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Qin X, Xu J, An X, Yang J, Wang Y, Dou M, Wang M, Huang J, Fu Y. Insight of endophytic fungi promoting the growth and development of woody plants. Crit Rev Biotechnol 2024; 44:78-99. [PMID: 36592988 DOI: 10.1080/07388551.2022.2129579] [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: 01/29/2022] [Revised: 04/04/2022] [Accepted: 04/16/2022] [Indexed: 01/04/2023]
Abstract
Microorganisms play an important role in plant growth and development. In particular, endophytic fungi is one of the important kinds of microorganisms and has a mutually beneficial symbiotic relationship with host plants. Endophytic fungi have many substantial benefits to host plants, especially for woody plants, such as accelerating plant growth, enhancing stress resistance, promoting nutrient absorption, resisting pathogens and etc. However, the effects of endophytic fungi on the growth and development of woody plants have not been systematically summarized. In this review, the functions of endophytic fungi for the growth and development of woody plants have been mainly reviewed, including regulating plant growth (e.g., flowering, root elongation, etc.) by producing nutrients and plant hormones, and improving plant disease, insect resistance and heavy metal resistance by producing secondary metabolites. In addition, the diversity of endophytic fungi could improve the ability of woody plants to adapt to adverse environment. The components produced by endophytic fungi have excellent potential for the growth and development of woody plants. This review has systematically discussed the potential regulation mechanism of endophytic fungi regulating the growth and development of woody plants, it would be of great significance for the development and utilization of endophytic fungi resource from woody plants for the protection of forest resources.
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Affiliation(s)
- Xiangyu Qin
- Key Laboratory of Forest Plant Ecology, Ministry of Education, Northeast Forestry University, Harbin, PR China
- College of Chemistry, Chemical Engineering and Resource Utilization, Northeast Forestry University, Harbin, PR China
| | - Jian Xu
- Key Laboratory of Forest Plant Ecology, Ministry of Education, Northeast Forestry University, Harbin, PR China
- College of Chemistry, Chemical Engineering and Resource Utilization, Northeast Forestry University, Harbin, PR China
| | - Xiaoli An
- Key Laboratory of Forest Plant Ecology, Ministry of Education, Northeast Forestry University, Harbin, PR China
- College of Chemistry, Chemical Engineering and Resource Utilization, Northeast Forestry University, Harbin, PR China
| | - Jie Yang
- Key Laboratory of Forest Plant Ecology, Ministry of Education, Northeast Forestry University, Harbin, PR China
- College of Chemistry, Chemical Engineering and Resource Utilization, Northeast Forestry University, Harbin, PR China
| | - Yao Wang
- Key Laboratory of Forest Plant Ecology, Ministry of Education, Northeast Forestry University, Harbin, PR China
- College of Chemistry, Chemical Engineering and Resource Utilization, Northeast Forestry University, Harbin, PR China
| | - Meijia Dou
- Key Laboratory of Forest Plant Ecology, Ministry of Education, Northeast Forestry University, Harbin, PR China
- College of Chemistry, Chemical Engineering and Resource Utilization, Northeast Forestry University, Harbin, PR China
| | - Minggang Wang
- The College of Forestry, Beijing Forestry University, Beijing, PR China
| | - Jin Huang
- Key Laboratory of Forest Plant Ecology, Ministry of Education, Northeast Forestry University, Harbin, PR China
- College of Chemistry, Chemical Engineering and Resource Utilization, Northeast Forestry University, Harbin, PR China
| | - Yujie Fu
- The College of Forestry, Beijing Forestry University, Beijing, PR China
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Bizjak T, Sellstedt A, Gratz R, Nordin A. Presence and activity of nitrogen-fixing bacteria in Scots pine needles in a boreal forest: a nitrogen-addition experiment. TREE PHYSIOLOGY 2023; 43:1354-1364. [PMID: 37073466 PMCID: PMC10423461 DOI: 10.1093/treephys/tpad048] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 04/11/2023] [Indexed: 05/03/2023]
Abstract
Endophytic nitrogen-fixing bacteria have been detected and isolated from the needles of conifer trees growing in North American boreal forests. Because boreal forests are nutrient-limited, these bacteria could provide an important source of nitrogen for tree species. This study aimed to determine their presence and activity in a Scandinavian boreal forest, using immunodetection of nitrogenase enzyme subunits and acetylene-reduction assays of native Scots pine (Pinus sylvestris L.) needles. The presence and rate of nitrogen fixation by endophytic bacteria were compared between control plots and fertilized plots in a nitrogen-addition experiment. In contrast to the expectation that nitrogen-fixation rates would decline in fertilized plots, as seen, for instance, with nitrogen-fixing bacteria associated with bryophytes, there was no difference in the presence or activity of nitrogen-fixing bacteria between the two treatments. The extrapolated calculated rate of nitrogen fixation relevant for the forest stand was 20 g N ha-1 year-1, which is rather low compared with Scots pine annual nitrogen use but could be important for the nitrogen-poor forest in the long term. In addition, of 13 colonies of potential nitrogen-fixing bacteria isolated from the needles on nitrogen-free media, 10 showed in vitro nitrogen fixation. In summary, 16S rRNA sequencing identified the species as belonging to the genera Bacillus, Variovorax, Novosphingobium, Sphingomonas, Microbacterium and Priestia, which was confirmed by Illumina whole-genome sequencing. Our results confirm the presence of endophytic nitrogen-fixing bacteria in Scots pine needles and suggest that they could be important for the long-term nitrogen budget of the Scandinavian boreal forest.
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Affiliation(s)
- Tinkara Bizjak
- Umeå Plant Science Centre (UPSC), Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, 901 83 Umeå, Sweden
| | - Anita Sellstedt
- Umeå Plant Science Centre (UPSC), Department of Plant Physiology, Umeå University, 901 87 Umeå, Sweden
| | - Regina Gratz
- Umeå Plant Science Centre (UPSC), Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, 901 83 Umeå, Sweden
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, 901 83 Umeå, Sweden
| | - Annika Nordin
- Umeå Plant Science Centre (UPSC), Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, 901 83 Umeå, Sweden
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Li X, Lang D, Wang J, Zhang W, Zhang X. Plant-beneficial Streptomyces dioscori SF1 potential biocontrol and plant growth promotion in saline soil within the arid and semi-arid areas. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023:10.1007/s11356-023-27362-x. [PMID: 37145360 DOI: 10.1007/s11356-023-27362-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 04/27/2023] [Indexed: 05/06/2023]
Abstract
Environmental challenges like salinity, drought, fungal phytopathogens, and pesticides directly or/and indirectly influence the environment and agricultural yields. Certain beneficial endophytic Streptomyces sp. can ameliorate environmental stresses and be utilized as crop growth promoters under adverse conditions. Herein, Streptomyces dioscori SF1 (SF1) isolated from seeds of Glycyrrhiza uralensis tolerated fungal phytopathogens and abiotic stresses (drought, salt, and acid base). Strain SF1 showed multifarious plant growth promotion characteristics, including the production of indole acetic acid (IAA), ammonia, siderophores, ACC deaminase, extracellular enzymes, the ability of potassium solubilization, and nitrogen fixation. The dual plate assay showed that strain SF1 inhibited 63.21 ± 1.53%, 64.84 ± 1.35%, and 74.19 ± 2.88% of Rhizoctonia solani, Fusarium acuminatum, and Sclerotinia sclerotiorum, respectively. The detached root assays showed that strain SF1 significantly reduced the number of rotten sliced roots, and the biological control effect on sliced roots of Angelica sinensis, Astragalus membranaceus, and Codonopsis pilosula was 93.33%, 86.67%, and 73.33%, respectively. Furthermore, the strain SF1 significantly increased the growth parameters and biochemical indicators of adversity in G. uralensis seedlings under drought and/or salt conditions, including radicle length and diameter, hypocotyl length and diameter, dry weight, seedling vigor index, antioxidant enzyme activity, and non-enzymatic antioxidant content. In conclusion, the strain SF1 can be used to develop environmental protection biological control agents, improve the anti-disease activity of plants, and promote plant growth in salinity soil within arid and semi-arid regions.
