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Pal G, Saxena S, Kumar K, Verma A, Kumar D, Shukla P, Pandey A, White J, Verma SK. Seed endophytic bacterium Lysinibacillus sp. (ZM1) from maize (Zea mays L.) shapes its root architecture through modulation of auxin biosynthesis and nitrogen metabolism. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2024; 212:108731. [PMID: 38761545 DOI: 10.1016/j.plaphy.2024.108731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2024] [Revised: 04/25/2024] [Accepted: 05/13/2024] [Indexed: 05/20/2024]
Abstract
Seed endophytic bacteria have been shown to promote the growth and development of numerous plants. However, the underlying mechanism still needs to be better understood. The present study aims to investigate the role of a seed endophytic bacterium Lysinibacillus sp. (ZM1) in promoting plant growth and shaping the root architecture of maize seedlings. The study explores how bacteria-mediated auxin biosynthesis and nitrogen metabolism affect plant growth promotion and shape the root architecture of maize seedlings. The results demonstrate that ZM1 inoculation significantly enhances root length, root biomass, and the number of seminal roots in maize seedlings. Additionally, the treated seedlings exhibit increased shoot biomass and higher levels of photosynthetic pigments. Confocal laser scanning microscopy (CLSM) analysis revealed extensive colonization of ZM1 on root hairs, as well as in the cortical and stellar regions of the root. Furthermore, LC-MS analysis demonstrated elevated auxin content in the roots of the ZM1 treated maize seedlings compared to the uninoculated control. Inoculation with ZM1 significantly increased the levels of endogenous ammonium content, GS, and GOGAT enzyme activities in the roots of treated maize seedlings compared to the control, indicating enhanced nitrogen metabolism. Furthermore, inoculation of bacteria under nitrogen-deficient conditions enhanced plant growth, as evidenced by increased root shoot length, fresh and dry weights, average number of seminal roots, and content of photosynthetic pigments. Transcript analysis indicated upregulation of auxin biosynthetic genes, along with genes involved in nitrogen metabolism at different time points in roots of ZM1-treated maize seedlings. Collectively, our findings highlight the positive impact of Lysinibacillus sp. ZM1 inoculation on maize seeds by improving root architecture through modulation of auxin biosynthesis and affecting various nitrogen metabolism related parameters. These findings provide valuable insights into the potential utilization of seed endophytic bacteria as biofertilizers to enhance plant growth and yield in nutrient deficient soils.
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Affiliation(s)
- Gaurav Pal
- Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi, Uttar Pradesh, 221005, India; Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, 276957612, USA.
| | - Samiksha Saxena
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Kanchan Kumar
- Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi, Uttar Pradesh, 221005, India
| | - Anand Verma
- Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi, Uttar Pradesh, 221005, India
| | - Deepak Kumar
- Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi, Uttar Pradesh, 221005, India
| | - Pooja Shukla
- Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi, Uttar Pradesh, 221005, India
| | - Ashutosh Pandey
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - James White
- Department of Plant Biology, Rutgers University, New Brunswick, NJ, USA
| | - Satish K Verma
- Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi, Uttar Pradesh, 221005, India.
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2
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Jensen CNG, Pang JKY, Hahn CM, Gottardi M, Husted S, Moelbak L, Kovács ÁT, Fimognari L, Schulz A. Differential influence of Bacillus subtilis strains on Arabidopsis root architecture through common and distinct plant hormonal pathways. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2024; 339:111936. [PMID: 38042415 DOI: 10.1016/j.plantsci.2023.111936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Accepted: 11/28/2023] [Indexed: 12/04/2023]
Abstract
Plant growth-promoting microbes (PGPM) can enhance crop yield and health, but knowledge of their mode-of-action is limited. We studied the influence of two Bacillus subtilis strains, the natural isolate ALC_02 and the domesticated 168 Gö, on Arabidopsis and hypothesized that they modify the root architecture by modulating hormone transport or signaling. Both bacteria promoted increase of shoot and root surface area in vitro, but through different root anatomical traits. Mutant plants deficient in auxin transport or signaling responded less to the bacterial strains than the wild-type, and application of the auxin transport inhibitor NPA strongly reduced the influence of the strains. Both bacteria produced auxin and enhanced shoot auxin levels in DR5::GUS reporter plants. Accordingly, most of the beneficial effects of the strains were dependent on functional auxin transport and signaling, while only 168 Gö depended on functional ethylene signaling. As expected, only ALC_02 stimulated plant growth in soil, unlike 168 Gö that was previously reported to have reduced biofilms. Collectively, the results highlight that B. subtilis strains can have strikingly different plant growth-promoting properties, dependent on what experimental setup they are tested in, and the importance of choosing the right PGPM for a desired root phenotype.
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Affiliation(s)
- Camilla Niketa Gadomska Jensen
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark; Plant Health Innovation, Chr-Hansen A/S, Taastrup, Denmark
| | - Janet Ka Yan Pang
- Bacterial Interactions and Evolution Group, DTU Bioengineering, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Charlotte Marie Hahn
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark
| | | | - Søren Husted
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Lars Moelbak
- Plant Health Innovation, Chr-Hansen A/S, Taastrup, Denmark
| | - Ákos T Kovács
- Bacterial Interactions and Evolution Group, DTU Bioengineering, Technical University of Denmark, Kgs. Lyngby, Denmark
| | | | - Alexander Schulz
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark.
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3
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Chang W, Yang C, Liu T, Tian P, Zhang S, Dai X, Igarashi Y, Luo F. Revealing the phosphate-solubilizing characteristics and mechanisms of the plant growth-promoting bacterium Agrobacterium deltaense C1. J Appl Microbiol 2024; 135:lxad284. [PMID: 38061837 DOI: 10.1093/jambio/lxad284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 11/22/2023] [Accepted: 12/06/2023] [Indexed: 01/11/2024]
Abstract
AIMS This study explores the phosphate (Pi)-solubilizing characteristics and mechanisms of a novel phosphate-solubilizing bacterium, Agrobacterium deltaense C1 (C1 hereafter). METHODS AND RESULTS The growth-promoting effects of C1 were investigated by gnotobiotic experiments, and the Pi-solubilizing mechanism was revealed by extracellular metabolomics, liquid chromatography analysis, and reverse transcription quantitative polymerase chain reaction. Results showed that C1 significantly increased Arabidopsis biomass and total phosphorus (P) content under P deficiency. Under Ca3(PO4)2 condition, the presence of C1 resulted in a significant and negative correlation between available P content and medium pH changes, implying that Pi dissolution occurs through acid release. Metabolomics revealed C1's ability to release 99 organic acids, with gluconic acid (GA), citric acid, and α-ketoglutaric acid contributing 64.86%, 9.58%, and 0.94%, respectively, to Pi solubilization. These acids were significantly induced by P deficiency. Moreover, C1's Pi solubilization may remain significant even in the presence of available P, as evidenced by substantial pH reduction and high gcd gene expression. Additionally, C1 produced over 10 plant growth-promoting substances. CONCLUSIONS C1 dissolves Pi primarily by releasing GA, which enhances plant growth under P deficiency. Notably, its Pi solubilization effect is not significantly limited by available Pi.
