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Mishra S, Zhang X, Yang X. Plant communication with rhizosphere microbes can be revealed by understanding microbial functional gene composition. Microbiol Res 2024; 284:127726. [PMID: 38643524 DOI: 10.1016/j.micres.2024.127726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2023] [Revised: 03/26/2024] [Accepted: 04/12/2024] [Indexed: 04/23/2024]
Abstract
Understanding rhizosphere microbial ecology is necessary to reveal the interplay between plants and associated microbial communities. The significance of rhizosphere-microbial interactions in plant growth promotion, mediated by several key processes such as auxin synthesis, enhanced nutrient uptake, stress alleviation, disease resistance, etc., is unquestionable and well reported in numerous literature. Moreover, rhizosphere research has witnessed tremendous progress due to the integration of the metagenomics approach and further shift in our viewpoint from taxonomic to functional diversity over the past decades. The microbial functional genes corresponding to the beneficial functions provide a solid foundation for the successful establishment of positive plant-microbe interactions. The microbial functional gene composition in the rhizosphere can be regulated by several factors, e.g., the nutritional requirements of plants, soil chemistry, soil nutrient status, pathogen attack, abiotic stresses, etc. Knowing the pattern of functional gene composition in the rhizosphere can shed light on the dynamics of rhizosphere microbial ecology and the strength of cooperation between plants and associated microbes. This knowledge is crucial to realizing how microbial functions respond to unprecedented challenges which are obvious in the Anthropocene. Unraveling how microbes-mediated beneficial functions will change under the influence of several challenges, requires knowledge of the pattern and composition of functional genes corresponding to beneficial functions such as biogeochemical functions (nutrient cycle), plant growth promotion, stress mitigation, etc. Here, we focus on the molecular traits of plant growth-promoting functions delivered by a set of microbial functional genes that can be useful to the emerging field of rhizosphere functional ecology.
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Affiliation(s)
- Sandhya Mishra
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Yunnan 666303, China.
| | - Xianxian Zhang
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Yunnan 666303, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaodong Yang
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Yunnan 666303, China.
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Mahmoud FM, Pritsch K, Siani R, Benning S, Radl V, Kublik S, Bunk B, Spröer C, Schloter M. Comparative genomic analysis of strain Priestia megaterium B1 reveals conserved potential for adaptation to endophytism and plant growth promotion. Microbiol Spectr 2024:e0042224. [PMID: 38916310 DOI: 10.1128/spectrum.00422-24] [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: 02/21/2024] [Accepted: 05/17/2024] [Indexed: 06/26/2024] Open
Abstract
In our study, we aimed to explore the genomic and phenotypic traits of Priestia megaterium strain B1, which was isolated from root material of healthy apple plants, to adapt to the endophytic lifestyle and promote plant growth. We identified putative genes encoding proteins involved in chemotaxis, flagella biosynthesis, biofilm formation, secretory systems, detoxification, transporters, and transcription regulation. Furthermore, B1 exhibited both swarming and swimming motilities, along with biofilm formation. Both genomic and physiological analyses revealed the potential of B1 to promote plant growth through the production of indole-3-acetic acid and siderophores, as well as the solubilization of phosphate and zinc. To deduce potential genomic features associated with endophytism across members of P. megaterium strains, we conducted a comparative genomic analysis involving 27 and 31 genomes of strains recovered from plant and soil habitats, respectively, in addition to our strain B1. Our results indicated a closed pan genome and comparable genome size of strains from both habitats, suggesting a facultative host association and adaptive lifestyle to both habitats. Additionally, we performed a sparse Partial Least Squares Discriminant Analysis to infer the most discriminative functional features of the two habitats based on Pfam annotation. Despite the distinctive clustering of both groups, functional enrichment analysis revealed no significant enrichment of any Pfam domain in both habitats. Furthermore, when assessing genetic elements related to adaptation to endophytism in each individual strain, we observed their widespread presence among strains from both habitats. Moreover, all members displayed potential genetic elements for promoting plant growth.IMPORTANCEBoth genomic and phenotypic analyses yielded valuable insights into the capacity of P. megaterium B1 to adapt to the plant niche and enhance its growth. The comparative genomic analysis revealed that P. megaterium members, whether derived from soil or plant sources, possess the essential genetic machinery for interacting with plants and enhancing their growth. The conservation of these traits across various strains of this species extends its potential application as a bio-stimulant in diverse environments. This significance also applies to strain B1, particularly regarding its application to enhance the growth of plants facing apple replant disease conditions.
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Affiliation(s)
- Fatma M Mahmoud
- Research Unit for Comparative Microbiome Analysis, Helmholtz Munich, German Research Center for Environmental Health, Neuherberg, Germany
- Botany and Microbiology Department, Faculty of Science, Suez Canal University, Ismailia, Egypt
| | - Karin Pritsch
- Research Unit for Environmental Simulations, Helmholtz Munich, German Research Center for Environmental Health, Neuherberg, Germany
| | - Roberto Siani
- Research Unit for Comparative Microbiome Analysis, Helmholtz Munich, German Research Center for Environmental Health, Neuherberg, Germany
| | - Sarah Benning
- Research Unit for Comparative Microbiome Analysis, Helmholtz Munich, German Research Center for Environmental Health, Neuherberg, Germany
| | - Viviane Radl
- Research Unit for Comparative Microbiome Analysis, Helmholtz Munich, German Research Center for Environmental Health, Neuherberg, Germany
| | - Susanne Kublik
- Research Unit for Comparative Microbiome Analysis, Helmholtz Munich, German Research Center for Environmental Health, Neuherberg, Germany
| | - Boyke Bunk
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany
| | - Cathrin Spröer
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany
| | - Michael Schloter
- Research Unit for Comparative Microbiome Analysis, Helmholtz Munich, German Research Center for Environmental Health, Neuherberg, Germany
- Chair for Environmental Microbiology, TUM School of Life Sciences, Technical University of Munich, Munich, Germany
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Ahmed A, He P, He Y, Singh BK, Wu Y, Munir S, He P. Biocontrol of plant pathogens in omics era-with special focus on endophytic bacilli. Crit Rev Biotechnol 2024; 44:562-580. [PMID: 37055183 DOI: 10.1080/07388551.2023.2183379] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Accepted: 02/06/2023] [Indexed: 04/15/2023]
Abstract
Nearly all plants and their organs are inhabited by endophytic microbes which play a crucial role in plant fitness and stress resilience. Harnessing endophytic services can provide effective solutions for a sustainable increase in agriculture productivity and can be used as a complement or alternative to agrochemicals. Shifting agriculture practices toward the use of nature-based solutions can contribute directly to the global challenges of food security and environmental sustainability. However, microbial inoculants have been used in agriculture for several decades with inconsistent efficacy. Key reasons of this inconsistent efficacy are linked to competition with indigenous soil microflora and inability to colonize plants. Endophytic microbes provide solutions to both of these issues which potentially make them better candidates for microbial inoculants. This article outlines the current advancements in endophytic research with special focus on endophytic bacilli. A better understanding of diverse mechanisms of disease control by bacilli is essential to achieve maximum biocontrol efficacy against multiple phytopathogens. Furthermore, we argue that integration of emerging technologies with strong theoretical frameworks have the potential to revolutionize biocontrol approaches based on endophytic microbes.
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Affiliation(s)
- Ayesha Ahmed
- State Key Laboratory for Conservation and Utilization of Bio-resources in Yunnan, Yunnan Agricultural University, Kunming, Yunnan, China
| | - Pengfei He
- State Key Laboratory for Conservation and Utilization of Bio-resources in Yunnan, Yunnan Agricultural University, Kunming, Yunnan, China
| | - Yueqiu He
- State Key Laboratory for Conservation and Utilization of Bio-resources in Yunnan, Yunnan Agricultural University, Kunming, Yunnan, China
| | - Brajesh K Singh
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith South, New South Wales, Australia
- Global Centre for Land Based Innovation, Western Sydney University, Penrith South, New South Wales, Australia
| | - Yixin Wu
- State Key Laboratory for Conservation and Utilization of Bio-resources in Yunnan, Yunnan Agricultural University, Kunming, Yunnan, China
| | - Shahzad Munir
- State Key Laboratory for Conservation and Utilization of Bio-resources in Yunnan, Yunnan Agricultural University, Kunming, Yunnan, China
| | - Pengbo He
- State Key Laboratory for Conservation and Utilization of Bio-resources in Yunnan, Yunnan Agricultural University, Kunming, Yunnan, China
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Hung SHW, Yeh PH, Huang TC, Huang SY, Wu IC, Liu CH, Lin YH, Chien PR, Huang FC, Ho YN, Kuo CH, Hwang HH, Chiang EPI, Huang CC. A cyclic dipeptide for salinity stress alleviation and the trophic flexibility of endophyte provide insights into saltmarsh plant-microbe interactions. ISME COMMUNICATIONS 2024; 4:ycae041. [PMID: 38707842 PMCID: PMC11070113 DOI: 10.1093/ismeco/ycae041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 02/23/2024] [Accepted: 03/20/2024] [Indexed: 05/07/2024]
Abstract
In response to climate change, the nature of endophytes and their applications in sustainable agriculture have attracted the attention of academics and agro-industries. This work focused on the endophytic halophiles of the endangered Taiwanese salt marsh plant, Bolboschoenus planiculmis, and evaluated the functions of these isolates through in planta salinity stress alleviation assay using Arabidopsis. The endophytic strain Priestia megaterium BP01R2, which can promote plant growth and salinity tolerance, was further characterized through multi-omics approaches. The transcriptomics results suggested that BP01R2 could function by tuning hormone signal transduction, energy-producing metabolism, multiple stress responses, etc. In addition, the cyclodipeptide cyclo(L-Ala-Gly), which was identified by metabolomics analysis, was confirmed to contribute to the alleviation of salinity stress in stressed plants via exogenous supplementation. In this study, we used multi-omics approaches to investigate the genomics, metabolomics, and tropisms of endophytes, as well as the transcriptomics of plants in response to the endophyte. The results revealed the potential molecular mechanisms underlying the occurrence of biostimulant-based plant-endophyte symbioses with possible application in sustainable agriculture.
