151
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Muraro GB, de Almeida Carvalho-Estrada P, de Oliveira Pasetti MH, Santos MC, Nussio LG. Bacterial dynamics of sugarcane silage in the tropics. Environ Microbiol 2021; 23:5979-5991. [PMID: 33587777 DOI: 10.1111/1462-2920.15428] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 02/08/2021] [Indexed: 12/15/2022]
Abstract
The objective of this study was to evaluate changes in the bacterial community in sugarcane silage, in distinct soil types along the storage period. We depicted the bacterial community associated with sugarcane, before and after ensiling, through a massive sequencing of the gene 16S rRNA using MiSeq platform. The ensilage process shifted the composition of the bacterial community from the heterofermentative lactic acid bacteria Leuconostoc to bacteria belonging to the genera Acinetobacter, Ralstonia and Novosphingobium. However, this shift did not convey statically significant differences in alfa diversity metrics. In addition, similarity percentage analysis showed that the bacterial Operational Taxonomic Units that were primarily responsible for the observed differences were Leuconostoc, Pseudomonas, Acinetobacter, Ralstonia, Fructobacillus, Novosphingobium, Lactobacillus, Burkholderia and Clostridium sensu stricto 1. The storage period was the most important factor responsible for changes in the bacterial community of silages. Results confirmed that the type of soil did not influence the dissimilarity found among samples.
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Affiliation(s)
- Gisele Bonato Muraro
- Animal Science Department, College of Agriculture "Luiz de Queiroz", University of São Paulo, Piracicaba, 13418-900, Brazil
| | | | | | - Mateus Castilho Santos
- Animal Science Department, College of Agriculture "Luiz de Queiroz", University of São Paulo, Piracicaba, 13418-900, Brazil.,Lallemand Animal Nutrition, Aparecida de Goiânia, Goiás, 74923-090, Brazil
| | - Luiz Gustavo Nussio
- Animal Science Department, College of Agriculture "Luiz de Queiroz", University of São Paulo, Piracicaba, 13418-900, Brazil
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152
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Haruna A, Yahaya SM. Recent Advances in the Chemistry of Bioactive Compounds from Plants and Soil Microbes: a Review. CHEMISTRY AFRICA 2021. [PMCID: PMC7869076 DOI: 10.1007/s42250-020-00213-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Bioactive compounds derived from plants and microbial sources are required for the survival of the human race and groundbreaking research must continue in this line. Plants and microbes are the major sources of naturally occurring bioactive compounds for numerous biotechnological applications. Recent progress in the fields of bioactive compounds and soil chemistry in agriculture has since given man a lead to the discovery of potent drugs that combat both human and plant diseases. The soil provides the medium for the growth of medicinal plants, but its contamination greatly affects the quality of drugs, food crops, and other essential elements present in the plants which give strength to the body. This area has attracted the attention of scientists and the drug industry toward developing more potent drugs from medicinal plants grown in different soil. The studies of the effect of various parameters and the properties of soil such as; effect of heavy metals, pH, soil organic matter, and phytoremediation process have given a measure of some quality dependence of the soil producing secondary metabolites and soil containing microbes. The information provided will be useful in determine the action of microbes and their interaction with the soil and all true plants producing drugs. Some active compounds in plants and microbes, their properties, and applications have been described in this review. The soil microbes, activities and their interactions, effects of soil particle size, dispersibility and stability of microbes in the soil, and the future outlook for the development of novel active compounds have been reported.
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153
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Jovičić-Petrović J, Karličić V, Petrović I, Ćirković S, Ristić-Djurović JL, Raičević V. Biomagnetic Priming-Possible Strategy to Revitalize Old Mustard Seeds. Bioelectromagnetics 2021; 42:238-249. [PMID: 33544924 DOI: 10.1002/bem.22328] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 01/13/2021] [Accepted: 01/21/2021] [Indexed: 01/04/2023]
Abstract
Different priming methods were developed to improve seed germination and the early growth of seedlings. This study aimed to examine the combined effect of bacterial inoculation and static magnetic field on white mustard (Sinapis alba L.) germination. A plant growth-promoting bacterial strain Bacillus amyloliquefaciens D5 ARV was used for biopriming. The static magnetic field of 90 mT was applied for 5 and 15 min. Analyses of abscisic acid, chlorophyll, anthocyanins, flavonoids content, nitrogen balance index, and bacterial indole-3-acetic acid were used to explain observed effects. Bacterial inoculation improved seed germination, whereas exposure to 90 mT for 15 min suppressed germination. Such an unfavorable effect was neutralized when the treatment with the static magnetic field was combined with bacterial inoculation. The highest germination percentage was a result of synergistic action of B. amyloliquefaciens D5 ARV and 15 min long exposure to 90 mT, which induced an increase of 53.20% in the number of germinated seeds. The static magnetic field induced the increase of bacterial indole-3-acetic acid production threefold times. Biomagnetic priming caused a metabolic shift from primary to secondary metabolism in the white mustard seedlings. An adequate combination of biological priming and static magnetic field treatment can be successfully used in old seed revitalization and germination improvements. © 2021 Bioelectromagnetics Society.
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Affiliation(s)
| | - Vera Karličić
- Faculty of Agriculture, University of Belgrade, Belgrade, Serbia
| | - Ivana Petrović
- Faculty of Agriculture, University of Belgrade, Belgrade, Serbia
| | - Saša Ćirković
- Institute of Physics, University of Belgrade, Belgrade, Serbia
| | | | - Vera Raičević
- Faculty of Agriculture, University of Belgrade, Belgrade, Serbia
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154
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Neelakandan P, Young CC, Hameed A, Wang YN, Chen KN, Shen FT. Volatile 1-octanol of tea (Camellia sinensis L.) fuels cell division and indole-3-acetic acid production in phylloplane isolate Pseudomonas sp. NEEL19. Sci Rep 2021; 11:2788. [PMID: 33531600 PMCID: PMC7854675 DOI: 10.1038/s41598-021-82442-7] [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: 07/06/2020] [Accepted: 01/20/2021] [Indexed: 01/30/2023] Open
Abstract
Tea leaves possess numerous volatile organic compounds (VOC) that contribute to tea's characteristic aroma. Some components of tea VOC were known to exhibit antimicrobial activity; however, their impact on bacteria remains elusive. Here, we showed that the VOC of fresh aqueous tea leaf extract, recovered through hydrodistillation, promoted cell division and tryptophan-dependent indole-3-acetic acid (IAA) production in Pseudomonas sp. NEEL19, a solvent-tolerant isolate of the tea phylloplane. 1-octanol was identified as one of the responsible volatiles stimulating cell division, metabolic change, swimming motility, putative pili/nanowire formation and IAA production, through gas chromatography-mass spectrometry, microscopy and partition petri dish culture analyses. The bacterial metabolic responses including IAA production increased under 1-octanol vapor in a dose-dependent manner, whereas direct-contact in liquid culture failed to elicit such response. Thus, volatile 1-octanol emitting from tea leaves is a potential modulator of cell division, colonization and phytohormone production in NEEL19, possibly influencing the tea aroma.
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Affiliation(s)
- Poovarasan Neelakandan
- grid.260542.70000 0004 0532 3749Department of Soil & Environmental Sciences, College of Agriculture and Natural Resources, National Chung Hsing University, Taichung, 40227 Taiwan, ROC
| | - Chiu-Chung Young
- grid.260542.70000 0004 0532 3749Department of Soil & Environmental Sciences, College of Agriculture and Natural Resources, National Chung Hsing University, Taichung, 40227 Taiwan, ROC ,grid.260542.70000 0004 0532 3749Innovation and Development Center of Sustainable Agriculture (IDCSA), National Chung Hsing University, Taichung, 40227 Taiwan, ROC
| | - Asif Hameed
- grid.260542.70000 0004 0532 3749Department of Soil & Environmental Sciences, College of Agriculture and Natural Resources, National Chung Hsing University, Taichung, 40227 Taiwan, ROC ,Yenepoya Research Centre, Yenepoya Deemed to be University, Mangalore, 575018 India
| | - Yu-Ning Wang
- grid.260542.70000 0004 0532 3749Department of Soil & Environmental Sciences, College of Agriculture and Natural Resources, National Chung Hsing University, Taichung, 40227 Taiwan, ROC
| | - Kui-Nuo Chen
- grid.260542.70000 0004 0532 3749Department of Soil & Environmental Sciences, College of Agriculture and Natural Resources, National Chung Hsing University, Taichung, 40227 Taiwan, ROC
| | - Fo-Ting Shen
- grid.260542.70000 0004 0532 3749Department of Soil & Environmental Sciences, College of Agriculture and Natural Resources, National Chung Hsing University, Taichung, 40227 Taiwan, ROC ,grid.260542.70000 0004 0532 3749Innovation and Development Center of Sustainable Agriculture (IDCSA), National Chung Hsing University, Taichung, 40227 Taiwan, ROC
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155
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Bonatelli ML, Lacerda-Júnior GV, dos Reis Junior FB, Fernandes-Júnior PI, Melo IS, Quecine MC. Beneficial Plant-Associated Microorganisms From Semiarid Regions and Seasonally Dry Environments: A Review. Front Microbiol 2021; 11:553223. [PMID: 33519722 PMCID: PMC7845453 DOI: 10.3389/fmicb.2020.553223] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 12/03/2020] [Indexed: 11/13/2022] Open
Abstract
Semiarid regions are apparently low biodiversity environments; however, these environments may host a phylogenetically diverse microbial community associated with plants. Their microbial inhabitants are often recruited to withstand stressful settings and improve plant growth under harsh conditions. Thus, plant-associated microorganisms isolated from semiarid and seasonally dry environments will be detailed in the present review, focusing on plant growth promotion potential and the microbial ability to alleviate plant abiotic stress. Initially, we explored the role of microbes from dry environments around the world, and then, we focused on seasonally dry Brazilian biomes, the Caatinga and the Cerrado. Cultivable bacteria from semiarid and seasonally dry environments have demonstrated great plant growth promotion traits such as plant hormone production, mobilization of insoluble nutrients, and mechanisms related to plant abiotic stress alleviation. Several of these isolates were able to improve plant growth under stressful conditions commonly present in typical semiarid regions, such as high salinity and drought. Additionally, we highlight the potential of plants highly adapted to seasonal climates from the Caatinga and Cerrado biomes as a suitable pool of microbial inoculants to maintain plant growth under abiotic stress conditions. In general, we point out the potential for the exploitation of new microbial inoculants from plants growing in dry environments to ensure a sustainable increase in agricultural productivity in a future climate change scenario.
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Affiliation(s)
- Maria Leticia Bonatelli
- Department of Genetics, Luiz de Queiroz College of Agriculture, University of São Paulo, Piracicaba, Brazil
| | | | | | | | - Itamar Soares Melo
- Brazilian Agricultural Research Corporation, Embrapa Meio Ambiente, Jaguariúna, Brazil
| | - Maria Carolina Quecine
- Department of Genetics, Luiz de Queiroz College of Agriculture, University of São Paulo, Piracicaba, Brazil
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156
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Castillo-Alfonso F, Rojas MM, Salgado-Bernal I, Carballo ME, Olivares-Hernández R, González-Bacerio J, Guisán JM, Del Monte-Martínez A. Optimization of theoretical maximal quantity of cells to immobilize on solid supports in the rational design of immobilized derivatives strategy. World J Microbiol Biotechnol 2021; 37:9. [PMID: 33392828 DOI: 10.1007/s11274-020-02972-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 11/29/2020] [Indexed: 11/24/2022]
Abstract
Current worldwide challenges are to increase the food production and decrease the environmental contamination by industrial emissions. For this, bacteria can produce plant growth promoter phytohormones and mediate the bioremediation of sewage by heavy metals removal. We developed a Rational Design of Immobilized Derivatives (RDID) strategy, applicable for protein, spore and cell immobilization and implemented in the RDID1.0 software. In this work, we propose new algorithms to optimize the theoretical maximal quantity of cells to immobilize (tMQCell) on solid supports, implemented in the RDIDCell software. The main modifications to the preexisting algorithms are related to the sphere packing theory and exclusive immobilization on the support surface. We experimentally validated the new tMQCell parameter by electrostatic immobilization of ten microbial strains on AMBERJET® 4200 Cl- porous solid support. All predicted tMQCell match the practical maximal quantity of cells to immobilize with a 10% confidence. The values predicted by the RDIDCell software are more accurate than the values predicted by the RDID1.0 software. 3-indolacetic acid (IAA) production by one bacterial immobilized derivative was higher (~ 2.6 μg IAA-like indoles/108 cells) than that of the cell suspension (1.5 μg IAA-like indoles/108 cells), and higher than the tryptophan amount added as indole precursor. Another bacterial immobilized derivative was more active (22 μg Cr(III)/108 cells) than the resuspended cells (14.5 μg Cr(III)/108 cells) in bioconversion of Cr(VI) to Cr(III). Optimized RDID strategy can be used to synthesize bacterial immobilized derivatives with useful biotechnological applications.
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Affiliation(s)
- Freddy Castillo-Alfonso
- Centro de Estudio de Proteínas, Universidad de La Habana, Calle 25, #455, e/J e I, Vedado, 10400, Havana, Cuba.,Posgrado en Ciencias Naturales e Ingeniería, Universidad Autónoma Metropolitana, Unidad Cuajimalpa. Av. Vasco de Quiroga 4871, Col. Santa Fe Cuajimalpa, Delegación Cuajimalpa, 05348, Mexico, Mexico
| | - Marcia M Rojas
- Departamento de Microbiología y Virología, Universidad de La Habana, Calle 25, #455, e/J e I, Vedado, 10400, Havana, Cuba
| | - Irina Salgado-Bernal
- Departamento de Microbiología y Virología, Universidad de La Habana, Calle 25, #455, e/J e I, Vedado, 10400, Havana, Cuba
| | - María E Carballo
- Departamento de Microbiología y Virología, Universidad de La Habana, Calle 25, #455, e/J e I, Vedado, 10400, Havana, Cuba
| | - Roberto Olivares-Hernández
- Universidad Autónoma Metropolitana, Unidad Cuajimalpa. Av. Vasco de Quiroga 4871, Col. Santa Fe Cuajimalpa, Delegación Cuajimalpa, 05348, Mexico, Mexico
| | - Jorge González-Bacerio
- Centro de Estudio de Proteínas, Universidad de La Habana, Calle 25, #455, e/J e I, Vedado, 10400, Havana, Cuba. .,Departamento de Bioquímica, Facultad de Biología, Universidad de La Habana, Calle 25, #455, e/J e I, Vedado, 10400, Havana, Cuba.
| | - José M Guisán
- Departamento de Biocatálisis, Instituto de Catálisis y Petroleoquímica, Consejo Superior de Investigaciones Científicas (CSIC), Campus Cantoblanco, 28049, Madrid, Spain
| | - Alberto Del Monte-Martínez
- Centro de Estudio de Proteínas, Universidad de La Habana, Calle 25, #455, e/J e I, Vedado, 10400, Havana, Cuba.