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Affiliation(s)
- Xiaokang Li
- College of Pharmacy, Ningxia Medical University, Yinchuan, 750004, China
| | - Duoyong Lang
- Laboratory Animal Center, Ningxia Medical University, Yinchuan, 750004, China
| | - Jianhuan Wang
- College of Pharmacy, Ningxia Medical University, Yinchuan, 750004, China
| | - Wenjin Zhang
- College of Pharmacy, Ningxia Medical University, Yinchuan, 750004, China
| | - Xinhui Zhang
- College of Pharmacy, Ningxia Medical University, Yinchuan, 750004, China.
- Ningxia Engineering and Technology Research Center of Regional Characteristic Traditional Chinese Medicine, Ningxia Collaborative Innovation Center of Regional Characteristic Traditional Chinese Medicine, Key Laboratory of Ningxia Minority Medicine Modernization, Ministry of Education, Yinchuan, 750004, China.
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Characterization of Seed Mycobiota Using Culture-Dependent and Culture-Independent Approaches. Methods Mol Biol 2022; 2605:65-78. [PMID: 36520389 DOI: 10.1007/978-1-0716-2871-3_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Seed fungi are potentially important for their roles in seedling microbiome assembly and seedling health, but surveys of full seed fungal communities remain limited. While culture-dependent methods have been used to characterize some members of the seed mycobiota, recent culture-independent studies have improved the ease in identifying and characterizing full seed fungal communities. In this chapter, we describe how to survey seed fungi using both traditional culture-based methods and culture-free metabarcoding. We first describe protocols for the isolation and long-term preservation of fungal strains from individual seeds and for the extraction and amplification of DNA from such fungal isolates for identification with Sanger sequencing. We also detail how to extract, amplify, and sequence fungal DNA directly from individual seeds. Finally, we provide suggestions for troubleshooting media choices, PCR inhibition by isolates and plant tissue, and PCR limitation by low fungal DNA.
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Li Y, Yang R, Häggblom MM, Li M, Guo L, Li B, Kolton M, Cao Z, Soleimani M, Chen Z, Xu Z, Gao W, Yan B, Sun W. Characterization of diazotrophic root endophytes in Chinese silvergrass (Miscanthus sinensis). MICROBIOME 2022; 10:186. [PMID: 36329505 PMCID: PMC9632085 DOI: 10.1186/s40168-022-01379-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 09/22/2022] [Indexed: 05/23/2023]
Abstract
BACKGROUND Phytoremediation is a potentially cost-effective way to remediate highly contaminated mine tailing sites. However, nutrient limitations, especially the deficiency of nitrogen (N), can hinder the growth of plants and impair the phytoremediation of mine tailings. Nevertheless, pioneer plants can successfully colonize mine tailings and exhibit potential for tailing phytoremediation. Diazotrophs, especially diazotrophic endophytes, can promote the growth of their host plants. This was tested in a mine-tailing habitat by a combination of field sampling, DNA-stable isotope probing (SIP) analysis, and pot experiments. RESULTS Bacteria belonging to the genera Herbaspirillum, Rhizobium, Devosia, Pseudomonas, Microbacterium, and Delftia are crucial endophytes for Chinese silvergrass (Miscanthus sinensis) grown in the tailing, the model pioneer plant selected in this study. Further, DNA-SIP using 15N2 identified Pseudomonas, Rhizobium, and Exiguobacterium as putative diazotrophic endophytes of M. sinensis. Metagenomic-binning suggested that these bacteria contained essential genes for nitrogen fixation and plant growth promotion. Finally, two diazotrophic endophytes Rhizobium sp. G-14 and Pseudomonas sp. Y-5 were isolated from M. sinensis. Inoculation of another pioneer plant in mine tailings, Bidens pilosa, with diazotrophic endophytes resulted in successful plant colonization, significantly increased nitrogen fixation activity, and promotion of plant growth. CONCLUSIONS This study indicated that diazotrophic endophytes have the potential to promote the growth of pioneer plant B. pilosa in mine tailings. Video Abstract.
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Affiliation(s)
- Yongbin Li
- Guangdong Key Laboratory of Integrated Agro-Environmental Pollution Control and Management, Institute of Eco-Environmental and Soil Sciences, National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Academy of Sciences, Guangzhou, 510650, China
- Joint Laboratory for Environmental Pollution and Control, Guangdong-Hong Kong-Macao, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China
| | - Rui Yang
- Guangdong Key Laboratory of Integrated Agro-Environmental Pollution Control and Management, Institute of Eco-Environmental and Soil Sciences, National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Academy of Sciences, Guangzhou, 510650, China
| | - Max M Häggblom
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, NJ, 08901, USA
| | - Mengyan Li
- Department of Chemistry and Environmental Science, New Jersey Institute of Technology, Newark, NJ, 07102, USA
| | - Lifang Guo
- Guangdong Key Laboratory of Integrated Agro-Environmental Pollution Control and Management, Institute of Eco-Environmental and Soil Sciences, National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Academy of Sciences, Guangzhou, 510650, China
| | - Baoqin Li
- Guangdong Key Laboratory of Integrated Agro-Environmental Pollution Control and Management, Institute of Eco-Environmental and Soil Sciences, National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Academy of Sciences, Guangzhou, 510650, China
| | - Max Kolton
- Guangdong Key Laboratory of Integrated Agro-Environmental Pollution Control and Management, Institute of Eco-Environmental and Soil Sciences, National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Academy of Sciences, Guangzhou, 510650, China
- Joint Laboratory for Environmental Pollution and Control, Guangdong-Hong Kong-Macao, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China
- French Associates Institute for Agriculture and Biotechnology of Drylands, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Zhiguo Cao
- School of Environment, Key Laboratory of Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Henan Normal University, Xinxiang, 453007, China
| | - Mohsen Soleimani
- Department of Natural Resources, Isfahan University of Technology, Isfahan, Iran
| | - Zheng Chen
- Department of Health and Environmental Sciences, Xi'an Jiaotong-Liverpool University, Suzhou, 215123, China
| | - Zhimin Xu
- Engineering and Technology Research Center for Agricultural Land Pollution Prevention and Control of Guangdong Higher Education Institutes, College of Resources and Environment, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China
| | - Wenlong Gao
- Guangdong Key Laboratory of Integrated Agro-Environmental Pollution Control and Management, Institute of Eco-Environmental and Soil Sciences, National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Academy of Sciences, Guangzhou, 510650, China
- Joint Laboratory for Environmental Pollution and Control, Guangdong-Hong Kong-Macao, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China
| | - Bei Yan
- Guangdong Key Laboratory of Integrated Agro-Environmental Pollution Control and Management, Institute of Eco-Environmental and Soil Sciences, National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Academy of Sciences, Guangzhou, 510650, China
- Joint Laboratory for Environmental Pollution and Control, Guangdong-Hong Kong-Macao, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China
| | - Weimin Sun
- Guangdong Key Laboratory of Integrated Agro-Environmental Pollution Control and Management, Institute of Eco-Environmental and Soil Sciences, National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Academy of Sciences, Guangzhou, 510650, China.
- Joint Laboratory for Environmental Pollution and Control, Guangdong-Hong Kong-Macao, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China.
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Culturable Seed Microbiota of Populus trichocarpa. Pathogens 2021; 10:pathogens10060653. [PMID: 34074042 PMCID: PMC8225106 DOI: 10.3390/pathogens10060653] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 05/09/2021] [Accepted: 05/17/2021] [Indexed: 11/29/2022] Open
Abstract
Plants harbor a diverse community of microbes, whose interactions with their host and each other can influence plant health and fitness. While microbiota in plant vegetative tissues has been extensively studied, less is known about members of the seed microbiota. We used culture-based surveys to identify bacteria and fungi found in the seeds of the model tree, Populus trichocarpa, collected from different sites. We found that individual P. trichocarpa seeds typically contained zero or one microbe, with common taxa including species of Cladosporium, Aureobasidium, Diaporthe, Alternaria, and Pseudomonas, a bacterium. Pseudomonas isolates were associated with seed mortality and were negatively associated with the occurrence of fungal isolates within Epicoccum, Alternaria, and Aureobasidium from the same seed. Next, we conducted an inoculation experiment with one of the isolated seed microbes, Pseudomonas syringae pv. syringae, and found that it reduced seed germination and increased seedling mortality for P. trichocarpa. Our findings highlight common fungi and bacteria in the seeds of P. trichocarpa, prompting further study of their functional consequences. Moreover, our study confirms that P. syringae pv. syringae is a seed pathogen of P. trichocarpa and is the first report that P. syringae pv. syringae is a lethal seedling pathogen of P. trichocarpa, allowing for future work on the pathogenicity of this bacterium in seedlings and potential antagonism with other seed microbes.
