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Wang Z, Liu J, White JF, Li C. Epichloë bromicola from wild barley improves salt-tolerance of cultivated barley by altering physiological responses to salt stress. Front Microbiol 2022; 13:1044735. [PMID: 36504776 PMCID: PMC9730248 DOI: 10.3389/fmicb.2022.1044735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 11/02/2022] [Indexed: 11/25/2022] Open
Abstract
Introduction Epichloë bromicola is a cultivable fungal endophyte that lives in symbiosis with wild barley (Hordeum brevisubulatum) to which it confers salt tolerance. This study tested the hypothesis that E. bromicola derived from wild barley has the potential to increase salt tolerance in cultivated barley under salt stress. Methods To test this hypothesis, the growth response, physiological parameters, and metabolic profiles of barley plants inoculated with E. bromicola (E+) and those not inoculated with E. bromicola (E-) were compared under salt stress. Results Compared with E- barley plants, E+ barley plants had significantly increased plant height, shoot biomass, total biomass, chlorophyll content, osmotic synthesis, and accumulation of stress adaptation metabolites. E. bromicola increased the salt stress tolerance of cultivated barley, and the positive effects correlated with different salt stress conditions. Discussion These results suggest that E. bromicola has promising potential for enhancing the salt tolerance of barley. New insights into the mechanisms underlying this barley-fungal endophyte association are provided, and interesting questions regarding the role of E. bromicola in fungus-enhanced tolerance to salt stress in this symbiosis are raised.
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Affiliation(s)
- Zhengfeng Wang
- Economic Crops and Malt Barley Research Institute, Gansu Academy of Agricultural Science, Lanzhou, China
| | - Jing Liu
- State Key Laboratory of Herbage Improvement and Grassland Agro-Ecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, Engineering Research Center of Grassland Industry, Ministry of Education, Gansu Tech Innovation Center of Western China Grassland Industry, Centre for Grassland Microbiome, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, China
| | - James F. White
- Department of Plant Biology, Rutgers University, New Brunswick, NJ, United States
| | - Chunjie Li
- Grassland Research Center of National Forestry and Grassland Administration, Chinese Academy of Forestry Sciences, Beijing, China,*Correspondence: Chunjie Li
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Liu B, Ju Y, Xia C, Zhong R, Christensen MJ, Zhang X, Nan Z. The effect of Epichloë endophyte on phyllosphere microbes and leaf metabolites in Achnatherum inebrians. iScience 2022; 25:104144. [PMID: 35402863 PMCID: PMC8991375 DOI: 10.1016/j.isci.2022.104144] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 01/09/2022] [Accepted: 03/21/2022] [Indexed: 11/21/2022] Open
Abstract
Upon exposure to the prevailing environment, leaves become increasingly colonized by fungi and bacteria located on the surface (epiphytic) or within (endophytic) the leaves. Many cool season grasses, including Achnatherum inebrians, host a seed-borne, intercellular, mutualistic Epichloë fungal endophyte, the growth of which is synchronized with the host grass. A study utilizing illumina sequencing was used to examine the epiphytic and endophytic microbial communities in Epichloë endophyte-infected and endophyte-free A. inebrians plants growing under hot dry field conditions. The presence of Epichloë endophyte increased the Shannon and decreased Simpson diversity of bacterial and fungal communities. Sphingomonas and Hymenobacter bacteria and Filobasidium and Mycosphaerella fungi were growing largely epiphytically, whereas Methylobacterium, Escherichia-Shigella, and the fungus Blumeria were mostly found within leaves with the location of colonization influenced by the Epichloë endophyte. In addition, leaf metabolites in Epichloë-infected and Epichloë-free leaves were examined using LC/MS. Epichloë was significantly correlated with 132 metabolites. Epichloë altered the composition and diversity of phyllosphere microbial communities 414 detected metabolites were annotated, of which the 132 differential metabolites There were 229 significant correlations between metabolites and microbial phyla
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Affiliation(s)
- Bowen Liu
- State Key Laboratory of Grassland Agro-ecosystems, Center for Grassland Microbiome, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, People's Republic of China
| | - Yawen Ju
- State Key Laboratory of Grassland Agro-ecosystems, Center for Grassland Microbiome, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, People's Republic of China
| | - Chao Xia
- State Key Laboratory of Grassland Agro-ecosystems, Center for Grassland Microbiome, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, People's Republic of China
| | - Rui Zhong
- State Key Laboratory of Grassland Agro-ecosystems, Center for Grassland Microbiome, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, People's Republic of China
| | | | - Xingxu Zhang
- State Key Laboratory of Grassland Agro-ecosystems, Center for Grassland Microbiome, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, People's Republic of China
| | - Zhibiao Nan
- State Key Laboratory of Grassland Agro-ecosystems, Center for Grassland Microbiome, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, People's Republic of China
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Garnica S, Liao Z, Hamard S, Waller F, Parepa M, Bossdorf O. Environmental stress determines the colonization and impact of an endophytic fungus on invasive knotweed. Biol Invasions 2022. [DOI: 10.1007/s10530-022-02749-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
AbstractThere is increasing evidence that microbes play a key role in some plant invasions. A diverse and widespread but little understood group of plant-associated microbes are the fungal root endophytes of the order Sebacinales. They are associated with exotic populations of invasive knotweed (Reynoutria ssp.) in Europe, but their effects on the invaders are unknown. We used the recently isolated Sebacinales root endophyte Serendipita herbamans to experimentally inoculate invasive knotweed and study root colonisation and effects on knotweed growth under different environmental conditions. We verified the inoculation success and fungal colonisation through immunofluorescence microscopy and qPCR. We found that S. herbamans strongly colonized invasive knotweed in low-nutrient and shade environments, but much less under drought or benign conditions. At low nutrients, the endophyte had a positive effect on plant growth, whereas the opposite was true under shaded conditions. Our study demonstrates that the root endophyte S. herbamans has the potential to colonize invasive knotweed fine roots and impact its growth, and it could thus also play a role in natural populations. Our results also show that effects of fungal endophytes on plants can be strongly environment-dependent, and may only be visible under stressful environmental conditions.