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157
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Insights into the early stages of plant-endophytic bacteria interaction. World J Microbiol Biotechnol 2021; 37:13. [PMID: 33392741 DOI: 10.1007/s11274-020-02966-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 11/21/2020] [Indexed: 12/11/2022]
Abstract
The plant holobiont is a complex entity composed of the plant and the organisms that live in and on it including its microbiota. The plant microbiota includes, among other microorganisms, bacterial endophytes, which are bacteria that can invade living plant tissues without causing symptoms of disease. The interaction between the endophytic bacterial microbiota and their plant host has profound influences on their fitness and depends on biotic and abiotic factors. For these interactions to be established, the bacteria have to be present at the right time, in the right place either colonizing the soil or the seed. In this review we summarize the current knowledge regarding the sources of the bacterial endophytic microbiome and the processes involved in the assemblage of the resulting community during the initial stages of plant development. The adaptations that allow the spatial approximation of soil- and seed-borne bacteria towards infection and colonization of the internal tissues of plants will be addressed in this review.
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158
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Eichmann R, Richards L, Schäfer P. Hormones as go-betweens in plant microbiome assembly. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 105:518-541. [PMID: 33332645 PMCID: PMC8629125 DOI: 10.1111/tpj.15135] [Citation(s) in RCA: 77] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 12/10/2020] [Accepted: 12/11/2020] [Indexed: 05/04/2023]
Abstract
The interaction of plants with complex microbial communities is the result of co-evolution over millions of years and contributed to plant transition and adaptation to land. The ability of plants to be an essential part of complex and highly dynamic ecosystems is dependent on their interaction with diverse microbial communities. Plant microbiota can support, and even enable, the diverse functions of plants and are crucial in sustaining plant fitness under often rapidly changing environments. The composition and diversity of microbiota differs between plant and soil compartments. It indicates that microbial communities in these compartments are not static but are adjusted by the environment as well as inter-microbial and plant-microbe communication. Hormones take a crucial role in contributing to the assembly of plant microbiomes, and plants and microbes often employ the same hormones with completely different intentions. Here, the function of hormones as go-betweens between plants and microbes to influence the shape of plant microbial communities is discussed. The versatility of plant and microbe-derived hormones essentially contributes to the creation of habitats that are the origin of diversity and, thus, multifunctionality of plants, their microbiota and ultimately ecosystems.
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Affiliation(s)
- Ruth Eichmann
- Institute of Molecular BotanyUlm UniversityUlm89069Germany
| | - Luke Richards
- School of Life SciencesUniversity of WarwickCoventryCV4 7ALUK
| | - Patrick Schäfer
- Institute of Molecular BotanyUlm UniversityUlm89069Germany
- School of Life SciencesUniversity of WarwickCoventryCV4 7ALUK
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159
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Alberton D, Valdameri G, Moure VR, Monteiro RA, Pedrosa FDO, Müller-Santos M, de Souza EM. What Did We Learn From Plant Growth-Promoting Rhizobacteria (PGPR)-Grass Associations Studies Through Proteomic and Metabolomic Approaches? FRONTIERS IN SUSTAINABLE FOOD SYSTEMS 2020. [DOI: 10.3389/fsufs.2020.607343] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Plant growth stimulation by microorganisms that interact in a mutually beneficial manner remains poorly understood. Understanding the nature of plant-bacteria interactions may open new routes for plant productivity enhancement, especially cereal crops consumed by humans. Proteomic and metabolomic analyses are particularly useful for elucidating these mechanisms. A complete depiction of these mechanisms will prompt researchers to develop more efficient plant-bacteria associations. The success of microorganisms as biofertilizers may replace the current massive use of chemical fertilizers, mitigating many environmental and economic issues. In this review, we discuss the recent advances and current state of the art in proteomics and metabolomics studies involving grass-bacteria associations. We also discuss essential subjects involved in the bacterial plant-growth promotion, such, nitrogen fixation, plant stress, defense responses, and siderophore production.
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160
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Alibrandi P, Schnell S, Perotto S, Cardinale M. Diversity and Structure of the Endophytic Bacterial Communities Associated With Three Terrestrial Orchid Species as Revealed by 16S rRNA Gene Metabarcoding. Front Microbiol 2020; 11:604964. [PMID: 33519751 PMCID: PMC7839077 DOI: 10.3389/fmicb.2020.604964] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 11/23/2020] [Indexed: 01/13/2023] Open
Abstract
The endophytic microbiota can establish mutualistic or commensalistic interactions within the host plant tissues. We investigated the bacterial endophytic microbiota in three species of Mediterranean orchids (Neottia ovata, Serapias vomeracea, and Spiranthes spiralis) by metabarcoding of the 16S rRNA gene. We examined whether the different orchid species and organs, both underground and aboveground, influenced the endophytic bacterial communities. A total of 1,930 operational taxonomic units (OTUs) were obtained, mainly Proteobacteria and Actinobacteria, whose distribution model indicated that the plant organ was the main determinant of the bacterial community structure. The co-occurrence network was not modular, suggesting a relative homogeneity of the microbiota between both plant species and organs. Moreover, the decrease in species richness and diversity in the aerial vegetative organs may indicate a filtering effect by the host plant. We identified four hub OTUs, three of them already reported as plant-associated taxa (Pseudoxanthomonas, Rhizobium, and Mitsuaria), whereas Thermus was an unusual member of the plant microbiota. Core microbiota analysis revealed a selective and systemic ascent of bacterial communities from the vegetative to the reproductive organs. The core microbiota was also maintained in the S. spiralis seeds, suggesting a potential vertical transfer of the microbiota. Surprisingly, some S. spiralis seed samples displayed a very rich endophytic microbiota, with a large number of OTUs shared with the roots, a situation that may lead to a putative restoring process of the root-associated microbiota in the progeny. Our results indicate that the bacterial community has adapted to colonize the orchid organs selectively and systemically, suggesting an active involvement in the orchid holobiont.
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Affiliation(s)
- Pasquale Alibrandi
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
- Institute of Applied Microbiology, Justus-Liebig-University Giessen, Giessen, Germany
| | - Sylvia Schnell
- Institute of Applied Microbiology, Justus-Liebig-University Giessen, Giessen, Germany
| | - Silvia Perotto
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
| | - Massimiliano Cardinale
- Institute of Applied Microbiology, Justus-Liebig-University Giessen, Giessen, Germany
- Department of Biological and Environmental Sciences and Technologies, University of Salento, Lecce, Italy
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161
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Yarlagadda V, Medina R, Johnson TA, Koteva KP, Cox G, Thaker MN, Wright GD. Resistance-Guided Discovery of Elfamycin Antibiotic Producers with Antigonococcal Activity. ACS Infect Dis 2020; 6:3163-3173. [PMID: 33164482 DOI: 10.1021/acsinfecdis.0c00467] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The rise of bacterial antibiotic resistance coupled with a diminished antibiotic drug pipeline underlines the importance of developing rational strategies to discover new antimicrobials. Microbially derived natural products are the basis for most of the antibiotic arsenal available to modern medicine. Here, we demonstrate a resistance-based approach to identify producers of elfamycins, an under-explored class of natural product antibiotics that target the essential translation factor EF-Tu. Antibiotic producers carry self-resistance genes to avoid suicide. These genes are often found within the same biosynthetic gene cluster (BGC) responsible for making the antibiotic, and we exploited this trait to identify members of the kirromycin class of elfamycin producers. Genome mining of Streptomyces spp. led to the identification of three isolates that harbor kirromycin-resistant EF-Tu (EF-TuKirR) within predicted natural product BGCs. Activity-guided purification on extracts of one of the Streptomyces isolates, which was not known to produce an elfamycin, identified it as a producer of phenelfamycin B, a linear polyketide. Phenelfamycin B demonstrates impressive antibacterial activity (MIC ∼ 1 μg/mL) against multidrug-resistant Neisseria gonorrhoeae, a clinically important Gram negative pathogen. The antigonococcal activity of phenelfamycin was shown to be the result of inhibition of protein biosynthesis by binding to EF-Tu. These results indicate that a resistance-based approach of identifying elfamycin producers is translatable to other antibiotic classes that can identify new and overlooked antibiotics necessary to address the antibiotic crisis.
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Affiliation(s)
- Venkateswarlu Yarlagadda
- David Braley Center for Antibiotic Discovery, M.G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario L8S 4K1, Canada
| | - Ricardo Medina
- Department of Microbiology, Chemical Bioactive Center, Central University Marta Abreu de las Villas, Santa Clara 54830, Villa Clara, Cuba
| | - Timothy A. Johnson
- Department of Animal Sciences, Purdue University College of Agriculture, West Lafayette, Indiana 47907, United States
| | - Kalinka P. Koteva
- David Braley Center for Antibiotic Discovery, M.G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario L8S 4K1, Canada
| | - Georgina Cox
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - Maulik N. Thaker
- Novartis Institutes for Biomedical Research, 250 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Gerard D. Wright
- David Braley Center for Antibiotic Discovery, M.G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario L8S 4K1, Canada
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162
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Phour M, Sehrawat A, Sindhu SS, Glick BR. Interkingdom signaling in plant-rhizomicrobiome interactions for sustainable agriculture. Microbiol Res 2020; 241:126589. [DOI: 10.1016/j.micres.2020.126589] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 08/19/2020] [Accepted: 08/21/2020] [Indexed: 12/24/2022]
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163
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Dey R, Raghuwanshi R. Comprehensive assessment of growth parameters for screening endophytic bacterial strains in Solanum lycopersicum (Tomato). Heliyon 2020; 6:e05325. [PMID: 33134591 PMCID: PMC7586120 DOI: 10.1016/j.heliyon.2020.e05325] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 09/21/2020] [Accepted: 10/19/2020] [Indexed: 11/29/2022] Open
Abstract
Conventional agricultural practices demand application of pesticides for better yield, yet their uncontrolled use for longer duration exhibit deleterious effects on the soil health and subsequent plant productivity. These circumstances have displayed alarming effects on food security in the modern world. Therefore, biological solutions to the crisis can be practiced in consideration to their environmental benefits. Bacterial endophytes are ubiquitous in the phytosystem and beneficial for the plant growth and productivity. The present study aimed to obtain endophytic bacterial strains that can be developed as effective plant growth promoters. For this purpose twelve strains of bacterial endophytes were isolated from different plant sources and their putative plant growth promoting attributes were analyzed by morphological and biochemical studies. Subsequently these isolates were inoculated in the Solanum lycopersicum (Tomato) and the factors like germination percentage, seedling length, biomass production, and leaf variables were analyzed. However, the vigour index was considered as the prime parameter for determining plant growth. In essence, RR2 and RR4 strains were observed as effective growth promoter, hence in future they can be utilized as effective biofertilizers.
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Affiliation(s)
- Riddha Dey
- Department of Botany, Institute of Science, Banaras Hindu University, Varanasi 221005, Uttar Pradesh, India
| | - Richa Raghuwanshi
- Department of Botany, Mahila Mahavidyalaya, Banaras Hindu University, Varanasi 221005, Uttar Pradesh, India
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164
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Water Conservation and Plant Survival Strategies of Rhizobacteria under Drought Stress. AGRONOMY-BASEL 2020. [DOI: 10.3390/agronomy10111683] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Drylands are stressful environment for plants growth and production. Plant growth-promoting rhizobacteria (PGPR) acts as a rampart against the adverse impacts of drought stress in drylands and enhances plant growth and is helpful in agricultural sustainability. PGPR improves drought tolerance by implicating physio-chemical modifications called rhizobacterial-induced drought endurance and resilience (RIDER). The RIDER response includes; alterations of phytohormonal levels, metabolic adjustments, production of bacterial exopolysaccharides (EPS), biofilm formation, and antioxidant resistance, including the accumulation of many suitable organic solutes such as carbohydrates, amino acids, and polyamines. Modulation of moisture status by these PGPRs is one of the primary mechanisms regulating plant growth, but studies on their effect on plant survival are scarce in sandy/desert soil. It was found that inoculated plants showed high tolerance to water-deficient conditions by delaying dehydration and maintaining the plant’s water status at an optimal level. PGPR inoculated plants had a high recovery rate after rewatering interms of similar biomass at flowering compared to non-stressed plants. These rhizobacteria enhance plant tolerance and also elicit induced systemic resistance of plants to water scarcity. PGPR also improves the root growth and root architecture, thereby improving nutrient and water uptake. PGPR promoted accumulation of stress-responsive plant metabolites such as amino acids, sugars, and sugar alcohols. These metabolites play a substantial role in regulating plant growth and development and strengthen the plant’s defensive system against various biotic and abiotic stresses, in particular drought stress.
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Toniutti MA, Albicoro FJ, Castellani LG, López García SL, Fornasero LV, Zuber NE, Vera LM, Vacca C, Cafiero JH, Winkler A, Kalinowski J, Lagares A, Torres Tejerizo GA, Del Papa MF. Genome sequence of Bradyrhizobium yuanmingense strain P10 130, a highly efficient nitrogen-fixing bacterium that could be used for Desmodium incanum inoculation. Gene 2020; 768:145267. [PMID: 33122079 DOI: 10.1016/j.gene.2020.145267] [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: 05/10/2020] [Revised: 08/08/2020] [Accepted: 10/20/2020] [Indexed: 10/23/2022]
Abstract
Strain P10 130, an isolated Bradyrhizobium strain from Argentina which promotes the growth of the leguminous plant Desmodium incanum by different mechanisms was previously selected as the best candidate for D. incanum inoculation based on broader selective criteria. A close relationship between this strain and B. yuanmingense was determined by MALDI BioTyper identification and 16S rRNA gene phylogenetic analysis. This study aimed to analyse the genome sequence of B. yuanmingense P10 130 in order to deepen our knowledge regarding its plant growth-promoting traits and to establish its phylogenetic relationship with other species of Bradyrhizobium genus. The genome size of strain P10 130 was estimated to be 7.54 Mb that consisted of 65 contigs. Genome Average Nucleotide Identity (ANI) analysis revealed that B. yuanmingense CCBAU 10071 T was the closest strain to P10 130 with ca. 96% identity. Further analysis of the genome of B. yuanmingense P10 130 identified 20 nod/nol/NOE, 14 nif/18 fix, 5 nap/5 nor genes, which may be potentially involved in nodulation, nitrogen fixation, and denitrification process respectively. Genome sequence of B. yuanmingense P10 130 is a valuable source of information to continue the research of its potential industrial production as a biofertilizer of D. incanum.