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Eid AM, Fouda A, Abdel-Rahman MA, Salem SS, Elsaied A, Oelmüller R, Hijri M, Bhowmik A, Elkelish A, Hassan SED. Harnessing Bacterial Endophytes for Promotion of Plant Growth and Biotechnological Applications: An Overview. PLANTS (BASEL, SWITZERLAND) 2021; 10:935. [PMID: 34067154 PMCID: PMC8151188 DOI: 10.3390/plants10050935] [Citation(s) in RCA: 61] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Revised: 04/29/2021] [Accepted: 05/03/2021] [Indexed: 12/19/2022]
Abstract
Endophytic bacteria colonize plants and live inside them for part of or throughout their life without causing any harm or disease to their hosts. The symbiotic relationship improves the physiology, fitness, and metabolite profile of the plants, while the plants provide food and shelter for the bacteria. The bacteria-induced alterations of the plants offer many possibilities for biotechnological, medicinal, and agricultural applications. The endophytes promote plant growth and fitness through the production of phytohormones or biofertilizers, or by alleviating abiotic and biotic stress tolerance. Strengthening of the plant immune system and suppression of disease are associated with the production of novel antibiotics, secondary metabolites, siderophores, and fertilizers such as nitrogenous or other industrially interesting chemical compounds. Endophytic bacteria can be used for phytoremediation of environmental pollutants or the control of fungal diseases by the production of lytic enzymes such as chitinases and cellulases, and their huge host range allows a broad spectrum of applications to agriculturally and pharmaceutically interesting plant species. More recently, endophytic bacteria have also been used to produce nanoparticles for medical and industrial applications. This review highlights the biotechnological possibilities for bacterial endophyte applications and proposes future goals for their application.
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Affiliation(s)
- Ahmed M. Eid
- Department of Botany and Microbiology, Faculty of Science, Al-Azhar University, Nasr City, Cairo 11884, Egypt; (A.M.E.); (M.A.A.-R.); (S.S.S.); (A.E.)
| | - Amr Fouda
- Department of Botany and Microbiology, Faculty of Science, Al-Azhar University, Nasr City, Cairo 11884, Egypt; (A.M.E.); (M.A.A.-R.); (S.S.S.); (A.E.)
| | - Mohamed Ali Abdel-Rahman
- Department of Botany and Microbiology, Faculty of Science, Al-Azhar University, Nasr City, Cairo 11884, Egypt; (A.M.E.); (M.A.A.-R.); (S.S.S.); (A.E.)
| | - Salem S. Salem
- Department of Botany and Microbiology, Faculty of Science, Al-Azhar University, Nasr City, Cairo 11884, Egypt; (A.M.E.); (M.A.A.-R.); (S.S.S.); (A.E.)
| | - Albaraa Elsaied
- Department of Botany and Microbiology, Faculty of Science, Al-Azhar University, Nasr City, Cairo 11884, Egypt; (A.M.E.); (M.A.A.-R.); (S.S.S.); (A.E.)
| | - Ralf Oelmüller
- Department of Plant Physiology, Matthias Schleiden Institute of Genetics, Bioinformatics and Molecular Botany, Friedrich-Schiller-University, 07743 Jena, Germany; (R.O.); (A.E.)
| | - Mohamed Hijri
- Biodiversity Centre, Institut de Recherche en Biologie Végétale, Université de Montréal and Jardin botanique de Montréal, Montréal, QC 22001, Canada;
- African Genome Center, Mohammed VI Polytechnic University (UM6P), 43150 Ben Guerir, Morocco
| | - Arnab Bhowmik
- Department of Natural Resources and Environmental Design, North Carolina A&T State University, Greensboro, NC 27411, USA;
| | - Amr Elkelish
- Department of Plant Physiology, Matthias Schleiden Institute of Genetics, Bioinformatics and Molecular Botany, Friedrich-Schiller-University, 07743 Jena, Germany; (R.O.); (A.E.)
- Botany Department, Faculty of Science, Suez Canal University, Ismailia 41522, Egypt
| | - Saad El-Din Hassan
- Department of Botany and Microbiology, Faculty of Science, Al-Azhar University, Nasr City, Cairo 11884, Egypt; (A.M.E.); (M.A.A.-R.); (S.S.S.); (A.E.)
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Hernández-Fernández M, Cordero-Bueso G, Ruiz-Muñoz M, Cantoral JM. Culturable Yeasts as Biofertilizers and Biopesticides for a Sustainable Agriculture: A Comprehensive Review. PLANTS (BASEL, SWITZERLAND) 2021; 10:822. [PMID: 33919047 PMCID: PMC8142971 DOI: 10.3390/plants10050822] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 04/07/2021] [Accepted: 04/19/2021] [Indexed: 01/18/2023]
Abstract
The extensive use of synthetic fertilizers and pesticides has negative consequences in terms of soil microbial biodiversity and environmental contamination. Faced with this growing concern, a proposed alternative agricultural method is the use of microorganisms as biofertilizers. Many works have been focused on bacteria, but the limited literature on yeasts and their potential ability to safely promote plant growth is gaining particular attention in recent years. Thus, the objective of this review is to highlight the application of yeasts as biological agents in different sectors of sustainable agricultural practices through direct or indirect mechanisms of action. Direct mechanisms include the ability of yeasts to provide soluble nutrients to plants, produce organic acids and phytohormones (indole-3-acetic acid). Indirect mechanisms involve the ability for yeasts to act as biocontrol agents through their high antifungal activity and lower insecticidal and herbicidal activity, and as soil bioremediating agents. They also act as protective agents against extreme environmental factors by activating defense mechanisms. It is evident that all the aspects that yeasts offer could be useful in the creation of quality biofertilizers and biopesticides. Hence, extensive research on yeasts could be promising and potentially provide an environmentally friendly solution to the increased crop production that will be required with a growing population.
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Affiliation(s)
| | - Gustavo Cordero-Bueso
- Laboratory of Microbiology, Department Biomedicine, Biotechnology and Public Health, University of Cádiz, Puerto Real, 11510 Cádiz, Spain; (M.H.-F.); (M.R.-M.); (J.M.C.)
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Howard MM, Muñoz CA, Kao-Kniffin J, Kessler A. Soil Microbiomes From Fallow Fields Have Species-Specific Effects on Crop Growth and Pest Resistance. FRONTIERS IN PLANT SCIENCE 2020; 11:1171. [PMID: 32849726 PMCID: PMC7419683 DOI: 10.3389/fpls.2020.01171] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 07/20/2020] [Indexed: 06/11/2023]
Abstract
Communities of microorganisms in the soil can affect plants' growth and interactions with aboveground herbivores. Thus, there is growing interest in utilizing soil microbiomes to improve plant performance in agriculture (e.g., for pest control), but little is known about the phenotypic responses of various crop species to different microbiomes. In this study, we inoculated four crop species from different botanical families, maize (Zea mays, Poaceae), cucumber (Cucumis sativus, Cucurbitaceae), tomato (Solanum lycopersicum, Solanaceae), and lettuce (Lactuca sativa, Asteraceae), with diverse soil microbiomes originating from actively-managed agricultural fields or fallow fields under varying stages of succession (1, 3, and 16-years post-agriculture) sourced from a large-scale field experiment. We compared the crops' responses to these different microbiomes by assessing their growth and resistance to two generalist insect pests, cabbage looper (Trichoplusia ni) and fall armyworm (Spodoptera frugiperda). These different microbiomes affected both plant growth and resistance, but the effects were species-specific. For instance, lettuce produced the largest leaves when inoculated with a 3-year fallow microbiome, the microbiome in which cucumber performed worst. Plants were generally more resistant to T. ni when inoculated with the later succession microbiomes, particularly in contrast to those treated with agricultural microbiomes. However, for tomato plants, the opposite pattern was observed with regard to S. frugiperda resistance. Collectively, these results indicate that plant responses to microbiomes are species-specific and emphasize the need to characterize the responses of taxonomically diverse plant species to different microbiomes.