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Azevedo RP, Alves NM, Costa IA, Domingues MIS, Bandória NDA, de Figueiredo UJ, de Medeiros FHV, Silva BM, Cardoso PG. Endophytic Fungi Assures Tropical Forage Grass Growth by Water Stress Tolerances. Curr Microbiol 2021; 78:4060-4071. [PMID: 34636936 DOI: 10.1007/s00284-021-02672-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 09/27/2021] [Indexed: 11/25/2022]
Abstract
Forage plants is the base of beef and dairy cattle production. While water stress limits agricultural production worldwide, endophytic fungi can play a beneficial role for plants, such as tolerance to biotic and abiotic stresses. The objective of this work was to evaluate the effect of inoculation of the endophytic fungi Paraconiothyrium estuarinum (CML 3695, CML 3696, CML 3699) and Paraconiothyrium cyclothyrioides (CML 3697, CML 3698) on agronomic characteristics of two forage species, Brachiaria brizantha (A. Rich) Stapf. cv. Marandu and Megathyrsus maximus Jacq. cv. BRS Mombaça, under different available water capacities. The treatments simulated a long drought period (LDH) equivalent to 10% of the available water capacity (AWC) and simulated 7 (7 DH) and 14 days of drought (14 DH) without water supply. The grasses were evaluated for length and dry weight of shoots and roots. All treatments reached humidity below the permanent wilting point (PWP) and the highest variation in soil moisture was observed at 14 DH, for both grass species. The endophytic fungi promoted an average 15% increase in shoot length (SL) for B. brizantha and an increase of 34% for SL, 266% for Dry Shoot Mass (SDM), and 340% for Dry Root Mass (RDM) for M. maximus treated with P. estuarinum (CML 3699) at 7 DH. Paraconiothyrium estuarinum (CML 3699) guaranteed the highest tolerance to water deficit and sustainable growth performance to both tested grasses.
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Affiliation(s)
- Raphael Passaglia Azevedo
- Departamento de Ciência do Solo, Universidade Federal de Lavras, Lavras, Minas Gerais, 37200-900, Brazil
| | - Natálie Martins Alves
- Departamento de Biologia, Universidade Federal de Lavras, Lavras, Minas Gerais, 37200-900, Brazil
| | - Ingrid Araújo Costa
- Departamento de Biologia, Universidade Federal de Lavras, Lavras, Minas Gerais, 37200-900, Brazil
| | | | | | | | | | - Bruno Montoani Silva
- Departamento de Ciência do Solo, Universidade Federal de Lavras, Lavras, Minas Gerais, 37200-900, Brazil.
| | - Patrícia Gomes Cardoso
- Departamento de Biologia, Universidade Federal de Lavras, Lavras, Minas Gerais, 37200-900, Brazil
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Rush TA, Shrestha HK, Gopalakrishnan Meena M, Spangler MK, Ellis JC, Labbé JL, Abraham PE. Bioprospecting Trichoderma: A Systematic Roadmap to Screen Genomes and Natural Products for Biocontrol Applications. Front Fungal Biol 2021; 2:716511. [PMID: 37744103 PMCID: PMC10512312 DOI: 10.3389/ffunb.2021.716511] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Accepted: 08/10/2021] [Indexed: 09/26/2023]
Abstract
Natural products derived from microbes are crucial innovations that would help in reaching sustainability development goals worldwide while achieving bioeconomic growth. Trichoderma species are well-studied model fungal organisms used for their biocontrol properties with great potential to alleviate the use of agrochemicals in agriculture. However, identifying and characterizing effective natural products in novel species or strains as biological control products remains a meticulous process with many known challenges to be navigated. Integration of recent advancements in various "omics" technologies, next generation biodesign, machine learning, and artificial intelligence approaches could greatly advance bioprospecting goals. Herein, we propose a roadmap for assessing the potential impact of already known or newly discovered Trichoderma species for biocontrol applications. By screening publicly available Trichoderma genome sequences, we first highlight the prevalence of putative biosynthetic gene clusters and antimicrobial peptides among genomes as an initial step toward predicting which organisms could increase the diversity of natural products. Next, we discuss high-throughput methods for screening organisms to discover and characterize natural products and how these findings impact both fundamental and applied research fields.