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Affiliation(s)
- Wenying Chang
- Chongqing Key Laboratory of Bio-resource Development for Bioenergy, College of Resources and Environment, Southwest University, Chongqing 400715, China
- Research Center of Bioenergy and Bioremediation, College of Resources and Environment, Southwest University, Chongqing 400715, China
| | - Caiyun Yang
- Chongqing Key Laboratory of Bio-resource Development for Bioenergy, College of Resources and Environment, Southwest University, Chongqing 400715, China
- Research Center of Bioenergy and Bioremediation, College of Resources and Environment, Southwest University, Chongqing 400715, China
- Interdisciplinary Research Centre for Agriculture Green Development in Yangtze River Basin, Department of Environmental Sciences and Engineering, College of Resources and Environment, Southwest University, Chongqing 400716, China
| | - Ting Liu
- Chongqing Key Laboratory of Bio-resource Development for Bioenergy, College of Resources and Environment, Southwest University, Chongqing 400715, China
- Research Center of Bioenergy and Bioremediation, College of Resources and Environment, Southwest University, Chongqing 400715, China
| | - Peili Tian
- Chongqing Key Laboratory of Bio-resource Development for Bioenergy, College of Resources and Environment, Southwest University, Chongqing 400715, China
- Research Center of Bioenergy and Bioremediation, College of Resources and Environment, Southwest University, Chongqing 400715, China
- Interdisciplinary Research Centre for Agriculture Green Development in Yangtze River Basin, Department of Environmental Sciences and Engineering, College of Resources and Environment, Southwest University, Chongqing 400716, China
| | - Siqi Zhang
- Interdisciplinary Research Centre for Agriculture Green Development in Yangtze River Basin, Department of Environmental Sciences and Engineering, College of Resources and Environment, Southwest University, Chongqing 400716, China
| | - Xianzhu Dai
- Chongqing Key Laboratory of Bio-resource Development for Bioenergy, College of Resources and Environment, Southwest University, Chongqing 400715, China
- Research Center of Bioenergy and Bioremediation, College of Resources and Environment, Southwest University, Chongqing 400715, China
| | - Yasuo Igarashi
- Chongqing Key Laboratory of Bio-resource Development for Bioenergy, College of Resources and Environment, Southwest University, Chongqing 400715, China
- Research Center of Bioenergy and Bioremediation, College of Resources and Environment, Southwest University, Chongqing 400715, China
| | - Feng Luo
- Chongqing Key Laboratory of Bio-resource Development for Bioenergy, College of Resources and Environment, Southwest University, Chongqing 400715, China
- Research Center of Bioenergy and Bioremediation, College of Resources and Environment, Southwest University, Chongqing 400715, China
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Yang L, Zhou M, Zu M, Zuo J, Yuan Y. Comprehensive Microbiome and Metabolome Analyses Reveal the Medicinal Components of Paeonia lactiflora. PLANTS (BASEL, SWITZERLAND) 2023; 12:1612. [PMID: 37111836 PMCID: PMC10143425 DOI: 10.3390/plants12081612] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 03/14/2023] [Accepted: 04/03/2023] [Indexed: 06/19/2023]
Abstract
Paeonia lactiflora Pall. is not only a traditional ornamental plant, but also an important medicinal plant. Currently, some P. lactiflora cultivars are used for ornamental purposes, but their potential medicinal value is ignored. To explore the medicinal potential of the ornamental varieties, the medicinal cultivar 'Hangbaishao' (HS) and the ornamental cultivar 'Zifengyu' (ZFY) were selected, and microbiome and metabolome analyses were performed to compare the composition of the endophytes and metabolites in the roots. The diversity and abundance of bacteria were not significantly different between HS and ZFY; however, the diversity and abundance of endophytic fungi in the ornamental cultivar ZFY were much higher than those in the medicinal cultivar HS. The flavonoids and phenolic acid contents of the ornamental cultivar ZFY were significantly higher than those of the medicinal cultivar HS, indicating that ZFY has medicinal value. The differences in root endophytes between HS and ZFY may lead to differences in phenolic acids and flavonoids. To explore the relationship between endophytes and the accumulation of phenolic acids and flavonoids, a joint analyses of the microbiome and metabolome were performed. The key bacterium, Ruminococcaceae bacterium GD7, led to the accumulation of phenolic acids and flavonoids in the ZFY. This study contributes to future research on the potential medicinal value of ornamental P. lactiflora and provides a new approach for realizing the 'dual use of medicine and appreciation' of P. lactiflora.
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5
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Zhao Y, Zhang F, Mickan B, Wang D. Inoculation of wheat with Bacillus sp. wp-6 altered amino acid and flavonoid metabolism and promoted plant growth. PLANT CELL REPORTS 2023; 42:165-179. [PMID: 36348065 DOI: 10.1007/s00299-022-02947-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 10/29/2022] [Indexed: 06/16/2023]
Abstract
Inoculation of wheat seedling with Bacillus sp. wp-6 changed amino acid metabolism and flavonoid synthesis and promoted plant growth. Plant growth-promoting rhizobacteria (PGPR), which can reduce the use of agrochemicals, is vital for the development of sustainable agriculture. In this study, proteomics and metabolomics analyses were performed to investigate the effects of inoculation with a PGPR, Bacillus sp. wp-6, on wheat (Triticum aestivum L.) seedling growth. The results showed that inoculation with Bacillus sp. wp-6 increased shoot and root fresh weights by 19% and 18%, respectively, after 40 days. The expression levels of alpha-linolenic acid metabolism-related proteins and metabolites (lipoxygenase 2, allene oxide synthase 2, jasmonic acid, 17-hydroxylinolenic acid) and flavonoid biosynthesis-related proteins and metabolites (chalcone synthase 2 and PHC 4'-O-glucoside) were up-regulated. In addition, the expression levels of amino acid metabolism-related proteins (NADH-dependent glutamate synthase, bifunctional aspartokinase/homoserine, anthranilate synthase alpha subunit 1, and 3-phosphoshikimate 1-carboxyvinyltransferase) and metabolites (L-aspartate, L-arginine, and S-glutathionyl-L-cysteine) were also significantly up-regulated. Among them, NADH-dependent glutamate synthase and bifunctional aspartokinase/homoserine could act as regulators of nitrogen metabolism. Overall, inoculation of wheat with Bacillus sp. wp-6 altered alpha-linolenic acid metabolism, amino acid metabolism, and flavonoid synthesis and promoted wheat seedling growth. This study will deepen our understanding of the mechanism by which Bacillus sp. wp-6 promotes wheat growth using proteomics and metabolomics.
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Affiliation(s)
- Yaguang Zhao
- Key Laboratory of Oasis Ecological Agriculture of Xinjiang Production and Construction Corps, Shihezi University, North 4th Street No. 221, Shihezi, 832003, Xinjiang, China
| | - Fenghua Zhang
- Key Laboratory of Oasis Ecological Agriculture of Xinjiang Production and Construction Corps, Shihezi University, North 4th Street No. 221, Shihezi, 832003, Xinjiang, China.
| | - Bede Mickan
- Institute of Agriculture, School of Agriculture and Environment, The University of Western Australia, 35 Stirling Highway, Crawley, Perth, WA, 6001, Australia
| | - Dan Wang
- Key Laboratory of Oasis Ecological Agriculture of Xinjiang Production and Construction Corps, Shihezi University, North 4th Street No. 221, Shihezi, 832003, Xinjiang, China
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6
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Wild Wheat Rhizosphere-Associated Plant Growth-Promoting Bacteria Exudates: Effect on Root Development in Modern Wheat and Composition. Int J Mol Sci 2022; 23:ijms232315248. [PMID: 36499572 PMCID: PMC9740669 DOI: 10.3390/ijms232315248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 11/15/2022] [Accepted: 11/28/2022] [Indexed: 12/12/2022] Open
Abstract
Diazotrophic bacteria isolated from the rhizosphere of a wild wheat ancestor, grown from its refuge area in the Fertile Crescent, were found to be efficient Plant Growth-Promoting Rhizobacteria (PGPR), upon interaction with an elite wheat cultivar. In nitrogen-starved plants, they increased the amount of nitrogen in the seed crop (per plant) by about twofold. A bacterial growth medium was developed to investigate the effects of bacterial exudates on root development in the elite cultivar, and to analyze the exo-metabolomes and exo-proteomes. Altered root development was observed, with distinct responses depending on the strain, for instance, with respect to root hair development. A first conclusion from these results is that the ability of wheat to establish effective beneficial interactions with PGPRs does not appear to have undergone systematic deep reprogramming during domestication. Exo-metabolome analysis revealed a complex set of secondary metabolites, including nutrient ion chelators, cyclopeptides that could act as phytohormone mimetics, and quorum sensing molecules having inter-kingdom signaling properties. The exo-proteome-comprised strain-specific enzymes, and structural proteins belonging to outer-membrane vesicles, are likely to sequester metabolites in their lumen. Thus, the methodological processes we have developed to collect and analyze bacterial exudates have revealed that PGPRs constitutively exude a highly complex set of metabolites; this is likely to allow numerous mechanisms to simultaneously contribute to plant growth promotion, and thereby to also broaden the spectra of plant genotypes (species and accessions/cultivars) with which beneficial interactions can occur.
