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Laranjeira SS, Alves IG, Marques G. Chickpea (Cicer arietinum L.) Seeds as a Reservoir of Endophytic Plant Growth-Promoting Bacteria. Curr Microbiol 2022; 79:277. [PMID: 35907956 DOI: 10.1007/s00284-022-02942-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 06/17/2022] [Indexed: 11/30/2022]
Abstract
The seed microbiome, the primary source of inoculum for plants, may play an important role in plant growth, health and productivity. However, the structure and function of chickpea seed endophytes are poorly characterized. Bacteria with beneficial characteristics can be selected by the plant and transmitted vertically via the seed to benefit the next generation. Studying the diversity and multifunctionality of seed microbial communities can provide innovative opportunities in the field of plant-microbe interaction. This study aimed to isolate, identify and characterize culturable endophytic bacteria from chickpea (Cicer arietinum L.) seeds. Phylogenetic analysis based on 16S rDNA showed that the endophytic bacteria belong to the genera Mesorhizobium, Burkholderia, Bacillus, Priestia, Paenibacillus, Alcaligenes, Acinetobacter, Rahnella, Enterobacter, Tsukamurella, and Microbacterium. The most frequently observed genus was Bacillus; however, rhizobia typically associated with chickpea roots were also found, which is a novel finding of this study. Siderophore production and phosphorus solubilization were the most widespread plant growth-promoting features, while hydrogen cyanide production was relatively rare among the isolates. Most of the isolates possess two or more plant growth-promoting features; however, only Bacillus thuringiensis Y2B, a well-known entomopathogenic bacteria, exhibited the presence of all plant growth-promoting traits evaluated. Results suggest that endophytic bacteria such as Bacillus, Mesorhizobium, and Burkholderia may be vertically transferred from inoculated plants to seeds to benefit the next generation.
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Affiliation(s)
- Sara S Laranjeira
- Centre for Research and Technology of Agro-Environmental and Biological Sciences, CITAB, University of Trás-os-Montes e Alto Douro, UTAD, Quinta de Prados, 5000-801, Vila Real, Portugal
| | - Isabel G Alves
- Centre for Research and Technology of Agro-Environmental and Biological Sciences, CITAB, University of Trás-os-Montes e Alto Douro, UTAD, Quinta de Prados, 5000-801, Vila Real, Portugal
| | - Guilhermina Marques
- Centre for Research and Technology of Agro-Environmental and Biological Sciences, CITAB, University of Trás-os-Montes e Alto Douro, UTAD, Quinta de Prados, 5000-801, Vila Real, Portugal.
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Hitching a Ride: Examining the Ability of a Specialist Baculovirus to Translocate through Its Insect Host's Food Plant. Pathogens 2021; 10:pathogens10111500. [PMID: 34832655 PMCID: PMC8624388 DOI: 10.3390/pathogens10111500] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 11/13/2021] [Accepted: 11/15/2021] [Indexed: 11/22/2022] Open
Abstract
Plant vascular systems can translocate the entomopathogen Bacillus thuringiensis from the soil into plant tissues. However, whether other soil dwelling entomopathogens utilize plant vascular tissue for movement has not yet been fully explored. We used Spodoptera frugiperda multiple nucleopolyhedrovirus (SfMNPV) to evaluate whether baculoviruses, a common entomopathogen and bioinsecticide, can be transported through the plant vascular pathways of Zea mays. We found that our treatments did not allow a sufficient virus translocation into the plant to induce a lethal infection in insects, which was confirmed by a molecular analysis. While other entomopathogens translocate, baculoviruses may not be one of them.
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García-Suárez R, Verduzco-Rosas LA, Ibarra JE. Isolation and characterization of two highly insecticidal, endophytic strains of Bacillus thuringiensis. FEMS Microbiol Ecol 2021; 97:fiab080. [PMID: 34117749 DOI: 10.1093/femsec/fiab080] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 06/10/2021] [Indexed: 11/14/2022] Open
Abstract
Recent discovery of endophytic strains of Bacillus thuringiensis significantly improves the knowledge on its ecology. It also may be a new source for the isolation of insecticidal strains. This report shows the characterization of two endophytic, highly insecticidal strains of B. thuringiensis. Strains LBIT-1250L and LBIT-1251P were isolated from lavender and Poinsettia sap, respectively. Their parasporal crystals were very similar in morphology to those shown by serotypes israelensis and kurstaki, respectively. Bioassays on Aedes aegypti fourth instar larvae and on Manduca sexta first instar larvae, respectively, showed significantly higher levels of toxicity than those of their standard counterparts, IPS-82 (israelensis) and HD-1 (kurstaki) strains, respectively. Characterization of both strains included the sequencing of flagellin (hag) gene, plasmid and Bc Rep-PCR patterns and crystal protein content. All four characterization features indicated that LBIT1250L is highly related to the IPS-82 standard (serotype H-14: israelensis); while the LBIT-1251P was highly related to the HD-1 standard (serotype H-3a3b3c kurstaki). These results indicate that endophytic strains of B. thuringiensis may be a new source of potential insecticidal strains and opens more in-depth studies about the role of this bacterium in such a specialized habitat.