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Affiliation(s)
- Tomás A. Rush
- Oak Ridge National Laboratory, Biosciences Division, Oak Ridge, TN, United States
| | - Him K. Shrestha
- Oak Ridge National Laboratory, Biosciences Division, Oak Ridge, TN, United States
- Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, Knoxville, TN, United States
| | | | - Margaret K. Spangler
- Oak Ridge National Laboratory, Biosciences Division, Oak Ridge, TN, United States
- Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, Knoxville, TN, United States
| | - J. Christopher Ellis
- Oak Ridge National Laboratory, Biosciences Division, Oak Ridge, TN, United States
| | - Jesse L. Labbé
- Oak Ridge National Laboratory, Biosciences Division, Oak Ridge, TN, United States
- Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, Knoxville, TN, United States
| | - Paul E. Abraham
- Oak Ridge National Laboratory, Biosciences Division, Oak Ridge, TN, United States
- Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, Knoxville, TN, United States
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Caradus JR, Johnson LJ. Epichloë Fungal Endophytes-From a Biological Curiosity in Wild Grasses to an Essential Component of Resilient High Performing Ryegrass and Fescue Pastures. J Fungi (Basel) 2020; 6:E322. [PMID: 33261217 PMCID: PMC7720123 DOI: 10.3390/jof6040322] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 11/13/2020] [Accepted: 11/18/2020] [Indexed: 12/15/2022] Open
Abstract
The relationship between Epichloë endophytes found in a wide range of temperate grasses spans the continuum from antagonistic to mutualistic. The diversity of asexual mutualistic types can be characterised by the types of alkaloids they produce in planta. Some of these are responsible for detrimental health and welfare issues of ruminants when consumed, while others protect the host plant from insect pests and pathogens. In many temperate regions they are an essential component of high producing resilient tall fescue and ryegrass swards. This obligate mutualism between fungus and host is a seed-borne technology that has resulted in several commercial products being used with high uptake rates by end-user farmers, particularly in New Zealand and to a lesser extent Australia and USA. However, this has not happened by chance. It has been reliant on multi-disciplinary research teams undertaking excellent science to understand the taxonomic relationships of these endophytes, their life cycle, symbiosis regulation at both the cellular and molecular level, and the impact of secondary metabolites, including an understanding of their mammalian toxicity and bioactivity against insects and pathogens. Additionally, agronomic trials and seed biology studies of these microbes have all contributed to the delivery of robust and efficacious products. The supply chain from science, through seed companies and retailers to the end-user farmer needs to be well resourced providing convincing information on the efficacy and ensuring effective quality control to result in a strong uptake of these Epichloë endophyte technologies in pastoral agriculture.
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Affiliation(s)
- John R. Caradus
- Grasslanz Technology Ltd., Palmerston North PB11008, New Zealand
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Wang J, Hou W, Christensen MJ, Li X, Xia C, Li C, Nan Z. Role of Epichloë Endophytes in Improving Host Grass Resistance Ability and Soil Properties. J Agric Food Chem 2020; 68:6944-6955. [PMID: 32551564 DOI: 10.1021/acs.jafc.0c01396] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The past decade has witnessed significant advances in understanding the interaction between grasses and systemic fungal endophytes of the genus Epichloë, with evidence that plants have evolved multiple strategies to cope with abiotic stresses by reprogramming physiological responses. Soil nutrients directly affect plant growth, while soil microbes are also closely connected to plant growth and health. Epichloë endophytes could affect soil fertility by modifying soil nutrient contents and soil microbial diversity. Therefore, we analyze recent advances in our understanding of the role of Epichloë endophytes under the various abiotic stresses and the role of grass-Epichloë symbiosis on soil fertility. Various cool-season grasses are infected by Epichloë species, which contribute to health, growth, persistence, and seed survival of host grasses by regulating key systems, including photosynthesis, osmotic regulation, and antioxidants and activity of key enzymes of host physiology processes under abiotic stresses. The Epichloë endophyte offers significant prospects to magnify the crop yield, plant resistance, and food safety in ecological systems by modulating soil physiochemical properties and soil microbes. The enhancing resistance of host grasses to abiotic stresses by an Epichloë endophyte is a complex manifestation of different physiological and biochemical events through regulating soil properties and soil microbes by the fungal endophyte. The Epichloë-mediated mechanisms underlying regulation of abiotic stress responses are involved in osmotic adjustment, antioxidant machinery, photosynthetic system, and activity of key enzymes critical in developing plant adaptation strategies to abiotic stress. Therefore, the Epichloë endophytes are an attractive choice in increasing resistance of plants to abiotic stresses and are also a good candidate for improving soil fertility and regulating microbial diversity to improve plant growth.