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7
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De Palma M, Scotti R, D’Agostino N, Zaccardelli M, Tucci M. Phyto-Friendly Soil Bacteria and Fungi Provide Beneficial Outcomes in the Host Plant by Differently Modulating Its Responses through (In)Direct Mechanisms. PLANTS (BASEL, SWITZERLAND) 2022; 11:2672. [PMID: 36297696 PMCID: PMC9612229 DOI: 10.3390/plants11202672] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 10/08/2022] [Accepted: 10/09/2022] [Indexed: 06/16/2023]
Abstract
Sustainable agricultural systems based on the application of phyto-friendly bacteria and fungi are increasingly needed to preserve soil fertility and microbial biodiversity, as well as to reduce the use of chemical fertilizers and pesticides. Although there is considerable attention on the potential applications of microbial consortia as biofertilizers and biocontrol agents for crop management, knowledge on the molecular responses modulated in host plants because of these beneficial associations is still incomplete. This review provides an up-to-date overview of the different mechanisms of action triggered by plant-growth-promoting microorganisms (PGPMs) to promote host-plant growth and improve its defense system. In addition, we combined available gene-expression profiling data from tomato roots sampled in the early stages of interaction with Pseudomonas or Trichoderma strains to develop an integrated model that describes the common processes activated by both PGPMs and highlights the host's different responses to the two microorganisms. All the information gathered will help define new strategies for the selection of crop varieties with a better ability to benefit from the elicitation of microbial inoculants.
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Affiliation(s)
- Monica De Palma
- Institute of Biosciences and BioResources, Research Division Portici, National Research Council, 80055 Portici, Italy
| | - Riccardo Scotti
- CREA Research Centre for Vegetable and Ornamental Crops, Via Cavalleggeri 25, 84098 Pontecagnano Faiano (SA), Italy
| | - Nunzio D’Agostino
- Department of Agricultural Sciences, University of Naples Federico II, 80055 Portici, Italy
| | - Massimo Zaccardelli
- CREA Research Centre for Vegetable and Ornamental Crops, Via Cavalleggeri 25, 84098 Pontecagnano Faiano (SA), Italy
| | - Marina Tucci
- Institute of Biosciences and BioResources, Research Division Portici, National Research Council, 80055 Portici, Italy
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8
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Tiwari PK, Yadav J, Singh AK, Srivastava R, Srivastava AK, Sahu PK, Srivastava AK, Saxena AK. Architectural analysis of root system and phytohormone biosynthetic genes expression in wheat (Triticum aestivum L.) inoculated with Penicillium oxalicum. Lett Appl Microbiol 2022; 75:1596-1606. [PMID: 36086890 DOI: 10.1111/lam.13827] [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: 02/25/2022] [Revised: 06/16/2022] [Accepted: 08/23/2022] [Indexed: 11/29/2022]
Abstract
In this study, a fungal plant growth promoter Penicillium oxalicum T4 isolated from non-rhizosphere soil of Arunachal Pradesh, India, was screened for different plant growth promoting traits in a gnotobiotic study. Though inoculation improved the overall growth of the plants, critical differences were observed in root architecture. Confocal Laser Scanning Microscope, Scanning electron microscope and stereo microscopic study showed that inoculated wheat plants could develop profuse root hairs as compared to control. Root scanning indicated improvement in cumulative root length, root area, root volume, number of forks, links, crossings, and other parameters. Confocal scanning laser microscope indicated signs of endophytic colonization in wheat roots. Gene expression studies revealed that inoculation of T4 modulated the genes affecting root hair development. Significant differences were marked in the expression levels of TaRSL4, TaEXPB1, TaEXPB23, PIN-FORMED protein, kaurene oxidase, lipoxygenase, ACC synthase, ACC oxidase, 9-cis-epoxycarotenoid dioxygenase, and ABA 8'-hydroxylase genes. These genes contribute to early plant development and ultimately to biomass accumulation and yield. The results suggested that P. oxalicum T4 has potential for growth promotion in wheat and perhaps also in other cereals.
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Affiliation(s)
- Praveen K Tiwari
- ICAR-National Bureau of Agriculturally Important Microorganisms, Maunath Bhanjan, 275103, Uttar Pradesh, India
| | - Jagriti Yadav
- ICAR-National Bureau of Agriculturally Important Microorganisms, Maunath Bhanjan, 275103, Uttar Pradesh, India
| | - Alok K Singh
- ICAR-National Bureau of Agriculturally Important Microorganisms, Maunath Bhanjan, 275103, Uttar Pradesh, India
| | - Ruchi Srivastava
- ICAR-National Bureau of Agriculturally Important Microorganisms, Maunath Bhanjan, 275103, Uttar Pradesh, India
| | - Anchal K Srivastava
- ICAR-National Bureau of Agriculturally Important Microorganisms, Maunath Bhanjan, 275103, Uttar Pradesh, India
| | - Pramod K Sahu
- ICAR-National Bureau of Agriculturally Important Microorganisms, Maunath Bhanjan, 275103, Uttar Pradesh, India
| | - Alok K Srivastava
- ICAR-National Bureau of Agriculturally Important Microorganisms, Maunath Bhanjan, 275103, Uttar Pradesh, India
| | - Anil K Saxena
- ICAR-National Bureau of Agriculturally Important Microorganisms, Maunath Bhanjan, 275103, Uttar Pradesh, India
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9
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Luo Y, Zhou M, Wang F, Sheng H. Sphingomonas psychrotolerans sp. nov., isolated from root surface of Leontopodium leontopodioides in the Tianshan Mountains, Xinjiang, China. Int J Syst Evol Microbiol 2022; 72. [DOI: 10.1099/ijsem.0.005396] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A novel rod-shaped, Gram-stain-negative, aerobic bacterial strain, designated Cra20T, was isolated from the root surface of Leontopodium leontopodioides collected in the Tianshan Mountains, Xinjiang, PR China. Phylogenetic analysis based on 16S rRNA gene sequences, indicated that strain Cra20T was affiliated with the genus
Sphingomonas
, and was most closely related to
Sphingomonas gei
ZFGT-11T (99.0 %),
Sphingomonas naasensis
KIS18-15T (97.8%) and
Sphingomonas kyeonggiensis
THG-DT81T (97.2 %). The average nucleotide identity values between strain Cra20T,
S. gei
ZFGT-11T,
S. naasensis
KIS18-15T and
S. kyeonggiensis
THG-DT81T were 86.2, 84.2 and 78.2 %, respectively. The genomic DNA G+C content of strain Cra20T was 65.6 mol% (whole genome sequence), and Q-10 was the predominant ubiquinone. The major cellular fatty acids of strain Cra20T were summed feature 8 (comprising C18 : 1
ω6c and/or C18 : 1
ω7c, 67.3 %) and C14 : 0 2-OH (6.4 %). On the basis of genotypic, phenotypic and biochemical data, strain Cra20T is considered to represent a novel species of the genus
Sphingomonas
, for which the name Sphingomonas psychrotolerans sp. nov. is proposed. The type strain is Cra20T (=CGMCC 1.15510T=NBRC 112697T).