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Affiliation(s)
| | - Francisco Javier Albicoro
- IBBM - Instituto de Biotecnología y Biología Molecular, CONICET - Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Calles 47 y 115 (1900) La Plata, Argentina
| | - Lucas Gabriel Castellani
- IBBM - Instituto de Biotecnología y Biología Molecular, CONICET - Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Calles 47 y 115 (1900) La Plata, Argentina
| | - Silvina Laura López García
- IBBM - Instituto de Biotecnología y Biología Molecular, CONICET - Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Calles 47 y 115 (1900) La Plata, Argentina
| | | | - Nicolás Emilio Zuber
- IBBM - Instituto de Biotecnología y Biología Molecular, CONICET - Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Calles 47 y 115 (1900) La Plata, Argentina
| | - Leda Mailén Vera
- IBBM - Instituto de Biotecnología y Biología Molecular, CONICET - Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Calles 47 y 115 (1900) La Plata, Argentina
| | - Carolina Vacca
- IBBM - Instituto de Biotecnología y Biología Molecular, CONICET - Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Calles 47 y 115 (1900) La Plata, Argentina
| | - Juan Hilario Cafiero
- IBBM - Instituto de Biotecnología y Biología Molecular, CONICET - Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Calles 47 y 115 (1900) La Plata, Argentina
| | - Anika Winkler
- CeBiTec - Centrum für Biotechnologie, Universität Bielefeld, Bielefeld, Germany
| | - Jörn Kalinowski
- CeBiTec - Centrum für Biotechnologie, Universität Bielefeld, Bielefeld, Germany
| | - Antonio Lagares
- IBBM - Instituto de Biotecnología y Biología Molecular, CONICET - Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Calles 47 y 115 (1900) La Plata, Argentina
| | - Gonzalo Arturo Torres Tejerizo
- IBBM - Instituto de Biotecnología y Biología Molecular, CONICET - Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Calles 47 y 115 (1900) La Plata, Argentina.
| | - María Florencia Del Papa
- IBBM - Instituto de Biotecnología y Biología Molecular, CONICET - Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Calles 47 y 115 (1900) La Plata, Argentina.
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Luziatelli F, Gatti L, Ficca AG, Medori G, Silvestri C, Melini F, Muleo R, Ruzzi M. Metabolites Secreted by a Plant-Growth-Promoting Pantoea agglomerans Strain Improved Rooting of Pyrus communis L. cv Dar Gazi Cuttings. Front Microbiol 2020; 11:539359. [PMID: 33162945 PMCID: PMC7591501 DOI: 10.3389/fmicb.2020.539359] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Accepted: 09/09/2020] [Indexed: 11/13/2022] Open
Abstract
Strains belonging to Pantoea agglomerans species are known for their ability to produce metabolites that can act in synergy with auxins to induce the adventitious root (AR) formation. The latter is critically important in the agamic propagation of several woody species, including pear (Pyrus communis L.), playing a considerable role in the commercial nursery farms including those using micropropagation techniques. When grown on a medium amended with tryptophan, the plant-growth-promoting (PGP) strain P. agglomerans C1 produces a cocktail of auxin and auxin-like molecules that can be utilized as biostimulants to improve the rooting of vegetable (Solanum lycopersicum L.) and woody crop species (Prunus rootstock GF/677 and hazelnut). In this study, we evaluated the morphological and molecular responses induced by strain C1 exometabolites in microcuttings of P. communis L. cv Dar Gazi and the potential benefits arising from their application. Results showed that exometabolites by P. agglomerans C1 induced a direct and earlier emergence of roots from stem tissues and determined modifications of root morphological parameters and root architecture compared to plants treated with the synthetic hormone indole-3-butyric acid (IBA). Transcription analysis revealed differences in the temporal expression pattern of ARF17 gene when IBA and C1 exometabolites were used alone, while together they also determined changes in the expression pattern of other key auxin-regulated plant genes. These results suggest that the phenotypic and molecular changes triggered by P. agglomerans C1 are dependent on different stimulatory and inhibitory effects that auxin-like molecules and other metabolites secreted by this strain have on the gene regulatory network of the plant. This evidence supports the hypothesis that the strategies used to harness the metabolic potential of PGP bacteria are key factors in obtaining novel biostimulants for sustainable agriculture. Our results demonstrate that metabolites secreted by strain C1 can be successfully used to increase the efficiency of micropropagation of pear through tissue culture techniques.
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Affiliation(s)
- Francesca Luziatelli
- Department for Innovation in Biological, Agrofood and Forest Systems (DIBAF), University of Tuscia, Viterbo, Italy
| | - Lorenzo Gatti
- Department of Agricultural and Forest Sciences (DAFNE), University of Tuscia, Viterbo, Italy
| | - Anna Grazia Ficca
- Department for Innovation in Biological, Agrofood and Forest Systems (DIBAF), University of Tuscia, Viterbo, Italy
| | - Gabriele Medori
- Department of Agricultural and Forest Sciences (DAFNE), University of Tuscia, Viterbo, Italy
| | - Cristian Silvestri
- Department of Agricultural and Forest Sciences (DAFNE), University of Tuscia, Viterbo, Italy
| | - Francesca Melini
- Department for Innovation in Biological, Agrofood and Forest Systems (DIBAF), University of Tuscia, Viterbo, Italy
- CREA Research Centre for Food and Nutrition, Rome, Italy
| | - Rosario Muleo
- Department of Agricultural and Forest Sciences (DAFNE), University of Tuscia, Viterbo, Italy
| | - Maurizio Ruzzi
- Department for Innovation in Biological, Agrofood and Forest Systems (DIBAF), University of Tuscia, Viterbo, Italy
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167
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Mesa-Marín J, Pérez-Romero JA, Redondo-Gómez S, Pajuelo E, Rodríguez-Llorente ID, Mateos-Naranjo E. Impact of Plant Growth Promoting Bacteria on Salicornia ramosissima Ecophysiology and Heavy Metal Phytoremediation Capacity in Estuarine Soils. Front Microbiol 2020; 11:553018. [PMID: 33042058 PMCID: PMC7527472 DOI: 10.3389/fmicb.2020.553018] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 08/13/2020] [Indexed: 12/01/2022] Open
Abstract
Salicornia ramosissima is a C3 halophyte that grows naturally in South Western Spain salt marshes, under soil salinity and heavy metal pollution (mostly Cu, Zn, As, and Pb) caused by both natural and anthropogenic pressure. However, very few works have reported the phytoremediation potential of S. ramosissima. In this work, we studied a microbe-assisted phytoremediation strategy under greenhouse conditions. We inoculated plant growth promoting (PGP) and heavy metal resistant bacteria in pots with S. ramosissima and natural non-polluted and polluted sediments collected from Spanish estuaries. Then, we analyzed plant ecophysiological and metal phytoaccumulation response. Our data suggested that inoculation in polluted sediments improved S. ramosissima plant growth in terms of relative growth rate (RGR) (32%) and number of new branches (61%). S. ramosissima photosynthetic fitness was affected by heavy metal presence in soil, but bacteria inoculation improved the photochemical apparatus integrity and functionality, as reflected by increments in net photosynthetic rate (21%), functionality of PSII (Fm and Fv/Fm) and electron transport rate, according to OJIP derived parameters. Beneficial effect of bacteria in polluted sediments was also observed by augmentation of intrinsic water use efficiency (28%) and slightly water content (2%) in inoculated S. ramosissima. Finally, our results demonstrated that S. ramosissima was able to accumulate great concentrations of heavy metals, mostly at root level, up to 200 mg Kg–1 arsenic, 0.50 mg Kg–1 cadmium, 400 mg Kg–1 copper, 25 mg Kg–1 nickel, 300 mg Kg–1 lead, and 300 mg Kg–1 zinc. Bioaugmentation incremented S. ramosissima heavy metal phytoremediation potential due to plant biomass increment, which enabled a greater accumulation capacity. Thus, our results suggest the potential use of heavy metal resistant PGPB to ameliorate the capacity of S. ramosissima as candidate for phytoremediation of salty polluted ecosystems.
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Affiliation(s)
- Jennifer Mesa-Marín
- Departamento de Biología Molecular y Bioquímica, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
| | - Jesús A Pérez-Romero
- Departamento de Biología Vegetal y Ecología, Facultad de Biología, Universidad de Sevilla, Seville, Spain
| | - Susana Redondo-Gómez
- Departamento de Biología Vegetal y Ecología, Facultad de Biología, Universidad de Sevilla, Seville, Spain
| | - Eloísa Pajuelo
- Departamento de Microbiología y Parasitología, Facultad de Farmacia, Universidad de Sevilla, Seville, Spain
| | | | - Enrique Mateos-Naranjo
- Departamento de Biología Vegetal y Ecología, Facultad de Biología, Universidad de Sevilla, Seville, Spain
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168
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Laird TS, Flores N, Leveau JHJ. Bacterial catabolism of indole-3-acetic acid. Appl Microbiol Biotechnol 2020; 104:9535-9550. [PMID: 33037916 DOI: 10.1007/s00253-020-10938-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 09/21/2020] [Accepted: 09/27/2020] [Indexed: 12/18/2022]
Abstract
Indole-3-acetic acid (IAA) is a molecule with the chemical formula C10H9NO2, with a demonstrated presence in various environments and organisms, and with a biological function in several of these organisms, most notably in plants where it acts as a growth hormone. The existence of microorganisms with the ability to catabolize or assimilate IAA has long been recognized. To date, two sets of gene clusters underlying this property in bacteria have been identified and characterized: one (iac) is responsible for the aerobic degradation of IAA into catechol, and another (iaa) for the anaerobic conversion of IAA to 2-aminobenzoyl-CoA. Here, we summarize the literature on the products, reactions, and pathways that these gene clusters encode. We explore two hypotheses about the benefit that iac/iaa gene clusters confer upon their bacterial hosts: (1) exploitation of IAA as a source of carbon, nitrogen, and energy; and (2) interference with IAA-dependent processes and functions in other organisms, including plants. The evidence for both hypotheses will be reviewed for iac/iaa-carrying model strains of Pseudomonas putida, Enterobacter soli, Acinetobacter baumannii, Paraburkholderia phytofirmans, Caballeronia glathei, Aromatoleum evansii, and Aromatoleum aromaticum, more specifically in the context of access to IAA in the environments from which these bacteria were originally isolated, which include not only plants, but also soils and sediment, as well as patients in hospital environments. We end the mini-review with an outlook for iac/iaa-inspired research that addresses current gaps in knowledge, biotechnological applications of iac/iaa-encoded enzymology, and the use of IAA-destroying bacteria to treat pathologies related to IAA excess in plants and humans. KEY POINTS: • The iac/iaa gene clusters encode bacterial catabolism of the plant growth hormone IAA. • Plants are not the only environment where IAA or IAA-degrading bacteria can be found. • The iac/iaa genes allow growth at the expense of IAA; other benefits remain unknown.
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Affiliation(s)
- Tyler S Laird
- Department of Plant Pathology, University of California Davis, Davis, CA, 95616, USA
| | - Neptali Flores
- Department of Plant Pathology, University of California Davis, Davis, CA, 95616, USA
| | - Johan H J Leveau
- Department of Plant Pathology, University of California Davis, Davis, CA, 95616, USA.
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169
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dos Santos RM, Diaz PAE, Lobo LLB, Rigobelo EC. Use of Plant Growth-Promoting Rhizobacteria in Maize and Sugarcane: Characteristics and Applications. FRONTIERS IN SUSTAINABLE FOOD SYSTEMS 2020. [DOI: 10.3389/fsufs.2020.00136] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
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170
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Yang L, Yang K. Biological function of Klebsiella variicola and its effect on the rhizosphere soil of maize seedlings. PeerJ 2020; 8:e9894. [PMID: 32995084 PMCID: PMC7501803 DOI: 10.7717/peerj.9894] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 08/17/2020] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Deterioration of the ecological environment in recent years has led to increasing soil salinization, which severely affects the cultivation of agricultural crops. While research has focused on improving soil environment through the application of pollution-free microbial fertilizers, there are relatively few plant growth-promoting bacteria suitable for saline-alkali environments. Although Klebsiella variicola can adapt to saline-alkali environments to successfully colonize rhizosphere microenvironments, only a few studies have investigated its role in promoting crop growth. Its effect on the crop rhizosphere soil microenvironment is especially unclear. METHODS In this study, the biological function of K. variicola and its colonization in maize seedling rhizosphere soil were studied in detail through selective media and ultraviolet spectrophotometry. The effects of K. variicola on the rhizosphere soil microenvironment and the growth of maize seedlings in saline-alkali and neutral soils were systematically analysed using the colorimetric method, the potassium dichromate volumetric method, and the diffusion absorption method. RESULTS Our results showed that K. variicola played a role in indole acetic acid, acetoin, ammonia, phosphorus, and potassium production, as well as in nitrogen fixation. A high level of colonization was observed in the rhizosphere soil of maize seedlings. Following the application of K. variicola in neutral and saline-alkali soils, the nutrient composition of rhizosphere soil of maize seedlings increased in varying degrees, more notably in saline-alkali soil. The content of organic matter, alkali-hydrolysable nitrogen, available phosphorus, available potassium, alkaline phosphatase, sucrase, urease, and catalase increased by 64.22%, 117.39%, 175.64%, 28.63%, 146.08%, 76.77%, 86.60%, and 45.29%, respectively, insaline-alkalisoil. CONCLUSION K.variicola, therefore, performed a variety of biological functions to promote the growth of maize seedlings and effectively improve the level of soil nutrients and enzymes in the rhizosphere of maize seedlings, undersaline-alkali stress conditions. It played an important role in enhancing the rhizosphere microenvironment of maize seedlings under saline-alkali stress.