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Affiliation(s)
- Jianfeng Wang
- State Key Laboratory of Grassland Agro-Ecosystems, Center for Grassland Microbiome, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, Engineering Research Center of Grassland Industry, Ministry of Education, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou Gansu 730000, People's Republic of China
| | - Wenpeng Hou
- State Key Laboratory of Grassland Agro-Ecosystems, Center for Grassland Microbiome, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, Engineering Research Center of Grassland Industry, Ministry of Education, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou Gansu 730000, People's Republic of China
| | - Michael J Christensen
- Grasslands Research Centre, AgResearch, Private Bag 11-008, Palmerston North 4442, New Zealand
| | - Xiuzhang Li
- State Key Laboratory of Grassland Agro-Ecosystems, Center for Grassland Microbiome, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, Engineering Research Center of Grassland Industry, Ministry of Education, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou Gansu 730000, People's Republic of China
- State Key Laboratory of Plateau Ecology and Agriculture, Qinghai Academy of Animal and Veterinary Sciences, Qinghai University, Xining, Qinghai 810016, People's Republic of China
| | - Chao Xia
- State Key Laboratory of Grassland Agro-Ecosystems, Center for Grassland Microbiome, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, Engineering Research Center of Grassland Industry, Ministry of Education, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou Gansu 730000, People's Republic of China
| | - Chunjie Li
- State Key Laboratory of Grassland Agro-Ecosystems, Center for Grassland Microbiome, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, Engineering Research Center of Grassland Industry, Ministry of Education, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou Gansu 730000, People's Republic of China
| | - Zhibiao Nan
- State Key Laboratory of Grassland Agro-Ecosystems, Center for Grassland Microbiome, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, Engineering Research Center of Grassland Industry, Ministry of Education, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou Gansu 730000, People's Republic of China
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Bao G, Song M, Wang Y, Saikkonen K, Wang H. Interactive effects of Epichloë fungal and host origins on the seed germination of Achnatherum inebrians. Symbiosis 2019. [DOI: 10.1007/s13199-019-00636-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Shymanovich T, Faeth SH. Environmental factors affect the distribution of two Epichloë fungal endophyte species inhabiting a common host grove bluegrass ( Poa alsodes). Ecol Evol 2019; 9:6624-6642. [PMID: 31236248 PMCID: PMC6580270 DOI: 10.1002/ece3.5241] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 04/17/2019] [Accepted: 04/18/2019] [Indexed: 01/24/2023] Open
Abstract
AIM The endophyte Epichloë alsodes, with known insecticidal properties, is found in a majority of Poa alsodes populations across a latitudinal gradient from North Carolina to New York. A second endophyte, E. schardlii var. pennsylvanica, with known insect-deterring effects, is limited to a few populations in Pennsylvania. We explored whether such disparate differences in distributions could be explained by selection from biotic and abiotic environmental factors. LOCATION Along the Appalachian Mountains from North Carolina to New York, USA. TAXON Fungi. METHODS Studied correlations of infection frequencies with abiotic and biotic environmental factors. Checked endophyte vertical transmission rates and effects on overwintering survival. With artificial inoculations for two host populations with two isolates per endophyte species, tested endophyte-host compatibility. Studied effects of isolates on host performances in greenhouse experiment with four water-nutrients treatments. RESULTS Correlation analysis revealed positive associations of E. alsodes frequency with July Max temperatures, July precipitation, and soil nitrogen and phosphorous and negative associations with insect damage and soil magnesium and potassium. Plants infected with E. alsodes had increased overwintering survival compared to plants infected with E. schardlii or uninfected (E-) plants. Artificial inoculations indicated that E. alsodes had better compatibility with a variety of host genotypes than did E. schardlii. The experiment with reciprocally inoculated plants grown under different treatments revealed a complexity of interactions among hosts, endophyte species, isolate within species, host plant origin, and environmental factors. Neither of the endophyte species increased plant biomass, but some of the isolates within each species had other effects on plant growth such as increased root:shoot ratio, number of tillers, and changes in plant height that might affect host fitness. MAIN CONCLUSION In the absence of clear and consistent effects of the endophytes on host growth, the differences in endophyte-mediated protection against herbivores may be the key factor determining distribution differences of the two endophyte species.
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Affiliation(s)
- Tatsiana Shymanovich
- Biology DepartmentUniversity of North Carolina at GreensboroGreensboroNorth Carolina
| | - Stanley H. Faeth
- Biology DepartmentUniversity of North Carolina at GreensboroGreensboroNorth Carolina
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Gibert A, Tozer W, Westoby M. Plant performance response to eight different types of symbiosis. New Phytol 2019; 222:526-542. [PMID: 30697746 DOI: 10.1111/nph.15392] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Accepted: 07/07/2018] [Indexed: 06/09/2023]
Abstract
Almost all plant species interact with one or more symbioses somewhere within their distribution range. Bringing together plant trait data and growth responses to symbioses spanning 552 plant species, we provide for the first time on a large scale (597 studies) a quantitative synthesis on plant performance differences between eight major types of symbiosis, including mycorrhizas, N-fixing bacteria, fungal endophytes and ant-plant interactions. Frequency distributions of plant growth responses varied considerably between different types of symbiosis, in terms of both mean effect and 'risk', defined here as percentage of experiments reporting a negative effect of symbiosis on plants. Contrary to expectation, plant traits were poor predictors of growth response across and within all eight symbiotic associations. Our analysis showed no systematic additive effect when a host plant engaged in two functionally different symbioses. This synthesis suggests that plant species' ecological strategies have little effect in determining the influence of a symbiosis on host plant growth. Reliable quantification of differences in plant performance across symbioses will prove valuable for developing general hypotheses on how species become engaged in mutualisms without a guarantee of net returns.