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Affiliation(s)
- Yang Luo
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, PR China
- School of Life Sciences, Shangrao Normal University, Shangrao Agricultural Technology Innovation Research Institute, Shangrao 334000, PR China
| | - Meng Zhou
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, PR China
- School of Life Sciences, Shangrao Normal University, Shangrao Agricultural Technology Innovation Research Institute, Shangrao 334000, PR China
| | - Fang Wang
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, PR China
| | - Hongmei Sheng
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, PR China
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10
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Gao B, Chai X, Huang Y, Wang X, Han Z, Xu X, Wu T, Zhang X, Wang Y. Siderophore production in
Pseudomonas
sp. strain
SP3
enhances iron acquisition in apple rootstock. J Appl Microbiol 2022; 133:720-732. [DOI: 10.1111/jam.15591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 04/18/2022] [Accepted: 04/22/2022] [Indexed: 11/28/2022]
Affiliation(s)
- Beibei Gao
- College of Horticulture China Agricultural University Beijing 100193 P. R. China
- Key Laboratory of Biology and Genetic Improvement of Horticultural (Nutrition and Physiology), the Ministry of Agriculture and Rural Affairs China Agricultural University Beijing 100193 P. R. China
| | - Xiaofen Chai
- College of Horticulture China Agricultural University Beijing 100193 P. R. China
- Key Laboratory of Biology and Genetic Improvement of Horticultural (Nutrition and Physiology), the Ministry of Agriculture and Rural Affairs China Agricultural University Beijing 100193 P. R. China
| | - Yimei Huang
- College of Horticulture China Agricultural University Beijing 100193 P. R. China
- Key Laboratory of Biology and Genetic Improvement of Horticultural (Nutrition and Physiology), the Ministry of Agriculture and Rural Affairs China Agricultural University Beijing 100193 P. R. China
| | - Xiaona Wang
- College of Horticulture China Agricultural University Beijing 100193 P. R. China
- Key Laboratory of Biology and Genetic Improvement of Horticultural (Nutrition and Physiology), the Ministry of Agriculture and Rural Affairs China Agricultural University Beijing 100193 P. R. China
| | - Zhenhai Han
- College of Horticulture China Agricultural University Beijing 100193 P. R. China
- Key Laboratory of Biology and Genetic Improvement of Horticultural (Nutrition and Physiology), the Ministry of Agriculture and Rural Affairs China Agricultural University Beijing 100193 P. R. China
| | - Xuefeng Xu
- College of Horticulture China Agricultural University Beijing 100193 P. R. China
- Key Laboratory of Biology and Genetic Improvement of Horticultural (Nutrition and Physiology), the Ministry of Agriculture and Rural Affairs China Agricultural University Beijing 100193 P. R. China
| | - Ting Wu
- College of Horticulture China Agricultural University Beijing 100193 P. R. China
- Key Laboratory of Biology and Genetic Improvement of Horticultural (Nutrition and Physiology), the Ministry of Agriculture and Rural Affairs China Agricultural University Beijing 100193 P. R. China
| | - Xinzhong Zhang
- College of Horticulture China Agricultural University Beijing 100193 P. R. China
- Key Laboratory of Biology and Genetic Improvement of Horticultural (Nutrition and Physiology), the Ministry of Agriculture and Rural Affairs China Agricultural University Beijing 100193 P. R. China
| | - Yi Wang
- College of Horticulture China Agricultural University Beijing 100193 P. R. China
- Key Laboratory of Biology and Genetic Improvement of Horticultural (Nutrition and Physiology), the Ministry of Agriculture and Rural Affairs China Agricultural University Beijing 100193 P. R. China
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11
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Plant-Growth-Promoting Potential of PGPE Isolated from Dactylis glomerata L. Microorganisms 2022; 10:microorganisms10040731. [PMID: 35456782 PMCID: PMC9032031 DOI: 10.3390/microorganisms10040731] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Revised: 03/26/2022] [Accepted: 03/26/2022] [Indexed: 11/17/2022] Open
Abstract
Plant-growth-promoting endophytes (PGPE) are a kind of beneficial microorganisms which could inhabit plant tissues to antagonize certain plant pathogens and promote the host plant’s growth and development. At present, many studies have confirmed the mutualistic effect of endophytes with plants, but there are few systematic studies on beneficial roles between endophytes and Dactylis glomerata, especially on the PGPE characteristics of the forage and environmental restoration plant. This study aimed to isolate PGPE from D. glomerata, evaluate their effects on plant growth, and ultimately acquire desirable microbial inoculants for agricultural use. First, endophytes were isolated from D. glomerata by plant re-inoculation experiment, and identified by morphological and molecular analyses. Fixation medium and methods were carried out to assess the nitrogen fixation ability of the strains. Then, the ability to dissolve phosphorus was determined by the Olsen and silicate medium methods; secretory IAA was measured by Salkowski colorimetric method; and the inhibitive effects on phytopathogen were observed by confrontation culture. Twenty-one strains were isolated from four varieties of D. glomerata, among which 14 strains with plant-growth-promoting characteristics were obtained by re-inoculation experiments, including seven endophytic bacteria and seven endophytic fungi. Further evaluation of three selected strains with the most significant PGP attributes were performed by using the pot re-inoculation experiment which revealed that TG2-B derived from Myroides odoratimimus was the most effective plant-growth-promoting agent due to its ability to produce high levels of IAA; the strain Bacillus cereus exhibited the most robust ability in dissolving inorganic phosphorus; and Trichoderma harzianum manifested a conspicuously antagonistic effect against a variety of plant pathogens. For the first time, this study reports the identification of D. glomerata endophytes that were able to promote plant growth and have a considerable antagonistic effects on plant pathogens, which could be considered as microbial inoculants for using in improving crop production and plant disease control.
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Schroeder MM, Gomez MY, McLain N, Gachomo EW. Bradyrhizobium japonicum IRAT FA3 Alters Arabidopsis thaliana Root Architecture via Regulation of Auxin Efflux Transporters PIN2, PIN3, PIN7, and ABCB19. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2022; 35:215-229. [PMID: 34941379 DOI: 10.1094/mpmi-05-21-0118-r] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Beneficial rhizobacteria can stimulate changes in plant root development. Although root system growth is mediated by multiple factors, the regulated distribution of the phytohormone auxin within root tissues plays a principal role. Auxin transport facilitators help to generate the auxin gradients and maxima that determine root structure. Here, we show that the plant-growth-promoting rhizobacterial strain Bradyrhizobium japonicum IRAT FA3 influences specific auxin efflux transporters to alter Arabidopsis thaliana root morphology. Gene expression profiling of host transcripts in control and B. japonicum-inoculated roots of the wild-type A. thaliana accession Col-0 confirmed upregulation of PIN2, PIN3, PIN7, and ABCB19 with B. japonicum and identified genes potentially contributing to a diverse array of auxin-related responses. Cocultivation of the bacterium with loss-of-function auxin efflux transport mutants revealed that B. japonicum requires PIN3, PIN7, and ABCB19 to increase lateral root development and utilizes PIN2 to reduce primary root length. Accelerated lateral root primordia production due to B. japonicum was not observed in single pin3, pin7, or abcb19 mutants, suggesting independent roles for PIN3, PIN7, and ABCB19 during the plant-microbe interaction. Our work demonstrates B. japonicum's influence over host transcriptional reprogramming during plant interaction with this beneficial microbe and the subsequent alterations to root system architecture.[Formula: see text] Copyright © 2022 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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Affiliation(s)
- Mercedes M Schroeder
- Department of Microbiology and Plant Pathology, University of California-Riverside, Riverside, CA 92521, U.S.A
| | - Melissa Y Gomez
- Department of Microbiology and Plant Pathology, University of California-Riverside, Riverside, CA 92521, U.S.A
| | - Nathan McLain
- Department of Microbiology and Plant Pathology, University of California-Riverside, Riverside, CA 92521, U.S.A
| | - Emma W Gachomo
- Department of Microbiology and Plant Pathology, University of California-Riverside, Riverside, CA 92521, U.S.A
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Sahu PK, Singh S, Singh UB, Chakdar H, Sharma PK, Sarma BK, Teli B, Bajpai R, Bhowmik A, Singh HV, Saxena AK. Inter-Genera Colonization of Ocimum tenuiflorum Endophytes in Tomato and Their Complementary Effects on Na +/K + Balance, Oxidative Stress Regulation, and Root Architecture Under Elevated Soil Salinity. Front Microbiol 2021; 12:744733. [PMID: 34733259 PMCID: PMC8558678 DOI: 10.3389/fmicb.2021.744733] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 09/06/2021] [Indexed: 11/25/2022] Open
Abstract
Endophytic bacilli of ethano-botanical plant Ocimum tenuiflorum were screened for salt stress-alleviating traits in tomato. Four promising O. tenuiflorum endophytes (Bacillus safensis BTL5, Bacillus haynesii GTR8, Bacillus paralicheniformis GTR11, and Bacillus altitudinis GTS16) were used in this study. Confocal scanning laser microscopic studies revealed the inter-genera colonization of O. tenuiflorum endophytes in tomato plants, giving insights for widening the applicability of potential endophytes to other crops. Furthermore, in a pot trial under 150 mM NaCl concentration, the inoculated endophytes contributed in reducing salt toxicity and improving recovery from salt-induced oxidative stress by different mechanisms. Reduction in reactive oxygen species (ROS) (sub-cellular H2O2 and superoxide) accumulation was observed besides lowering programmed cell death and increasing chlorophyll content. Endophyte inoculation supplemented the plant antioxidant enzyme system via the modulation of enzymatic antioxidants, viz., peroxidase, ascorbate peroxidase, superoxide dismutase, and catalase, apart from increasing proline and total phenolics. Antioxidants like proline have dual roles of antioxidants and osmoregulation, which might also have contributed to improved water relation under elevated salinity. Root architecture, viz., root length, projection area, surface area, average diameter, tips, forks, crossings, and the number of links, was improved upon inoculation, indicating healthy root growth and enhanced nutrient flow and water homeostasis. Regulation of Na+/K+ balance and water homeostasis in the plants were also evident from the modulation in the expression of abiotic stress-responsive genes, viz., LKT1, NHX1, SOS1, LePIP2, SlERF16, and SlWRKY39. Shoot tissues staining with light-excitable Na+ indicator Sodium GreenTM Tetra (tetramethylammonium) salt showed low sodium transport and accumulation in endophyte-inoculated plants. All four endophytes exhibited different mechanisms for stress alleviation and indicated complementary effects on plant growth. Furthermore, this could be harnessed in the form of a consortium for salt stress alleviation. The present study established inter-genera colonization of O. tenuiflorum endophytes in tomato and revealed its potential in maintaining Na+/K+ balance, reducing ROS, and improving root architecture under elevated salinity.