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Affiliation(s)
- Mia M. Howard
- Plant Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, United States
| | | | - Jenny Kao-Kniffin
- Horticulture Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, United States
| | - André Kessler
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, United States
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Firrincieli A, Khorasani M, Frank AC, Doty SL. Influences of Climate on Phyllosphere Endophytic Bacterial Communities of Wild Poplar. FRONTIERS IN PLANT SCIENCE 2020; 11:203. [PMID: 32184800 PMCID: PMC7058686 DOI: 10.3389/fpls.2020.00203] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 02/11/2020] [Indexed: 05/02/2023]
Abstract
Plant-associated microbial communities play a central role in the plant response to biotic and abiotic stimuli, improving plant fitness under challenging growing conditions. Many studies have focused on the characterization of changes in abundance and composition of root-associated microbial communities as a consequence of the plant response to abiotic factors such as altered soil nutrients and drought. However, changes in composition in response to abiotic factors are still poorly understood concerning the endophytic community associated to the phyllosphere, the above-ground plant tissues. In the present study, we applied high-throughput 16S rDNA gene sequencing of the phyllosphere endophytic bacterial communities colonizing wild Populus trichocarpa (black cottonwood) plants growing in native, nutrient-limited environments characterized by hot-dry (xeric) riparian zones (Yakima River, WA), riparian zones with mid hot-dry (Tieton and Teanaway Rivers, WA) and moist (mesic) climates (Snoqualmie, Skykomish and Skagit Rivers, WA). From sequencing data, 587 Amplicon Sequence Variants (ASV) were identified. Surprisingly, our data show that a core microbiome could be found in phyllosphere-associated endophytic communities in trees growing on opposite sides of the Cascades Mountain Range. Considering only taxa appearing in at least 90% of all samples within each climatic zone, the core microbiome was dominated only by two ASVs affiliated Pseudomonadaceae and two ASVs of the Enterobacteriaceae family. Alpha-diversity measures indicated that plants colonizing hot-dry environments showed a lower diversity than those from mid hot-dry and moist climates. Beta-diversity measures showed that bacterial composition was significantly different across sampling sites. Accordingly, we found that specific ASV affiliated to Pseudomonadaceae and Enterobacteriaceae were significantly more abundant in the phyllosphere endophytic community colonizing plants adapted to the xeric environment. In summary, this study highlights that sampling site is the major driver of variation and that only a few ASV showed a distribution that significantly correlated to climate variables.
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Affiliation(s)
- Andrea Firrincieli
- School of Environmental and Forest Sciences, College of the Environment, University of Washington, Seattle, WA, United States
| | - Mahsa Khorasani
- School of Environmental and Forest Sciences, College of the Environment, University of Washington, Seattle, WA, United States
| | - A. Carolin Frank
- Life & Environmental Sciences School of Natural Sciences, University of California, Merced, Merced, CA, United States
- Sierra Nevada Research Institute, School of Natural Sciences, University of California, Merced, Merced, CA, United States
| | - Sharon Lafferty Doty
- School of Environmental and Forest Sciences, College of the Environment, University of Washington, Seattle, WA, United States
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12
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Rho H, Doty SL, Kim SH. Endophytes alleviate the elevated CO2-dependent decrease in photosynthesis in rice, particularly under nitrogen limitation. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:707-718. [PMID: 31587073 PMCID: PMC6945999 DOI: 10.1093/jxb/erz440] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 09/26/2019] [Indexed: 05/18/2023]
Abstract
The positive effects of high atmospheric CO2 concentrations [CO2] decrease over time in most C3 plants because of down-regulation of photosynthesis. A notable exception to this trend is plants hosting N-fixing bacteria. The decrease in photosynthetic capacity associated with an extended exposure to high [CO2] was therefore studied in non-nodulating rice that can establish endophytic interactions. Rice plants were inoculated with diazotrophic endophytes isolated from the Salicaceae and CO2 response curves of photosynthesis were determined in the absence or presence of endophytes at the panicle initiation stage. Non-inoculated plants grown under elevated [CO2] showed a down-regulation of photosynthesis compared to those grown under ambient [CO2]. In contrast, the endophyte-inoculated plants did not show a decrease in photosynthesis associated with high [CO2], and they exhibited higher photosynthetic electron transport and mesophyll conductance rates than non-inoculated plants under high [CO2]. The endophyte-dependent alleviation of decreases in photosynthesis under high [CO2] led to an increase in water-use efficiency. These effects were most pronounced when the N supply was limited. The results suggest that inoculation with N-fixing endophytes could be an effective means of improving plant growth under high [CO2] by alleviating N limitations.
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Affiliation(s)
- Hyungmin Rho
- School of Environmental and Forest Sciences, College of the Environment, University of Washington, Seattle, WA, USA
| | - Sharon Lafferty Doty
- School of Environmental and Forest Sciences, College of the Environment, University of Washington, Seattle, WA, USA
| | - Soo-Hyung Kim
- School of Environmental and Forest Sciences, College of the Environment, University of Washington, Seattle, WA, USA
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13
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Cordero J, de Freitas JR, Germida JJ. Bacterial microbiome associated with the rhizosphere and root interior of crops in Saskatchewan, Canada. Can J Microbiol 2019; 66:71-85. [PMID: 31658427 DOI: 10.1139/cjm-2019-0330] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Rhizosphere and root associated bacteria are key components of plant microbiomes and influence crop production. In sustainable agriculture, it is important to investigate bacteria diversity in various plant species and how edaphic factors influence the bacterial microbiome. In this study, we used high-throughput sequencing to assess bacterial communities associated with the rhizosphere and root interior of canola, wheat, field pea, and lentil grown at four locations in Saskatchewan, Canada. Rhizosphere bacteria communities exhibited distinct profiles among crops and sampling locations. However, each crop was associated with distinct root endophytic bacterial communities, suggesting that crop species may influence the selection of root bacterial microbiome. Proteobacteria, Actinobacteria, and Bacteroidetes were the dominant phyla in the root interior, whereas Gemmatimonadetes, Firmicutes, and Acidobacteria were prevalent in the rhizosphere soil. Pseudomonas and Stenotrophomonas were predominant in the rhizosphere and root interior, whereas Acinetobacter, Arthrobacter, Rhizobium, Streptomyces, Variovorax, and Xanthomonas were dominant in the root interior of all crops. The relative abundance of specific bacterial groups in the rhizosphere correlated with soil pH and silt and organic matter contents; however, there was no correlation between root endophytes and analyzed soil properties. These results suggest that the root microbiome may be modulated by plant factors rather than soil characteristics.
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Affiliation(s)
- Jorge Cordero
- Department of Soil Science, University of Saskatchewan, 51 Campus Drive, Saskatoon, SK S7N 5A8, Canada.,Department of Soil Science, University of Saskatchewan, 51 Campus Drive, Saskatoon, SK S7N 5A8, Canada
| | - J Renato de Freitas
- Department of Soil Science, University of Saskatchewan, 51 Campus Drive, Saskatoon, SK S7N 5A8, Canada.,Department of Soil Science, University of Saskatchewan, 51 Campus Drive, Saskatoon, SK S7N 5A8, Canada
| | - James J Germida
- Department of Soil Science, University of Saskatchewan, 51 Campus Drive, Saskatoon, SK S7N 5A8, Canada
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14
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Identification of Novel Endophytic Yeast Strains from Tangerine Peel. Curr Microbiol 2019; 76:1066-1072. [DOI: 10.1007/s00284-019-01721-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 06/19/2019] [Indexed: 01/14/2023]
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15
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Aghai MM, Khan Z, Joseph MR, Stoda AM, Sher AW, Ettl GJ, Doty SL. The Effect of Microbial Endophyte Consortia on Pseudotsuga menziesii and Thuja plicata Survival, Growth, and Physiology Across Edaphic Gradients. Front Microbiol 2019; 10:1353. [PMID: 31275276 PMCID: PMC6591459 DOI: 10.3389/fmicb.2019.01353] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 05/31/2019] [Indexed: 11/17/2022] Open
Abstract
Increased frequency of droughts and degraded edaphic conditions decreases the success of many reforestation efforts in the Pacific Northwest. Microbial endophyte consortia have been demonstrated to contribute to plant growth promotion and protection from abiotic and biotic stresses – specifically drought conditions – across a number of food crops but for limited tree species. Our research aimed to investigate the potential to improve establishment of economically and ecologically important conifers through a series of in situ field trials and ex situ simulations. Microbial endophyte consortia from Salicaceae, previously shown to confer drought tolerance, and conifer endophyte strains with potentially symbiotic traits were selected for trials with Douglas-fir (Pseudotsuga menziesii) and western redcedar (Thuja plicata). Reductive experimentation was used to subject seedlings to a spectrum of simulated drought levels or presence/absence of fertilizer, testing hypotheses that endophyte consortia impart improved drought resistance and growth promotion, respectively. Inoculation from Salicaceae consortia significantly (p ≤ 0.05) improved survival among seedlings of both species subject to increasing drought stress, with T. plicata seedlings surviving at twofold higher rates in extreme drought conditions. Both species demonstrated improved growth 540 days after inoculation of seed with conifer derived consortia. In the carefully controlled greenhouse experiments with both species, seedling Fv/Fm and SPAD values remained significantly (p ≤ 0.05) more stable in inoculated treatment groups as stress increased. Our findings confirm that multi-strain consortia may be applied as seed or field amendment to conifers, and the approach is efficient in garnering a positive growth response and can mitigate abiotic stressors.