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Affiliation(s)
- Anais Gibert
- Department of Biological Sciences, Macquarie University, Sydney, NSW, 2109, Australia
| | - Wade Tozer
- Department of Biological Sciences, Macquarie University, Sydney, NSW, 2109, Australia
| | - Mark Westoby
- Department of Biological Sciences, Macquarie University, Sydney, NSW, 2109, Australia
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11
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Jia T, Wang RH, Chai BF. Various Phyllosphere and Soil Bacterial Communities of Natural Grasses and the Impact Factors in a Copper Tailings Dam. Curr Microbiol 2018; 76:7-14. [PMID: 30310969 DOI: 10.1007/s00284-018-1575-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 09/26/2018] [Indexed: 10/28/2022]
Abstract
Copper mining caused severe damage to the ecological environment of mining areas. The combination of microbe and plant remediation has an application potential in improving the absorption and transformation efficiency of heavy metals. The phyllosphere is the largest biointerface on the planet, and bacteria are the dominant microbial inhabitants of the phyllosphere, believed to be critical to plant growth and health. This study investigated the phyllospheric and soil bacteria communities using high-throughput sequencing, and endophyte infection statuses of four natural grasses by toluidine blue heparin assay. Results showed variation in phyllospheric bacterial community structure. Gammaproteobacteria were the most abundant bacterial population. Bacilli were found in the phyllosphere of Bothriochloa ischaemum and Imperata cylindrica, while Clostridia were only found in Calamagrostis epigejos. Alphaproteobacteria were the dominant bacteria in soil. In addition, bacterial communities were influenced by endophytic infection statuses. Oxalobacteraceae was associated with soil carbon and sulfur. Enterobacteriaceae had negative correlation with the ratio of soil carbon and nitrogen, and had positive correlation with Cd content. These results offer useful insights into phyllospheric bacterial community variance in four different natural grasses in a copper tailings dam.
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Affiliation(s)
- Tong Jia
- Institute of Loess Plateau, Shanxi University, Taiyuan, 030006, Shanxi, China.
| | - Rui-Hong Wang
- Institute of Loess Plateau, Shanxi University, Taiyuan, 030006, Shanxi, China
| | - Bao-Feng Chai
- Institute of Loess Plateau, Shanxi University, Taiyuan, 030006, Shanxi, China
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Bu Y, Guo P, Ji Y, Zhang S, Yu H, Wang Z. Effects of Epichloë sinica on Roegneria kamoji seedling physiology under PEG-6000 simulated drought stress. Symbiosis 2019; 77:123-32. [DOI: 10.1007/s13199-018-0570-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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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. Microb Ecol 2018; 75:407-418. [PMID: 28840330 DOI: 10.1007/s00248-017-1054-3] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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Wang J, Zhou Y, Lin W, Li M, Wang M, Wang Z, Kuang Y, Tian P. Effect of an Epichloë endophyte on adaptability to water stress in Festuca sinensis. FUNGAL ECOL 2017. [DOI: 10.1016/j.funeco.2017.08.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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16
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Faeth SH, Oberhofer M, Saari S, Haskins KE, Shymanovich T. Does hybridization of endophytic symbionts in a native grass increase fitness in resource-limited environments? Ecology 2017; 98:138-149. [PMID: 28052394 DOI: 10.1002/ecy.1626] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Revised: 10/03/2016] [Accepted: 10/13/2016] [Indexed: 11/10/2022]
Abstract
Hybridization is common among plants, animals and microbes. However, the ecological consequences of hybridization for microbes are far less understood than for plants and animals. For symbiotic Epichloë fungi, hybridization is widespread and may augment the well-known benefits of the endophytes to their grass hosts, especially in stressful environments. We tested the hybrid fitness hypothesis (HFH) that hybrid endophytes enhance fitness in stressful environments relative to non-hybrid endophytes. In a long-term field experiment, we monitored growth and reproduction of hybrid-infected (H+), non-hybrid infected (NH+), naturally endophyte free (E-) plants and those plants from which the endophyte had been experimentally removed (H- and NH-) in resource-rich and resource-poor environments. Infection by both endophyte species enhanced growth and reproduction. H+ plants outperformed NH+ plants in terms of growth by the end of the experiment, supporting HFH. However, H+ plants only outperformed NH+ plants in the resource-rich treatment, contrary to HFH. Plant genotypes associated with each endophyte species had strong effects on growth and reproduction. Our results provide some support the HFH hypothesis but not based upon adaptation to stressful environments. Our results reinforce the notion of a complex interplay between endophyte and plant genotype and environmental factors that determine fitness of the symbiotum.