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Affiliation(s)
- Lijuan Yang
- College of Agronomy, Heilongjiang Bayi Agricultural University, Daqing, Heilongjiang, People’s Republic of China
- Key Laboratory of Crop Germplasm Improvement and Cultivation in Cold Regions of Education Department, Daqing, Heilongjiang, People’s Republic of China
| | - Kejun Yang
- Key Laboratory of Crop Germplasm Improvement and Cultivation in Cold Regions of Education Department, Daqing, Heilongjiang, People’s Republic of China
- College of Graduate, Heilongjiang Bayi Agricultural University, Daqing, Heilongjiang, People’s Republic of China
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Siqueira ACO, Mascarin GM, Gonçalves CRNCB, Marcon J, Quecine MC, Figueira A, Delalibera Í. Multi-Trait Biochemical Features of Metarhizium Species and Their Activities That Stimulate the Growth of Tomato Plants. FRONTIERS IN SUSTAINABLE FOOD SYSTEMS 2020. [DOI: 10.3389/fsufs.2020.00137] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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172
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Lu K, Jin Q, Lin Y, Lu W, Li S, Zhou C, Jin J, Jiang Q, Ling L, Xiao M. Cell-Free Fermentation Broth of Bacillus velezensis Strain S3-1 Improves Pak Choi Nutritional Quality and Changes the Bacterial Community Structure of the Rhizosphere Soil. Front Microbiol 2020; 11:2043. [PMID: 33071994 PMCID: PMC7533579 DOI: 10.3389/fmicb.2020.02043] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 08/03/2020] [Indexed: 11/13/2022] Open
Abstract
Bacillus velezensis is a plant growth-promoting rhizobacteria (PGPR) that has long been proven to improve the growth of plants, and it has been widely used in agriculture. However, in many reports, we observed that during the application of bacterial fluids, it appeared that the effect of the cell-free fermentation broth (CFB) was ignored. The purpose of this study is to compare the effect of the no inoculation treatment (CK), the B. velezensis strain S3-1 treatment (S), the CFB treatment in the Pak choi, soil bacterial community structure, soil enzyme activity, and field soil properties. The results have shown that, compared to the inoculation B. velezensis strain S3-1 treatment and the no-inoculation treatment; the inoculation of the CFB treatment can significantly enhance the soluble protein, soluble solids, ascorbic acid of Pak choi and increase the total phosphorus content and electrical conductivity (EC) in the soil. Based on high-throughput sequencing data, our analysis of soil microbial communities used R, NETWORK, and PICRUSt showed that the CFB treatment can enhance the relative abundance of Acidobacteria in the soil, decrease the abundance of native Bacillus in the soil, change the microbial community structure of the top 50 operational taxonomic units (OTUs), and improve soil microbial carbon metabolism and nitrogen metabolism. Overall, we observed that CFB treatment can also improve plant nutrition and change soil microbial communities. This study provides new insights for the application of microbial fertilizers in agricultural production.
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Affiliation(s)
- Kaiheng Lu
- Shanghai Engineering and Technical Research Center of Plant Germplasm Resources, College of Life Sciences, Shanghai Normal University, Shanghai, China
| | - Qing Jin
- Shanghai Engineering and Technical Research Center of Plant Germplasm Resources, College of Life Sciences, Shanghai Normal University, Shanghai, China
| | - Yibo Lin
- Shanghai Engineering and Technical Research Center of Plant Germplasm Resources, College of Life Sciences, Shanghai Normal University, Shanghai, China
| | - Wenwei Lu
- Shanghai Engineering and Technical Research Center of Plant Germplasm Resources, College of Life Sciences, Shanghai Normal University, Shanghai, China
| | - Songshuo Li
- Shanghai Engineering and Technical Research Center of Plant Germplasm Resources, College of Life Sciences, Shanghai Normal University, Shanghai, China
| | - Chenhao Zhou
- Shanghai Engineering and Technical Research Center of Plant Germplasm Resources, College of Life Sciences, Shanghai Normal University, Shanghai, China
| | - Jieren Jin
- Shanghai Engineering and Technical Research Center of Plant Germplasm Resources, College of Life Sciences, Shanghai Normal University, Shanghai, China
| | - Qiuyan Jiang
- Shanghai Engineering and Technical Research Center of Plant Germplasm Resources, College of Life Sciences, Shanghai Normal University, Shanghai, China
| | - Lichen Ling
- Shanghai Engineering and Technical Research Center of Plant Germplasm Resources, College of Life Sciences, Shanghai Normal University, Shanghai, China
| | - Ming Xiao
- Shanghai Engineering and Technical Research Center of Plant Germplasm Resources, College of Life Sciences, Shanghai Normal University, Shanghai, China
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173
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Coal-Degrading Bacteria Display Characteristics Typical of Plant Growth Promoting Rhizobacteria. Processes (Basel) 2020. [DOI: 10.3390/pr8091111] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Coal mining produces large quantities of discard that is stockpiled in large dumps. This stockpiled material, termed coal discard, poses an environmental threat emphasising the need for appropriate bioremediation. Here, metagenomic analysis of the 16S rRNA from ten coal-degrading strains previously isolated from coal slurry from discard dumps and from the rhizosphere of diesel-contaminated sites was used to establish genetic relatedness to known plant growth-promoting (PGP) bacteria in the NCBI database. Measurement of indole and ammonium production and solubilisation of P and K were used to screen bacteria for PGP characteristics. BLAST analysis revealed ≥ 99% homology of six isolates with reference PGP strains of Bacillus, Escherichia, Citrobacter, Serratia, Exiguobacterium and Microbacterium, while two strains showed 94% and 91% homology with Proteus. The most competent PGP strains were Proteus strain ECCN 20b, Proteus strain ECCN 23b and Serratia strain ECCN 24b isolated from diesel-contaminated soil. In response to L-trp supplementation, the concentration of indolic compounds (measured as indole-3-acetic acid) increased. Production of ammonium and solubilisation of insoluble P by these strains was also apparent. Only Serratia strain ECCN 24b was capable of solubilising insoluble K. Production of indoles increased following exposure to increasing aliquots of coal discard, suggesting no negative effect of this material on indole production by these coal-degrading bacterial isolates and that these bacteria may indeed possess PGP characteristics.
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174
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Duca DR, Glick BR. Indole-3-acetic acid biosynthesis and its regulation in plant-associated bacteria. Appl Microbiol Biotechnol 2020; 104:8607-8619. [PMID: 32875364 DOI: 10.1007/s00253-020-10869-5] [Citation(s) in RCA: 67] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 08/19/2020] [Accepted: 08/26/2020] [Indexed: 11/28/2022]
Abstract
Numerous studies have reported the stimulation of plant growth following inoculation with an IAA-producing PGPB. However, the specific mode of IAA production by the PGPB is rarely elucidated. In part, this is due to the overwhelming complexity of IAA biosynthesis and regulation. The promiscuity of the enzymes implicated in IAA biosynthesis adds another element of complexity when attempting to decipher their role in IAA biosynthesis. To date, the majority of research on IAA biosynthesis describes three separate pathways classified in terms of their intermediates-indole acetonitrile (IAN), indole acetamide (IAM), and indole pyruvic acid (IPA). Each of these pathways is mediated by a set of enzymes, many of which are traditionally assumed to exist for that specific catalytic role. This lends the possibility of missing other, novel, enzymes that may also incidentally serve that function. Some of these pathways are constitutively expressed, while others are inducible. Some enzymes involved in IAA biosynthesis are known to be regulated by IAA or by IAA precursors, as well as by a multitude of environmental cues. This review aims to provide an update to our current understanding of the biosynthesis and regulation of IAA in bacteria. KEY POINTS: • IAA produced by PGPB improves bacterial stress tolerance and promotes plant growth. • Bacterial IAA biosynthesis is convoluted; multiple interdependent pathways. • Biosynthesis of IAA is regulated by IAA, IAA-precursors, and environmental factors.
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Affiliation(s)
- Daiana R Duca
- Department of Biology, University of Waterloo, Waterloo, Ontario, N2L 3G1, Canada.
| | - Bernard R Glick
- Department of Biology, University of Waterloo, Waterloo, Ontario, N2L 3G1, Canada
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175
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Mestre MC, Severino ME, Fontenla S. Evaluation and selection of culture media for the detection of auxin-like compounds and phosphate solubilization on soil yeasts. Rev Argent Microbiol 2020; 53:78-83. [PMID: 32891499 DOI: 10.1016/j.ram.2020.06.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 04/14/2020] [Accepted: 06/17/2020] [Indexed: 11/18/2022] Open
Abstract
The detection of characteristics associated with plant growth promotion has been studied frequently on bacteria and some of these detection methods were also used on yeasts. Sometimes, these methods, designed for prokaryotes, were used with no prior analysis regarding growth and production on eukaryotes. The aim of the present study was to assess and select the best suitable media for the detection of auxin-like compound production and inorganic-P solubilization on yeast strains. Already published media and new formulations, as well as yeasts with different genetic backgrounds were used for the comparison. Media were selected based on the adequate growth of yeast strains and reliable recognition of the studied features either by an easy detection of the metabolite (color or halo production) or simple medium preparation (low number of reagent and regular autoclaving). We propose here the use of the new DEV medium with glucose and with tryptophan to identify auxin-like compounds producers; and CPM medium (a variation from Custer's Chalk Medium) as base medium to identify yeasts capable of inorganic-P solubilization.
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Affiliation(s)
- María Cecilia Mestre
- IPATEC (Universidad Nacional del Comahue-CONICET), Quintral 1250, Bariloche (8400), Río Negro, Argentina; Laboratorio de Microbiología Aplicada y Biotecnología, Centro Regional Universitario Bariloche, Universidad Nacional del Comahue, Quintral 1250, Bariloche (8400), Río Negro, Argentina.
| | - María Elena Severino
- Laboratorio de Química Orgánica, Centro Regional Universitario Bariloche (CRUB), UNCO, Quintral 1250, Bariloche (8400), Río Negro, Argentina
| | - Sonia Fontenla
- IPATEC (Universidad Nacional del Comahue-CONICET), Quintral 1250, Bariloche (8400), Río Negro, Argentina; Laboratorio de Microbiología Aplicada y Biotecnología, Centro Regional Universitario Bariloche, Universidad Nacional del Comahue, Quintral 1250, Bariloche (8400), Río Negro, Argentina
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Rushabh S, Kajal C, Prittesh P, Amaresan N, Krishnamurthy R. Isolation, characterization, and optimization of indole acetic acid–producing Providencia species (7MM11) and their effect on tomato (Lycopersicon esculentum) seedlings. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2020. [DOI: 10.1016/j.bcab.2020.101732] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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177
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Screening of Bacterial Endophytes Able to Promote Plant Growth and Increase Salinity Tolerance. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10175767] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Bacterial endophytes can colonize plant tissues without harming the plant. Instead, they are often able to increase plant growth and tolerance to environmental stresses. In this work, new strains of bacterial endophytes were isolated from three economically important crop plants (sorghum, cucumber and tomato) grown in three different regions in soils with different management. All bacterial strains were identified by 16S rRNA sequencing and characterized for plant beneficial traits. Based on physiological activities, we selected eight strains that were further tested for their antibiotic resistance profile and for the ability to efficiently colonize the interior of sorghum plants. According to the results of the re-inoculation test, five strains were used to inoculate sorghum seeds. Then, plant growth promotion activity was assessed on sorghum plants exposed to salinity stress. Only two bacterial endophytes increased plant biomass, but three of them delayed or reduced plant salinity stress symptoms. These five strains were then characterized for the ability to produce the enzyme 1-aminocyclopropane-1-carboxylate (ACC) deaminase, which is involved in the increase of stress tolerance. Pseudomonas brassicacearum SVB6R1 was the only strain that was able to produce this enzyme, suggesting that ACC deaminase is not the only physiological trait involved in conferring plant tolerance to salt stress in these bacterial strains.
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178
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Romano I, Ventorino V, Ambrosino P, Testa A, Chouyia FE, Pepe O. Development and Application of Low-Cost and Eco-Sustainable Bio-Stimulant Containing a New Plant Growth-Promoting Strain Kosakonia pseudosacchari TL13. Front Microbiol 2020; 11:2044. [PMID: 33013749 PMCID: PMC7461993 DOI: 10.3389/fmicb.2020.02044] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 08/03/2020] [Indexed: 01/26/2023] Open
Abstract
The use of beneficial microbes as inoculants able to improve fitness, growth and health of plants also in stress conditions is an attractive low-cost and eco-friendly alternative strategy to harmful chemical inputs. Thirteen potential plant growth-promoting bacteria were isolated from the rhizosphere of wheat plants cultivated under drought stress and nitrogen deficiency. Among these, the two isolates TL8 and TL13 showed multiple plant growth promotion activities as production of indole-3-acetic acid (IAA), siderophores, ammonia, and 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase production, the ability to solubilize phosphate as well as exerted antimicrobial activity against plant pathogens as Botrytis spp. and Phytophthora spp. The two selected strains were identified as Kosakonia pseudosacchari by sequencing of 16S rRNA gene. They resulted also tolerant to abiotic stress and were able to efficiently colonize plant roots as observed in vitro assay under fluorescence microscope. Based on the best PGP properties, the strain K. pseudosacchari TL13 was selected to develop a new microbial based formulate. A sustainable and environmentally friendly process for inoculant production was developed using agro-industrial by-products for microbial growth. Moreover, the application of K. pseudosacchari TL13- based formulates in pot experiment improved growth performance of maize plants.