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Affiliation(s)
- Matthew M Aghai
- UW Center for Sustainable Forestry at Pack Forest, Eatonville, WA, United States.,School of Environmental and Forest Sciences, University of Washington, Seattle, WA, United States
| | - Zareen Khan
- School of Environmental and Forest Sciences, University of Washington, Seattle, WA, United States
| | - Matthew R Joseph
- School of Environmental and Forest Sciences, University of Washington, Seattle, WA, United States
| | - Aubrey M Stoda
- School of Environmental and Forest Sciences, University of Washington, Seattle, WA, United States
| | - Andrew W Sher
- School of Environmental and Forest Sciences, University of Washington, Seattle, WA, United States
| | - Gregory J Ettl
- UW Center for Sustainable Forestry at Pack Forest, Eatonville, WA, United States.,School of Environmental and Forest Sciences, University of Washington, Seattle, WA, United States
| | - Sharon L Doty
- School of Environmental and Forest Sciences, University of Washington, Seattle, WA, United States
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16
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Mukherjee G, Saha C, Naskar N, Mukherjee A, Mukherjee A, Lahiri S, Majumder AL, Seal A. An Endophytic Bacterial Consortium modulates multiple strategies to improve Arsenic Phytoremediation Efficacy in Solanum nigrum. Sci Rep 2018; 8:6979. [PMID: 29725058 PMCID: PMC5934359 DOI: 10.1038/s41598-018-25306-x] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 04/16/2018] [Indexed: 12/31/2022] Open
Abstract
Endophytic microbes isolated from plants growing in contaminated habitats possess specialized properties that help their host detoxify the contaminant/s. The possibility of using microbe-assisted phytoremediation for the clean-up of Arsenic (As) contaminated soils of the Ganga-Brahmaputra delta of India, was explored using As-tolerant endophytic microbes from an As-tolerant plant Lantana camara collected from the contaminated site and an intermediate As-accumulator plant Solanum nigrum. Endophytes from L. camara established within S. nigrum as a surrogate host. The microbes most effectively improved plant growth besides increasing bioaccumulation and root-to-shoot transport of As when applied as a consortium. Better phosphate nutrition, photosynthetic performance, and elevated glutathione levels were observed in consortium-treated plants particularly under As-stress. The consortium maintained heightened ROS levels in the plant without any deleterious effect and concomitantly boosted distinct antioxidant defense mechanisms in the shoot and root of As-treated plants. Increased consortium-mediated As(V) to As(III) conversion appeared to be a crucial step in As-detoxification/translocation. Four aquaporins were differentially regulated by the endophytes and/or As. The most interesting finding was the strong upregulation of an MRP transporter in the root by the As + endophytes, which suggested a major alteration of As-detoxification/accumulation pattern upon endophyte treatment that improved As-phytoremediation.
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Affiliation(s)
- Gairik Mukherjee
- Department of Biotechnology, Dr. B. C. Guha Centre for Genetic Engineering and Biotechnology, University of Calcutta, 35, Ballygunge Circular Road, Kolkata, 700019, India
| | - Chinmay Saha
- Department of Endocrinology & Metabolism, Institute Of Post Graduate Medical Education & Research and SSKM Hospital, Room No. 9A, 4th Floor, Ronald Ross Building, 244, AJC Bose Road, Kolkata, 700020, India
| | - Nabanita Naskar
- Department of Environmental Science, University of Calcutta, 35, Ballygunge Circular Road, Kolkata, 700019, India
- Saha Institute of Nuclear Physics, Sector - 1, Block - AF Bidhannagar, Kolkata, 700064, India
| | - Abhishek Mukherjee
- Homi Bhabha National Institute, 1/AF Bidhannagar, Kolkata, 700064, India
| | - Arghya Mukherjee
- Department of Biotechnology, Dr. B. C. Guha Centre for Genetic Engineering and Biotechnology, University of Calcutta, 35, Ballygunge Circular Road, Kolkata, 700019, India
| | - Susanta Lahiri
- Saha Institute of Nuclear Physics, Sector - 1, Block - AF Bidhannagar, Kolkata, 700064, India
- Homi Bhabha National Institute, 1/AF Bidhannagar, Kolkata, 700064, India
| | - Arun Lahiri Majumder
- Division of Plant Biology, Bose Institute, P-1/12 CIT Scheme VIIM, Kolkata, 700054, India
| | - Anindita Seal
- Department of Biotechnology, Dr. B. C. Guha Centre for Genetic Engineering and Biotechnology, University of Calcutta, 35, Ballygunge Circular Road, Kolkata, 700019, India.
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17
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Rho H, Van Epps V, Wegley N, Doty SL, Kim SH. Salicaceae Endophytes Modulate Stomatal Behavior and Increase Water Use Efficiency in Rice. FRONTIERS IN PLANT SCIENCE 2018; 9:188. [PMID: 29552021 PMCID: PMC5840156 DOI: 10.3389/fpls.2018.00188] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Accepted: 01/31/2018] [Indexed: 05/18/2023]
Abstract
Bacterial and yeast endophytes isolated from the Salicaceae family have been shown to promote growth and alleviate stress in plants from different taxa. To determine the physiological pathways through which endophytes affect plant water relations, we investigated leaf water potential, whole-plant water use, and stomatal responses of rice plants to Salicaceae endophyte inoculation under CO2 enrichment and water deficit. Daytime stomatal conductance and stomatal density were lower in inoculated plants compared to controls. Leaf ABA concentrations increased with endophyte inoculation. As a result, transpirational water use decreased significantly with endophyte inoculation while biomass did not change or slightly increased. This response led to a significant increase in cumulative water use efficiency at harvest. Different endophyte strains produced the same results in host plant water relations and stomatal responses. These stomatal responses were also observed under elevated CO2 conditions, and the increase in water use efficiency was more pronounced under water deficit conditions. The effect on water use efficiency was positively correlated with daily light integrals across different experiments. Our results provide insights on the physiological mechanisms of plant-endophyte interactions involving plant water relations and stomatal functions.
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Affiliation(s)
- Hyungmin Rho
- School of Environmental and Forest Sciences, College of the Environment, University of Washington, Seattle, WA, United States
| | - Victor Van Epps
- Department of Biology, University of Washington, Seattle, WA, United States
| | - Nicholas Wegley
- School of Environmental and Forest Sciences, College of the Environment, University of Washington, Seattle, WA, United States
| | - Sharon L. Doty
- School of Environmental and Forest Sciences, College of the Environment, University of Washington, Seattle, WA, United States
| | - Soo-Hyung Kim
- School of Environmental and Forest Sciences, College of the Environment, University of Washington, Seattle, WA, United States
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18
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Rho H, Hsieh M, Kandel SL, Cantillo J, Doty SL, Kim SH. Do Endophytes Promote Growth of Host Plants Under Stress? A Meta-Analysis on Plant Stress Mitigation by Endophytes. MICROBIAL ECOLOGY 2018; 75:407-418. [PMID: 28840330 DOI: 10.1007/s00248-017-1054-3] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 08/07/2017] [Indexed: 05/18/2023]
Abstract
Endophytes are microbial symbionts living inside plants and have been extensively researched in recent decades for their functions associated with plant responses to environmental stress. We conducted a meta-analysis of endophyte effects on host plants' growth and fitness in response to three abiotic stress factors: drought, nitrogen deficiency, and excessive salinity. Ninety-four endophyte strains and 42 host plant species from the literature were evaluated in the analysis. Endophytes increased biomass accumulation of host plants under all three stress conditions. The stress mitigation effects by endophytes were similar among different plant taxa or functional groups with few exceptions; eudicots and C4 species gained more biomass than monocots and C3 species with endophytes, respectively, under drought conditions. Our analysis supports the effectiveness of endophytes in mitigating drought, nitrogen deficiency, and salinity stress in a wide range of host species with little evidence of plant-endophyte specificity.