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Affiliation(s)
- Stanley H Faeth
- Department of Biology, University of North Carolina at Greensboro, Greensboro, North Carolina, 27402, USA
| | - Martina Oberhofer
- Department of Pharmacognosy, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria
| | - Susanna Saari
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg C, Denmark
| | - Kristin E Haskins
- Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona, 86011, USA
| | - Tatsiana Shymanovich
- Department of Biology, University of North Carolina at Greensboro, Greensboro, North Carolina, 27402, USA
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Bell‐Dereske L, Gao X, Masiello CA, Sinsabaugh RL, Emery SM, Rudgers JA. Plant–fungal symbiosis affects litter decomposition during primary succession. OIKOS 2016. [DOI: 10.1111/oik.03648] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Lukas Bell‐Dereske
- Dept of Biology, MSC03‐2020 Univ. of New Mexico Albuquerque NM 87131‐0001 USA
| | - Xiaodong Gao
- Dept of Earth Science Rice Univ. Houston TX 77005 USA
| | | | | | - Sarah M. Emery
- Dept of Biology Univ. of Louisville Louisville KY 40292 USA
| | - Jennifer A. Rudgers
- Dept of Biology, MSC03‐2020 Univ. of New Mexico Albuquerque NM 87131‐0001 USA
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18
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Xia C, Li N, Zhang X, Feng Y, Christensen MJ, Nan Z. An Epichloë endophyte improves photosynthetic ability and dry matter production of its host Achnatherum inebrians infected by Blumeria graminis under various soil water conditions. FUNGAL ECOL 2016. [DOI: 10.1016/j.funeco.2016.04.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Jia T, Oberhofer M, Shymanovich T, Faeth SH. Effects of Hybrid and Non-hybrid Epichloë Endophytes and Their Associated Host Genotypes on the Response of a Native Grass to Varying Environments. Microb Ecol 2016; 72:185-196. [PMID: 26909796 DOI: 10.1007/s00248-016-0743-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2015] [Accepted: 02/15/2016] [Indexed: 06/05/2023]
Abstract
Asexual Epichloë endophytes are prevalent in cool season grasses, and many are of hybrid origin. Hybridization of asexual endophytes is thought to provide a rapid influx of genetic variation that may be adaptive to endophyte-host grass symbiota in stressful environments. For Arizona fescue (Festuca arizonica), hybrid symbiota are commonly found in resource-poor environments, whereas non-hybrid symbiota are more common in resource-rich environments. There have been very few experimental tests where infection, hybrid and non-hybrid status, and plant genotype have been controlled to tease apart their effects on host phenotype and fitness in different environments. We conducted a greenhouse experiment where hybrid (H) and non-hybrid (NH) endophytes were inoculated into plant genotypes that were originally uninfected (E-) or once infected with either the H or NH endophytes. Nine endophyte and plant genotypic group combinations were grown under low and high water and nutrient treatments. Inoculation with the resident H endophyte enhanced growth and altered allocation to roots and shoots, but these effects were greatest in resource-rich environments, contrary to expectations. We found no evidence of co-adaptation between endophyte species and their associated host genotypes. However, naturally E- plants performed better when inoculated with the hybrid endophyte, suggesting these plants were derived from H infected lineages. Our results show complex interactions between endophyte species of hybrid and non-hybrid origin with their host plant genotypes and environmental factors.
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Affiliation(s)
- Tong Jia
- Institute of Loess Plateau, Shanxi University, Taiyuan, 030006, China.
| | - Martina Oberhofer
- Department of Biology, University of North Carolina Greensboro, 321 McIver Street, Greensboro, NC, 27412, USA
| | - Tatsiana Shymanovich
- Department of Biology, University of North Carolina Greensboro, 321 McIver Street, Greensboro, NC, 27412, USA
| | - Stanley H Faeth
- Department of Biology, University of North Carolina Greensboro, 321 McIver Street, Greensboro, NC, 27412, USA
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Saikkonen K, Young CA, Helander M, Schardl CL. Endophytic Epichloë species and their grass hosts: from evolution to applications. Plant Mol Biol 2016; 90:665-75. [PMID: 26542393 PMCID: PMC4819788 DOI: 10.1007/s11103-015-0399-6] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 10/26/2015] [Indexed: 05/21/2023]
Abstract
The closely linked fitness of the Epichloë symbiont and the host grass is presumed to align the coevolution of the species towards specialization and mutually beneficial cooperation. Ecological observations demonstrating that Epichloë-grass symbioses can modulate grassland ecosystems via both above- and belowground ecosystem processes support this. In many cases the detected ecological importance of Epichloë species is directly or indirectly linked to defensive mutualism attributable to alkaloids of fungal-origin. Now, modern genetic and molecular techniques enable the precise studies on evolutionary origin of endophytic Epichloë species, their coevolution with host grasses and identification the genetic variation that explains phenotypic diversity in ecologically relevant characteristics of Epichloë-grass associations. Here we briefly review the most recent findings in these areas of research using the present knowledge of the genetic variation that explains the biosynthetic pathways driving the diversity of alkaloids produced by the endophyte. These findings underscore the importance of genetic interplay between the fungus and the host in shaping their coevolution and ecological role in both natural grass ecosystems, and in the agricultural arena.