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Affiliation(s)
- Rosalina García-Suárez
- Departamento de Biotecnología y Bioquímica, Centro de Investigación y de Estudios Avanzados del IPN, Apartado postal 629, 36500 Irapuato, Gto., Mexico
| | - Luis A Verduzco-Rosas
- Departamento de Biotecnología y Bioquímica, Centro de Investigación y de Estudios Avanzados del IPN, Apartado postal 629, 36500 Irapuato, Gto., Mexico
| | - Jorge E Ibarra
- Departamento de Biotecnología y Bioquímica, Centro de Investigación y de Estudios Avanzados del IPN, Apartado postal 629, 36500 Irapuato, Gto., Mexico
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Belousova ME, Malovichko YV, Shikov AE, Nizhnikov AA, Antonets KS. Dissecting the Environmental Consequences of Bacillus thuringiensis Application for Natural Ecosystems. Toxins (Basel) 2021; 13:toxins13050355. [PMID: 34065665 PMCID: PMC8155924 DOI: 10.3390/toxins13050355] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Revised: 05/10/2021] [Accepted: 05/13/2021] [Indexed: 12/30/2022] Open
Abstract
Bacillus thuringiensis (Bt), a natural pathogen of different invertebrates, primarily insects, is widely used as a biological control agent. While Bt-based preparations are claimed to be safe for non-target organisms due to the immense host specificity of the bacterium, the growing evidence witnesses the distant consequences of their application for natural communities. For instance, upon introduction to soil habitats, Bt strains can affect indigenous microorganisms, such as bacteria and fungi, and further establish complex relationships with local plants, ranging from a mostly beneficial demeanor, to pathogenesis-like plant colonization. By exerting a direct effect on target insects, Bt can indirectly affect other organisms in the food chain. Furthermore, they can also exert an off-target activity on various soil and terrestrial invertebrates, and the frequent acquisition of virulence factors unrelated to major insecticidal toxins can extend the Bt host range to vertebrates, including humans. Even in the absence of direct detrimental effects, the exposure to Bt treatment may affect non-target organisms by reducing prey base and its nutritional value, resulting in delayed alleviation of their viability. The immense phenotypic plasticity of Bt strains, coupled with the complexity of ecological relationships they can engage in, indicates that further assessment of future Bt-based pesticides' safety should consider multiple levels of ecosystem organization and extend to a wide variety of their inhabitants.
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Affiliation(s)
- Maria E. Belousova
- Laboratory for Proteomics of Supra-Organismal Systems, All-Russia Research Institute for Agricultural Microbiology (ARRIAM), 196608 St. Petersburg, Russia; (M.E.B.); (Y.V.M.); (A.E.S.); (A.A.N.)
| | - Yury V. Malovichko
- Laboratory for Proteomics of Supra-Organismal Systems, All-Russia Research Institute for Agricultural Microbiology (ARRIAM), 196608 St. Petersburg, Russia; (M.E.B.); (Y.V.M.); (A.E.S.); (A.A.N.)
- Faculty of Biology, St. Petersburg State University, 199034 St. Petersburg, Russia
| | - Anton E. Shikov
- Laboratory for Proteomics of Supra-Organismal Systems, All-Russia Research Institute for Agricultural Microbiology (ARRIAM), 196608 St. Petersburg, Russia; (M.E.B.); (Y.V.M.); (A.E.S.); (A.A.N.)
- Faculty of Biology, St. Petersburg State University, 199034 St. Petersburg, Russia
| | - Anton A. Nizhnikov
- Laboratory for Proteomics of Supra-Organismal Systems, All-Russia Research Institute for Agricultural Microbiology (ARRIAM), 196608 St. Petersburg, Russia; (M.E.B.); (Y.V.M.); (A.E.S.); (A.A.N.)