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Affiliation(s)
- Ida Romano
- Department of Agricultural Sciences, University of Naples Federico II, Naples, Italy
| | - Valeria Ventorino
- Department of Agricultural Sciences, University of Naples Federico II, Naples, Italy
| | - Patrizia Ambrosino
- Agriges S.r.l. - Nutrizione Speciale per L'Agricoltura Biologica e Integrata, San Salvatore Telesino, Italy
| | - Antonino Testa
- Department of Agricultural Sciences, University of Naples Federico II, Naples, Italy
| | - Fatima Ezzahra Chouyia
- Department of Agricultural Sciences, University of Naples Federico II, Naples, Italy.,Department of Biology, Faculty of Sciences and Techniques, Hassan II University of Casablanca, Casablanca, Morocco
| | - Olimpia Pepe
- Department of Agricultural Sciences, University of Naples Federico II, Naples, Italy
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179
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Vieira Velloso CC, de Oliveira CA, Gomes EA, Lana UGDP, de Carvalho CG, Guimarães LJM, Pastina MM, de Sousa SM. Genome-guided insights of tropical Bacillus strains efficient in maize growth promotion. FEMS Microbiol Ecol 2020; 96:5891423. [DOI: 10.1093/femsec/fiaa157] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 08/10/2020] [Indexed: 02/06/2023] Open
Abstract
ABSTRACT
Plant growth promoting bacteria (PGPB) are an efficient and sustainable alternative to mitigate biotic and abiotic stresses in maize. This work aimed to sequence the genome of two Bacillus strains (B116 and B119) and to evaluate their plant growth-promoting (PGP) potential in vitro and their capacity to trigger specific responses in different maize genotypes. Analysis of the genomic sequences revealed the presence of genes related to PGP activities. Both strains were able to produce biofilm and exopolysaccharides, and solubilize phosphate. The strain B119 produced higher amounts of IAA-like molecules and phytase, whereas B116 was capable to produce more acid phosphatase. Maize seedlings inoculated with either strains were submitted to polyethylene glycol-induced osmotic stress and showed an increase of thicker roots, which resulted in a higher root dry weight. The inoculation also increased the total dry weight and modified the root morphology of 16 out of 21 maize genotypes, indicating that the bacteria triggered specific responses depending on plant genotype background. Maize root remodeling was related to growth promotion mechanisms found in genomic prediction and confirmed by in vitro analysis. Overall, the genomic and phenotypic characterization brought new insights to the mechanisms of PGP in tropical Bacillus.
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Affiliation(s)
- Camila Cristina Vieira Velloso
- Universidade Federal de São João del-Rei, Rua Padre João Pimentel, 80 - Dom Bosco, São João del-Rei - MG, 36301-158, Brazil
| | - Christiane Abreu de Oliveira
- Centro Universitário de Sete Lagoas, Avenida Marechal Castelo Branco, 2765 - Santo Antonio, Sete Lagoas - MG, 35701-242, Brazil
- Embrapa Milho e Sorgo,Rodovia MG 424 Km 45, Zona Rural, Sete Lagoas - MG, 35701-970, Brazil
| | - Eliane Aparecida Gomes
- Embrapa Milho e Sorgo,Rodovia MG 424 Km 45, Zona Rural, Sete Lagoas - MG, 35701-970, Brazil
| | - Ubiraci Gomes de Paula Lana
- Centro Universitário de Sete Lagoas, Avenida Marechal Castelo Branco, 2765 - Santo Antonio, Sete Lagoas - MG, 35701-242, Brazil
- Embrapa Milho e Sorgo,Rodovia MG 424 Km 45, Zona Rural, Sete Lagoas - MG, 35701-970, Brazil
| | - Chainheny Gomes de Carvalho
- Centro Universitário de Sete Lagoas, Avenida Marechal Castelo Branco, 2765 - Santo Antonio, Sete Lagoas - MG, 35701-242, Brazil
| | | | - Maria Marta Pastina
- Universidade Federal de São João del-Rei, Rua Padre João Pimentel, 80 - Dom Bosco, São João del-Rei - MG, 36301-158, Brazil
- Embrapa Milho e Sorgo,Rodovia MG 424 Km 45, Zona Rural, Sete Lagoas - MG, 35701-970, Brazil
| | - Sylvia Morais de Sousa
- Universidade Federal de São João del-Rei, Rua Padre João Pimentel, 80 - Dom Bosco, São João del-Rei - MG, 36301-158, Brazil
- Centro Universitário de Sete Lagoas, Avenida Marechal Castelo Branco, 2765 - Santo Antonio, Sete Lagoas - MG, 35701-242, Brazil
- Embrapa Milho e Sorgo,Rodovia MG 424 Km 45, Zona Rural, Sete Lagoas - MG, 35701-970, Brazil
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180
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Streptomyces Endophytes Promote Host Health and Enhance Growth across Plant Species. Appl Environ Microbiol 2020; 86:AEM.01053-20. [PMID: 32561579 PMCID: PMC7414947 DOI: 10.1128/aem.01053-20] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 06/10/2020] [Indexed: 01/07/2023] Open
Abstract
We must reduce reliance on agrochemicals, and there is increasing interest in using bacterial strains to promote plant growth and protect against disease. Our study follows up reports that Arabidopsis thaliana specifically recruits Streptomyces bacteria to its roots. We test the hypotheses that they offer benefits to their A. thaliana hosts and that strains isolated from these plants might be used as probiotics. We isolated Streptomyces strains from A. thaliana roots and genome sequenced five phylogenetically distinct strains. Genome mining and bioassays indicated that all five have plant growth-promoting properties, including production of indole-3-acetic acid (IAA), siderophores, and aminocyclopropane-1-carboxylate (ACC) deaminase. Three strains significantly increased A. thaliana growth in vitro and in combination in soil. Another produces potent filipin-like antifungals and protected germinating wheat seeds against the fungal pathogen Gaeumannomyces graminis var. tritici (wheat take-all fungus). We conclude that introducing Streptomyces strains into the root microbiome provides significant benefits to plants. Streptomyces bacteria are ubiquitous in soils and are well known for producing secondary metabolites, including antimicrobials. Increasingly, they are being isolated from plant roots, and several studies have shown they are specifically recruited to the rhizosphere and the endosphere of the model plant Arabidopsis thaliana. Here, we test the hypothesis that Streptomyces bacteria have a beneficial effect on A. thaliana growth and could potentially be used as plant probiotics. To do this, we selectively isolated streptomycetes from surface-washed A. thaliana roots and generated high-quality genome sequences for five strains, which we named L2, M2, M3, N1, and N2. Reinfection of A. thaliana plants with L2, M2, and M3 significantly increased plant biomass individually and in combination, whereas N1 and N2 had a negative effect on plant growth, likely due to their production of polyene natural products which can bind to phytosterols and reduce plant growth. N2 exhibits broad-spectrum antimicrobial activity and makes filipin-like polyenes, including 14-hydroxyisochainin which inhibits the take-all fungus, Gaeumannomyces graminis var. tritici. N2 antifungal activity as a whole was upregulated ∼2-fold in response to indole-3-acetic acid (IAA), suggesting a possible role during competition in the rhizosphere. Furthermore, coating wheat seeds with N2 spores protected wheat seedlings against take-all disease. We conclude that at least some soil-dwelling streptomycetes confer growth-promoting benefits on A. thaliana, while others might be exploited to protect crops against disease. IMPORTANCE We must reduce reliance on agrochemicals, and there is increasing interest in using bacterial strains to promote plant growth and protect against disease. Our study follows up reports that Arabidopsis thaliana specifically recruits Streptomyces bacteria to its roots. We test the hypotheses that they offer benefits to their A. thaliana hosts and that strains isolated from these plants might be used as probiotics. We isolated Streptomyces strains from A. thaliana roots and genome sequenced five phylogenetically distinct strains. Genome mining and bioassays indicated that all five have plant growth-promoting properties, including production of indole-3-acetic acid (IAA), siderophores, and aminocyclopropane-1-carboxylate (ACC) deaminase. Three strains significantly increased A. thaliana growth in vitro and in combination in soil. Another produces potent filipin-like antifungals and protected germinating wheat seeds against the fungal pathogen Gaeumannomyces graminis var. tritici (wheat take-all fungus). We conclude that introducing Streptomyces strains into the root microbiome provides significant benefits to plants.
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181
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Djami-Tchatchou AT, Harrison GA, Harper CP, Wang R, Prigge MJ, Estelle M, Kunkel BN. Dual Role of Auxin in Regulating Plant Defense and Bacterial Virulence Gene Expression During Pseudomonas syringae PtoDC3000 Pathogenesis. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2020; 33:1059-1071. [PMID: 32407150 PMCID: PMC7810136 DOI: 10.1094/mpmi-02-20-0047-r] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Modification of host hormone biology is a common strategy used by plant pathogens to promote disease. For example, the bacterial pathogen strain Pseudomonas syringae DC3000 (PtoDC3000) produces the plant hormone auxin (indole-3-acetic acid [IAA]) to promote PtoDC3000 growth in plant tissue. Previous studies suggest that auxin may promote PtoDC3000 pathogenesis through multiple mechanisms, including both suppression of salicylic acid (SA)-mediated host defenses and via an unknown mechanism that appears to be independent of SA. To test if host auxin signaling is important during pathogenesis, we took advantage of Arabidopsis thaliana lines impaired in either auxin signaling or perception. We found that disruption of auxin signaling in plants expressing an inducible dominant axr2-1 mutation resulted in decreased bacterial growth and that this phenotype was suppressed by introducing the sid2-2 mutation, which impairs SA synthesis. Thus, host auxin signaling is required for normal susceptibility to PtoDC3000 and is involved in suppressing SA-mediated defenses. Unexpectedly, tir1 afb1 afb4 afb5 quadruple-mutant plants lacking four of the six known auxin coreceptors that exhibit decreased auxin perception, supported increased levels of bacterial growth. This mutant exhibited elevated IAA levels and reduced SA-mediated defenses, providing additional evidence that auxin promotes disease by suppressing host defense. We also investigated the hypothesis that IAA promotes PtoDC3000 virulence through a direct effect on the pathogen and found that IAA modulates expression of virulence genes, both in culture and in planta. Thus, in addition to suppressing host defenses, IAA acts as a microbial signaling molecule that regulates bacterial virulence gene expression.
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Affiliation(s)
| | | | - Chris P. Harper
- Department of Biology, Washington University, St. Louis, MO, U.S.A
| | - Renhou Wang
- Division of Biological Sciences, Section of Cell & Developmental Biology, University California San Diego, San Diego, CA, U.S.A
| | - Michael J. Prigge
- Division of Biological Sciences, Section of Cell & Developmental Biology, University California San Diego, San Diego, CA, U.S.A
| | - Mark Estelle
- Division of Biological Sciences, Section of Cell & Developmental Biology, University California San Diego, San Diego, CA, U.S.A
| | - Barbara N. Kunkel
- Department of Biology, Washington University, St. Louis, MO, U.S.A
- Corresponding author: B. N. Kunkel;
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182
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Márquez R, Blanco EL, Aranguren Y. Bacillus strain selection with plant growth-promoting mechanisms as potential elicitors of systemic resistance to gray mold in pepper plants. Saudi J Biol Sci 2020; 27:1913-1922. [PMID: 32714014 PMCID: PMC7376110 DOI: 10.1016/j.sjbs.2020.06.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2019] [Revised: 06/05/2020] [Accepted: 06/06/2020] [Indexed: 12/15/2022] Open
Abstract
Bacillus licheniformis induced resistance against gray mold in pepper plants. Bacillus licheniformis and Bacillus pumilus inhibited the growth of Botrytis cinerea and Fusarium solani. Plant growth promoting mechanisms were confirmed by isolated Bacillus strains.
Certain soil bacteria produce beneficial effects on the growth and health of plants; hence, their use is steadily increasing. Five strains of Bacillus with plant growth-promoting potential were selected in this study, which produced indole-3-acetic acid levels below 50 µg.mL−1. On the other hand, while only strains M8 and M15 dissolved phosphorus, the latter was the only strain that did not produce siderophores. Only strains M8 and M16 significantly inhibited the in vitro growth of Botrytis cinerea and Fusarium solani phytopathogens, whose inhibition ranges fluctuated between 60% and 63% for strains M8 and M16 against B. cinerea and between 40% and 53% for strains M8 and M16 against F. solani. Based on these results, the need to implement resistance induction against gray mold on pepper plants was determined using strains M8 and M16. In this case, strain M16 inhibited the propagation of the necrotic spot by approximately 70%, whereas strain M8 significantly reduced the superoxide dismutase activity in systemic leaves, which substantially increased in plants inoculated with strain M8 and infected with the pathogen. Accordingly, the use of native rhizobacteria may entail biotechnological progress for the integrated management of crops in agriculture industry.
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Affiliation(s)
- Robert Márquez
- Laboratorio de Fitobiotecnología, Departamento de Biología, Facultad de Ciencias, Universidad de Los Andes, Mérida, Venezuela.,Laboratorio de Investigación en Biotecnología y Química de Polímeros, Decanato de Investigación, Universidad Nacional Experimental del Táchira, San Cristóbal, Venezuela.,Laboratorio de Fisiología Molecular de Plantas, Departamento de Biología, Universidade Federal de Lavras, Lavras, Brazil
| | - Erika Lorena Blanco
- Laboratorio de Fitobiotecnología, Departamento de Biología, Facultad de Ciencias, Universidad de Los Andes, Mérida, Venezuela.,Laboratorio de Investigación en Biotecnología y Química de Polímeros, Decanato de Investigación, Universidad Nacional Experimental del Táchira, San Cristóbal, Venezuela
| | - Yani Aranguren
- Laboratorio de Investigación en Microbiología, Facultad de Ciencias Básicas y Biomédicas, Universidad Simón Bolívar, Barranquilla, Colombia
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183
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Saint-Vincent PMB, Ridout M, Engle NL, Lawrence TJ, Yeary ML, Tschaplinski TJ, Newcombe G, Pelletier DA. Isolation, Characterization, and Pathogenicity of Two Pseudomonas syringae Pathovars from Populus trichocarpa Seeds. Microorganisms 2020; 8:microorganisms8081137. [PMID: 32731357 PMCID: PMC7465253 DOI: 10.3390/microorganisms8081137] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 07/21/2020] [Accepted: 07/23/2020] [Indexed: 11/16/2022] Open
Abstract
Pseudomonas syringae is a ubiquitous plant pathogen, infecting both woody and herbaceous plants and resulting in devastating agricultural crop losses. Characterized by a remarkable specificity for plant hosts, P. syringae pathovars utilize a number of virulence factors including the type III secretion system and effector proteins to elicit disease in a particular host species. Here, two Pseudomonas syringae strains were isolated from diseased Populustrichocarpa seeds. The pathovars were capable of inhibiting poplar seed germination and were selective for the Populus genus. Sequencing of the newly described organisms revealed similarity to phylogroup II pathogens and genomic regions associated with woody host-associated plant pathogens, as well as genes for specific virulence factors. The host response to infection, as revealed through metabolomics, is the induction of the stress response through the accumulation of higher-order salicylates. Combined with necrosis on leaf surfaces, the plant appears to quickly respond by isolating infected tissues and mounting an anti-inflammatory defense. This study improves our understanding of the initial host response to epiphytic pathogens in Populus and provides a new model system for studying the effects of a bacterial pathogen on a woody host plant in which both organisms are fully genetically sequenced.