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Affiliation(s)
- Kari Saikkonen
- Management and Production of Renewable Resources, Natural Resources Institute Finland (Luke), Itäinen Pitkäkatu 3, 20520, Turku, Finland.
| | - Carolyn A Young
- The Samuel Roberts Noble Foundation, Ardmore, OK, 73401, USA
| | - Marjo Helander
- Management and Production of Renewable Resources, Natural Resources Institute Finland (Luke), Itäinen Pitkäkatu 3, 20520, Turku, Finland
- Section of Ecology, Department of Biology, University of Turku, 20014, Turku, Finland
| | - Christopher L Schardl
- Department of Plant Pathology, University of Kentucky, Lexington, KY, 40546-0312, USA
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Abstract
Hybridization in fungi has recently been recognized as a major force in the generation of new fungal plant pathogens. These include the grass pathogen Zymoseptoria pseudotritici and the powdery mildew pathogen Blumeria graminis triticale of triticale. Hybridization also plays an important role in the transfer of genetic material between species. This process is termed introgressive hybridization and involves extensive backcrossing between hybrid and the parental species. Introgressive hybridization has contributed substantially to the successful spread of plant pathogens such as Ophiostoma ulmi and O. novo-ulmi, the causal agents of Dutch elm disease, and other tree pathogens such as the rust pathogen Melampsora. Hybridization occurs more readily between species that have previously not coexisted, so-called allopatric species. Reproductive barriers between allopatric species are likely to be more permissive allowing interspecific mating to occur. The bringing together of allopatric species of plant pathogens by global agricultural trade consequently increases the potential for hybridization between pathogen species. In light of global environmental changes, agricultural development, and the facilitated long-distance spread of fungal plant pathogens, hybridization should be considered an important mechanism whereby new pathogens may emerge. Recent studies have gained insight into the genetics and biology of fungal hybrids. Here I summarize current knowledge about hybrid speciation and introgressive hybridization. I propose that future studies will benefit greatly from the availability of large genome data sets and that genome data provide a powerful resource in combination with experimental approaches for analyses of hybrid species.
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Affiliation(s)
- Eva H Stukenbrock
- Environmental Genomics, Christian-Albrechts University of Kiel, Am Botanischen Garten 9-11, 24118 Kiel, Germany and Max Planck Institute for Evolutionary Biology, August-Thienemann-Str. 2, 24306 Plön, Germany
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22
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Hume DE, Ryan GD, Gibert A, Helander M, Mirlohi A, Sabzalian MR. Epichloë Fungal Endophytes for Grassland Ecosystems. Sustainable Agriculture Reviews 2016. [DOI: 10.1007/978-3-319-26777-7_6] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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23
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Lledó S, Rodrigo S, Poblaciones MJ, Santamaria O. Biomass yield, mineral content, and nutritive value of Poa pratensis as affected by non-clavicipitaceous fungal endophytes. Mycol Prog 2015; 14. [DOI: 10.1007/s11557-015-1093-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Xia C, Zhang X, Christensen MJ, Nan Z, Li C. Epichloë endophyte affects the ability of powdery mildew (Blumeria graminis) to colonise drunken horse grass (Achnatherum inebrians). FUNGAL ECOL 2015. [DOI: 10.1016/j.funeco.2015.02.003] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Shymanovich T, Saari S, Lovin ME, Jarmusch AK, Jarmusch SA, Musso AM, Charlton ND, Young CA, Cech NB, Faeth SH. Alkaloid variation among epichloid endophytes of sleepygrass (Achnatherum robustum) and consequences for resistance to insect herbivores. J Chem Ecol 2014; 41:93-104. [PMID: 25501262 DOI: 10.1007/s10886-014-0534-x] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2014] [Revised: 08/30/2014] [Accepted: 12/02/2014] [Indexed: 10/24/2022]
Abstract
Epichloid endophytes are well known symbionts of many cool-season grasses that may alleviate environmental stresses for their hosts. For example, endophytes produce alkaloid compounds that may be toxic to invertebrate or vertebrate herbivores. Achnatherum robustum, commonly called sleepygrass, was aptly named due to the presence of an endophyte that causes toxic effects to livestock and wildlife. Variation in alkaloid production observed in two A. robustum populations located near Weed and Cloudcroft in the Lincoln National Forest, New Mexico, suggests two different endophyte species are present in these populations. Genetic analyses of endophyte-infected samples revealed major differences in the endophyte alkaloid genetic profiles from the two populations, which were supported with chemical analyses. The endophyte present in the Weed population was shown to produce chanoclavine I, paspaline, and terpendoles, so thus resembles the previously described Epichloë funkii. The endophyte present in the Cloudcroft population produces chanoclavineI, ergonovine, lysergic acid amide, and paspaline, and is an undescribed endophyte species. We observed very low survival rates for aphids feeding on plants infected with the Cloudcroft endophyte, while aphid survival was better on endophyte infected plants in the Weed population. This observation led to the hypothesis that the alkaloid ergonovine is responsible for aphid mortality. Direct testing of aphid survival on oat leaves supplemented with ergonovine provided supporting evidence for this hypothesis. The results of this study suggest that alkaloids produced by the Cloudcroft endophyte, specifically ergonovine, have insecticidal properties.