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Affiliation(s)
- Pramod K Sahu
- ICAR-National Bureau of Agriculturally Important Microorganisms, Maunath Bhanjan, India
| | - Shailendra Singh
- ICAR-National Bureau of Agriculturally Important Microorganisms, Maunath Bhanjan, India
| | - Udai B Singh
- ICAR-National Bureau of Agriculturally Important Microorganisms, Maunath Bhanjan, India
| | - Hillol Chakdar
- ICAR-National Bureau of Agriculturally Important Microorganisms, Maunath Bhanjan, India
| | - Pawan K Sharma
- ICAR-National Bureau of Agriculturally Important Microorganisms, Maunath Bhanjan, India
| | - Birinchi K Sarma
- Department of Mycology and Plant Pathology, Institute of Agricultural Science, Banaras Hindu University, Varanasi, India
| | - Basavaraj Teli
- Department of Mycology and Plant Pathology, Institute of Agricultural Science, Banaras Hindu University, Varanasi, India
| | - Raina Bajpai
- Department of Mycology and Plant Pathology, Institute of Agricultural Science, Banaras Hindu University, Varanasi, India
| | - Arpan Bhowmik
- ICAR-Indian Agricultural Statistics Research Institute, New Delhi, India
| | - Harsh V Singh
- ICAR-National Bureau of Agriculturally Important Microorganisms, Maunath Bhanjan, India
| | - Anil K Saxena
- ICAR-National Bureau of Agriculturally Important Microorganisms, Maunath Bhanjan, India
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Bargaz A, Elhaissoufi W, Khourchi S, Benmrid B, Borden KA, Rchiad Z. Benefits of phosphate solubilizing bacteria on belowground crop performance for improved crop acquisition of phosphorus. Microbiol Res 2021; 252:126842. [PMID: 34438221 DOI: 10.1016/j.micres.2021.126842] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 07/31/2021] [Accepted: 08/04/2021] [Indexed: 10/20/2022]
Abstract
Although research on plant growth promoting bacteria began in the 1950s, basic and applied research on bacteria improving use of phosphorus (P) continues to be a priority among many agricultural research institutions. Ultimately, identifying agriculturally beneficial microbes, notably P solubilizing bacteria (PSB), that enhance the efficient use of P supports more sustainable cropping systems and the judicious use of mineral nutrients. In parallel, there is more attention on improving crop root P acquisition of existing soil P pools as well as by increasing the proportion of fertilizer P that is taken up by crops. Today, new lines of research are emerging to investigate the co-optimization of PSB-fertilizer-crop root processes for improved P efficiency and agricultural performance. In this review, we compile and summarize available findings on the beneficial effects of PSB on crop production with a focus on crop P acquisition via root system responses at the structural, functional and transcriptional levels. We discuss the current state of knowledge on the mechanisms of PSB-mediated P availability, both soil- and root-associated, as well as crop uptake via P solubilization, mineralization and mobilization, mainly through the production of organic acids and P-hydrolyzing enzymes, and effects on phytohormone signaling for crop root developement. The systematic changes caused by PSB on crop roots are discussed and contextualized within promising functional trait-based frameworks. We also detail agronomic profitability of P (mineral and organic) and PSB co-application, in amended soils and inoculated crops, establishing the connection between the influence of PSB on agroecosystem production and the impact of P fertilization on microbial diversity and crop functional traits for P acquisition.
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Affiliation(s)
- Adnane Bargaz
- Mohammed VI Polytechnic University, Agrobiosciences Program, Plant & Soil Microbiome Subprogram, Bengurir, 43150, Morocco.
| | - Wissal Elhaissoufi
- Mohammed VI Polytechnic University, Agrobiosciences Program, Plant & Soil Microbiome Subprogram, Bengurir, 43150, Morocco; Cadi Ayyad University, Faculty of Sciences and Techniques, Biology Dep., Marrakech, Morocco
| | - Said Khourchi
- Mohammed VI Polytechnic University, Agrobiosciences Program, Plant & Soil Microbiome Subprogram, Bengurir, 43150, Morocco; University of Liège, Gembloux Agro-Bio Tech, Liège, Belgium
| | - Bouchra Benmrid
- Mohammed VI Polytechnic University, Agrobiosciences Program, Plant & Soil Microbiome Subprogram, Bengurir, 43150, Morocco
| | - Kira A Borden
- University of British Columbia, Faculty of Land and Food Systems, Vancouver, V6T 1Z4, Canada
| | - Zineb Rchiad
- Mohammed VI Polytechnic University, Agrobiosciences Program, Plant & Soil Microbiome Subprogram, Bengurir, 43150, Morocco
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15
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Samaras A, Roumeliotis E, Ntasiou P, Karaoglanidis G. Bacillus subtilis MBI600 Promotes Growth of Tomato Plants and Induces Systemic Resistance Contributing to the Control of Soilborne Pathogens. PLANTS 2021; 10:plants10061113. [PMID: 34072940 PMCID: PMC8229581 DOI: 10.3390/plants10061113] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 05/26/2021] [Accepted: 05/26/2021] [Indexed: 11/16/2022]
Abstract
Bacillus subtilis MBI600 (Bs MBI600) is a recently commercialized plant-growth-promoting rhizobacterium (PGPR). In this study, we investigated the effects of Bs MBI600 on the growth of tomato and its biocontrol efficacy against three main soilborne tomato pathogens (Rhizoctonia solani, Pythium ultimum, and Fusarium oxysporum f.sp. radicis-lycopersici-Forl). Furthermore, the root colonization ability of the Bs MBI600 strain on tomato roots was analyzed in vivo with a yellow fluorescence protein (yfp)-labeled strain, revealing strong colonization ability, which was affected by the root growth substrate. The application of Bs MBI600 on tomato plants resulted in significant increases in shoot and root lengths. Transcriptional activation of two auxin-related genes (SiPin6 and SiLax4) was observed. Single applications of Bs MBI600 on inoculated tomato plants with pathogens revealed satisfactory control efficacy compared to chemical treatment. Transcriptomic analysis of defense-related genes used as markers of the salicylic acid (SA) signaling pathway (PR-1A and GLUA) or jasmonic acid/ethylene (JA/ET) signaling pathway (CHI3, LOXD, and PAL) showed increased transcription patterns in tomato plants treated with Bs MBI600 or Forl. These results indicate the biochemical and molecular mechanisms that are activated after the application of Bs MBI600 on tomato plants and suggest that induction of systemic resistance (ISR) occurred.
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Affiliation(s)
- Anastasios Samaras
- Plant Pathology Laboratory, Forestry and Natural Environment, Faculty of Agriculture, Aristotle University of Thessaloniki, P.O. Box 269, 54124 Thessaloniki, Greece; (A.S.); (P.N.)
| | - Efstathios Roumeliotis
- Department of Agriculture, Theodoropoulou Terma, University of Patras, 27200 Amaliada, Greece;
| | - Panagiota Ntasiou
- Plant Pathology Laboratory, Forestry and Natural Environment, Faculty of Agriculture, Aristotle University of Thessaloniki, P.O. Box 269, 54124 Thessaloniki, Greece; (A.S.); (P.N.)
| | - George Karaoglanidis
- Plant Pathology Laboratory, Forestry and Natural Environment, Faculty of Agriculture, Aristotle University of Thessaloniki, P.O. Box 269, 54124 Thessaloniki, Greece; (A.S.); (P.N.)