- Faculty of Biology, St. Petersburg State University, 199034 St. Petersburg, Russia
| | - Kirill S. Antonets
- Laboratory for Proteomics of Supra-Organismal Systems, All-Russia Research Institute for Agricultural Microbiology (ARRIAM), 196608 St. Petersburg, Russia; (M.E.B.); (Y.V.M.); (A.E.S.); (A.A.N.)
- Faculty of Biology, St. Petersburg State University, 199034 St. Petersburg, Russia
- Correspondence:
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Verduzco-Rosas LA, García-Suárez R, López-Tlacomulco JJ, Ibarra JE. Selection and characterization of two Bacillus thuringiensis strains showing nematicidal activity against Caenorhabditis elegans and Meloidogyne incognita. FEMS Microbiol Lett 2021; 368:6171021. [PMID: 33720297 DOI: 10.1093/femsle/fnaa186] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 03/12/2021] [Indexed: 12/26/2022] Open
Abstract
Bacillus thuringiensis has been widely used as a biological control agent against insect pests. Additionally, nematicidal strains have been under investigation. In this report, 310 native strains of B. thuringiensis against Caenorhabditis elegans were tested. Only the LBIT-596 and LBIT-107 strains showed significant mortality. LC50s of spore-crystal complexes were estimated at 37.18 and 31.89 μg/mL for LBIT-596 and LBIT-107 strains, respectively, while LC50s of partially purified crystals was estimated at 23.76 and 20.25 μg/mL for LBIT-596 and LBIT-107, respectively. The flagellin gene sequence and plasmid patterns indicated that LBIT-596 and LBIT-107 are not related to each other. Sequences from internal regions of a cry5B and a cyt1A genes were found in the LBIT-596 strain, while a cry21A, a cry14A and a cyt1A genes were found in the LBIT-107 strain. Genome sequence of the LBIT-107 strain showed new cry genes, along with other virulence factors, hence, total nematicidal activity of the LBIT-107 strain may be the result of a multifactorial effect. The highlight of this contribution is that translocation of spore-crystal suspensions of LBIT-107 into tomato plants inoculated at their rhizosphere decreased up to 90% the number of galls of Meloidogyne incognita, perhaps the most important nematode pest in the world.
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Affiliation(s)
- Luis A Verduzco-Rosas
- Departamento de Biotecnología y Bioquímica, Centro de Investigación y de Estudios Avanzados del IPN, Apartado postal 629, 36500 Irapuato, Gto. Mexico
| | - Rosalina García-Suárez
- Departamento de Biotecnología y Bioquímica, Centro de Investigación y de Estudios Avanzados del IPN, Apartado postal 629, 36500 Irapuato, Gto. Mexico
| | - José J López-Tlacomulco
- Departamento de Biotecnología y Bioquímica, Centro de Investigación y de Estudios Avanzados del IPN, Apartado postal 629, 36500 Irapuato, Gto. Mexico
| | - Jorge E Ibarra
- Departamento de Biotecnología y Bioquímica, Centro de Investigación y de Estudios Avanzados del IPN, Apartado postal 629, 36500 Irapuato, Gto. Mexico
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Dorta SDO, Balbinotte J, Monnerat R, Lopes JRS, da Cunha T, Zanardi OZ, de Miranda MP, Machado MA, de Freitas-Astúa J. Selection of Bacillus thuringiensis strains in citrus and their pathogenicity to Diaphorina citri (Hemiptera: Liviidae) nymphs. INSECT SCIENCE 2020; 27:519-530. [PMID: 30548193 DOI: 10.1111/1744-7917.12654] [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: 10/03/2018] [Revised: 11/16/2018] [Accepted: 11/26/2018] [Indexed: 05/24/2023]
Abstract
Bacillus thuringiensis (Bt) toxins are effective in controlling insect pests either through the spraying of products or when expressed in transgenic crops. The discovery of endophytic Bt strains opened new perspectives for studies aimed at the control of sap-sucking insects, such as the Asian citrus psyllid Diaphorina citri Kuwayama (Hemiptera: Liviidae), a vector of "Candidatus Liberibacter spp.," associated with citrus huanglongbing (HLB). In this study, translocation of endophytic Bt strains in citrus seedlings inoculated with Bt suspension delivered by soil-drench, and their systemic pathogenicity to D. citri nymphs were investigated. The pathogenicity of three wild-type Bt strains against D. citri third-instar nymphs was demonstrated. Among the 10 recombinant strains tested (each of them harboring a single cry or cyt gene), 3 can be highlighted, causing 42%-77% and 66%-90% nymphal mortality at 2 and 5 d after inoculation, respectively. The isolation of Bt cells from young citrus shoots and dead nymphs, and PCR performed with specific primers, confirmed the involvement of the Bt strains in the psyllid mortality. This is the first report showing the translocation of Bt strains from citrus seedling roots to shoots and their potential to control D. citri nymphs that fed on these soil-drench inoculated seedlings. The Bt strains that caused the highest mortality rates have the potential to be used as bioinsecticides to control D. citri and the identified genes can be used for the production of transgenic Bt citrus.