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Affiliation(s)
- Shih-Hsun Walter Hung
- Department of Life Sciences, National Chung Hsing University, Taichung 402202, Taiwan
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 115201, Taiwan
- Advanced Plant and Food Crop Biotechnology Center, National Chung Hsing University, Taichung 402202, Taiwan
| | - Pin-Hsien Yeh
- Department of Life Sciences, National Chung Hsing University, Taichung 402202, Taiwan
| | - Tsai-Ching Huang
- Department of Life Sciences, National Chung Hsing University, Taichung 402202, Taiwan
| | - Shao-Yu Huang
- Department of Life Sciences, National Chung Hsing University, Taichung 402202, Taiwan
| | - I-Chen Wu
- Department of Life Sciences, National Chung Hsing University, Taichung 402202, Taiwan
| | - Chia-Ho Liu
- Department of Life Sciences, National Chung Hsing University, Taichung 402202, Taiwan
| | - Yu-Hsi Lin
- Department of Life Sciences, National Chung Hsing University, Taichung 402202, Taiwan
| | - Pei-Ru Chien
- Department of Life Sciences, National Chung Hsing University, Taichung 402202, Taiwan
| | - Fan-Chen Huang
- Department of Life Sciences, National Chung Hsing University, Taichung 402202, Taiwan
| | - Ying-Ning Ho
- Institute of Marine Biology, College of Life Science, National Taiwan Ocean University, Keelung 202301, Taiwan
- Centre of Excellence for the Oceans, National Taiwan Ocean University, Keelung 202301, Taiwan
- Taiwan Ocean Genome Center, National Taiwan Ocean University, Keelung 202301, Taiwan
| | - Chih-Horng Kuo
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 115201, Taiwan
- Biotechnology Center, National Chung Hsing University, Taichung 402202, Taiwan
| | - Hau-Hsuan Hwang
- Department of Life Sciences, National Chung Hsing University, Taichung 402202, Taiwan
- Advanced Plant and Food Crop Biotechnology Center, National Chung Hsing University, Taichung 402202, Taiwan
- Innovation and Development Center of Sustainable Agriculture, National Chung Hsing University, Taichung 402202, Taiwan
| | - En-Pei Isabel Chiang
- Advanced Plant and Food Crop Biotechnology Center, National Chung Hsing University, Taichung 402202, Taiwan
- Innovation and Development Center of Sustainable Agriculture, National Chung Hsing University, Taichung 402202, Taiwan
- Department of Food Science and Biotechnology, National Chung Hsing University, Taichung 402202, Taiwan
| | - Chieh-Chen Huang
- Department of Life Sciences, National Chung Hsing University, Taichung 402202, Taiwan
- Advanced Plant and Food Crop Biotechnology Center, National Chung Hsing University, Taichung 402202, Taiwan
- Innovation and Development Center of Sustainable Agriculture, National Chung Hsing University, Taichung 402202, Taiwan
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Wu X, Zhao Z, Zhao Z, Zhang Y, Li M, Yu Q. Analysis of the Potassium-Solubilizing Priestia megaterium Strain NK851 and Its Potassium Feldspar-Binding Proteins. Int J Mol Sci 2023; 24:14226. [PMID: 37762528 PMCID: PMC10531590 DOI: 10.3390/ijms241814226] [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: 05/30/2023] [Revised: 08/23/2023] [Accepted: 08/24/2023] [Indexed: 09/29/2023] Open
Abstract
Potassium-solubilizing bacteria are an important microbial group that play a critical role in releasing mineral potassium from potassium-containing minerals, e.g., potassium feldspar. Their application may reduce eutrophication caused by overused potassium fertilizers and facilitate plants to utilize environmental potassium. In this study, a high-efficiency potassium-solubilizing bacterium, named NK851, was isolated from the Astragalus sinicus rhizosphere soil. This bacterium can grow in the medium with potassium feldspar as the sole potassium source, releasing 157 mg/L and 222 mg/L potassium after 3 days and 5 days of incubation, respectively. 16S rDNA sequencing and cluster analysis showed that this strain belongs to Priestia megaterium. Genome sequencing further revealed that this strain has a genome length of 5,305,142 bp, encoding 5473 genes. Among them, abundant genes are related to potassium decomposition and utilization, e.g., the genes involved in adherence to mineral potassium, potassium release, and intracellular trafficking. Moreover, the strong potassium-releasing capacity of NK851 is not attributed to the acidic pH but is attributed to the extracellular potassium feldspar-binding proteins, such as the elongation factor TU and the enolase that contains potassium feldspar-binding cavities. This study provides new information for exploration of the bacterium-mediated potassium solubilization mechanisms.
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Affiliation(s)
- Xinyue Wu
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin 300071, China; (X.W.); (Z.Z.); (Z.Z.); (M.L.)
| | - Zijian Zhao
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin 300071, China; (X.W.); (Z.Z.); (Z.Z.); (M.L.)
| | - Zirun Zhao
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin 300071, China; (X.W.); (Z.Z.); (Z.Z.); (M.L.)
| | - Youjun Zhang
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China;
| | - Mingchun Li
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin 300071, China; (X.W.); (Z.Z.); (Z.Z.); (M.L.)
| | - Qilin Yu
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin 300071, China; (X.W.); (Z.Z.); (Z.Z.); (M.L.)
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Liu Q, Li L, Chen Y, Wang S, Xue L, Meng W, Jiang J, Cao X. Diversity of Endophytic Microbes in Taxus yunnanensis and Their Potential for Plant Growth Promotion and Taxane Accumulation. Microorganisms 2023; 11:1645. [PMID: 37512818 PMCID: PMC10383522 DOI: 10.3390/microorganisms11071645] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 06/12/2023] [Accepted: 06/21/2023] [Indexed: 07/30/2023] Open
Abstract
Taxus spp. are ancient tree species that have survived from the Quaternary glacier period, and their metabolites, such as taxol, have been used as anticancer drugs globally. Plant-endophytic microbial interaction plays a crucial role in exerting a profound impact on host growth and secondary metabolite synthesis. In this study, high-throughput sequencing was employed to explore endophytic microbial diversity in the roots, stems, and leaves of the Taxus yunnanensis (T. yunnanensis). The analysis revealed some dominant genera of endophytic bacteria, such as Pseudomonas, Neorhizobium, Acidovorax, and Flavobacterium, with Cladosporium, Phyllosticta, Fusarium, and Codinaeopsis as prominent endophytic fungi genera. We isolated 108 endophytic bacteria and 27 endophytic fungi from roots, stems, and leaves. In vitro assays were utilized to screen for endophytic bacteria with growth-promoting capabilities, including IAA production, cellulase, siderophore production, protease and ACC deaminase activity, inorganic phosphate solubilization, and nitrogen fixation. Three promising strains, Kocuria sp. TRI2-1, Micromonospora sp. TSI4-1, and Sphingomonas sp. MG-2, were selected based on their superior growth-promotion characteristics. These strains exhibited preferable plant growth promotion when applied to Arabidopsis thaliana growth. Fermentation broths of these three strains were also found to significantly promote the accumulation of taxanes in T. yunnanensis stem cells, among which strain TSI4-1 demonstrated outstanding increase potentials, with an effective induction of taxol, baccatin III, and 10-DAB contents. After six days of treatment, the contents of these metabolites were 3.28 times, 2.23 times, and 2.17 times the initial amounts, reaching 8720, 331, and 371 ng/g of dry weight of stem cells, respectively. These findings present new insight into the industrialization of taxol production through Taxus stem cell fermentation, thereby promoting the conservation of wild Taxus resources by maximizing their potential economic benefits.
