 was isolated from soils of Hubei province, Central China and was first described in 1985. This strain is capable to nodulate American and Asiatic soybean cultivars and many other different legumes and is so far the best studied fast-growing soybean-nodulating strain. Additionally to the chromosome S. fredii HH103 carries five indigenous plasmids. The largest plasmid (pSfrHH103e) harbours genes for the production of diverse surface polysaccharides, such as exopolysaccharides (EPS), lipopolysaccharides (LPS), and capsular polysaccharides (KPS). The second largest plasmid (pSfrHH103d) is a typical symbiotic plasmid (pSym), carrying nodulation and nitrogen fixation genes. The present mini review focuses on symbiotic properties of S. fredii HH103, in particular on nodulation and surface polysaccharides aspects. The model strain S. fredii HH103 was chosen for genomic sequencing, which is currently in progress. First analyses of the draft genome sequence revealed an extensive synteny between the chromosomes of S. fredii HH103 and Rhizobium sp. NGR234.
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Affiliation(s)
- Isabel Margaret
- Departamento de Microbiología, Universidad de Sevilla, Sevilla, Spain
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Rosenblueth M, Martinez-Romero JC, Reyes-Prieto M, Rogel MA, Martinez-Romero E. Environmental mycobacteria: a threat to human health? DNA Cell Biol 2011; 30:633-40. [PMID: 21595554 DOI: 10.1089/dna.2011.1231] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
In many cases, bacterial pathogens are close relatives to nonpathogens. Pathogens seem to be limited lineages within nonpathogenic bacteria. Nonpathogenic isolates are generally more diverse and widespread in the environment and it is generally considered that environmental bacteria do not pose a risk to human health as clinical isolates do; this may not be the case with mycobacteria, but environmental mycobacteria have not been well studied. It is documented that several environmental mycobacteria constitute a source for human infections. Diverse mycobacterial environmental isolates are rarely involved in human disease. Environmental mycobacteria may have a role in degradation of different compounds. Environmental mycobacteria have had a long interaction with humans, maybe as long as the human species, and may have contributed to human evolution.
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Affiliation(s)
- Mónica Rosenblueth
- Centro de Ciencias Genomicas, Universidad Nacional Autonoma de Mexico, Cuernavaca, Morelos, Mexico
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Saeki K. Rhizobial measures to evade host defense strategies and endogenous threats to persistent symbiotic nitrogen fixation: a focus on two legume-rhizobium model systems. Cell Mol Life Sci 2011; 68:1327-39. [PMID: 21365276 PMCID: PMC11114668 DOI: 10.1007/s00018-011-0650-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2011] [Revised: 02/15/2011] [Accepted: 02/15/2011] [Indexed: 10/18/2022]
Abstract
The establishment and maintenance of rhizobium-legume symbioses require a sequence of highly regulated and coordinated events between the organisms. Although the interaction is mutually beneficial under nitrogen-limited conditions, it can resemble a pathogenic infection at some stages. Some host legumes mount defense reactions, including the production of reactive oxygen species (ROS) and defensin-like antimicrobial compounds. To subvert these host defenses, the infecting rhizobial cells can use measures to passively protect themselves and actively modulate host functions. This review first describes the establishment and maintenance of active nodules, as well as the external and endogenous attack and threat stages. Next, recent studies of ROS scavenging enzymes, the BacA protein originally found in Sinorhizobium meliloti, and the type III/IV secretion systems are discussed, with a focus on two legume-rhizobium model systems.
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Affiliation(s)
- Kazuhiko Saeki
- Department of Biological Sciences, Faculty of Science, Nara Women's University, Kitauoya Nishimachi, Nara, Japan.
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