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Affiliation(s)
- Tatsiana Shymanovich
- Department of Biology, University of North Carolina Greensboro, 312 Eberhart Bldg., Greensboro, NC, 27412, USA,
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Oberhofer M, Leuchtmann A. Horizontal transmission, persistence and competition capabilities of Epichloë endophytes in Hordelymus europaeus grass hosts using dual endophyte inocula. FUNGAL ECOL 2014; 11:37-49. [DOI: 10.1016/j.funeco.2014.04.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Charlton ND, Craven KD, Afkhami ME, Hall BA, Ghimire SR, Young CA. Interspecific hybridization and bioactive alkaloid variation increases diversity in endophytic Epichloë species of Bromus laevipes. FEMS Microbiol Ecol 2014; 90:276-89. [PMID: 25065688 DOI: 10.1111/1574-6941.12393] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Revised: 05/27/2014] [Accepted: 07/18/2014] [Indexed: 11/29/2022] Open
Abstract
Studying geographic variation of microbial mutualists, especially variation in traits related to benefits they provide their host, is critical for understanding how these associations impact key ecological processes. In this study, we investigate the phylogenetic population structure of Epichloë species within Bromus laevipes, a native cool-season bunchgrass found predominantly in California. Phylogenetic classification supported inference of three distinct Epichloë taxa, of which one was nonhybrid and two were interspecific hybrids. Inheritance of mating-type idiomorphs revealed that at least one of the hybrid species arose from independent hybridization events. We further investigated the geographic variation of endophyte-encoded alkaloid genes, which is often associated with key benefits of natural enemy protection for the host. Marker diversity at the ergot alkaloid, loline, indole-diterpene, and peramine loci revealed four alkaloid genotypes across the three identified Epichloë species. Predicted chemotypes were tested using endophyte-infected plant material that represented each endophyte genotype, and 11 of the 13 predicted alkaloids were confirmed. This multifaceted approach combining phylogenetic, genotypic, and chemotypic analyses allowed us to reconstruct the diverse evolutionary histories of Epichloë species present within B. laevipes and highlight the complex and dynamic processes underlying these grass-endophyte symbioses.
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Affiliation(s)
- Nikki D Charlton
- Forage Improvement Division, The Samuel Roberts Noble Foundation, Ardmore, OK, USA
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28
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Yang T, Ma S, Dai CC. Drought degree constrains the beneficial effects of a fungal endophyte on Atractylodes lancea. J Appl Microbiol 2014; 117:1435-49. [PMID: 25080260 DOI: 10.1111/jam.12615] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Revised: 07/22/2014] [Accepted: 07/28/2014] [Indexed: 01/11/2023]
Abstract
AIMS Plants, fungal endophytes (FEs) and the changing environment interact with each other forming an interlaced network. This study evaluates nonadditive and interactive effects of the FE Acremonium strictum and drought treatment on Atractylodes lancea plantlets. METHODS AND RESULTS By applying FEs (meristem cultures of At. lancea, fungal inoculation of Ac. strictum and plantlet acclimatization) and drought treatment (regular watering, mild drought, severe drought), a research system of At. lancea ramets under different treatments was established. During 12 days of drought treatment, the plantlets' physiological responses and basic growth traits were measured and analysed. Although drought and FE presence affected plantlet traits to differing degrees, the interactive effects of the two were more pronounced. In particular under mild drought treatment, the FE conferred drought tolerance to plantlets by enhancing leaf soluble sugars, proteins, proline and antioxidant enzyme activity; decreasing the degree of plasmalemma oxidation; and increasing the host's abscisic acid level and root:shoot ratio. When exposed to regular watering or severe drought, these effects were not significant. CONCLUSIONS Plant traits plasticity was conferred by dual effects of drought stress and FEs, and these factors are interactive. Although FEs can help plants cope with drought stress, the beneficial effects are strictly constrained by drought degree. SIGNIFICANCE AND IMPACT OF THE STUDY During finite environmental stress, FEs can benefit plants, and for this reason, they may alleviate the effects of climate change on plants. However, because the benefits of FEs are highly context dependent, the role of FEs in a changing background should be re-assessed.
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Affiliation(s)
- T Yang
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Sciences, Nanjing Normal University, Nanjing, China; State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China; University of Chinese Academy of Sciences, Beijing, China
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Card SD, Faville MJ, Simpson WR, Johnson RD, Voisey CR, de Bonth ACM, Hume DE. Mutualistic fungal endophytes in the Triticeae - survey and description. FEMS Microbiol Ecol 2014; 88:94-106. [PMID: 24754753 DOI: 10.1111/1574-6941.12273] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2013] [Revised: 12/09/2013] [Accepted: 12/14/2013] [Indexed: 11/29/2022] Open
Abstract
Grasses of the tribe Triticeae were screened to determine the presence of mutualistic epichloae fungal endophytes. Over 1500 accessions, from more than 250 species, encompassing 22 genera within the Triticeae were screened using immunodetection and direct staining/microscopy techniques. Only two genera, Elymus and Hordeum, were identified as harbouring epichloae endophytes with accessions native to a range of countries including Canada, China, Iran, Kazakhstan, Kyrgyzstan, Mongolia, Russia and the USA. Genetic analysis based on simple sequence repeat data revealed that the majority of endophytes cluster according to geographical regions rather than to host species; many strains isolated from Hordeum grouped with those derived from Elymus, and amongst the Elymus-derived strains, there was no clear correspondence between clustering topology and host species. This is the first detailed survey demonstrating the genetic diversity of epichloae endophytes within the Triticeae and highlights the importance of germplasm centres for not only preserving the genetic diversity of plant species but also the beneficial microorganisms they may contain.
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Affiliation(s)
- Stuart D Card
- AgResearch Ltd, Grasslands Research Centre, Palmerston North, New Zealand
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