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Affiliation(s)
- Qiao Liu
- Key Laboratory of Biotechnology for Medicinal Plants of Jiangsu Province, School of Life Sciences, Jiangsu Normal University, Xuzhou 221116, China
| | - Ludan Li
- Key Laboratory of Biotechnology for Medicinal Plants of Jiangsu Province, School of Life Sciences, Jiangsu Normal University, Xuzhou 221116, China
| | - Yujie Chen
- Key Laboratory of Biotechnology for Medicinal Plants of Jiangsu Province, School of Life Sciences, Jiangsu Normal University, Xuzhou 221116, China
| | - Sai Wang
- Key Laboratory of Biotechnology for Medicinal Plants of Jiangsu Province, School of Life Sciences, Jiangsu Normal University, Xuzhou 221116, China
| | - Lina Xue
- Key Laboratory of Biotechnology for Medicinal Plants of Jiangsu Province, School of Life Sciences, Jiangsu Normal University, Xuzhou 221116, China
| | - Weiying Meng
- Key Laboratory of Biotechnology for Medicinal Plants of Jiangsu Province, School of Life Sciences, Jiangsu Normal University, Xuzhou 221116, China
| | - Jihong Jiang
- Key Laboratory of Biotechnology for Medicinal Plants of Jiangsu Province, School of Life Sciences, Jiangsu Normal University, Xuzhou 221116, China
| | - Xiaoying Cao
- Key Laboratory of Biotechnology for Medicinal Plants of Jiangsu Province, School of Life Sciences, Jiangsu Normal University, Xuzhou 221116, China
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Zhang D, He J, Cheng P, Zhang Y, Khan A, Wang S, Li Z, Zhao S, Zhan X, Ma F, Li X, Guan Q. 4-methylumbelliferone (4-MU) enhances drought tolerance of apple by regulating rhizosphere microbial diversity and root architecture. HORTICULTURE RESEARCH 2023; 10:uhad099. [PMID: 37427035 PMCID: PMC10327542 DOI: 10.1093/hr/uhad099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Accepted: 05/04/2023] [Indexed: 07/11/2023]
Abstract
The dwarfing rootstocks-mediated high-density apple orchard is becoming the main practice management. Currently, dwarfing rootstocks are widely used worldwide, but their shallow root system and drought sensitivity necessitate high irrigation requirements. Here, the root transcriptome and metabolome of dwarfing (M9-T337, a drought-sensitive rootstock) and vigorous rootstocks (Malus sieversii, a drought-tolerant species, is commonly used as a rootstock) showed that a coumarin derivative, 4-Methylumbelliferon (4-MU), was found to accumulate significantly in the roots of vigorous rootstock under drought condition. When exogenous 4-MU was applied to the roots of dwarfing rootstock under drought treatment, the plants displayed increased root biomass, higher root-to-shoot ratio, greater photosynthesis, and elevated water use efficiency. In addition, diversity and structure analysis of the rhizosphere soil microbial community demonstrated that 4-MU treatment increased the relative abundance of putatively beneficial bacteria and fungi. Of these, Pseudomonas, Bacillus, Streptomyces, and Chryseolinea bacterial strains and Acremonium, Trichoderma, and Phoma fungal strains known for root growth, or systemic resistance against drought stress, were significantly accumulated in the roots of dwarfing rootstock after 4-MU treatment under drought stress condition. Taken together, we identified a promising compound-4-MU, as a useful tool, to strengthen the drought tolerance of apple dwarfing rootstock.
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Affiliation(s)
- Dehui Zhang
- State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Yangling 712100, China
- College of Life Science, Northwest A&F University, Yangling 712100, China
| | - Jieqiang He
- State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Yangling 712100, China
| | - Pengda Cheng
- State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Yangling 712100, China
| | - Yutian Zhang
- State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Yangling 712100, China
| | - Abid Khan
- Department of Horticulture, The University of Haripur, Haripur 22620, Pakistan
| | - Shicong Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Yangling 712100, China
| | - Zhongxing Li
- State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Yangling 712100, China
| | - Shuang Zhao
- State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Yangling 712100, China
| | - Xiangqiang Zhan
- State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Yangling 712100, China
| | - Fengwang Ma
- State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Yangling 712100, China
| | - Xuewei Li
- State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Yangling 712100, China
| | - Qingmei Guan
- State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Yangling 712100, China
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Dhole AM, Shelat HN, Patel HK, Jhala YK. Evaluation of the Co-inoculation Effect of Rhizobium and Plant Growth Promoting Non-rhizobial Endophytes on Vigna radiata. Curr Microbiol 2023; 80:167. [PMID: 37024674 DOI: 10.1007/s00284-023-03266-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 03/11/2023] [Indexed: 04/08/2023]
Abstract
A unique feature of leguminous plants is the establishment of symbiotic bacterial genera inside root or stem nodules that is being recently re-evaluated for investigating the micro-flora discrete to nitrogen fixation. The present research was carried out to evaluate non-rhizobial endophytes and Rhizobium from root nodules of Vigna radiata and ascertain their co-inoculation effect in pot and field conditions. Each strain displayed one or more plant growth-promoting behaviors in varying degrees. The ability to fix nitrogen was observed in all strains; however, a noticeable enhancement in nitrogen fixation was observed when all three strains were co-inoculated. All three strains were found to possess the nifH gene, which plays a key role in the nitrogen fixation process. However, only Rhizobium sp. AAU B3 also had the nodD gene present. Furthermore, combinations of all three strains produced the highest levels of phosphate solubilization, potash mobilisation, Indole Acetic Acid (IAA), and the stress-relieving enzyme 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase. Interestingly, the succession of the root nodule formation within root hairs seedlings was observed under a fluorescence microscope and two NRE were found to be located inside the root nodules, indicating that they are endophytic. Additionally, a pot and field investigation revealed that the combination of chosen Rhizobium and NRE strains had a favorable impact on the growth and yield characteristics of a green gram. Selected bio-inoculants can reduce the utilization of synthetic fertilizers by 75%, which might lead to the restoration of the soil's health. Therefore, these bio-inoculants might be explored commercially for sustainable agriculture production.
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Affiliation(s)
- Archana M Dhole
- B. A. College of Agriculture, Anand Agricultural University, Anand, Gujarat, 388110, India.
| | - Harsha N Shelat
- B. A. College of Agriculture, Anand Agricultural University, Anand, Gujarat, 388110, India
| | - Hiren K Patel
- B. A. College of Agriculture, Anand Agricultural University, Anand, Gujarat, 388110, India
| | - Yogeshvari K Jhala
- B. A. College of Agriculture, Anand Agricultural University, Anand, Gujarat, 388110, India
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Li Q, Zhang W, Liao S, Xing D, Xiao Y, Zhou D, Yang Q. Mechanism of lead adsorption by a Bacillus cereus strain with indole-3-acetic acid secretion and inorganic phosphorus dissolution functions. BMC Microbiol 2023; 23:57. [PMID: 36869296 PMCID: PMC9985246 DOI: 10.1186/s12866-023-02795-z] [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: 11/29/2022] [Accepted: 02/14/2023] [Indexed: 03/05/2023] Open
Abstract
BACKGROUND Heavy metal pollution has become a major source of environmental pollution because of increasing industrialization. Microbial remediation is a promising approach to remediate lead-contaminated environments owing to its cost-effective, environment-friendly, ecologically sustainable, and highly efficient properties. In this study, the growth-promoting functions and lead-adsorption ability of Bacillus cereus SEM-15 were examined, and the functional mechanism of the strain was preliminarily identified using scanning electron microscopy, energy spectrum, infrared spectrum, and genome analyses, providing theoretical support for utilization of B. cereus SEM-15 in heavy metals remediation. RESULTS B. cereus SEM-15 showed strong ability to dissolve inorganic phosphorus and secrete indole-3-acetic acid. The lead adsorption efficiency of the strain at lead ion concentration of 150 mg/L was more than 93%. Single factor analysis revealed the optimal conditions for heavy metal adsorption by B. cereus SEM-15 (adsorption time, initial lead ion concentration, pH, and inoculum amount were 10 min, 50-150 mg/L, 6-7, and 5 g/L, respectively) in nutrient-free environment, with the lead adsorption rate reaching 96.58%. Scanning electron microscopy of B. cereus SEM-15 cells before and after lead adsorption showed adherence of a large number of granular precipitates to the cell surface after lead adsorption. X-Ray photoelectron spectroscopy and Fourier transform infrared spectroscopy results indicated the characteristic peaks of Pb-O, Pb-O-R (R = functional group), and Pb-S bonds after lead adsorption, and a shift in the characteristic peaks of bonds and groups related to C, N, and O. Genome annotation results showed the presence of genes related to heavy metals tolerance and plant growth promotion in B. cereus SEM-15, providing a molecular basis for the strain's heavy metals tolerance and plant growth promotion functions. CONCLUSIONS This study analyzed the lead adsorption characteristics of B. cereus SEM-15 and the associated influencing factors, and discussed the adsorption mechanism and related functional genes, providing a basis for clarifying the underlying molecular mechanism and offering a reference for further research on plant-microorganisms combined remediation of heavy metals polluted environments.
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Affiliation(s)
- Qingrong Li
- Sericultural and Agri-Food Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, 510610, China.,Key Laboratory of Urban Agriculture in South China, Ministry of Agriculture and Rural Affairs, GuangZhou, 510610, China
| | - Wenbo Zhang
- Sericultural and Agri-Food Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, 510610, China
| | - Sentai Liao
- Sericultural and Agri-Food Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, 510610, China
| | - Dongxu Xing
- Sericultural and Agri-Food Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, 510610, China.,Key Laboratory of Urban Agriculture in South China, Ministry of Agriculture and Rural Affairs, GuangZhou, 510610, China
| | - Yang Xiao
- Sericultural and Agri-Food Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, 510610, China.,Key Laboratory of Urban Agriculture in South China, Ministry of Agriculture and Rural Affairs, GuangZhou, 510610, China
| | - Donglai Zhou
- Sericultural and Agri-Food Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, 510610, China
| | - Qiong Yang
- Sericultural and Agri-Food Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, 510610, China. .,Key Laboratory of Urban Agriculture in South China, Ministry of Agriculture and Rural Affairs, GuangZhou, 510610, China.