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Affiliation(s)
- Hyungmin Rho
- School of Environmental and Forest Sciences, College of the Environment, University of Washington, Seattle, WA, 98195-2100, USA.
| | - Marian Hsieh
- School of Environmental and Forest Sciences, College of the Environment, University of Washington, Seattle, WA, 98195-2100, USA
| | - Shyam L Kandel
- School of Environmental and Forest Sciences, College of the Environment, University of Washington, Seattle, WA, 98195-2100, USA
| | - Johanna Cantillo
- Department of Biology, University of Washington, Seattle, WA, 98195-1800, USA
| | - Sharon L Doty
- School of Environmental and Forest Sciences, College of the Environment, University of Washington, Seattle, WA, 98195-2100, USA
| | - Soo-Hyung Kim
- School of Environmental and Forest Sciences, College of the Environment, University of Washington, Seattle, WA, 98195-2100, USA
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19
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20
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Kandel SL, Joubert PM, Doty SL. Bacterial Endophyte Colonization and Distribution within Plants. Microorganisms 2017; 5:E77. [PMID: 29186821 PMCID: PMC5748586 DOI: 10.3390/microorganisms5040077] [Citation(s) in RCA: 225] [Impact Index Per Article: 32.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 11/21/2017] [Accepted: 11/23/2017] [Indexed: 11/16/2022] Open
Abstract
The plant endosphere contains a diverse group of microbial communities. There is general consensus that these microbial communities make significant contributions to plant health. Both recently adopted genomic approaches and classical microbiology techniques continue to develop the science of plant-microbe interactions. Endophytes are microbial symbionts residing within the plant for the majority of their life cycle without any detrimental impact to the host plant. The use of these natural symbionts offers an opportunity to maximize crop productivity while reducing the environmental impacts of agriculture. Endophytes promote plant growth through nitrogen fixation, phytohormone production, nutrient acquisition, and by conferring tolerance to abiotic and biotic stresses. Colonization by endophytes is crucial for providing these benefits to the host plant. Endophytic colonization refers to the entry, growth and multiplication of endophyte populations within the host plant. Lately, plant microbiome research has gained considerable attention but the mechanism allowing plants to recruit endophytes is largely unknown. This review summarizes currently available knowledge about endophytic colonization by bacteria in various plant species, and specifically discusses the colonization of maize plants by Populus endophytes.
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Affiliation(s)
| | | | - Sharon L. Doty
- School of Environmental and Forest Sciences, College of the Environment, University of Washington, Seattle, WA 98195-2100, USA; (S.L.K.); (P.M.J.)
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21
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Transmission of Bacterial Endophytes. Microorganisms 2017; 5:microorganisms5040070. [PMID: 29125552 PMCID: PMC5748579 DOI: 10.3390/microorganisms5040070] [Citation(s) in RCA: 174] [Impact Index Per Article: 24.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 11/06/2017] [Accepted: 11/07/2017] [Indexed: 01/02/2023] Open
Abstract
Plants are hosts to complex communities of endophytic bacteria that colonize the interior of both below- and aboveground tissues. Bacteria living inside plant tissues as endophytes can be horizontally acquired from the environment with each new generation, or vertically transmitted from generation to generation via seed. A better understanding of bacterial endophyte transmission routes and modes will benefit studies of plant–endophyte interactions in both agricultural and natural ecosystems. In this review, we provide an overview of the transmission routes that bacteria can take to colonize plants, including vertically via seeds and pollen, and horizontally via soil, atmosphere, and insects. We discuss both well-documented and understudied transmission routes, and identify gaps in our knowledge on how bacteria reach the inside of plants. Where little knowledge is available on endophytes, we draw from studies on bacterial plant pathogens to discuss potential transmission routes. Colonization of roots from soil is the best studied transmission route, and probably the most important, although more studies of transmission to aerial parts and stomatal colonization are needed, as are studies that conclusively confirm vertical transfer. While vertical transfer of bacterial endophytes likely occurs, obligate and strictly vertically transferred symbioses with bacteria are probably unusual in plants. Instead, plants appear to benefit from the ability to respond to a changing environment by acquiring its endophytic microbiome anew with each generation, and over the lifetime of individuals.
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22
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Endophytic Plant Growth Promoting Bacteria and Yeast from Mahua flower enhance Growth, Yield and Nutrient Uptake in Greengram. JOURNAL OF PURE AND APPLIED MICROBIOLOGY 2017. [DOI: 10.22207/jpam.11.3.40] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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23
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Kandel SL, Firrincieli A, Joubert PM, Okubara PA, Leston ND, McGeorge KM, Mugnozza GS, Harfouche A, Kim SH, Doty SL. An In vitro Study of Bio-Control and Plant Growth Promotion Potential of Salicaceae Endophytes. Front Microbiol 2017; 8:386. [PMID: 28348550 PMCID: PMC5347143 DOI: 10.3389/fmicb.2017.00386] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Accepted: 02/23/2017] [Indexed: 11/13/2022] Open
Abstract
Microbial communities in the endosphere of Salicaceae plants, poplar (Populus trichocarpa) and willow (Salix sitchensis), have been demonstrated to be important for plant growth promotion, protection from biotic and abiotic stresses, and degradation of toxic compounds. Our study aimed to investigate bio-control activities of Salicaceae endophytes against various soil borne plant pathogens including Rhizoctonia solani AG-8, Fusarium culmorum, Gaeumannomyces graminis var. tritici, and Pythium ultimum. Additionally, different plant growth promoting traits such as biological nitrogen fixation (BNF), indole-3-acetic acid (IAA) biosynthesis, phosphate solubilization, and siderophore production were assessed in all bio-control positive strains. Burkholderia, Rahnella, Pseudomonas, and Curtobacterium were major endophyte genera that showed bio-control activities in the in-vitro assays. The bio-control activities of Burkholderia strains were stronger across all tested plant pathogens as compared to other stains. Genomes of sequenced Burkholderia strains WP40 and WP42 were surveyed to identify the putative genes involved in the bio-control activities. The ocf and hcnABC gene clusters responsible for biosynthesis of the anti-fungal metabolites, occidiofungin and hydrogen cyanide, are present in the genomes of WP40 and WP42. Nearly all endophyte strains showing the bio-control activities produced IAA, solubilized tricalcium phosphate, and synthesized siderophores in the culture medium. Moreover, some strains reduced acetylene into ethylene in the acetylene reduction assay, a common assay used for BNF. Salicaceae endophytes could be useful for bio-control of various plant pathogens, and plant growth promotion possibly through the mechanisms of BNF, IAA production, and nutrient acquisition.