- Correspondence:
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16
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Verma SK, Sahu PK, Kumar K, Pal G, Gond SK, Kharwar RN, White JF. Endophyte roles in nutrient acquisition, root system architecture development and oxidative stress tolerance. J Appl Microbiol 2021; 131:2161-2177. [PMID: 33893707 DOI: 10.1111/jam.15111] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 04/06/2021] [Accepted: 04/16/2021] [Indexed: 01/01/2023]
Abstract
Plants associate with communities of microbes (bacteria and fungi) that play critical roles in plant development, nutrient acquisition and oxidative stress tolerance. The major share of plant microbiota is endophytes which inhabit plant tissues and help them in various capacities. In this article, we have reviewed what is presently known with regard to how endophytic microbes interact with plants to modulate root development, branching, root hair formation and their implications in overall plant development. Endophytic microbes link the interactions of plants, rhizospheric microbes and soil to promote nutrient solubilization and further vectoring these nutrients to the plant roots making the soil-plant-microbe continuum. Further, plant roots internalize microbes and oxidatively extract nutrients from microbes in the rhizophagy cycle. The oxidative interactions between endophytes and plants result in the acquisition of nutrients by plants and are also instrumental in oxidative stress tolerance of plants. It is evident that plants actively cultivate microbes internally, on surfaces and in soils to acquire nutrients, modulate development and improve health. Understanding this continuum could be of greater significance in connecting endophytes with the hidden half of the plant that can also be harnessed in applied terms to enhance nutrient acquisition through the development of favourable root system architecture for sustainable production under stress conditions.
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Affiliation(s)
- S K Verma
- Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - P K Sahu
- National Bureau of Agriculturally Important Microorganism, Mau, Uttar Pradesh, India
| | - K Kumar
- Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - G Pal
- Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - S K Gond
- Botany Section, MMV, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - R N Kharwar
- Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - J F White
- Department of Plant Biology, Rutgers University, New Brunswick, NJ, USA
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17
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Grover M, Bodhankar S, Sharma A, Sharma P, Singh J, Nain L. PGPR Mediated Alterations in Root Traits: Way Toward Sustainable Crop Production. FRONTIERS IN SUSTAINABLE FOOD SYSTEMS 2021. [DOI: 10.3389/fsufs.2020.618230] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The above ground growth of the plant is highly dependent on the belowground root system. Rhizosphere is the zone of continuous interplay between plant roots and soil microbial communities. Plants, through root exudates, attract rhizosphere microorganisms to colonize the root surface and internal tissues. Many of these microorganisms known as plant growth promoting rhizobacteria (PGPR) improve plant growth through several direct and indirect mechanisms including biological nitrogen fixation, nutrient solubilization, and disease-control. Many PGPR, by producing phytohormones, volatile organic compounds, and secondary metabolites play important role in influencing the root architecture and growth, resulting in increased surface area for nutrient exchange and other rhizosphere effects. PGPR also improve resource use efficiency of the root system by improving the root system functioning at physiological levels. PGPR mediated root trait alterations can contribute to agroecosystem through improving crop stand, resource use efficiency, stress tolerance, soil structure etc. Thus, PGPR capable of modulating root traits can play important role in agricultural sustainability and root traits can be used as a primary criterion for the selection of potential PGPR strains. Available PGPR studies emphasize root morphological and physiological traits to assess the effect of PGPR. However, these traits can be influenced by various external factors and may give varying results. Therefore, it is important to understand the pathways and genes involved in plant root traits and the microbial signals/metabolites that can intercept and/or intersect these pathways for modulating root traits. The use of advanced tools and technologies can help to decipher the mechanisms involved in PGPR mediated determinants affecting the root traits. Further identification of PGPR based determinants/signaling molecules capable of regulating root trait genes and pathways can open up new avenues in PGPR research. The present review updates recent knowledge on the PGPR influence on root architecture and root functional traits and its benefits to the agro-ecosystem. Efforts have been made to understand the bacterial signals/determinants that can play regulatory role in the expression of root traits and their prospects in sustainable agriculture. The review will be helpful in providing future directions to the researchers working on PGPR and root system functioning.
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18
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Goswami M, Deka S. Isolation of a novel rhizobacteria having multiple plant growth promoting traits and antifungal activity against certain phytopathogens. Microbiol Res 2020; 240:126516. [DOI: 10.1016/j.micres.2020.126516] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 05/03/2020] [Accepted: 05/04/2020] [Indexed: 10/24/2022]
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Effects of Plant Growth Promoting Rhizobacteria on the Content of Abscisic Acid and Salt Resistance of Wheat Plants. PLANTS 2020; 9:plants9111429. [PMID: 33114358 PMCID: PMC7690891 DOI: 10.3390/plants9111429] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 10/22/2020] [Accepted: 10/22/2020] [Indexed: 11/17/2022]
Abstract
Although salinity inhibits plant growth, application of appropriate rhizosphere bacteria can diminish this negative effect. We studied one possible mechanism that may underlie this beneficial response. Wheat plants were inoculated with Bacillus subtilis IB-22 and Pseudomonas mandelii IB-Ki14 and their consequences for growth, water relations, and concentrations of the hormone abscisic acid (ABA) were followed in the presence of soil salinity. Salinity alone increased ABA concentration in wheat leaves and roots and this was associated with decreased stomatal conductance, but also with chlorophyll loss. Bacterial treatment raised ABA concentrations in roots, suppressed accumulation of leaf ABA, decreased chlorophyll loss, and promoted leaf area and transpiration. However, water balance was maintained due to increased water uptake by inoculated plants, brought about in part by a larger root system. The effect may be the outcome of ABA action since the hormone is known to maintain root extension in stressed plants. Root ABA concentration was highest in salt-stressed plants inoculated with B. subtilis and this contributed to greater root hydraulic conductivity. We conclude that bacteria can raise salt resistance in wheat by increasing root ABA, resulting in larger root systems that can also possess enhanced hydraulic conductivity thereby supporting better-hydrated leaves.
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20
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Hussain A, Ullah I, Naseem M. Plant-Associated Microbes Alter Root Growth by Modulating Root Apical Meristem. Methods Mol Biol 2020; 2094:49-58. [PMID: 31797290 DOI: 10.1007/978-1-0716-0183-9_6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Rhizobacteria are known to produce a variety of signal molecules which may modify plant growth by interfering with phytohormone balance. Among the microbial signals are phytohormones, known to contribute to plant endogenous pool of phytohormones. The current chapter describes different methods to study the regulation of gene expression in root apical meristem in response to rhizobacterial inoculation. We describe protocol for the detection of in planta modulation of CKs and IAA by rhizobacteria and their impact on root growth, dissecting the underlying plant signaling pathway by RNA sequencing.
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Affiliation(s)
- Anwar Hussain
- Department of Botany, Garden Campus, Abdul Wali Khan University, Mardan, Khyber Pakhtunkhwa, Pakistan.
| | - Ihsan Ullah
- Department of Environmental Science, Islamic International University Islamabad, Islamabad, Pakistan
| | - Muhammad Naseem
- Department of Life and Environmental Sciences, College of Natural and Health Sciences, Zayed University, Abu Dhabi, UAE
- Department of Bioinformatics, Biocenter, Functional Genomics and Systems Biology Group, University of Würzburg, Würzburg, Germany
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21
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Water-soluble phosphorus contributes significantly to shaping the community structure of rhizospheric bacteria in rocky desertification areas. Sci Rep 2019; 9:18408. [PMID: 31804618 PMCID: PMC6895182 DOI: 10.1038/s41598-019-54943-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Accepted: 11/21/2019] [Indexed: 02/01/2023] Open
Abstract
Microorganisms play important roles in soil improvement. Therefore, clarifying the contribution of environmental factors in shaping the microbial community structure is beneficial to improve soil fertility in karst rocky desertification areas. Here, the bacterial community structures of eight rhizospheric soil samples collected from perennial fruit plantations were analysed using an Illumina HiSeq2500 platform. The diversity and abundance of bacteria in rocky desertification areas were significantly lower than those in non-rocky desertification areas, while the bacterial community structure was not significantly different between root surface and non-root surface soils in the same rhizospheric soil samples. Proteobacteria predominated in rocky desertification areas, while Actinobacteria predominated in non-rocky desertification areas. Correlation analysis revealed that water-soluble phosphorus content (r2 = 0.8258), latitude (r2 = 0.7556), altitude (r2 = 0.7501), and the age of fruit trees (r2 = 0.7321) were positively correlated with the bacterial community structure, while longitude, pH, and total phosphorus content did not significantly influence the soil bacterial community structure. As water-soluble phosphorus content is derived from insoluble phosphorus minerals, supplementing phosphorus-solubilising bacteria to soils in rocky desertification areas is a feasible strategy for accelerating the dissolution of insoluble phosphorus minerals and improving agricultural production and environment ecology.