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10
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Ali N, Swarnkar MK, Veer R, Kaushal P, Pati AM. Temperature-induced modulation of stress-tolerant PGP genes bioprospected from Bacillus sp. IHBT-705 associated with saffron ( Crocus sativus) rhizosphere: A natural -treasure trove of microbial biostimulants. FRONTIERS IN PLANT SCIENCE 2023; 14:1141538. [PMID: 36923125 PMCID: PMC10009223 DOI: 10.3389/fpls.2023.1141538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 02/14/2023] [Indexed: 06/18/2023]
Abstract
There is a renewed interest in sustainable agriculture wherein novel plant growth-promoting rhizobacteria (PGPR) are being explored for developing efficient biostimulants. The key requirement of a microbe to qualify as a good candidate for developing a biostimulant is its intrinsic plant growth-promoting (PGP) characteristics. Though numerous studies have been conducted to assess the beneficial effects of PGPRs on plant growth under normal and stressed conditions but not much information is available on the characterization of intrinsic traits of PGPR under stress. Here, we focused on understanding how temperature stress impacts the functionality of key stress tolerant and PGP genes of Bacillus sp. IHBT-705 isolated from the rhizosphere of saffron (Crocus sativus). To undertake the study, Bacillus sp. IHBT-705 was grown under varied temperature regimes, their PGP traits were assessed from very low to very high-temperature range and the expression trend of targeted stress tolerant and PGP genes were analyzed. The results illustrated that Bacillus sp. IHBT-705 is a stress-tolerant PGPR as it survived and multiplied in temperatures ranging from 4°C-50°C, tolerated a wide pH range (5-11), withstood high salinity (8%) and osmolarity (10% PEG). The PGP traits varied under different temperature regimes indicating that temperature influences the functionality of PGP genes. This was further ascertained through whole genome sequencing followed by gene expression analyses wherein certain genes like cspB, cspD, hslO, grpE, rimM, trpA, trpC, trpE, fhuC, fhuD, acrB5 were found to be temperature sensitive while, cold tolerant (nhaX and cspC), heat tolerant (htpX) phosphate solubilization (pstB1), siderophore production (fhuB and fhuG), and root colonization (xerC1 and xerC2) were found to be highly versatile as they could express well both under low and high temperatures. Further, the biostimulant potential was checked through a pot study on rice (Oryza sativa), wherein the application of Bacillus sp. IHBT-705 improved the length of shoots, roots, and number of roots over control. Based on the genetic makeup, stress tolerance potential, retention of PGP traits under stress, and growth-promoting potential, Bacillus sp. IHBT-705 could be considered a good candidate for developing biostimulants.
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Affiliation(s)
- Nilofer Ali
- Biotechnology Division, CSIR-Institute of Himalayan Bioresource Technology, Palampur, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Mohit Kumar Swarnkar
- Biotechnology Division, CSIR-Institute of Himalayan Bioresource Technology, Palampur, India
| | - Raj Veer
- Incubatee at Chief Minister Startup Scheme, Shimla, India
| | - Priya Kaushal
- Biotechnology Division, CSIR-Institute of Himalayan Bioresource Technology, Palampur, India
| | - Aparna Maitra Pati
- Biotechnology Division, CSIR-Institute of Himalayan Bioresource Technology, Palampur, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
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11
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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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12
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Rodrigues-dos Santos AS, Rebelo-Romão I, Zhang H, Vílchez JI. Discerning Transcriptomic and Biochemical Responses of Arabidopsis thaliana Treated with the Biofertilizer Strain Priestia megaterium YC4-R4: Boosting Plant Central and Secondary Metabolism. PLANTS (BASEL, SWITZERLAND) 2022; 11:3039. [PMID: 36432768 PMCID: PMC9697256 DOI: 10.3390/plants11223039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 10/26/2022] [Accepted: 11/02/2022] [Indexed: 06/16/2023]
Abstract
As a response to the current challenges in agriculture, the application of alternatives to a more sustainable management is required. Thus, biofertilizers begin to emerge as a reliable alternative to improve crop development and resistance to stresses. Among other effects on the plant, the use of beneficial strains may cause changes in their metabolic regulation, as in cell wall biogenesis and in nutrient/ion transportation, improving their growth process. Previous works showed that inoculation with the strain Priestia megaterium YC4-R4 effectively promoted vegetative growth of Arabidopsis thaliana Col-0 plants. Hence, the present work recorded a strain-mediated induction of several pathways of the central and secondary metabolism of the plant, as the induction of lipid, cellulose, phenol, and flavonoid biosynthesis, by using transcriptomic and biochemical analyses.
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Affiliation(s)
| | - Inês Rebelo-Romão
- Instituto de Tecnologia Química e Biológica (ITQB)-NOVA Lisboa, 2780-157 Oeiras, Portugal
| | - Huiming Zhang
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Science, Chinese Academy of Sciences, Shanghai 200032, China
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng 475001, China
| | - Juan Ignacio Vílchez
- Instituto de Tecnologia Química e Biológica (ITQB)-NOVA Lisboa, 2780-157 Oeiras, Portugal
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Science, Chinese Academy of Sciences, Shanghai 200032, China
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13
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Priyanka, Srivastava S, Sharma S. Metabolomic insight into the synergistic mechanism of action of a bacterial consortium in plant growth promotion. J Biosci Bioeng 2022; 134:399-406. [PMID: 36088211 DOI: 10.1016/j.jbiosc.2022.07.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 07/04/2022] [Accepted: 07/24/2022] [Indexed: 10/14/2022]
Abstract
It has been established that a consortium consisting of compatible plant growth promoting rhizobacterial strains outperforms their individual impacts on plant attributes. While the phenomenon of synergism is extensively reported, the mechanism that underpins it is yet to be elucidated. In the present study the impact of three plant growth promoting bacteria, Azotobacter chroococcum (A), Priestia megaterium (formerly Bacillus megaterium) (B), and Pseudomonas sp. SK3 (P) was studied as a consortium on the growth attributes of pigeonpea. In addition, microbe-microbe interactions were investigated through metabolomic profiling to understand the mechanism of synergism. Plant growth experiments revealed that bacterial consortium A + B + P showed a significant increase in plant attributes such as shoot length, root length, fresh weight, and dry weight as compared to monocultures and two-membered consortia. Metabolomic profiling through high resolution liquid chromatograph mass spectrometer revealed the presence of a few bioactive compounds in the consortium that might play a potential role in the enhancement of biometric parameters of the plant. Several compounds, such as antipyrine, 6,6-dimethoxy-2,5,5-trimethyl-2-hexene, N-methyltryptamine, 2,2-dimethyl-3,4-bis(4-methoxyphenyl)-2H-1-benzopyran-7-ol acetate, N6-hydroxy-l-lysine, and l-furosin, were detected in the metabolome of the consortium, which was unique among all the treatments. The study also detected a few metabolites involved in sphingolipid biosynthesis (ketosphinganine and sphinganine) known for cell signaling in the consortium. This unravels the possible mechanism of synergism between bacterial strains in a consortium. The metabolomic profile would be helpful to strategically develop unique and more effective consortia that are tailored to the soil type.
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Affiliation(s)
- Priyanka
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, New Delhi 110016, India
| | - Sonal Srivastava
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, New Delhi 110016, India
| | - Shilpi Sharma
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, New Delhi 110016, India.
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14
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A Plant Endophytic Bacterium Priestia megaterium StrainBP-R2 Isolated from the Halophyte Bolboschoenus planiculmis Enhances Plant Growth under Salt and Drought Stresses. Microorganisms 2022; 10:microorganisms10102047. [PMID: 36296323 PMCID: PMC9610499 DOI: 10.3390/microorganisms10102047] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 09/29/2022] [Accepted: 10/14/2022] [Indexed: 11/17/2022] Open
Abstract
Global warming and climate change have contributed to the rise of weather extremes. Severe drought and soil salinization increase because of rising temperatures. Economically important crop production and plant growth and development are hindered when facing various abiotic stresses. Plant endophytic bacteria live inside host plants without causing visible harm and can be isolated from surface-sterilized plant tissues. Using plant endophytic bacteria to stimulate plant growth and increase environmental stress tolerance has become an alternative approach besides using the traditional breeding and genetically modifying approaches to select or create new crop types resistant to different environmental stresses. The plant endophytic bacterium, Priestia megaterium (previously known as Bacillus megaterium) strain BP-R2, was isolated from the surface-sterilized root tissues of the salt marsh halophyte Bolboschoenus planiculmis. The bacteria strain BP-R2 showed high tolerance to different sodium chloride (NaCl) concentrations and produced the auxin plant hormone, indole acetic acid (IAA), under various tested growth conditions. Inoculation of Arabidopsis and pak choi (Brassica rapa L. R. Chinensis Group) plants with the strain BP-R2 greatly enhanced different growth parameters of the host plants under normal and salt and drought stress conditions compared to that of the mock-inoculated plants. Furthermore, the hydrogen peroxide (H2O2) content, electrolyte leakage (EL), and malondialdehyde (MDA) concentration accumulated less in the BP-R2-inoculated plants than in the mock-inoculated control plants under salt and drought stresses. In summary, the plant endophytic bacterium strain BP-R2 increased host plant growth and stress tolerance to salt and drought conditions.
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15
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Li Q, Li H, Yang Z, Cheng X, Zhao Y, Qin L, Bisseling T, Cao Q, Willemsen V. Plant growth-promoting rhizobacterium Pseudomonas sp. CM11 specifically induces lateral roots. THE NEW PHYTOLOGIST 2022; 235:1575-1588. [PMID: 35510807 PMCID: PMC9546010 DOI: 10.1111/nph.18199] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Accepted: 04/28/2022] [Indexed: 06/10/2023]
Abstract
Plant growth-promoting rhizobacteria are involved in altering secondary root (SR) formation, but hitherto there has been no distinction between the different types of SRs upon induction of soil biota, and the genetic pathways involved. By using plate and soil systems, we studied the effects of the Pseudomonas strains CM11 and WCS417 on plant performance with a focus on root development. Through a combination of cellular, molecular and genetic analyses, we investigated the type of SRs induced upon CM11 and WCS417 root inoculation using genetic pathways associated with specific SR types. CM11 was shown to affect the root architecture differently from WCS417. CM11 inoculation leads to primary root arrest, whereas WCS417 reveals a longer primary root. Both CM11 and WCS417 activate the PLETHORA 3,5,7-controlled lateral root pathway, rather than the WUSCHEL-RELATED HOMEOBOX 11,12-controlled adventitious (lateral) root pathway. In addition, CM11 promotes plant growth in model and various crop species. It improves plant fitness traits, such as bigger shoots, faster bolting and higher yield in terms of seeds. Our results indicate that the root system architecture can be promoted by activation of PLETHORA 3,5,7 dependent primed lateral pre-branch sites upon inoculation with CM11, which creates great potential to gain a better understanding of root plasticity.