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Affiliation(s)
- Shyam L Kandel
- School of Environmental and Forest Sciences, College of the Environment, University of Washington Seattle, WA, USA
| | - Andrea Firrincieli
- Department for Innovation in Biological, Agro-Food and Forest Systems, University of Tuscia Viterbo, Italy
| | - Pierre M Joubert
- Department of Biology, University of Washington Seattle, WA, USA
| | - Patricia A Okubara
- Wheat Health, Genetics and Quality Research Unit, USDA-ARS Pullman, WA, USA
| | - Natalie D Leston
- Department of Plant Pathology, Washington State University Pullman, WA, USA
| | - Kendra M McGeorge
- Department of Plant Pathology, Washington State University Pullman, WA, USA
| | - Giuseppe S Mugnozza
- Department for Innovation in Biological, Agro-Food and Forest Systems, University of Tuscia Viterbo, Italy
| | - Antoine Harfouche
- Department for Innovation in Biological, Agro-Food and Forest Systems, University of Tuscia Viterbo, Italy
| | - Soo-Hyung Kim
- School of Environmental and Forest Sciences, College of the Environment, University of Washington Seattle, WA, USA
| | - Sharon L Doty
- School of Environmental and Forest Sciences, College of the Environment, University of Washington Seattle, WA, USA
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24
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Balseiro-Romero M, Gkorezis P, Kidd PS, Van Hamme J, Weyens N, Monterroso C, Vangronsveld J. Use of plant growth promoting bacterial strains to improve Cytisus striatus and Lupinus luteus development for potential application in phytoremediation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 581-582:676-688. [PMID: 28069305 DOI: 10.1016/j.scitotenv.2016.12.180] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Revised: 12/28/2016] [Accepted: 12/28/2016] [Indexed: 06/06/2023]
Abstract
Plant growth promoting (PGP) bacterial strains possess different mechanisms to improve plant development under common environmental stresses, and are therefore often used as inoculants in soil phytoremediation processes. The aims of the present work were to study the effects of a collection of plant growth promoting bacterial strains on plant development, antioxidant enzyme activities and nutritional status of Cytisus striatus and/or Lupinus luteus plants a) growing in perlite under non-stress conditions and b) growing in diesel-contaminated soil. For this, two greenhouse experiments were designed. Firstly, C. striatus and L. luteus plants were grown from seeds in perlite, and periodically inoculated with 6 PGP strains, either individually or in pairs. Secondly, L. luteus seedlings were grown in soil samples of the A and B horizons of a Cambisol contaminated with 1.25% (w/w) of diesel and inoculated with best PGP inoculant selected from the first experiment. The results indicated that the PGP strains tested in perlite significantly improved plant growth. Combination treatments provoked better growth of L. luteus than the respective individual strains, while individual inoculation treatments were more effective for C. striatus. L. luteus growth in diesel-contaminated soil was significantly improved in the presence of PGP strains, presenting a 2-fold or higher increase in plant biomass. Inoculants did not provoke significant changes in plant nutritional status, with the exception of a subset of siderophore-producing and P-solubilising bacterial strains that resulted in significantly modification of Fe or P concentrations in leaf tissues. Inoculants did not cause significant changes in enzyme activities in perlite experiments, however they significantly reduced oxidative stress in contaminated soils suggesting an improvement in plant tolerance to diesel. Some strains were applied to non-host plants, indicating a non-specific performance of their plant growth promotion. The use of PGP strains in phytoremediation may help plants to overcome contaminant and other soil stresses, increasing phytoremediation efficiency.
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Affiliation(s)
- María Balseiro-Romero
- Department of Soil Science and Agricultural Chemistry, University of Santiago de Compostela, Campus Vida, 15782 Santiago de Compostela, Spain.
| | - Panagiotis Gkorezis
- Centre for Environmental Sciences, University of Hasselt, Agoralaan Building B, 3590 Diepenbeek, Belgium
| | - Petra S Kidd
- Instituto de Investigacións Agrobiolóxicas de Galicia (IIAG), Consejo Superior de Investigaciones Científicas (CSIC), 15780 Santiago de Compostela, Spain
| | - Jonathan Van Hamme
- Department of Biological Sciences, Thompson Rivers University, Kamloops, Canada
| | - Nele Weyens
- Centre for Environmental Sciences, University of Hasselt, Agoralaan Building B, 3590 Diepenbeek, Belgium
| | - Carmen Monterroso
- Department of Soil Science and Agricultural Chemistry, University of Santiago de Compostela, Campus Vida, 15782 Santiago de Compostela, Spain
| | - Jaco Vangronsveld
- Centre for Environmental Sciences, University of Hasselt, Agoralaan Building B, 3590 Diepenbeek, Belgium
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25
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Saha C, Mukherjee G, Agarwal-Banka P, Seal A. A consortium of non-rhizobial endophytic microbes from Typha angustifolia functions as probiotic in rice and improves nitrogen metabolism. PLANT BIOLOGY (STUTTGART, GERMANY) 2016; 18:938-946. [PMID: 27453497 DOI: 10.1111/plb.12485] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2016] [Accepted: 07/19/2016] [Indexed: 06/06/2023]
Abstract
Endophytic microbes isolated from plants growing in nutrient-deficient environments often possess properties that improve nutrition of agriculturally important plants. A consortium of non-rhizobial endophytic microbes isolated from a macrophyte Typha angustifolia growing in the marginal wetlands associated with a Uranium mine was characterized for their beneficial effect on rice and the mechanisms of growth promotion were investigated. The microbes were identified and characterized for their potential plant growth promoting (PGP) properties. Effect of these microbes on nitrogen (N)-metabolism of rice was tested as Typha endophytes were predominantly (N)-fixing. Relative N-use efficiency and expression of genes involved in N-uptake and assimilation were investigated in treated plants. Evidence of horizontal gene transfer (HGT) of dinitrogen reductase gene was observed within the consortium from a Pseudomonas stutzeri strain. The consortium behaved as plant probiotic and showed substantial growth benefits to Typha, their natural host as well as to rice. Typha endophytes colonized rice endosphere significantly increasing biomass, shoot length and chlorophyll content in rice plants both under N-sufficient and N-deficient conditions. N-uptake and assimilation genes were upregulated in plants treated with the endophytes even after three weeks post infection. Our results suggested, HGT of nitrogen-fixation trait to be highly prevalent among endophytes isolated from nutrient-poor habitats of the uranium mine. A long-term nitrogen deficiency response in the treated plants was elicited by the consortium improving N-uptake, assimilation and relative N-use efficiency of rice plants. This appeared to be at least one of the main strategies of plant growth promotion.
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Affiliation(s)
- C Saha
- Department of Biotechnology, Dr. B. C. Guha Centre for Genetic Engineering and Biotechnology, University of Calcutta, Kolkata, India
| | - G Mukherjee
- Department of Biotechnology, Dr. B. C. Guha Centre for Genetic Engineering and Biotechnology, University of Calcutta, Kolkata, India
| | | | - A Seal
- Department of Biotechnology, Dr. B. C. Guha Centre for Genetic Engineering and Biotechnology, University of Calcutta, Kolkata, India.
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Khunnamwong P, Limtong S. Yamadazyma endophytica f.a. sp. nov., an ascomycetous yeast species isolated from leaf tissue. Int J Syst Evol Microbiol 2016; 66:2717-2723. [PMID: 27117789 DOI: 10.1099/ijsem.0.001113] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Strain DMKU-CE23T representing a novel yeast species was isolated from tissue of a corn leaf (Zea may L.) collected in Thailand. A phylogenetic analysis based on the combined sequences of the internal transcribed spacer (ITS) region and the D1/D2 region of the LSU rRNA gene indicated that strain DMKU-CE23T belongs to the Yamadazyma clade and is clearly distinct from other related species. It therefore represents a novel species of the genus Yamadazyma although the formation of ascospores was not observed. The strain of novel species was most closely related to the type strain of Yamadazyma epiphylla but with 5.1 % nucleotide substitutions in the ITS region and 3.7 % nucleotide substitutions in the D1/D2 region of the LSU rRNA gene. The name Yamadazyma endophytica f.a., sp. nov. is proposed. The type strain is DMKU-CE23T (=CBS 14163T=TBRC 5174T).
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Affiliation(s)
- Pannida Khunnamwong
- Department of Microbiology and Faculty of Science, Kasetsart University, Bangkok, Thailand
| | - Savitree Limtong
- Center for Advanced Studied in Tropical Natural Resources, National Research University and Kasetsart University, Thailand.,Department of Microbiology and Faculty of Science, Kasetsart University, Bangkok, Thailand
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Mestre MC, Fontenla S, Bruzone MC, Fernández NV, Dames J. Detection of plant growth enhancing features in psychrotolerant yeasts from Patagonia (Argentina). J Basic Microbiol 2016; 56:1098-1106. [PMID: 27106520 DOI: 10.1002/jobm.201500728] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 04/03/2016] [Indexed: 11/08/2022]
Abstract
This study explores the biotechnological potential for plant production of twelve psychrotolerant yeasts strains from Northwest-Patagonia. These strains were isolated from different substrates associated with Nothofagus sp. in native forests and Vaccinium sp. in a commercial plantation. Yeasts characterization was performed using in vitro assays to evaluate the production of auxin-like compounds and siderophores, ability to solubilize inorganic phosphate and to reduce common plant pathogen growth. Strain YF8.3 identified as Aureobasidium pullullans was the main producer of auxin-like and siderophores compounds. Phosphate solubilization was a characteristic observed by strains L8.12 and CRUB1775 identified as Holtermaniella takashimae and Candida maritima, respectively. Different yeast strains were able to inhibit the growth of Verticillium dahliae PPRI5569 and Pythium aphanidermatum PPRI 9009, but they all failed to inhibit the growth of Fusarium oxysporum PPRI5457. The present study, suggests that yeasts present in different environments in Northwestern-Patagonian have physiological in vitro features which may influence plant growth. These results are promising for the developing of biological products based on Patagonian yeasts for plant production in cold-temperate regions.