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Affiliation(s)
- Patricia MB Saint-Vincent
- Bioscience Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA; (P.M.S.-V.); (N.L.E.); (T.J.L.); (M.L.Y.); (T.J.T.)
- Geologic and Environmental Systems Directorate, National Energy Technology Laboratory, Pittsburgh, PA 15236, USA
| | - Mary Ridout
- Department of Forest, Rangeland and Fire Sciences, University of Idaho, Moscow, ID 83844, USA; (M.R.); (G.N.)
| | - Nancy L. Engle
- Bioscience Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA; (P.M.S.-V.); (N.L.E.); (T.J.L.); (M.L.Y.); (T.J.T.)
| | - Travis J. Lawrence
- Bioscience Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA; (P.M.S.-V.); (N.L.E.); (T.J.L.); (M.L.Y.); (T.J.T.)
| | - Meredith L. Yeary
- Bioscience Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA; (P.M.S.-V.); (N.L.E.); (T.J.L.); (M.L.Y.); (T.J.T.)
| | - Timothy J. Tschaplinski
- Bioscience Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA; (P.M.S.-V.); (N.L.E.); (T.J.L.); (M.L.Y.); (T.J.T.)
| | - George Newcombe
- Department of Forest, Rangeland and Fire Sciences, University of Idaho, Moscow, ID 83844, USA; (M.R.); (G.N.)
| | - Dale A. Pelletier
- Bioscience Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA; (P.M.S.-V.); (N.L.E.); (T.J.L.); (M.L.Y.); (T.J.T.)
- Correspondence:
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184
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Luziatelli F, Ficca AG, Bonini P, Muleo R, Gatti L, Meneghini M, Tronati M, Melini F, Ruzzi M. A Genetic and Metabolomic Perspective on the Production of Indole-3-Acetic Acid by Pantoea agglomerans and Use of Their Metabolites as Biostimulants in Plant Nurseries. Front Microbiol 2020; 11:1475. [PMID: 32765438 PMCID: PMC7381177 DOI: 10.3389/fmicb.2020.01475] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 06/05/2020] [Indexed: 12/11/2022] Open
Abstract
The species Pantoea agglomerans includes strains that are agronomically relevant for their growth-promoting or biocontrol traits. Molecular analysis demonstrated that the IPDC pathway involved in the conversion of tryptophan (Trp) to indole-3-acetic acid (IAA) is highly conserved among P. agglomerans strains at both gene and protein levels. Results also indicated that the promoter region controlling the inducible expression of ipdC gene differs from the model system Enterobacter cloacae, which is in accordance with the observation that P. agglomerans accumulates higher levels of IAA when cells are collected in the exponential phase of growth. To assess the potential applications of these microorganisms for IAA production, P. agglomerans C1, an efficient auxin-producer strain, was cultivated in 5 L fermenter so as to evaluate the effect of the medium formulation, the physiological state of the cells, and the induction timing on the volumetric productivity. Results demonstrated that higher IAA levels were obtained by using a saline medium amended with yeast extract and saccharose and by providing Trp, which acts both as a precursor and an inducer, to a culture in the exponential phase of growth. Untargeted metabolomic analysis revealed a significant effect of the carbon source on the exometabolome profile relative to IAA-related compounds and other plant bioactive signaling molecules. The IAA-enriched metabolites secreted in the culture medium by P. agglomerans C1 were used as plant biostimulants to run a series of trials at a large-scale nursery farm. Tests were carried out with in vitro and ex vitro systems following the regular protocols used for large-scale plant tree agamic propagation. Results obtained with 4,540 microcuttings of Prunus rootstock GF/677 and 1,080 plantlets of Corylus avellana L. showed that metabolites from strain C1 improved percentage of rooted-explant, number of adventitious root formation, plant survival, and quality of plant as vigor, with an increase in the leaf area between 17.5 and 42.7% compared to IBA-K (indole-3-butyric acid potassium salt)-treated plants.
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Affiliation(s)
- Francesca Luziatelli
- Department for Innovation in Biological, Agro-food and Forest systems (DIBAF), University of Tuscia, Viterbo, Italy
| | - Anna Grazia Ficca
- Department for Innovation in Biological, Agro-food and Forest systems (DIBAF), University of Tuscia, Viterbo, Italy
| | - Paolo Bonini
- Next-Generation Agronomics (NGA) Laboratory, Tarragona, Spain
| | - Rosario Muleo
- Department of Agricultural and Forestry Sciences (DAFNE), University of Tuscia, Viterbo, Italy
| | - Lorenzo Gatti
- Department of Agricultural and Forestry Sciences (DAFNE), University of Tuscia, Viterbo, Italy
| | | | - Michele Tronati
- Department for Innovation in Biological, Agro-food and Forest systems (DIBAF), University of Tuscia, Viterbo, Italy
| | - Francesca Melini
- Department for Innovation in Biological, Agro-food and Forest systems (DIBAF), University of Tuscia, Viterbo, Italy
- Council for Agricultural Research and Economics (CREA), Research Centre for Food and Nutrition, Rome, Italy
| | - Maurizio Ruzzi
- Department for Innovation in Biological, Agro-food and Forest systems (DIBAF), University of Tuscia, Viterbo, Italy
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185
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Legein M, Smets W, Vandenheuvel D, Eilers T, Muyshondt B, Prinsen E, Samson R, Lebeer S. Modes of Action of Microbial Biocontrol in the Phyllosphere. Front Microbiol 2020; 11:1619. [PMID: 32760378 PMCID: PMC7372246 DOI: 10.3389/fmicb.2020.01619] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Accepted: 06/22/2020] [Indexed: 12/12/2022] Open
Abstract
A fast-growing field of research focuses on microbial biocontrol in the phyllosphere. Phyllosphere microorganisms possess a wide range of adaptation and biocontrol factors, which allow them to adapt to the phyllosphere environment and inhibit the growth of microbial pathogens, thus sustaining plant health. These biocontrol factors can be categorized in direct, microbe-microbe, and indirect, host-microbe, interactions. This review gives an overview of the modes of action of microbial adaptation and biocontrol in the phyllosphere, the genetic basis of the mechanisms, and examples of experiments that can detect these mechanisms in laboratory and field experiments. Detailed insights in such mechanisms are key for the rational design of novel microbial biocontrol strategies and increase crop protection and production. Such novel biocontrol strategies are much needed, as ensuring sufficient and consistent food production for a growing world population, while protecting our environment, is one of the biggest challenges of our time.
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Affiliation(s)
- Marie Legein
- Environmental Ecology and Applied Microbiology, Department of Bioscience Engineering, University of Antwerp, Antwerp, Belgium
| | - Wenke Smets
- Environmental Ecology and Applied Microbiology, Department of Bioscience Engineering, University of Antwerp, Antwerp, Belgium
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA, United States
| | - Dieter Vandenheuvel
- Environmental Ecology and Applied Microbiology, Department of Bioscience Engineering, University of Antwerp, Antwerp, Belgium
| | - Tom Eilers
- Environmental Ecology and Applied Microbiology, Department of Bioscience Engineering, University of Antwerp, Antwerp, Belgium
| | - Babette Muyshondt
- Environmental Ecology and Applied Microbiology, Department of Bioscience Engineering, University of Antwerp, Antwerp, Belgium
| | - Els Prinsen
- Laboratory for Integrated Molecular Plant Physiology Research, Department of Biology, University of Antwerp, Antwerp, Belgium
| | - Roeland Samson
- Environmental Ecology and Applied Microbiology, Department of Bioscience Engineering, University of Antwerp, Antwerp, Belgium
| | - Sarah Lebeer
- Environmental Ecology and Applied Microbiology, Department of Bioscience Engineering, University of Antwerp, Antwerp, Belgium
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186
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Auxin biosynthesis in the phytopathogenic fungus Leptosphaeria maculans is associated with enhanced transcription of indole-3-pyruvate decarboxylase LmIPDC2 and tryptophan aminotransferase LmTAM1. Res Microbiol 2020; 171:174-184. [PMID: 32540203 DOI: 10.1016/j.resmic.2020.05.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 05/12/2020] [Accepted: 05/20/2020] [Indexed: 12/23/2022]
Abstract
Auxins are hormones that regulate growth and development in plants. Besides plants, various microorganisms also produce auxins. Here we investigate whether and how the phytopathogenic fungus Leptosphaeria maculans biosynthesizes auxins. We characterized the auxin profile of in vitro grown L. maculans. The culture was further supplied with the auxin biosynthetic-precursors tryptophan and tryptamine and gene expression and phytohormone content was analyzed. L. maculans in vitro produced IAA (indole-3-acetic acid) as the predominant auxin metabolite. IAA production could be further stimulated by supplying precursors. Expression of indole-3-pyruvate decarboxylase LmIPDC2, tryptophan aminotransferase LmTAM1 and nitrilase LmNIT1 genes was mainly upregulated after adding tryptophan and correlated with IAA production, suggesting that these genes are the key components of auxin biosynthesis in L. maculans. Tryptamine acted as a potent inducer of IAA production, though a pathway independent of LmIPDC2/LmTAM1 may be involved. Despite L. maculans being a rich source of bioactive IAA, the auxin metabolic profile of host plant Brassica napus was not altered upon infection. Exogenous IAA inhibited the growth of L. maculans in vitro when supplied in high concentration. Altogether, we showed that L. maculans is capable of IAA production and we have identified biosynthetic genes that were responsive to tryptophan treatment.
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187
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Endophytic microbes: biodiversity, plant growth-promoting mechanisms and potential applications for agricultural sustainability. Antonie van Leeuwenhoek 2020; 113:1075-1107. [PMID: 32488494 DOI: 10.1007/s10482-020-01429-y] [Citation(s) in RCA: 91] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 05/22/2020] [Indexed: 10/24/2022]
Abstract
Endophytic microbes are known to live asymptomatically inside their host throughout different stages of their life cycle and play crucial roles in the growth, development, fitness, and diversification of plants. The plant-endophyte association ranges from mutualism to pathogenicity. These microbes help the host to combat a diverse array of biotic and abiotic stressful conditions. Endophytic microbes play a major role in the growth promotion of their host by solubilizing of macronutrients such as phosphorous, potassium, and zinc; fixing of atmospheric nitrogen, synthesizing of phytohormones, siderophores, hydrogen cyanide, ammonia, and act as a biocontrol agent against wide array of phytopathogens. Endophytic microbes are beneficial to plants by directly promoting their growth or indirectly by inhibiting the growth of phytopathogens. Over a long period of co-evolution, endophytic microbes have attained the mechanism of synthesis of various hydrolytic enzymes such as pectinase, xylanases, cellulase, and proteinase which help in the penetration of endophytic microbes into tissues of plants. The effective usage of endophytic microbes in the form of bioinoculants reduce the usage of chemical fertilizers. Endophytic microbes belong to different phyla such as Actinobacteria, Acidobacteria, Bacteroidetes, Deinococcus-thermus, Firmicutes, Proteobacteria, and Verrucomicrobia. The most predominant and studied endophytic bacteria belonged to Proteobacteria followed by Firmicutes and then by Actinobacteria. The most dominant among reported genera in most of the leguminous and non-leguminous plants are Bacillus, Pseudomonas, Fusarium, Burkholderia, Rhizobium, and Klebsiella. In future, endophytic microbes have a wide range of potential for maintaining health of plant as well as environmental conditions for agricultural sustainability. The present review is focused on endophytic microbes, their diversity in leguminous as well as non-leguminous crops, biotechnological applications, and ability to promote the growth of plant for agro-environmental sustainability.
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188
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Saline and Arid Soils: Impact on Bacteria, Plants, and their Interaction. BIOLOGY 2020; 9:biology9060116. [PMID: 32498442 PMCID: PMC7344409 DOI: 10.3390/biology9060116] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 05/26/2020] [Accepted: 05/29/2020] [Indexed: 12/11/2022]
Abstract
Salinity and drought are the most important abiotic stresses hampering crop growth and yield. It has been estimated that arid areas cover between 41% and 45% of the total Earth area worldwide. At the same time, the world’s population is going to soon reach 9 billion and the survival of this huge amount of people is dependent on agricultural products. Plants growing in saline/arid soil shows low germination rate, short roots, reduced shoot biomass, and serious impairment of photosynthetic efficiency, thus leading to a substantial loss of crop productivity, resulting in significant economic damage. However, plants should not be considered as single entities, but as a superorganism, or a holobiont, resulting from the intimate interactions occurring between the plant and the associated microbiota. Consequently, it is very complex to define how the plant responds to stress on the basis of the interaction with its associated plant growth-promoting bacteria (PGPB). This review provides an overview of the physiological mechanisms involved in plant survival in arid and saline soils and aims at describing the interactions occurring between plants and its bacteriome in such perturbed environments. The potential of PGPB in supporting plant survival and fitness in these environmental conditions has been discussed.
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189
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Morffy N, Strader LC. Old Town Roads: routes of auxin biosynthesis across kingdoms. CURRENT OPINION IN PLANT BIOLOGY 2020; 55:21-27. [PMID: 32199307 PMCID: PMC7540728 DOI: 10.1016/j.pbi.2020.02.002] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 01/28/2020] [Accepted: 02/09/2020] [Indexed: 05/04/2023]
Abstract
Auxin is an important signaling molecule synthesized in organisms from multiple kingdoms of life, including land plants, green algae, and bacteria. In this review, we highlight the similarities and differences in auxin biosynthesis among these organisms. Tryptophan-dependent routes to IAA are found in land plants, green algae and bacteria. Recent sequencing efforts show that the indole-3-pyruvic acid pathway, one of the primary biosynthetic pathways in land plants, is also found in the green algae. These similarities raise questions about the origin of auxin biosynthesis. Future studies comparing auxin biosynthesis across kingdoms will shed light on its origin and role outside of the plant lineage.