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Affiliation(s)
- Qian Li
- Beijing Advanced Innovation Center for Tree Breeding by Molecular DesignBeijing University of AgricultureBeijing102206China
- Cluster of Plant Developmental BiologyLaboratory of Molecular BiologyWageningen University & ResearchDroevendaalsesteeg 16708 PBWageningenthe Netherlands
- Beijing Bei Nong Enterprise Management Co. LtdBeijing102206China
| | - Huchen Li
- Beijing Advanced Innovation Center for Tree Breeding by Molecular DesignBeijing University of AgricultureBeijing102206China
- Cluster of Plant Developmental BiologyLaboratory of Molecular BiologyWageningen University & ResearchDroevendaalsesteeg 16708 PBWageningenthe Netherlands
| | - Zhuang Yang
- Cluster of Plant Developmental BiologyLaboratory of Molecular BiologyWageningen University & ResearchDroevendaalsesteeg 16708 PBWageningenthe Netherlands
| | - Xu Cheng
- Cluster of Plant Developmental BiologyLaboratory of Molecular BiologyWageningen University & ResearchDroevendaalsesteeg 16708 PBWageningenthe Netherlands
| | - Yaceng Zhao
- College of Plant Science and TechnologyBeijing Key Laboratory for Agricultural Application and New TechniqueBeijing University of AgricultureBeijing102206China
| | - Ling Qin
- Beijing Advanced Innovation Center for Tree Breeding by Molecular DesignBeijing University of AgricultureBeijing102206China
- College of Plant Science and TechnologyBeijing Key Laboratory for Agricultural Application and New TechniqueBeijing University of AgricultureBeijing102206China
| | - Ton Bisseling
- Beijing Advanced Innovation Center for Tree Breeding by Molecular DesignBeijing University of AgricultureBeijing102206China
- Cluster of Plant Developmental BiologyLaboratory of Molecular BiologyWageningen University & ResearchDroevendaalsesteeg 16708 PBWageningenthe Netherlands
| | - Qingqin Cao
- Beijing Advanced Innovation Center for Tree Breeding by Molecular DesignBeijing University of AgricultureBeijing102206China
- College of Plant Science and TechnologyBeijing Key Laboratory for Agricultural Application and New TechniqueBeijing University of AgricultureBeijing102206China
| | - Viola Willemsen
- Cluster of Plant Developmental BiologyLaboratory of Molecular BiologyWageningen University & ResearchDroevendaalsesteeg 16708 PBWageningenthe Netherlands
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16
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Jiang L, Peng Y, Seo J, Jeon D, Jo MG, Lee JH, Jeong JC, Kim CY, Park HC, Lee J. Subtercola endophyticus sp. nov., a cold-adapted bacterium isolated from Abies koreana. Sci Rep 2022; 12:12114. [PMID: 35840645 PMCID: PMC9287328 DOI: 10.1038/s41598-022-16116-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 07/05/2022] [Indexed: 11/09/2022] Open
Abstract
A novel Gram-stain-positive, aerobic bacterial strain, designated AK-R2A1-2 T, was isolated from the surface-sterilized needle leaves of an Abies koreana tree. Strain AK-R2A1-2 T had 97.3% and 96.7% 16S rRNA gene sequence similarities with Subtercola boreus K300T and Subtercola lobariae 9583bT, respectively, but formed a distinct phyletic lineage from these two strains. Growth of strain AK-R2A1-2 T was observed at 4–25 °C at pH 5.0–8.0. Strain AK-R2A1-2 T contained menaquinone 9 (MK-9) and menaquinone 10 (MK-10) as the predominant respiratory quinones. The major cellular fatty acids were anteiso-C15:0 and summed feature 8 (C18:1ω7c or/and C18:1ω6c), and the polar lipids included diphosphatidylglycerol (DPG) and three unknown aminolipids, AKL2, AKL3, and AKL4. The complete genome of strain AK-R2A1-2 T was sequenced to understand the genetic basis of its survival at low temperatures. Multiple copies of cold-associated genes involved in cold-active chaperon, stress response, and DNA repair supported survival of the strain at low temperatures. Strain AK-R2A1-2 T was also able to significantly improve rice seedling growth under low temperatures. Thus, this strain represents a novel species of the genus Subtercola, and the proposed name is Subtercola endophyticus sp. nov. The type strain is AK-R2A1-2 T (= KCTC 49721 T = GDMCC 1.2921 T).
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Affiliation(s)
- Lingmin Jiang
- Korean Collection for Type Cultures (KCTC), Biological Resource Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Jeongeup, Jeollabuk-do, 56212, Republic of Korea
| | - Yuxin Peng
- Korean Collection for Type Cultures (KCTC), Biological Resource Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Jeongeup, Jeollabuk-do, 56212, Republic of Korea
| | - Jiyoon Seo
- Korean Collection for Type Cultures (KCTC), Biological Resource Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Jeongeup, Jeollabuk-do, 56212, Republic of Korea
| | - Doeun Jeon
- Korean Collection for Type Cultures (KCTC), Biological Resource Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Jeongeup, Jeollabuk-do, 56212, Republic of Korea
| | - Mi Gyeong Jo
- Korean Collection for Type Cultures (KCTC), Biological Resource Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Jeongeup, Jeollabuk-do, 56212, Republic of Korea
| | - Ju Huck Lee
- Korean Collection for Type Cultures (KCTC), Biological Resource Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Jeongeup, Jeollabuk-do, 56212, Republic of Korea
| | - Jae Cheol Jeong
- Korean Collection for Type Cultures (KCTC), Biological Resource Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Jeongeup, Jeollabuk-do, 56212, Republic of Korea
| | - Cha Young Kim
- Korean Collection for Type Cultures (KCTC), Biological Resource Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Jeongeup, Jeollabuk-do, 56212, Republic of Korea
| | - Hyeong Cheol Park
- Team of Vulnerable Ecological Research, Division of Climate and Ecology, Bureau of Conservation & Assessment Research, National Institute of Ecology (NIE), Seocheon, 33657, Republic of Korea
| | - Jiyoung Lee
- Korean Collection for Type Cultures (KCTC), Biological Resource Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Jeongeup, Jeollabuk-do, 56212, Republic of Korea.
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17
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Genome analysis uncovers the prolific antagonistic and plant growth-promoting potential of endophyte Bacillus velezensis K1. Gene 2022; 836:146671. [PMID: 35714801 DOI: 10.1016/j.gene.2022.146671] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 05/23/2022] [Accepted: 06/10/2022] [Indexed: 11/24/2022]
Abstract
Insights into the application of endophytic bacilli in sustainable agricultural practices have opened up new avenues for the inhibition of soil-borne pathogens and the improvement of plant health. Bacillus subtilis K1, an endophytic bacterium originally isolated from aerial roots of Ficus benghalensis is a potential biocontrol agent secreting a mixture of surfactins, iturins and fengycins. The current study extends the characterization of this bacterium through genomic and comparative genomics approaches. The sequencing of the bacterial genome at Illumina MiSeq platform revealed that it possessed a 4,103,502-bp circular chromosome with 45.98% GC content and 4325 predicted protein-coding sequences. Based on phylogenomics and whole-genome average nucleotide identity, the B. subtilis K1 was taxonomically classified as Bacillus velezensis. The formerly evaluated phenotypic traits viz. C-source utilization and lipopeptide-mediated fungal antagonism were correlated to their molecular determinants. The genome also harbored several genes associated with induced systemic resistance and plant growth promotion i.e, phytohormone production, nitrogen assimilation and reduction, siderophore production, phosphate solubilization, biofilm formation, swarming motility, acetoin and butanediol synthesis. The production of antifungal volatile organic compounds and plant growth promotion was experimentally demonstrated by volatile compound assay and seed germination assay on cumin and groundnut. The isolate also holds great prospects for application as a soil inoculant as indicated by enhancement in the growth of groundnut via in planta pot studies. Bacterial pan-genome analysis based on a comparison of whole genomes with eighteen other Bacillus strains was also conducted. Comparative examination of biosynthetic gene clusters across all genomes indicated that the largest number of gene clusters were harbored by the K1 genome. Based on the findings, we propose K1 as a model for scrutinizing non-ribosomally synthesized peptide synthetase and polyketide synthetase derived molecules.