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Affiliation(s)
| | - Sonia Fontenla
- INIBIOMA (Universidad Nacional del Comahue-CONICET), Bariloche, Argentina.,Laboratorio de Microbiología Aplicada y Biotecnología, Centro Regional Universitario Bariloche, Universidad Nacional del Comahue, Bariloche, Argentina
| | | | | | - Joanna Dames
- Mycorrhizal Research Laboratory, Department of Biochemistry and Microbiology, Rhodes University, Grahamstown, South Africa
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Increased Biomass of Nursery-Grown Douglas-Fir Seedlings upon Inoculation with Diazotrophic Endophytic Consortia. FORESTS 2015. [DOI: 10.3390/f6103582] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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29
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Khunnamwong P, Lertwattanasakul N, Jindamorakot S, Limtong S, Lachance MA. Description of Diutina gen. nov., Diutina siamensis, f.a. sp. nov., and reassignment of Candida catenulata, Candida mesorugosa, Candida neorugosa, Candida pseudorugosa, Candida ranongensis, Candida rugosa and Candida scorzettiae to the genus Diutina. Int J Syst Evol Microbiol 2015; 65:4701-4709. [PMID: 26410375 DOI: 10.1099/ijsem.0.000634] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Three strains (DMKU-RE28, DMKU-RE43T and DMKU-RE123) of a novel anamorphic yeast species were isolated from rice leaf tissue collected in Thailand. DNA sequence analysis demonstrated that the species forms a sister pair with Candida ranongensis CBS 10861T but differs by 24-30 substitutions in the LSU rRNA gene D1/D2 domains and 30-35 substitutions in the ITS region. A phylogenetic analysis based on both the small and the large rRNA gene subunits confirmed this connection and demonstrated the presence of a clade that also includes Candida catenulata, Candida mesorugosa, Candida neorugosa, Candida pseudorugosa, Candida rugosa and Candida scorzettiae. The clade is not closely affiliated to any known teleomorphic genus, and forms a well-separated lineage from currently recognized genera of the Saccharomycetales. Hence, the genus Diutina gen. nov. is proposed to accommodate members of the clade, including Diutina siamensis f.a. sp. nov. and the preceding seven Candida species. The type strain is DMKU-RE43T ( = CBS 13388T = BCC 61183T = NBRC 109695T).
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Affiliation(s)
- Pannida Khunnamwong
- Department of Microbiology, Faculty of Science, Kasetsart University, Bangkok, Thailand
| | | | - Sasitorn Jindamorakot
- Bioresources Technology Unit, National Center for Genetic Engineering and Biotechnology (BIOTEC), Pathumthani, Thailand
| | - Savitree Limtong
- Department of Microbiology, Faculty of Science, Kasetsart University, Bangkok, Thailand
- Center for Advanced Studies in Tropical Natural Resources, National Research University Kasetsart University, Thailand
| | - Marc-André Lachance
- Department of Biology, University of Western Ontario, London, Ontario, Canada
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Firrincieli A, Otillar R, Salamov A, Schmutz J, Khan Z, Redman RS, Fleck ND, Lindquist E, Grigoriev IV, Doty SL. Genome sequence of the plant growth promoting endophytic yeast Rhodotorula graminis WP1. Front Microbiol 2015; 6:978. [PMID: 26441909 PMCID: PMC4585186 DOI: 10.3389/fmicb.2015.00978] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2015] [Accepted: 09/03/2015] [Indexed: 12/22/2022] Open
Affiliation(s)
- Andrea Firrincieli
- Department for Innovation Biological, Agro-Food and Forest System, University of Tuscia Tuscia, Italy
| | - Robert Otillar
- U.S. Department of Energy Joint Genome Institute Walnut Creek, CA, USA
| | - Asaf Salamov
- U.S. Department of Energy Joint Genome Institute Walnut Creek, CA, USA
| | - Jeremy Schmutz
- U.S. Department of Energy Joint Genome Institute Walnut Creek, CA, USA ; HudsonAlpha Institute for Biotechnology Huntsville, AL, USA
| | - Zareen Khan
- School of Environmental and Forest Sciences, University of Washington Seattle, WA, USA
| | | | - Neil D Fleck
- School of Environmental and Forest Sciences, University of Washington Seattle, WA, USA
| | - Erika Lindquist
- U.S. Department of Energy Joint Genome Institute Walnut Creek, CA, USA
| | - Igor V Grigoriev
- U.S. Department of Energy Joint Genome Institute Walnut Creek, CA, USA
| | - Sharon L Doty
- School of Environmental and Forest Sciences, University of Washington Seattle, WA, USA
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Khunnamwong P, Surussawadee J, Jindamorakot S, Limtong S. W
ickerhamiella siamensis f.a., sp. nov., an endophytic and epiphytic yeast species isolated from sugar cane leaf. Int J Syst Evol Microbiol 2014; 64:3849-3855. [DOI: 10.1099/ijs.0.067702-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Six strains representing a novel yeast species were isolated from tissue (DMKU-SE106T, DMKU-SE110, DMKU-SE112 and DMKU-SE132) and the external surface (DMKU-SP335 and DMKU-SP406) of sugar cane leaves collected in Thailand. On the basis of morphological, biochemical, physiological and chemotaxonomic characteristics, and sequence analysis of the D1/D2 region of the LSU rRNA gene and the internal transcribed spacer (ITS) region, the six strains were found to represent a single novel species of the genus Wickerhamiella although the formation of ascospores was not observed. The sequences of the D1/D2 region of the LSU rRNA gene and ITS region of the six strains differed from each other by 0–2 and 2–3 nt substitutions, respectively. The novel species was related most closely to Candida infanticola but with 4.5–4.6 % nucleotide substitutions in the D1/D2 region of the LSU rRNA gene and 6.6–7.1 % nucleotide substitutions in the ITS region. The name Wickerhamiella siamensis f.a., sp. nov. is proposed. The type strain is DMKU-SE106T ( = BCC 61185T = NBRC 109697T = CBS 13331T).
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Affiliation(s)
- Pannida Khunnamwong
- Department of Microbiology, Faculty of Science, Kasetsart University, Bangkok, Thailand
| | - Janjira Surussawadee
- Department of Microbiology, Faculty of Science, Kasetsart University, Bangkok, Thailand
| | - Sasitorn Jindamorakot
- Bioresources Technology Unit, National Center for Genetic Engineering and Biotechnology (BIOTEC), Pathumthani, Thailand
| | - Savitree Limtong
- Center for Advanced Studied in Tropical Natural Resources, National Research University Kasetsart University, Thailand
- Department of Microbiology, Faculty of Science, Kasetsart University, Bangkok, Thailand
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Knoth JL, Kim SH, Ettl GJ, Doty SL. Biological nitrogen fixation and biomass accumulation within poplar clones as a result of inoculations with diazotrophic endophyte consortia. THE NEW PHYTOLOGIST 2014; 201:599-609. [PMID: 24117518 DOI: 10.1111/nph.12536] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Accepted: 08/29/2013] [Indexed: 05/18/2023]
Abstract
Sustainable production of biomass for bioenergy relies on low-input crop production. Inoculation of bioenergy crops with plant growth-promoting endophytes has the potential to reduce fertilizer inputs through the enhancement of biological nitrogen fixation (BNF). Endophytes isolated from native poplar growing in nutrient-poor conditions were selected for a series of glasshouse and field trials designed to test the overall hypothesis that naturally occurring diazotrophic endophytes impart growth promotion of the host plants. Endophyte inoculations contributed to increased biomass over uninoculated control plants. This growth promotion was more pronounced with multi-strain consortia than with single-strain inocula. Biological nitrogen fixation was estimated through (15)N isotope dilution to be 65% nitrogen derived from air (Ndfa). Phenotypic plasticity in biomass allocation and branch production observed as a result of endophyte inoculations may be useful in bioenergy crop breeding and engineering programs.
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Affiliation(s)
- Jenny L Knoth
- School of Environmental and Forest Sciences, College of the Environment, University of Washington, Seattle, WA, 98195-2100, USA
| | - Soo-Hyung Kim
- School of Environmental and Forest Sciences, College of the Environment, University of Washington, Seattle, WA, 98195-2100, USA
| | - Gregory J Ettl
- School of Environmental and Forest Sciences, College of the Environment, University of Washington, Seattle, WA, 98195-2100, USA
| | - Sharon L Doty
- School of Environmental and Forest Sciences, College of the Environment, University of Washington, Seattle, WA, 98195-2100, USA
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