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Affiliation(s)
- Nicholas Morffy
- Department of Biology, Washington University, St. Louis, MO 63130, United States; Center for Science and Engineering Living Systems (CSELS), Washington University, St. Louis, MO 63130, United States.
| | - Lucia C Strader
- Department of Biology, Washington University, St. Louis, MO 63130, United States; Center for Science and Engineering Living Systems (CSELS), Washington University, St. Louis, MO 63130, United States; Center for Engineering MechanoBiology, Washington University, St. Louis, MO 63130, United States.
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Azaroual SE, Hazzoumi Z, Mernissi NE, Aasfar A, Meftah Kadmiri I, Bouizgarne B. Role of Inorganic Phosphate Solubilizing Bacilli Isolated from Moroccan Phosphate Rock Mine and Rhizosphere Soils in Wheat (Triticum aestivum L) Phosphorus Uptake. Curr Microbiol 2020; 77:2391-2404. [PMID: 32468184 DOI: 10.1007/s00284-020-02046-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Accepted: 05/20/2020] [Indexed: 01/19/2023]
Abstract
This work aimed to assess the ability of plant growth-promoting Bacilli isolated from wheat rhizosphere and rock phosphate mine soils to convert inorganic phosphate (Pi) from Moroccan natural phosphate (NP) to soluble forms. The effect of these bacteria on wheat plants in order to increase their phosphorus (P) uptake in vitro was also investigated. Bacteria were isolated from wheat rhizosphere and natural rock phosphate soils and screened for their ability to solubilize Tri-Calcium Phosphate (TCP) and Natural Rock Phosphate (NP), to produce indole-3-acetic acid (IAA), siderophores and 1-aminocyclopropane-1-carboxylate (ACC) deaminase. Isolates were identified by 16S rRNA sequencing and tested for their capacity to increase wheat plants growth and their phosphorus uptake.Twenty-four strains belonging to Bacillus genus isolated from both biotopes were screened for their ability to solubilize Pi. The highest NP solubilization was showed by strains isolated from wheat rhizosphere. Solubilization of Pi was accompanied by organic acid production. Strains produce IAA, siderophore and ACC deaminase. Inoculation assays using efficient NP-solubilizing bacilli strains from both sources showed the ability of these isolates to increase wheat growth and the phosphorus uptake under in vitro conditions. Bacilli strains isolated from rhizosphere soil and natural rock phosphorus soil showed effective solubilization of Pi from rock phosphate. Phosphate solubilizing Bacilli were evaluated for their plant growth promotion under in vitro conditions. Results revealed the positive effect of all strains on biometric parameters and P content of wheat seedlings.
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Affiliation(s)
- Salah Eddine Azaroual
- Team: Microbial Biotechnology, Laboratory : Plant Biotechnology, Faculty of Sciences, Ibn Zohr University, Cité Dakhla, BP 8106, Agadir, Morocco.,Green Biotechnology Laboratory, Moroccan Foundation For Advanced Science Innovation and Research- Rue Mohammed Al Jazouli, Madinat Al Irfan, Rabat, Morocco
| | - Zakaria Hazzoumi
- Green Biotechnology Laboratory, Moroccan Foundation For Advanced Science Innovation and Research- Rue Mohammed Al Jazouli, Madinat Al Irfan, Rabat, Morocco
| | - Najib El Mernissi
- Green Biotechnology Laboratory, Moroccan Foundation For Advanced Science Innovation and Research- Rue Mohammed Al Jazouli, Madinat Al Irfan, Rabat, Morocco
| | - Abderrahim Aasfar
- Green Biotechnology Laboratory, Moroccan Foundation For Advanced Science Innovation and Research- Rue Mohammed Al Jazouli, Madinat Al Irfan, Rabat, Morocco
| | - Issam Meftah Kadmiri
- Green Biotechnology Laboratory, Moroccan Foundation For Advanced Science Innovation and Research- Rue Mohammed Al Jazouli, Madinat Al Irfan, Rabat, Morocco.
| | - Brahim Bouizgarne
- Team: Microbial Biotechnology, Laboratory : Plant Biotechnology, Faculty of Sciences, Ibn Zohr University, Cité Dakhla, BP 8106, Agadir, Morocco.
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191
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Song Z, Lu Y, Liu X, Wei C, Oladipo A, Fan B. Evaluation of Pantoea eucalypti FBS135 for pine (Pinus massoniana) growth promotion and its genome analysis. J Appl Microbiol 2020; 129:958-970. [PMID: 32329126 DOI: 10.1111/jam.14673] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 04/16/2020] [Accepted: 04/18/2020] [Indexed: 12/15/2022]
Abstract
AIMS Pinus massoniana is one of the most widely distributed forest plants in China. In this study, we isolated a bacterial endophyte (designated FBS135) from apical buds and needles of P. massoniana. Investigations were performed to understand the effects of the strain on pine growth, its genomic features and the functions of the plasmids it carries. METHODS AND RESULTS Based on its morphological features and 16S rRNA sequence, strain FBS135 was primarily identified as Pantoea eucalypti. We found that FBS135 not only promoted the growth of P. massoniana seedlings, but also significantly increased the survival rate of pine seedlings. The whole genome of FBS135 was sequenced, which revealed that the bacterium carries one chromosome and four plasmids. Its chromosome is 4 023 751 bp in size and contains dozens of genes involved in plant symbiosis. Curing one of the four plasmids, pPant1, resulted in a decrease in the size of the FBS135 colonies and the loss of the ability to synthesize yellow pigment, indicating that this plasmid may be very important for FBS135. CONCLUSIONS Pantoea eucalypti FBS135 has a genomic basis to be implicated in plant-associated lifestyle and was established to have the capability to promote pine growth. SIGNIFICANCE AND IMPACT OF THE STUDY To the best of our knowledge, this is the first report that such a bacterial species, P. eucalypti, was isolated from pine trees and evidenced to have pine beneficial activities. Our results elucidate the ecological effects of endophytes on forest plants as well as endophyte-plant interaction mechanisms.
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Affiliation(s)
- Z Song
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing, China
| | - Y Lu
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing, China
| | - X Liu
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing, China
| | - C Wei
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing, China
| | - A Oladipo
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing, China
| | - B Fan
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing, China
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192
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Endophytes Increased Fruit Quality with Higher Soluble Sugar Production in Honeycrisp Apple ( Malus pumila). Microorganisms 2020; 8:microorganisms8050699. [PMID: 32397574 PMCID: PMC7284893 DOI: 10.3390/microorganisms8050699] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 05/05/2020] [Accepted: 05/06/2020] [Indexed: 11/16/2022] Open
Abstract
Endophytes are fungi, bacteria, or yeast symbionts that live in the intercellular spaces or vascular tissues of host plants. Investigations indicate that endophytes isolated from the Salicaceae family (Populus and Salix) hosts provide several benefits that promote plant growth, including but not limited to di-nitrogen fixation, plant hormone production, nutrient acquisition, stress tolerance, and defense against phytopathogens. In exchange, the microorganisms receive domicile and photosynthates. Considering the known characteristics of nitrogen fixation and plant hormone production, we hypothesized that apple trees grown under nitrogen-limited conditions would show improved biometrics with endophyte inoculation. Our research objectives were to investigate the endophyte effects on plant physiology and fruiting. We examined these effects through ecophysiology metrics involving rates of photosynthesis, stomatal conductance and density, transpiration, biomass accretion, chlorophyll content and fluorescence, and fruit soluble sugar content and biomass. Our results showed evidence of the endophytes’ colonization in apple trees, decreased stomatal density, delayed leaf senescence, and increased lateral root biomass with endophytes. A highlight of the findings was a significant increase in both fruit soluble sugar content and biomass. Future research into the mechanistic underpinnings of this phenomenon stands to offer novel insights on how microbiota may alter carbohydrate metabolism under nitrogen-deficient conditions.
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193
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From Genome to Field-Observation of the Multimodal Nematicidal and Plant Growth-Promoting Effects of Bacillus firmus I-1582 on Tomatoes Using Hyperspectral Remote Sensing. PLANTS 2020; 9:plants9050592. [PMID: 32384661 PMCID: PMC7285481 DOI: 10.3390/plants9050592] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 04/20/2020] [Accepted: 04/29/2020] [Indexed: 12/26/2022]
Abstract
Root-knot nematodes are considered the most important group of plant-parasitic nematodes due to their wide range of plant hosts and subsequent role in yield losses in agricultural production systems. Chemical nematicides are the primary control method, but ecotoxicity issues with some compounds has led to their phasing-out and consequential development of new control strategies, including biological control. We evaluated the nematicidal activity of Bacillus firmus I-1582 in pot and microplot experiments against Meloidogyne luci. I-1582 reduced nematode counts by 51% and 53% compared to the untreated control in pot and microplot experiments, respectively. I-1582 presence in the rhizosphere had concurrent nematicidal and plant growth-promoting effects, measured using plant morphology, relative chlorophyll content, elemental composition and hyperspectral imaging. Hyperspectral imaging in the 400–2500 nm spectral range and supervised classification using partial least squares support vector machines successfully differentiated B. firmus-treated and untreated plants, with 97.4% and 96.3% accuracy in pot and microplot experiments, respectively. Visible and shortwave infrared spectral regions associated with chlorophyll, N–H and C–N stretches in proteins were most relevant for treatment discrimination. This study shows the ability of hyperspectral imaging to rapidly assess the success of biological measures for pest control.
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194
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Wang S, Ma L, Xu Y, Wang Y, Zhu N, Liu J, Dolfing J, Kerr P, Wu Y. The unexpected concentration-dependent response of periphytic biofilm during indole acetic acid removal. BIORESOURCE TECHNOLOGY 2020; 303:122922. [PMID: 32044647 DOI: 10.1016/j.biortech.2020.122922] [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: 11/30/2019] [Revised: 01/24/2020] [Accepted: 01/25/2020] [Indexed: 06/10/2023]
Abstract
Due to its extensive application in agriculture as a germinating agent and growth promoter, indole acetic acid (IAA) is present in a variety of aquatic ecosystems. To explore the response of microbial aggregates to exogenous IAA in aquatic ecosystems, periphytic biofilm, a typical microbial aggregate, was exposed to IAA at different concentrations. Results reveal an unexpected concentration-dependent effect of IAA on periphytic biofilm. Concentrations of IAA less than 10 mg/L inhibit periphytic growth, but stimulate growth when the IAA concentration exceeds 50 mg/L. Periphytic biofilm adapts to different IAA concentrations by antioxidant enzyme activation, community structure optimization and carbon-metabolism pattern change, and promotes bioremediation of IAA contaminated water in the process. The removal rates of IAA reached up to 95%-100%. This study reveals the capacity of periphytic biofilm for IAA removal in practice.
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Affiliation(s)
- Sichu Wang
- Zigui Ecological Station for Three Gorges Dam Project, State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, 71 East Beijing Road, Nanjing 210008, China; College of Advanced Agricultural Science, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lan Ma
- Zigui Ecological Station for Three Gorges Dam Project, State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, 71 East Beijing Road, Nanjing 210008, China; Agricultural Service Center of Qiandeng Town, 442 North Jingtang Road, Qiandeng Town, Kunshan 215300, China
| | - Ying Xu
- Zigui Ecological Station for Three Gorges Dam Project, State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, 71 East Beijing Road, Nanjing 210008, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yu Wang
- Zigui Ecological Station for Three Gorges Dam Project, State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, 71 East Beijing Road, Nanjing 210008, China; School of Resources, Environmental & Chemical Engineering and Key Laboratory of Poyang Lake Environment and Resource Utilization, Nanchang University, Nanchang, China
| | - Ningyuan Zhu
- Zigui Ecological Station for Three Gorges Dam Project, State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, 71 East Beijing Road, Nanjing 210008, China
| | - Junzhuo Liu
- Zigui Ecological Station for Three Gorges Dam Project, State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, 71 East Beijing Road, Nanjing 210008, China
| | - Jan Dolfing
- School of Engineering, Newcastle University, Newcastle NE1 7RU, United Kingdom
| | - Philip Kerr
- School of Biomedical Sciences, Charles Sturt University, Boorooma Street, Wagga Wagga, NSW 2678, Australia
| | - Yonghong Wu
- Zigui Ecological Station for Three Gorges Dam Project, State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, 71 East Beijing Road, Nanjing 210008, China; School of Engineering, Newcastle University, Newcastle NE1 7RU, United Kingdom.
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195
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Galindo FS, Filho MCMT, Buzetti S, Rodrigues WL, Fernandes GC, Boleta EHM, Neto MB, Pereira MRDA, Rosa PAL, Pereira ÍT, Gaspareto RN. Influence of Azospirillum brasilense associated with silicon and nitrogen fertilization on macronutrient contents in corn. OPEN AGRICULTURE 2020. [DOI: 10.1515/opag-2020-0013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Abstract
Information regarding the interaction between biological nitrogen fixation (BNF) with Azospirillum brasilense inoculation and the use of silicon (Si) is needed. Silicon exerts numerous benefits on grasses, especially when the plants are subjected to biotic and abiotic stresses, affecting plant nutrition. The aim of this research was to determine if there is a synergistic effect between the inoculation with A. brasilense and Si use, on macro-nutrient content in corn shoot and root. The field trial was performed in Selvíria, Brazil, on a Typic Rhodic Hapludox soil under no-till system. The experimental design was a completely randomized block design with four replicates arranged in a 2 × 5 × 2 triple factorial arrangement, consisting of two soil acidity corrective sources (dolomitic limestone and Ca and Mg silicate as sources of Si); five N doses (0, 50, 100, 150 and 200 kg ha-1 applied in topdressing); with and without seed inoculation with A. brasilense. The inoculation favored N concentration in shoots and increased the N and S concentration even when associated to high N rates in topdressing. The Si as Ca and Mg silicate associated with the increment of N rates does not promote an increase in the macronutrients uptake. Although it did not favor the N use, the Si also did not negatively affect the benefits of the A. brasilense.