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18
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Goswami G, Hazarika DJ, Chowdhury N, Bora SS, Sarmah U, Naorem RS, Boro RC, Barooah M. Proline confers acid stress tolerance to Bacillus megaterium G18. Sci Rep 2022; 12:8875. [PMID: 35614097 PMCID: PMC9133035 DOI: 10.1038/s41598-022-12709-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Accepted: 04/25/2022] [Indexed: 11/09/2022] Open
Abstract
Proline plays a multifunctional role in several organisms including bacteria in conferring protection under stress conditions. In this paper we report the role of proline in conferring acid tolerance to Bacillus megaterium G18. An acid susceptible mutant of B. megaterium G18 which required proline for its growth under acid stress condition was generated through Tn5 mutagenesis. Further, targeted inactivation of proC involved in osmo-adaptive proline synthesis in B. megaterium G18 resulted in the loss of ability of the bacterium to grow at low pH (pH 4.5). Exogenous supply of proline (1 mM) to the growth medium restored the ability of the mutant cells to grow at pH 4.5 which was not the same in case of other osmoprotectants tested. Proline was produced and secreted to extracellular medium by B. megaterium G18 when growing in low pH condition as evidenced by the use of Escherichia coli proline auxotrophs and HPLC analysis. Further, pHT01 vector based expression of full length proC gene in the ∆proC mutant cells restored the survival capacity of the mutant cells in acidic pH, suggesting that proline production is an important strategy employed by B. megaterium G18 to survive under acid stress induced osmotic stress.
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Affiliation(s)
- Gunajit Goswami
- DBT-North East Centre for Agricultural Biotechnology, Assam Agricultural University, Jorhat, Assam, 785013, India
| | - Dibya Jyoti Hazarika
- DBT-North East Centre for Agricultural Biotechnology, Assam Agricultural University, Jorhat, Assam, 785013, India
| | - Naimisha Chowdhury
- DBT-North East Centre for Agricultural Biotechnology, Assam Agricultural University, Jorhat, Assam, 785013, India
| | - Sudipta Sankar Bora
- DBT-North East Centre for Agricultural Biotechnology, Assam Agricultural University, Jorhat, Assam, 785013, India
| | - Unmona Sarmah
- DBT-North East Centre for Agricultural Biotechnology, Assam Agricultural University, Jorhat, Assam, 785013, India
| | - Romen Singh Naorem
- Department of Agricultural Biotechnology, Assam Agricultural University, Jorhat, Assam, 785013, India
| | - Robin Chandra Boro
- Department of Agricultural Biotechnology, Assam Agricultural University, Jorhat, Assam, 785013, India
| | - Madhumita Barooah
- Department of Agricultural Biotechnology, Assam Agricultural University, Jorhat, Assam, 785013, India.
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Dhole A, Shelat H. Non-Rhizobial Endophytes Associated with Nodules of Vigna radiata L. and Their Combined Activity with Rhizobium sp. Curr Microbiol 2022; 79:103. [PMID: 35157135 DOI: 10.1007/s00284-022-02792-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 01/31/2022] [Indexed: 11/27/2022]
Abstract
Root nodules of legume plants are devoted for hosting endophytic symbiotic bacteria that fix atmospheric nitrogen but recently proved as a niche for various non-rhizobial endophytes (NRE) also. In the present investigation, one rhizobial and two NRE were isolated and characterized as Rhizobium sp. AAU B3, Bacillus sp. AAU B6 and Bacillus sp. AAU B12. These isolates were studied for in vitro biocontrol activity against two pathogenic fungi. NRE isolates exhibited antifungal activity against root rot causing Macrophomina phaseolina (ITCC-6749) isolated from Vigna radiata and wilt causing pathogen Fusarium udum Butler isolated from Cajanus cajan in liquid as well as on solid medium. Furthermore, their antagonism was increased markedly when combined with Rhizobium sp. Moreover, Bacillus sp. AAU B6 showed amplification of the zwittermicin A gene (~ 950 bp) which is evident for the production of antibiotics. All three isolates showed HCN production in vitro also, Bacillus sp. AAU B12 exhibited amplification of its gene hcnC. Pathogenic fungal hyphae became thin, transparent, and bent as well as fungi lost their normal growth and branching patterns when exposed to volatile compounds produced by NRE. All the 3 isolates produced siderophores, however siderophore production was increased considerably when all three strains are mixed together. Furthermore, all the three isolates produced cell wall degrading enzymes (chitinase, protease, and cellulase) but lipolytic activity was exhibited only by Rhizobium sp. AAU B3. When NRE inoculated in combination of Rhizobium; overcomes the disease severity against M. phaseolina under pot study. Thus, from present study it is concluded that co-inoculation of NRE and Rhizobium sp. can be exploited as biocontrol bio-agents against M. phaseolina in green gram at field levels.
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Affiliation(s)
- Archana Dhole
- B. A. College of Agriculture, Anand Agricultural University, Anand, Gujarat, 388110, India.
| | - Harsha Shelat
- B. A. College of Agriculture, Anand Agricultural University, Anand, Gujarat, 388110, India
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Mutungi PM, Wekesa VW, Onguso J, Kanga E, Baleba SBS, Boga HI. Culturable Bacterial Endophytes Associated With Shrubs Growing Along the Draw-Down Zone of Lake Bogoria, Kenya: Assessment of Antifungal Potential Against Fusarium solani and Induction of Bean Root Rot Protection. FRONTIERS IN PLANT SCIENCE 2022; 12:796847. [PMID: 35222451 PMCID: PMC8864308 DOI: 10.3389/fpls.2021.796847] [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: 10/25/2021] [Accepted: 12/27/2021] [Indexed: 06/14/2023]
Abstract
Vascular shrubs growing along the draw-down zones of saline lakes must develop adaptive mechanisms to cope with high salinity, erratic environmental conditions, and other biotic and abiotic stresses. Microbial endophytes from plants growing in these unique environments harbor diverse metabolic and genetic profiles that play an important role in plant growth, health, and survival under stressful conditions. A variety of bacterial endophytes have been isolated from salt tolerant plants but their potential applications in agriculture have not been fully explored. To further address this gap, the present study sought to isolate culturable bacterial endophytes from shrubs growing along the draw-down zone of Lake Bogoria, a saline alkaline lake, and examined their functional characteristics and potential in the biocontrol of the bean root rot pathogen, Fusarium solani. We collected shrubs growing within 5 m distance from the shoreline of Lake Bogoria and isolated 69 bacterial endophytes. The endophytic bacteria were affiliated to three different phyla (Firmicutes, Proteobacteria, and Actinobacteria) with a bias in the genera, Bacillus, and they showed no tissue or plant specificity. All selected isolates were positive for catalase enzyme grown in 1.5 M NaCl; three isolates (B23, B19, and B53) produced indole acetic acid (IAA) and only one isolate, B23 did not solubilize phosphate on Pikovskaya agar. Isolates, B19 and B53 exhibited more than 50% of mycelial inhibition in the dual culture assay and completely inhibited the germination of F. solani spores in co-culture assays while two isolates, B07 and B39 had delayed fungal spore germination after an overnight incubation. All isolates were able to establish endophytic association in the roots, stems, and leaves of been seedlings in both seed soaking and drenching methods. Colonization of bean seedlings by the bacterial endophytes, B19 and B53 resulted in the biocontrol of F. solani in planta, reduced disease severity and incidence, and significantly increased both root and shoot biomass compared to the control. Taxonomic identification using 16S rRNA revealed that the two isolates belong to Enterobacter hormaechei subsp., Xiangfangensis and Bacillus megaterium. Our results demonstrate the potential use of these two isolates in the biocontrol of the bean root rot pathogen, F. solani and plant growth promotion.
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Affiliation(s)
- Priscillar Mumo Mutungi
- Institute for Biotechnology Research, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
- Ecological Monitoring Department, Kenya Wildlife Service, Nairobi, Kenya
| | | | - Justus Onguso
- Institute for Biotechnology Research, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
| | - Erustus Kanga
- State Department for Wildlife, Ministry of Tourism and Wildlife, Nairobi, Kenya
| | - Steve B. S. Baleba
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Hamadi Iddi Boga
- Botany Department, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
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21
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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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Kong WL, Wang YH, Wu XQ. Enhanced Iron Uptake in Plants by Volatile Emissions of Rahnella aquatilis JZ-GX1. FRONTIERS IN PLANT SCIENCE 2021; 12:704000. [PMID: 34394158 PMCID: PMC8362888 DOI: 10.3389/fpls.2021.704000] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 06/25/2021] [Indexed: 06/13/2023]
Abstract
Iron deficiency in soil has crucially restricted agricultural and forestry production. Volatile organic compounds (VOCs) produced by beneficial microorganisms have been proven to play an important role in inducing abiotic stress tolerance in plants. We investigated the effects of VOCs released by the rhizobacterium Rahnella aquatilis JZ-GX1 on the growth and root parameters of Arabidopsis thaliana under iron deficiency. The effect of the rhizobacterial VOCs on the gene expression in iron uptake and hormone signaling pathways were detected by RT-qPCR. Finally, the VOCs of the JZ-GX1 strain that could promote plant growth under iron deficiency stress were screened. The results showed that the JZ-GX1 strain could induce A. thaliana tolerance to iron deficiency stress by promoting the development of lateral roots and root hairs and increasing the activities of H+ ATPase and Fe3+ reductase. In addition, the AHA2, FRO2, and IRT1 genes of A. thaliana exposed to JZ-GX1-emitted VOCs were upregulated 25-, 1. 81-, and 1.35-fold, respectively, and expression of the abscisic acid (ABA) synthesis gene NCED3 was upregulated on both the 3rd and 5th days. Organic compounds were analyzed in the headspace of JZ-GX1 cultures, 2-undecanone and 3-methyl-1-butanol were found to promote Medicago sativa and A. thaliana growth under iron-limited conditions. These results demonstrated that the VOCs of R. aquatilis JZ-GX1 have good potential in promoting iron absorption in plants.