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Luo D, Langendries S, Mendez SG, De Ryck J, Liu D, Beirinckx S, Willems A, Russinova E, Debode J, Goormachtig S. Plant Growth Promotion Driven by a Novel Caulobacter Strain. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2019; 32:1162-1174. [PMID: 30933667 DOI: 10.1094/mpmi-12-18-0347-r] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Soil microbial communities hold great potential for sustainable and ecologically compatible agriculture. Although numerous plant-beneficial bacterial strains from a wide range of taxonomic groups have been reported, very little evidence is available on the plant-beneficial role of bacteria from the genus Caulobacter. Here, the mode of action of a Caulobacter strain, designated RHG1, which had originally been identified through a microbial screen for plant growth-promoting (PGP) bacteria in maize (Zea mays), is investigated in Arabidopsis thaliana. RHG1 colonized both roots and shoots of Arabidopsis, promoted lateral root formation in the root, and increased leaf number and leaf size in the shoot. The genome of RHG1 was sequenced and was utilized to look for PGP factors. Our data revealed that the bacterial production of nitric oxide, auxins, cytokinins, or 1-aminocyclopropane-1-carboxylate deaminase as PGP factors could be excluded. However, the analysis of brassinosteroid mutants suggests that an unknown PGP mechanism is involved that impinges directly or indirectly on the pathway of this growth hormone.
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Affiliation(s)
- Dexian Luo
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
- Center for Plant Systems Biology, VIB, 9052 Ghent, Belgium
| | - Sarah Langendries
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
- Center for Plant Systems Biology, VIB, 9052 Ghent, Belgium
| | - Sonia Garcia Mendez
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
- Center for Plant Systems Biology, VIB, 9052 Ghent, Belgium
- Department of Biochemistry and Microbiology, Faculty of Sciences, Ghent University, 9000 Ghent, Belgium
| | - Joren De Ryck
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
- Center for Plant Systems Biology, VIB, 9052 Ghent, Belgium
| | - Derui Liu
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
- Center for Plant Systems Biology, VIB, 9052 Ghent, Belgium
| | - Stien Beirinckx
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
- Center for Plant Systems Biology, VIB, 9052 Ghent, Belgium
- Plant Sciences Unit, Flanders Research Institute for Agriculture, Fisheries and Food (ILVO), 9820 Merelbeke, Belgium
| | - Anne Willems
- Department of Biochemistry and Microbiology, Faculty of Sciences, Ghent University, 9000 Ghent, Belgium
| | - Eugenia Russinova
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
- Center for Plant Systems Biology, VIB, 9052 Ghent, Belgium
| | - Jane Debode
- Plant Sciences Unit, Flanders Research Institute for Agriculture, Fisheries and Food (ILVO), 9820 Merelbeke, Belgium
| | - Sofie Goormachtig
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
- Center for Plant Systems Biology, VIB, 9052 Ghent, Belgium
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Herbert RA, Eng T, Martinez U, Wang B, Langley S, Wan K, Pidatala V, Hoffman E, Chen JC, Bissell MJ, Brown JB, Mukhopadhyay A, Mortimer JC. Rhizobacteria Mediate the Phytotoxicity of a Range of Biorefinery-Relevant Compounds. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2019; 38:1911-1922. [PMID: 31107972 PMCID: PMC6711798 DOI: 10.1002/etc.4501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 04/10/2019] [Accepted: 05/15/2019] [Indexed: 05/08/2023]
Abstract
Advances in engineering biology have expanded the list of renewable compounds that can be produced at scale via biological routes from plant biomass. In most cases, these chemical products have not been evaluated for effects on biological systems, defined in the present study as bioactivity, that may be relevant to their manufacture. For sustainable chemical and fuel production, the industry needs to transition from fossil to renewable carbon sources, resulting in unprecedented expansion in the production and environmental distribution of chemicals used in biomanufacturing. Further, although some chemicals have been assessed for mammalian toxicity, environmental and agricultural hazards are largely unknown. We assessed 6 compounds that are representative of the emerging biofuel and bioproduct manufacturing process for their effect on model plants (Arabidopsis thaliana, Sorghum bicolor) and show that several alter plant seedling physiology at submillimolar concentrations. However, these responses change in the presence of individual bacterial species from the A. thaliana root microbiome. We identified 2 individual microbes that change the effect of chemical treatment on root architecture and a pooled microbial community with different effects relative to its constituents individually. The present study indicates that screening industrial chemicals for bioactivity on model organisms in the presence of their microbiomes is important for biologically and ecologically relevant risk analyses. Environ Toxicol Chem 2019;38:1911-1922. © 2019 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC.
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Affiliation(s)
- Robin A. Herbert
- Biological Systems and Engineering DivisionBiosciences Area, Lawrence Berkeley National Laboratory, BerkeleyCaliforniaUSA
- Joint BioEnergy Institute, EmeryvilleCaliforniaUSA
| | - Thomas Eng
- Biological Systems and Engineering DivisionBiosciences Area, Lawrence Berkeley National Laboratory, BerkeleyCaliforniaUSA
- Joint BioEnergy Institute, EmeryvilleCaliforniaUSA
| | - Uriel Martinez
- Biological Systems and Engineering DivisionBiosciences Area, Lawrence Berkeley National Laboratory, BerkeleyCaliforniaUSA
- College of Science and EngineeringSan Francisco State University, San FranciscoCaliforniaUSA
| | - Brenda Wang
- Biological Systems and Engineering DivisionBiosciences Area, Lawrence Berkeley National Laboratory, BerkeleyCaliforniaUSA
| | - Sasha Langley
- Biological Systems and Engineering DivisionBiosciences Area, Lawrence Berkeley National Laboratory, BerkeleyCaliforniaUSA
| | - Kenneth Wan
- Biological Systems and Engineering DivisionBiosciences Area, Lawrence Berkeley National Laboratory, BerkeleyCaliforniaUSA
| | - Venkataramana Pidatala
- Biological Systems and Engineering DivisionBiosciences Area, Lawrence Berkeley National Laboratory, BerkeleyCaliforniaUSA
- Joint BioEnergy Institute, EmeryvilleCaliforniaUSA
| | - Elijah Hoffman
- Biological Systems and Engineering DivisionBiosciences Area, Lawrence Berkeley National Laboratory, BerkeleyCaliforniaUSA
| | - Joseph C. Chen
- College of Science and EngineeringSan Francisco State University, San FranciscoCaliforniaUSA
| | - Mina J. Bissell
- Biological Systems and Engineering DivisionBiosciences Area, Lawrence Berkeley National Laboratory, BerkeleyCaliforniaUSA
| | - James B. Brown
- Biological Systems and Engineering DivisionBiosciences Area, Lawrence Berkeley National Laboratory, BerkeleyCaliforniaUSA
- Environmental Genomics and System Biology DivisionBiosciences Area, Lawrence Berkeley National Laboratory, BerkeleyCaliforniaUSA
| | - Aindrila Mukhopadhyay
- Biological Systems and Engineering DivisionBiosciences Area, Lawrence Berkeley National Laboratory, BerkeleyCaliforniaUSA
- Joint BioEnergy Institute, EmeryvilleCaliforniaUSA
- Environmental Genomics and System Biology DivisionBiosciences Area, Lawrence Berkeley National Laboratory, BerkeleyCaliforniaUSA
| | - Jenny C. Mortimer
- Biological Systems and Engineering DivisionBiosciences Area, Lawrence Berkeley National Laboratory, BerkeleyCaliforniaUSA
- Joint BioEnergy Institute, EmeryvilleCaliforniaUSA
- Environmental Genomics and System Biology DivisionBiosciences Area, Lawrence Berkeley National Laboratory, BerkeleyCaliforniaUSA
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Gao J, Luo Y, Wei Y, Huang Y, Zhang H, He W, Sheng H, An L. Screening of plant growth promoting bacteria (PGPB) from rhizosphere and bulk soil of Caragana microphylla in different habitats and their effects on the growth of Arabidopsis seedlings. BIOTECHNOL BIOTEC EQ 2019. [DOI: 10.1080/13102818.2019.1629841] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Affiliation(s)
- Jiangli Gao
- Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Ministry of Education, Lanzhou University, Lanzhou, PR China
| | - Yang Luo
- Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Ministry of Education, Lanzhou University, Lanzhou, PR China
| | - Yali Wei
- Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Ministry of Education, Lanzhou University, Lanzhou, PR China
| | - Yaolong Huang
- Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Ministry of Education, Lanzhou University, Lanzhou, PR China
| | - Hua Zhang
- Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Ministry of Education, Lanzhou University, Lanzhou, PR China
| | - Wenliang He
- Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Ministry of Education, Lanzhou University, Lanzhou, PR China
| | - Hongmei Sheng
- Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Ministry of Education, Lanzhou University, Lanzhou, PR China
| | - Lizhe An
- Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Ministry of Education, Lanzhou University, Lanzhou, PR China
- The College of Forestry, Beijing Forestry University, Beijing, PR China
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Luo Y, Wang F, Huang Y, Zhou M, Gao J, Yan T, Sheng H, An L. Sphingomonas sp. Cra20 Increases Plant Growth Rate and Alters Rhizosphere Microbial Community Structure of Arabidopsis thaliana Under Drought Stress. Front Microbiol 2019; 10:1221. [PMID: 31231328 PMCID: PMC6560172 DOI: 10.3389/fmicb.2019.01221] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2018] [Accepted: 05/15/2019] [Indexed: 12/22/2022] Open
Abstract
The rhizosphere is colonized by a mass of microbes, including bacteria capable of promoting plant growth that carry out complex interactions. Here, by using a sterile experimental system, we demonstrate that Sphingomonas sp. Cra20 promotes the growth of Arabidopsis thaliana by driving developmental plasticity in the roots, thus stimulating the growth of lateral roots and root hairs. By investigating the growth dynamics of A. thaliana in soil with different water-content, we demonstrate that Cra20 increases the growth rate of plants, but does not change the time of reproductive transition under well-water condition. The results further show that the application of Cra20 changes the rhizosphere indigenous bacterial community, which may be due to the change in root structure. Our findings provide new insights into the complex mechanisms of plant and bacterial interactions. The ability to promote the growth of plants under water-deficit can contribute to the development of sustainable agriculture.
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Affiliation(s)
- Yang Luo
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Fang Wang
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Yaolong Huang
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Meng Zhou
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Jiangli Gao
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Taozhe Yan
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Hongmei Sheng
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Lizhe An
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, China
- The College of Forestry, Beijing Forestry University, Beijing, China
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26
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Complete genome sequence of Caulobacter flavus RHGG3 T, a type species of the genus Caulobacter with plant growth-promoting traits and heavy metal resistance. 3 Biotech 2019; 9:42. [PMID: 30675452 DOI: 10.1007/s13205-019-1569-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2018] [Accepted: 01/03/2019] [Indexed: 10/27/2022] Open
Abstract
Caulobacter flavus RHGG3T, a novel type species in the genus Caulobacter, originally isolated from rhizosphere soil of watermelon (Citrullus lanatus), has the ability to improve the growth of watermelon seedling and tolerate heavy metals. In vitro, C. flavus RHGG3T was able to solubilize phosphate (80.56 mg L-1), produce indole-3-acetic acid (IAA) (11.58 mg L-1) and was resistant to multiple heavy metals (copper, zinc, cadmium, cobalt and lead). Inoculating watermelon with this strain increased shoot and root length by 22.1% and 43.7%, respectively, and the total number of lateral roots by 55.9% compared to non-inoculated watermelon. In this study, we present the complete genome sequence of C. flavus RHGG3T, which was comprised of a single circular chromosome of 5,659,202 bp with a G + C content of 69.25%. An annotation analysis revealed that the C. flavus RHGG3T genome contained 5172 coding DNA sequences, 9 rRNA and 55 tRNA genes. Genes related to plant growth promotion (PGP), such as those associated with phosphate solubilization, nitrogen fixation, IAA, phenazine, volatile compounds, spermidine and cobalamin synthesis, were found in the C. flavus RHGG3T genome. Some genes responsible for heavy metal tolerance were also identified. The genome sequence of strain RHGG3T reported here provides new insight into the molecular mechanisms underlying the promotion of plant growth and the resistance to heavy metals in C. flavus. This study will be valuable for further exploration of the biotechnological applications of strain RHGG3T in agriculture.
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Vigani G, Rolli E, Marasco R, Dell'Orto M, Michoud G, Soussi A, Raddadi N, Borin S, Sorlini C, Zocchi G, Daffonchio D. Root bacterial endophytes confer drought resistance and enhance expression and activity of a vacuolar H + -pumping pyrophosphatase in pepper plants. Environ Microbiol 2018; 21:3212-3228. [PMID: 29786171 DOI: 10.1111/1462-2920.14272] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Revised: 05/03/2018] [Accepted: 05/07/2018] [Indexed: 11/29/2022]
Abstract
It has been previously shown that the transgenic overexpression of the plant root vacuolar proton pumps H+ -ATPase (V-ATPase) and H+ -PPase (V-PPase) confer tolerance to drought. Since plant-root endophytic bacteria can also promote drought tolerance, we hypothesize that such promotion can be associated to the enhancement of the host vacuolar proton pumps expression and activity. To test this hypothesis, we selected two endophytic bacteria endowed with an array of in vitro plant growth promoting traits. Their genome sequences confirmed the presence of traits previously shown to confer drought resistance to plants, such as the synthesis of nitric oxide and of organic volatile organic compounds. We used the two strains on pepper (Capsicuum annuum L.) because of its high sensitivity to drought. Under drought conditions, both strains stimulated a larger root system and enhanced the leaves' photosynthetic activity. By testing the expression and activity of the vacuolar proton pumps, H+ -ATPase (V-ATPase) and H+ -PPase (V-PPase), we found that bacterial colonization enhanced V-PPase only. We conclude that the enhanced expression and activity of V-PPase can be favoured by the colonization of drought-tolerance-inducing bacterial endophytes.
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Affiliation(s)
- Gianpiero Vigani
- Department of Life Sciences and Systems Biology, University of Turin, Plant Physiology Unit, 10135, Turin, Italy
| | - Eleonora Rolli
- Department of Food, Environmental and Nutritional Sciences (DeFENS), University of Milan, 20133, Milan, Italy
| | - Ramona Marasco
- Biological and Environmental Sciences and Engineering Division (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | - Marta Dell'Orto
- Department of Agricultural and Environmental Sciences, Production, Landscape, Agroenergy (DISAA), University of Milan, 20133, Milan, Italy
| | - Grégoire Michoud
- Biological and Environmental Sciences and Engineering Division (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | - Asma Soussi
- Biological and Environmental Sciences and Engineering Division (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | - Noura Raddadi
- Department of Civil, Alma Mater Studiorum University of Bologna, Chemical, Environmental and Materials Engineering (DICAM), Bologna, Italy
| | - Sara Borin
- Department of Food, Environmental and Nutritional Sciences (DeFENS), University of Milan, 20133, Milan, Italy
| | - Claudia Sorlini
- Department of Food, Environmental and Nutritional Sciences (DeFENS), University of Milan, 20133, Milan, Italy
| | - Graziano Zocchi
- Department of Agricultural and Environmental Sciences, Production, Landscape, Agroenergy (DISAA), University of Milan, 20133, Milan, Italy
| | - Daniele Daffonchio
- Biological and Environmental Sciences and Engineering Division (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
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28
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Wang TT, Ding P, Chen P, Xing K, Bai JL, Wan W, Jiang JH, Qin S. Complete genome sequence of endophyte Bacillus flexus KLBMP 4941 reveals its plant growth promotion mechanism and genetic basis for salt tolerance. J Biotechnol 2017; 260:38-41. [DOI: 10.1016/j.jbiotec.2017.09.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Revised: 09/01/2017] [Accepted: 09/02/2017] [Indexed: 12/16/2022]
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