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Affiliation(s)
- Sílvia de Oliveira Dorta
- Programa de Pós-Graduação em Microbiologia Agrícola, Escola Superior de Agricultura Luiz de Queiroz, Universidade de São Paulo, Piracicaba, SP, Brazil
- Laboratório de Biotecnologia, Centro de Citricultura Sylvio Moreira, Instituto Agronômico de Campinas, Cordeirópolis, SP, Brazil
| | - Juliana Balbinotte
- Laboratório de Insetos Vetores de Fitopatógenos, Departamento de Entomologia e Acarologia, Escola Superior de Agricultura Luiz de Queiroz, Universidade de São Paulo, Piracicaba, SP, Brazil
| | - Rose Monnerat
- Embrapa Recursos Genéticos e Biotecnologia, Brasília, DF, Brazil
| | - João Roberto Spotti Lopes
- Laboratório de Insetos Vetores de Fitopatógenos, Departamento de Entomologia e Acarologia, Escola Superior de Agricultura Luiz de Queiroz, Universidade de São Paulo, Piracicaba, SP, Brazil
| | - Tatiane da Cunha
- Programa de Pós-Graduação em Microbiologia Agrícola, Escola Superior de Agricultura Luiz de Queiroz, Universidade de São Paulo, Piracicaba, SP, Brazil
- Laboratório de Biotecnologia, Centro de Citricultura Sylvio Moreira, Instituto Agronômico de Campinas, Cordeirópolis, SP, Brazil
| | | | | | - Marcos Antonio Machado
- Laboratório de Biotecnologia, Centro de Citricultura Sylvio Moreira, Instituto Agronômico de Campinas, Cordeirópolis, SP, Brazil
| | - Juliana de Freitas-Astúa
- Embrapa Mandioca e Fruticultura, Cruz das Almas, BA, Brazil
- Laboratório de Bioquímica Fitopatológica, Instituto Biológico, São Paulo, SP, Brazil
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He W, Megharaj M, Wu CY, Subashchandrabose SR, Dai CC. Endophyte-assisted phytoremediation: mechanisms and current application strategies for soil mixed pollutants. Crit Rev Biotechnol 2019; 40:31-45. [PMID: 31656090 DOI: 10.1080/07388551.2019.1675582] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Phytoremediation uses plants and associated microbes to remove pollutants from the environment and is considered a promising bioremediation method. Compared with well-described single contaminant treatments, the number of studies reporting phytoremediation of soil mixed pollutants has increased recently. Endophytes, including bacteria and fungi, exhibit beneficial traits for the promotion of plant growth, stress alleviation, and biodegradation. Moreover, endophytes either directly or indirectly assist host plants to survive high concentrations of organic and inorganic pollutants in the soil. Endophytic microorganisms can also regulate the plant metabolism in different ways, exhibiting a variety of physiological characteristics. This review summarizes the taxa and physiological properties of endophytic microorganisms that may participate in the detoxification of contaminant mixtures. Furthermore, potential biomolecules that may enhance endophyte mediated phytoremediation are discussed. The practical applications of pollutant-degrading endophytes and current strategies for applying this valuable bio-resource to soil phytoremediation are summarized.
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Affiliation(s)
- Wei He
- College of Life Sciences, Nanjing Normal University, Nanjing, China.,Global Centre for Environmental Remediation (GCER), The University of Newcastle (UoN), Callaghan, Australia
| | - Mallavarapu Megharaj
- Global Centre for Environmental Remediation (GCER), The University of Newcastle (UoN), Callaghan, Australia
| | - Chun-Ya Wu
- College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Suresh R Subashchandrabose
- Global Centre for Environmental Remediation (GCER), The University of Newcastle (UoN), Callaghan, Australia
| | - Chuan-Chao Dai
- College of Life Sciences, Nanjing Normal University, Nanjing, China
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