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Affiliation(s)
- Wei-Liang Kong
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing, China
- Jiangsu Key Laboratory for Prevention and Management of Invasive Species, Nanjing Forestry University, Nanjing, China
| | - Ya-Hui Wang
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing, China
- Jiangsu Key Laboratory for Prevention and Management of Invasive Species, Nanjing Forestry University, Nanjing, China
| | - Xiao-Qin Wu
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing, China
- Jiangsu Key Laboratory for Prevention and Management of Invasive Species, Nanjing Forestry University, Nanjing, China
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Martins J, Ares A, Casais V, Costa J, Canhoto J. Identification and Characterization of Arbutus unedo L. Endophytic Bacteria Isolated from Wild and Cultivated Trees for the Biological Control of Phytophthora cinnamomi. PLANTS 2021; 10:plants10081569. [PMID: 34451613 PMCID: PMC8401287 DOI: 10.3390/plants10081569] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 07/27/2021] [Accepted: 07/28/2021] [Indexed: 11/16/2022]
Abstract
Arbutus unedo L. is a resilient tree with a circum-Mediterranean distribution. Besides its ecological relevance, it is vital for local economies as a fruit tree. Several microorganisms are responsible for strawberry tree diseases, leading to production constrictions. Thus, the development of alternative plant protection strategies is necessary, such as bacterial endophytes, which may increase their host’s overall fitness and productivity. As agricultural practices are a driving factor of microbiota, this paper aimed to isolate, identify and characterize endophytic bacteria from strawberry tree leaves from plants growing spontaneously in a natural environment as well as from plants growing in orchards. A total of 62 endophytes were isolated from leaves and identified as Bacillus, Paenibacillus, Pseudomonas, Sphingomonas and Staphylococcus. Although a slightly higher number of species was found in wild plants, no differences in terms of diversity indexes were found. Sixteen isolates were tested in vitro for their antagonistic effect against A. unedo mycopathogens. B. cereus was the most effective antagonist causing a growth reduction of 20% in Glomerella cingulata and 40% in Phytophthora cinnamomi and Mycosphaerella aurantia. Several endophytic isolates also exhibited plant growth-promoting potential. This study provides insights into the diversity of endophytic bacteria in A. unedo leaves and their potential role as growth promoters and pathogen antagonists.
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Affiliation(s)
- João Martins
- Department of Life Sciences, Centre for Functional Ecology, University of Coimbra, Calçada Martim de Freitas, 3000-456 Coimbra, Portugal; (J.M.); (A.A.); (V.C.); (J.C.)
| | - Aitana Ares
- Department of Life Sciences, Centre for Functional Ecology, University of Coimbra, Calçada Martim de Freitas, 3000-456 Coimbra, Portugal; (J.M.); (A.A.); (V.C.); (J.C.)
- Laboratory for Phytopathology, Instituto Pedro Nunes, 3030-199 Coimbra, Portugal
| | - Vinicius Casais
- Department of Life Sciences, Centre for Functional Ecology, University of Coimbra, Calçada Martim de Freitas, 3000-456 Coimbra, Portugal; (J.M.); (A.A.); (V.C.); (J.C.)
| | - Joana Costa
- Department of Life Sciences, Centre for Functional Ecology, University of Coimbra, Calçada Martim de Freitas, 3000-456 Coimbra, Portugal; (J.M.); (A.A.); (V.C.); (J.C.)
- Laboratory for Phytopathology, Instituto Pedro Nunes, 3030-199 Coimbra, Portugal
| | - Jorge Canhoto
- Department of Life Sciences, Centre for Functional Ecology, University of Coimbra, Calçada Martim de Freitas, 3000-456 Coimbra, Portugal; (J.M.); (A.A.); (V.C.); (J.C.)
- Correspondence:
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24
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Knežević M, Berić T, Buntić A, Delić D, Nikolić I, Stanković S, Stajković-Srbinović O. Potential of root nodule nonrhizobial endophytic bacteria for growth promotion of Lotus corniculatus L. and Dactylis glomerata L. J Appl Microbiol 2021; 131:2929-2940. [PMID: 34003543 DOI: 10.1111/jam.15152] [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: 03/10/2021] [Revised: 05/11/2021] [Accepted: 05/11/2021] [Indexed: 11/29/2022]
Abstract
AIMS This research aimed to isolate and characterize nonrhizobial endophytic bacteria from root nodules of Medicago sativa L. and Lotus corniculatus L. with plant growth-promoting characteristics and to test its activity in a pot experiment with acid soil. METHODS AND RESULTS Out of 44 nonrhizobial isolates, the majority exhibited indole-3-acetic acid (IAA) production; 29 produced siderophores, few isolates performed phosphate solubilization and/or produced lytic enzymes, while 30% of isolates showed notable antifungal activity. The most promising strains were identified as members of Bacillus, Pseudomonas and Serratia genera, based on 16S rRNA. Bacillus megaterium DZK1BH exhibited the overall best attributes for plant growth promotion and positively influenced the growth of L. corniculatus and Dactylis glomerata. CONCLUSIONS Root nodule endophytic B. megaterium DZK1BH could potentially be used as a biofertilizer for growing L. corniculatus L. and D. glomerata L. in acid soils, while Bacillus mojavensis L3 is a candidate for further antifungal potential investigation. SIGNIFICANCE OF IMPACT OF THE STUDY The use of root nodule endophytic bacteria with PGP traits may find its future application in organic agriculture, as their utilization could decrease the use of chemical fertilizers and pesticides and simultaneously promote plant growth, especially in soils with low production quality.
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Affiliation(s)
- M Knežević
- Department of Microbiology, Institute of Soil Science, Belgrade, Serbia
| | - T Berić
- Faculty of Biology, University of Belgrade, Belgrade, Serbia
| | - A Buntić
- Department of Microbiology, Institute of Soil Science, Belgrade, Serbia
| | - D Delić
- Department of Microbiology, Institute of Soil Science, Belgrade, Serbia
| | - I Nikolić
- Faculty of Biology, University of Belgrade, Belgrade, Serbia
| | - S Stanković
- Faculty of Biology, University of Belgrade, Belgrade, Serbia
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Soni R, Rawal K, Keharia H. Genomics assisted functional characterization of Paenibacillus polymyxa HK4 as a biocontrol and plant growth promoting bacterium. Microbiol Res 2021; 248:126734. [PMID: 33690069 DOI: 10.1016/j.micres.2021.126734] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 01/22/2021] [Accepted: 02/21/2021] [Indexed: 10/22/2022]
Abstract
The diseases caused by phytopathogens account for huge economic losses in the agricultural sector. Paenibacillus polymyxa is one of the agriculturally important biocontrol agents and plant growth promoting bacterium. This study describes the antifungal potential of P. polymyxa HK4 against an array of fungal phytopathogens and its ability to stimulate seed germination of cumin and groundnut under in vitro conditions. The cumin and groundnut seeds bacterized with HK4 exhibited enhanced germination efficiency in comparison to controls. The use of HK4 as a soil inoculant significantly promoted the shoot length and fresh weight of groundnut plants in pot studies. The draft genome analysis of HK4 revealed the genetic attributes for motility, root colonization, antagonism, phosphate solubilization, siderophore production and production of volatile organic compounds. The bacterium HK4 harnessed several hydrolytic enzymes that may assist its competence in the rhizosphere. The PCR amplification and sequence analysis of the conserved region of the fusA gene amplicon revealed the ability of HK4 to produce fusaricidin. Furthermore, the LC-ESI-MS/MS of crude cell pellet extract of HK4 confirmed the presence of fusaricidin as a major antifungal metabolite. This study demonstrated the potential of HK4 as a biocontrol agent and a plant growth promoter.
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Affiliation(s)
- Riteshri Soni
- Department of Biosciences, UGC-Centre of Advanced Study, Sardar Patel University, Satellite Campus, Vadtal Road, Bakrol, 388 315, Anand, Gujarat, India
| | - Khushboo Rawal
- Department of Biosciences, UGC-Centre of Advanced Study, Sardar Patel University, Satellite Campus, Vadtal Road, Bakrol, 388 315, Anand, Gujarat, India
| | - Hareshkumar Keharia
- Department of Biosciences, UGC-Centre of Advanced Study, Sardar Patel University, Satellite Campus, Vadtal Road, Bakrol, 388 315, Anand, Gujarat, India.
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26
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Abdullahi S, Haris H, Zarkasi KZ, Amir HG. Complete genome sequence of plant growth-promoting and heavy metal-tolerant Enterobacter tabaci 4M9 (CCB-MBL 5004). J Basic Microbiol 2021; 61:293-304. [PMID: 33491813 DOI: 10.1002/jobm.202000695] [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: 11/26/2020] [Revised: 12/30/2020] [Accepted: 01/10/2021] [Indexed: 11/10/2022]
Abstract
Enterobacter tabaci 4M9 (CCB-MBL 5004) was reported to have plant growth-promoting and heavy metal tolerance traits. It was able to tolerate more than 300 mg/L Cd, 600 mg/L As, and 500 mg/L Pb and still maintained the ability to produce plant growth-promoting substances under metal stress conditions. To explore the genetic basis of these beneficial traits, the complete genome sequencing of 4M9 was carried out using Pacific Bioscience (PacBio) sequencing technology. The complete genome consisted of one chromosome of 4,654,430 bp with a GC content of 54.6% and one plasmid of 51,135 bp with a GC content of 49.4%. Genome annotation revealed several genes involved in plant growth-promoting traits, including the production of siderophore, indole acetic acid, and 1-aminocyclopropane-1-carboxylate deaminase; solubilization of phosphate and potassium; and nitrogen metabolism. Similarly, genes involved in heavy metals (As, Co, Zn, Cu, Mn, Se, Cd, and Fe) tolerance were detected. These support its potential as a heavy metal-tolerant plant growth-promoting bacterium and a good genetic resource that can be employed to improve phytoremediation efficiency of heavy metal-contaminated soil via biotechnological techniques. This, to the best of our knowledge, is the first report on the complete genome sequence of heavy metal-tolerant plant growth-promoting E. tabaci.