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Affiliation(s)
- Fernando Shintate Galindo
- Department of Plant Health, Rural Engineering, and Soils, Faculdade de Engenharia de Ilha Solteira, Universidade Estadual Paulista “Júlio de Mesquita Filho” , Ilha Solteira , Sao Paulo State, Zip Code 15385-000 , Brazil
| | - Marcelo Carvalho Minhoto Teixeira Filho
- Department of Plant Health, Rural Engineering, and Soils, Faculdade de Engenharia de Ilha Solteira, Universidade Estadual Paulista “Júlio de Mesquita Filho” , Ilha Solteira , Sao Paulo State, Zip Code 15385-000 , Brazil
| | - Salatiér Buzetti
- Department of Plant Health, Rural Engineering, and Soils, Faculdade de Engenharia de Ilha Solteira, Universidade Estadual Paulista “Júlio de Mesquita Filho” , Ilha Solteira , Sao Paulo State, Zip Code 15385-000 , Brazil
| | - Willian Lima Rodrigues
- Department of Plant Health, Rural Engineering, and Soils, Faculdade de Engenharia de Ilha Solteira, Universidade Estadual Paulista “Júlio de Mesquita Filho” , Ilha Solteira , Sao Paulo State, Zip Code 15385-000 , Brazil
| | - Guilherme Carlos Fernandes
- Department of Plant Health, Rural Engineering, and Soils, Faculdade de Engenharia de Ilha Solteira, Universidade Estadual Paulista “Júlio de Mesquita Filho” , Ilha Solteira , Sao Paulo State, Zip Code 15385-000 , Brazil
| | - Eduardo Henrique Marcandalli Boleta
- Department of Plant Health, Rural Engineering, and Soils, Faculdade de Engenharia de Ilha Solteira, Universidade Estadual Paulista “Júlio de Mesquita Filho” , Ilha Solteira , Sao Paulo State, Zip Code 15385-000 , Brazil
| | - Maurício Barco Neto
- Department of Plant Health, Rural Engineering, and Soils, Faculdade de Engenharia de Ilha Solteira, Universidade Estadual Paulista “Júlio de Mesquita Filho” , Ilha Solteira , Sao Paulo State, Zip Code 15385-000 , Brazil
| | - Maikon Richer de Azambuja Pereira
- Department of Plant Health, Rural Engineering, and Soils, Faculdade de Engenharia de Ilha Solteira, Universidade Estadual Paulista “Júlio de Mesquita Filho” , Ilha Solteira , Sao Paulo State, Zip Code 15385-000 , Brazil
| | - Poliana Aparecida Leonel Rosa
- Department of Plant Health, Rural Engineering, and Soils, Faculdade de Engenharia de Ilha Solteira, Universidade Estadual Paulista “Júlio de Mesquita Filho” , Ilha Solteira , Sao Paulo State, Zip Code 15385-000 , Brazil
| | - Íngrid Torres Pereira
- Department of Plant Health, Rural Engineering, and Soils, Faculdade de Engenharia de Ilha Solteira, Universidade Estadual Paulista “Júlio de Mesquita Filho” , Ilha Solteira , Sao Paulo State, Zip Code 15385-000 , Brazil
| | - Rafaela Neris Gaspareto
- Department of Plant Health, Rural Engineering, and Soils, Faculdade de Engenharia de Ilha Solteira, Universidade Estadual Paulista “Júlio de Mesquita Filho” , Ilha Solteira , Sao Paulo State, Zip Code 15385-000 , Brazil
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Yang C, Ho YN, Makita R, Inoue C, Chien MF. A multifunctional rhizobacterial strain with wide application in different ferns facilitates arsenic phytoremediation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 712:134504. [PMID: 31831229 DOI: 10.1016/j.scitotenv.2019.134504] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 09/11/2019] [Accepted: 09/15/2019] [Indexed: 06/10/2023]
Abstract
Pteris vittata and Pteris multifida are widely studied As hyperaccumulators that absorb As mainly via roots. Hence, rhizobacteria exhibit promising potential in phytoextraction owing to their immense microbial diversity and interactions with plants. Pseudomonas vancouverensis strain m318 that contains aioA-like genes was screened from P. multifida's rhizosphere through the high As resistance (minimum inhibitory concentrations (MICs) against As(III): 16 mM; MICs against As(V): 320 mM), rapid As oxidation (98% oxidation by bacterial cultures (OD600nm = 1) from 200 μL of 0.1 mM As(III) within 24 h), predominant secretion of IAA (12.45 mg L-1) and siderophores (siderophore unit: 88%). Strain m318 showed significant chemotactic response and high colonization efficiency to P. vittata roots, which suggested its wide host affinity. Interestingly, inoculation with strain m318 enhanced the proportion of aioA-like genes in the rhizosphere. And in field trials, inoculation with strain m318 increased As accumulation in P. vittata by 48-146% and in P. multifida by 42-233%. Post-transplantation inoculations also increased As accumulation in both ferns. The abilities of the isolated multifunctional strain m318 and the increase in the rhizosphere microbial aioA-like genes are thus speculated to be involved in As transformation in the rhizospheres and roots of P. vittata and P. multifida.
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Affiliation(s)
- Chongyang Yang
- Graduate School of Environmental Studies, Tohoku University, Aramaki, Aoba-ku, 6-6-20 Aoba, Sendai 980-8579, Japan
| | - Ying-Ning Ho
- Graduate School of Environmental Studies, Tohoku University, Aramaki, Aoba-ku, 6-6-20 Aoba, Sendai 980-8579, Japan; Institute of Marine Biology and Center of Excellence for the Oceans, National Taiwan Ocean University, 2 Pei-Ning Road, Keelung 20224, Taiwan
| | - Ryota Makita
- Graduate School of Environmental Studies, Tohoku University, Aramaki, Aoba-ku, 6-6-20 Aoba, Sendai 980-8579, Japan
| | - Chihiro Inoue
- Graduate School of Environmental Studies, Tohoku University, Aramaki, Aoba-ku, 6-6-20 Aoba, Sendai 980-8579, Japan
| | - Mei-Fang Chien
- Graduate School of Environmental Studies, Tohoku University, Aramaki, Aoba-ku, 6-6-20 Aoba, Sendai 980-8579, Japan.
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197
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Rosa PAL, Mortinho ES, Jalal A, Galindo FS, Buzetti S, Fernandes GC, Barco Neto M, Pavinato PS, Teixeira Filho MCM. Inoculation With Growth-Promoting Bacteria Associated With the Reduction of Phosphate Fertilization in Sugarcane. FRONTIERS IN ENVIRONMENTAL SCIENCE 2020. [DOI: 10.3389/fenvs.2020.00032] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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198
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Ali S, Saldias S, Weerasuriya N, Delaney K, Kandasamy S, Lazarovits G. Corn microbial diversity and its relationship to yield. Can J Microbiol 2020; 66:457-473. [PMID: 32155347 DOI: 10.1139/cjm-2020-0002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
This study aimed to identify possible relationships between corn (Zea mays L.) productivity and its endosphere microbial community. Any insights would be used to develop testable hypotheses at the farm level. Sap was collected from 14 fields in 2014 and 10 fields in 2017, with a yield range of 10.1 to 21.7 tonnes per hectare (t/ha). The microbial sap communities were analyzed using terminal restriction fragment length polymorphism (TRFLP) and identified using an internal pure culture reference database and BLAST. This technique is rapid and inexpensive and is suitable for use at the grower level. Diversity, richness, and normalized abundances of each bacterial population in corn sap samples were evaluated to link the microbiome of a specific field to its yield. A negative trend was observed (r = -0.60), with higher-yielding fields having lower terminal restriction fragment (TRF) richness. A partial least square regression analysis of TRF intensity and binary data from 2014 identified 10 TRFs (bacterial genera) that positively, or negatively, correlated with corn yields, when either absent or present at certain levels or ratios. Using these observations, a model was developed that accommodated criteria for each of the 10 microbes and assigned a score for each field out of 10. Data collected in 2014 showed that sites with higher model scores were highly correlated with larger yields (r = 0.83). This correlation was also seen when the 2017 data set was used (r = 0.87). We were able to conclude that a positive significant effect was seen with the model score and yield (adjusted R2 = 0.67, F[1,22] = 46.7, p < 0.001) when combining 2014 and 2017 data. The results of this study are being expanded to identify the key microbes in the corn sap community that potentially impact corn yield, regardless of corn variety, geographic factors, or edaphic factors.
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Affiliation(s)
- Shimaila Ali
- A&L Biologicals, Agroecological Research Services Centre, 2136 Jetstream Road, London, ON N5V 3P5, Canada
| | - Soledad Saldias
- A&L Biologicals, Agroecological Research Services Centre, 2136 Jetstream Road, London, ON N5V 3P5, Canada
| | - Nimalka Weerasuriya
- A&L Biologicals, Agroecological Research Services Centre, 2136 Jetstream Road, London, ON N5V 3P5, Canada.,Department of Biology, University of Western Ontario, 1151 Richmond Street, London, ON N6A 3K7, Canada
| | - Kristen Delaney
- A&L Biologicals, Agroecological Research Services Centre, 2136 Jetstream Road, London, ON N5V 3P5, Canada
| | - Saveetha Kandasamy
- A&L Biologicals, Agroecological Research Services Centre, 2136 Jetstream Road, London, ON N5V 3P5, Canada
| | - George Lazarovits
- A&L Biologicals, Agroecological Research Services Centre, 2136 Jetstream Road, London, ON N5V 3P5, Canada.,Department of Biology, University of Western Ontario, 1151 Richmond Street, London, ON N6A 3K7, Canada
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199
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Nascimento FX, Hernández AG, Glick BR, Rossi MJ. Plant growth-promoting activities and genomic analysis of the stress-resistant Bacillus megaterium STB1, a bacterium of agricultural and biotechnological interest. BIOTECHNOLOGY REPORTS (AMSTERDAM, NETHERLANDS) 2020; 25:e00406. [PMID: 31886139 PMCID: PMC6920507 DOI: 10.1016/j.btre.2019.e00406] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 11/05/2019] [Accepted: 12/01/2019] [Indexed: 12/14/2022]
Abstract
In this work, the stress-resistant Bacillus megaterium STB1 is characterized and its ability to promote plant growth under normal and stress conditions is demonstrated. The genomic sequence of this bacterium, and a detailed analysis of the genes involved in facilitating its stress resistance and plant growth-promoting activities is also reported. The B. megaterium STB1 genome is rich in genetic elements involved in multiple stress resistance, xenobiotic degradation, pathogen antagonistic activities, and other traits related to soil and rhizosphere colonization. Moreover, genes participating in the biosynthesis of auxins and cytokinins, the modulation of polyamines, GABA, brassinosteroids and ethylene levels were also found. Ultimately, this study brings new insights into the role of B. megaterium as a plant growth-promoting bacterium and opens new opportunities for the development of novel strategies for agriculture and biotechnology.
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Affiliation(s)
- Francisco X. Nascimento
- IBET, Instituto de Biologia Experimental e Tecnológica, Oeiras, 2780-157, Portugal
- Laboratório de Microbiologia e Bioprocessos, MIP-CCB, Universidade Federal de Santa Catarina, Florianópolis, SC, 88040-900, Brazil
| | - Anabel G. Hernández
- Laboratório de Microbiologia e Bioprocessos, MIP-CCB, Universidade Federal de Santa Catarina, Florianópolis, SC, 88040-900, Brazil
| | - Bernard R. Glick
- Department of Biology, University of Waterloo, Waterloo, ON, N2L 3G1, Canada
| | - Márcio J. Rossi
- Laboratório de Microbiologia e Bioprocessos, MIP-CCB, Universidade Federal de Santa Catarina, Florianópolis, SC, 88040-900, Brazil
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200
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Lee S, Trịnh CS, Lee WJ, Jeong CY, Truong HA, Chung N, Kang CS, Lee H. Bacillus subtilis strain L1 promotes nitrate reductase activity in Arabidopsis and elicits enhanced growth performance in Arabidopsis, lettuce, and wheat. JOURNAL OF PLANT RESEARCH 2020; 133:231-244. [PMID: 31915951 DOI: 10.1007/s10265-019-01160-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 11/20/2019] [Indexed: 05/15/2023]
Abstract
Plant growth promoting rhizobacteria (PGPR) are a group of bacteria that promote plants growth in the rhizosphere. PGPRs are involved in various mechanisms that reinforce plant development. In this study, we screened for PGPRs that were effective in early growth of Arabidopsis thaliana when added to the media and one Bacillus subtilis strain L1 (Bs L1) was selected for further study. When Bs L1 was placed near the roots, seedlings showed notably stronger growth than that in the control, particularly in biomass and root hair. Quantitative reverse transcription polymerase chain reaction analysis revealed a high level of expression of the high affinity nitrate transporter gene, NRT2.1 in A. thaliana treated with Bs L1. After considering how Bs L1 could promote plant growth, we focused on nitrate, which is essential to plant growth. The nitrate content was lower in A. thaliana treated with Bs L1. However, examination of the activity of nitrate reductase revealed higher activity in plants treated with PGPR than in the control. Bs L1 had pronounced effects in representative crops (wheat and lettuce). These results suggest that Bs L1 promotes the assimilation and use of nitrate and plant growth.
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Affiliation(s)
- Seokjin Lee
- Department of Biosystems and Biotechnology, College of Life Sciences and Biotechnology, Korea University, Anam-dong 5-ga, Seongbuk-gu, Seoul, 136-713, Republic of Korea
| | - Cao Sơn Trịnh
- Department of Biosystems and Biotechnology, College of Life Sciences and Biotechnology, Korea University, Anam-dong 5-ga, Seongbuk-gu, Seoul, 136-713, Republic of Korea
| | - Won Je Lee
- Department of Biosystems and Biotechnology, College of Life Sciences and Biotechnology, Korea University, Anam-dong 5-ga, Seongbuk-gu, Seoul, 136-713, Republic of Korea
| | - Chan Young Jeong
- Department of Biosystems and Biotechnology, College of Life Sciences and Biotechnology, Korea University, Anam-dong 5-ga, Seongbuk-gu, Seoul, 136-713, Republic of Korea
| | - Hai An Truong
- Department of Biosystems and Biotechnology, College of Life Sciences and Biotechnology, Korea University, Anam-dong 5-ga, Seongbuk-gu, Seoul, 136-713, Republic of Korea
| | - Namhyun Chung
- Department of Biosystems and Biotechnology, College of Life Sciences and Biotechnology, Korea University, Anam-dong 5-ga, Seongbuk-gu, Seoul, 136-713, Republic of Korea
| | - Chon-Sik Kang
- Crop Breeding Division, National Institute of Crop Science, RDA, Wanju, 55365, Republic of Korea.
| | - Hojoung Lee
- Department of Biosystems and Biotechnology, College of Life Sciences and Biotechnology, Korea University, Anam-dong 5-ga, Seongbuk-gu, Seoul, 136-713, Republic of Korea.
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