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Affiliation(s)
- Saidu Abdullahi
- School of Biological Sciences, Universiti Sains Malaysia, Georgetown, Penang, Malaysia.,Department of Botany, Ahmadu Bello University, Zaria, Nigeria
| | - Hazzeman Haris
- School of Biological Sciences, Universiti Sains Malaysia, Georgetown, Penang, Malaysia
| | - Kamarul Z Zarkasi
- School of Biological Sciences, Universiti Sains Malaysia, Georgetown, Penang, Malaysia
| | - Hamzah G Amir
- School of Biological Sciences, Universiti Sains Malaysia, Georgetown, Penang, Malaysia
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27
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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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28
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Qin L, Tian P, Cui Q, Hu S, Jian W, Xie C, Yang X, Shen H. Bacillus circulans GN03 Alters the Microbiota, Promotes Cotton Seedling Growth and Disease Resistance, and Increases the Expression of Phytohormone Synthesis and Disease Resistance-Related Genes. FRONTIERS IN PLANT SCIENCE 2021; 12:644597. [PMID: 33936131 PMCID: PMC8079787 DOI: 10.3389/fpls.2021.644597] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 03/23/2021] [Indexed: 05/13/2023]
Abstract
Plant growth-promoting bacteria (PGPB) are components of the plant rhizosphere that promote plant growth and/or inhibit pathogen activity. To explore the cotton seedlings response to Bacillus circulans GN03 with high efficiency of plant growth promotion and disease resistance, a pot experiment was carried out, in which inoculations levels of GN03 were set at 104 and 108 cfu⋅mL-1. The results showed that GN03 inoculation remarkably enhanced growth promotion as well as disease resistance of cotton seedlings. GN03 inoculation altered the microbiota in and around the plant roots, led to a significant accumulation of growth-related hormones (indole acetic acid, gibberellic acid, and brassinosteroid) and disease resistance-related hormones (salicylic acid and jasmonic acid) in cotton seedlings, as determined with ELISA, up-regulated the expression of phytohormone synthesis-related genes (EDS1, AOC1, BES1, and GA20ox), auxin transporter gene (Aux1), and disease-resistance genes (NPR1 and PR1). Comparative genomic analyses was performed between GN03 and four similar species, with regards to phenotype, biochemical characteristics, and gene function. This study provides valuable information for applying the PGPB alternative, GN03, as a plant growth and disease-resistance promoting fertilizer.
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Affiliation(s)
- Lijun Qin
- College of Life Sciences, Chongqing Normal University, Chongqing, China
- Biological Science Research Center, Southwest University, Chongqing, China
| | - Peidong Tian
- College of Life Sciences, Chongqing Normal University, Chongqing, China
| | - Qunyao Cui
- College of Life Sciences, Chongqing Normal University, Chongqing, China
| | - Shuping Hu
- College of Life Sciences, Chongqing Normal University, Chongqing, China
| | - Wei Jian
- College of Life Sciences, Chongqing Normal University, Chongqing, China
| | - Chengjian Xie
- College of Life Sciences, Chongqing Normal University, Chongqing, China
| | - Xingyong Yang
- College of Life Sciences, Chongqing Normal University, Chongqing, China
- *Correspondence: Xingyong Yang,
| | - Hong Shen
- Biological Science Research Center, Southwest University, Chongqing, China
- College of Resources and Environment Science, Southwest University, Chongqing, China
- Hong Shen,
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29
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Garcia-Lemos AM, Großkinsky DK, Saleem Akhtar S, Nicolaisen MH, Roitsch T, Nybroe O, Veierskov B. Identification of Root-Associated Bacteria That Influence Plant Physiology, Increase Seed Germination, or Promote Growth of the Christmas Tree Species Abies nordmanniana. Front Microbiol 2020; 11:566613. [PMID: 33281762 PMCID: PMC7705201 DOI: 10.3389/fmicb.2020.566613] [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: 05/28/2020] [Accepted: 10/27/2020] [Indexed: 12/03/2022] Open
Abstract
Abies nordmanniana is used for Christmas tree production but poor seed germination and slow growth represent challenges for the growers. We addressed the plant growth promoting potential of root-associated bacteria isolated from A. nordmanniana. Laboratory screenings of a bacterial strain collection yielded several Bacillus and Paenibacillus strains that improved seed germination and produced indole-3-acetic acid. The impact of three of these strains on seed germination, plant growth and growth-related physiological parameters was then determined in greenhouse and field trials after seed inoculation, and their persistence was assessed by 16S rRNA gene-targeted bacterial community analysis. Two strains showed distinct and significant effects. Bacillus sp. s50 enhanced seed germination in the greenhouse but did not promote shoot or root growth. In accordance, this strain did not increase the level of soluble hexoses needed for plant growth but increased the level of storage carbohydrates. Moreover, strain s50 increased glutathione reductase and glutathione-S-transferase activities in the plant, which may indicate induction of systemic resistance during the early phase of plant development, as the strain showed poor persistence in the root samples (rhizosphere soil plus root tissue). Paenibacillus sp. s37 increased plant root growth, especially by inducing secondary root formation, under in greenhouse conditions, where it showed high persistence in the root samples. Under these conditions, it further it increased the level of soluble carbohydrates in shoots, and the levels of starch and non-structural carbohydrates in roots, stem and shoots. Moreover, it increased the chlorophyll level in the field trial. These findings indicate that this strain improves plant growth and vigor through effects on photosynthesis and plant carbohydrate reservoirs. The current results show that the two strains s37 and s50 could be considered for growth promotion programs of A. nordmanniana in greenhouse nurseries, and even under field conditions.
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Affiliation(s)
- Adriana M Garcia-Lemos
- Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg, Denmark
| | - Dominik K Großkinsky
- Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg, Denmark.,Bioresources Unit, Center for Health and Bioresources, AIT Austrian Institute of Technology GmbH, Tulln an der Donau, Austria
| | - Saqib Saleem Akhtar
- Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg, Denmark
| | - Mette Haubjerg Nicolaisen
- Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg, Denmark
| | - Thomas Roitsch
- Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg, Denmark.,Department of Adaptive Biotechnologies, Global Change Research Institute, Brno, Czechia
| | - Ole Nybroe
- Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg, Denmark
| | - Bjarke Veierskov
- Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg, Denmark
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Garcia-Lemos AM, Großkinsky DK, Saleem Akhtar S, Nicolaisen MH, Roitsch T, Nybroe O, Veierskov B. Identification of Root-Associated Bacteria That Influence Plant Physiology, Increase Seed Germination, or Promote Growth of the Christmas Tree Species Abies nordmanniana. Front Microbiol 2020. [PMID: 33281762 DOI: 10.3389/fmicb.2020.566613)] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/01/2023] Open
Abstract
Abies nordmanniana is used for Christmas tree production but poor seed germination and slow growth represent challenges for the growers. We addressed the plant growth promoting potential of root-associated bacteria isolated from A. nordmanniana. Laboratory screenings of a bacterial strain collection yielded several Bacillus and Paenibacillus strains that improved seed germination and produced indole-3-acetic acid. The impact of three of these strains on seed germination, plant growth and growth-related physiological parameters was then determined in greenhouse and field trials after seed inoculation, and their persistence was assessed by 16S rRNA gene-targeted bacterial community analysis. Two strains showed distinct and significant effects. Bacillus sp. s50 enhanced seed germination in the greenhouse but did not promote shoot or root growth. In accordance, this strain did not increase the level of soluble hexoses needed for plant growth but increased the level of storage carbohydrates. Moreover, strain s50 increased glutathione reductase and glutathione-S-transferase activities in the plant, which may indicate induction of systemic resistance during the early phase of plant development, as the strain showed poor persistence in the root samples (rhizosphere soil plus root tissue). Paenibacillus sp. s37 increased plant root growth, especially by inducing secondary root formation, under in greenhouse conditions, where it showed high persistence in the root samples. Under these conditions, it further it increased the level of soluble carbohydrates in shoots, and the levels of starch and non-structural carbohydrates in roots, stem and shoots. Moreover, it increased the chlorophyll level in the field trial. These findings indicate that this strain improves plant growth and vigor through effects on photosynthesis and plant carbohydrate reservoirs. The current results show that the two strains s37 and s50 could be considered for growth promotion programs of A. nordmanniana in greenhouse nurseries, and even under field conditions.
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Affiliation(s)
- Adriana M Garcia-Lemos
- Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg, Denmark
| | - Dominik K Großkinsky
- Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg, Denmark
- Bioresources Unit, Center for Health and Bioresources, AIT Austrian Institute of Technology GmbH, Tulln an der Donau, Austria
| | - Saqib Saleem Akhtar
- Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg, Denmark
| | - Mette Haubjerg Nicolaisen
- Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg, Denmark
| | - Thomas Roitsch
- Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg, Denmark
- Department of Adaptive Biotechnologies, Global Change Research Institute, Brno, Czechia
| | - Ole Nybroe
- Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg, Denmark
| | - Bjarke Veierskov
- Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg, Denmark
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