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Zhai Y, Chen Z, Malik K, Wei X, Li C, Chen T. Regulation of mineral elements in Hordeum brevisubulatum by Epichloë bromicola under Cd stress. INTERNATIONAL JOURNAL OF PHYTOREMEDIATION 2024; 26:1253-1268. [PMID: 38305734 DOI: 10.1080/15226514.2024.2307901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2024]
Abstract
In this study, wild barley (Hordeum brevisubulatum) infected (E+) and uninfected (E-) by Epichloë bromicola were used for hydroponic experiments during the seedling stage. Various attributes, such as the effect of fungal endophyte on the growth and development of wild barley, the absorption of cadmium (Cd) and mineral elements (Ca, Mg, Fe, Mn, Cu, Zn), subcellular distribution, and chemical forms were investigated under CdCl2 stress. The results showed that the fungal endophy significantly reduced the Ca content and percentage of plant roots under Cd stress. The Fe and Mn content of roots, the mineral element content of soluble fractions, and the stems in the pectin acid or protein-chelated state increased significantly in response to fungal endophy. Epichloë endophyte helped Cd2+ to enter into plants; and reduced the positive correlation of Ca-Fe and Ca-Mn in roots. In addition, it also decreased the correlation of soluble components Cd-Cu, Cd-Ca, Cd-Mg in roots, and the negative correlation between pectin acid or protein-chelated Cd in stems and mineral elements, to increase the absorbance of host for mineral elements. In conclusion, fungal endophy regulated the concentration and distribution of mineral elements, while storing more Cd2+ to resist the damage caused by Cd stress. The study could provide a ground for revealing the Cd tolerance mechanism of endophytic fungal symbionts.
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Affiliation(s)
- Yurun Zhai
- 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 Centre of Western China Grassland Industry, Center for Grassland Microbiome, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, China
| | - Zhenjiang Chen
- 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 Centre of Western China Grassland Industry, Center for Grassland Microbiome, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, China
| | - Kamran Malik
- 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 Centre of Western China Grassland Industry, Center for Grassland Microbiome, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, China
| | - Xuekai Wei
- 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 Centre of Western China Grassland Industry, Center for Grassland Microbiome, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, China
| | - Chunjie Li
- 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 Centre of Western China Grassland Industry, Center for Grassland Microbiome, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, China
| | - Taixiang Chen
- 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 Centre of Western China Grassland Industry, Center for Grassland Microbiome, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, China
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Rothchild KW, Hagar M, Berry D, Ryan KS. Two Iron(II), α-Ketoglutarate-Dependent Enzymes Encoded by the PPZ Gene Cluster of Metarhizium majus Enable Production of 8-Hydroxyperamine. J Am Chem Soc 2024; 146:10263-10267. [PMID: 38578094 DOI: 10.1021/jacs.4c01419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/06/2024]
Abstract
Entomopathogenic fungus Metarhizium majus contains the nine-gene PPZ cluster, with ppzA, encoding a peramine-producing nonribosomal peptide synthetase, as the central component. In this work, the roles of two α-ketoglutarate, iron-dependent oxygenases encoded by the PPZ genes ppzC and ppzD were elucidated. PpzD was found to produce both trans-4-hydroxy-l-proline and trans-3-hydroxy-l-proline in a 13.1:1 ratio, yielding a key precursor for peramine biosynthesis. PpzC was found to act directly on peramine, yielding the novel analogue 8-hydroxyperamine.
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Affiliation(s)
- Kristina W Rothchild
- Department of Chemistry, The University of British Columbia, Vancouver, BC V6T 1Z1, Canada
| | - Mostafa Hagar
- Department of Chemistry, The University of British Columbia, Vancouver, BC V6T 1Z1, Canada
| | - Daniel Berry
- Ferrier Research Institute, Victoria University of Wellington, Wellington, 6012, New Zealand
| | - Katherine S Ryan
- Department of Chemistry, The University of British Columbia, Vancouver, BC V6T 1Z1, Canada
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Yadav U, Anand V, Kumar S, Srivastava S, Mishra SK, Chauhan PS, Singh PC. Endophytic biofungicide Bacillus subtilis (NBRI-W9) reshapes the metabolic homeostasis disrupted by the chemical fungicide, propiconazole in tomato plants to provide sustainable immunity against non-target bacterial pathogens. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 343:123144. [PMID: 38123116 DOI: 10.1016/j.envpol.2023.123144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 11/05/2023] [Accepted: 12/10/2023] [Indexed: 12/23/2023]
Abstract
Chemical and microbial fungicides (Bio/fungicide) act differentially on plant systems. The present work assessed the metabolic profile of tomato plants vis-a-vis endophytic diversity after spraying of Propiconazole (PCZ) and endophytic biofungicide Bacillus subtilis (W9). Bio/fungicides were sprayed on tomato plants and evaluated for phenotypic, biochemical, and metabolic profiles after one week. In W9 treatment, a significant increase in relative abundance of several metabolites was observed including sugars, sugar alcohols, fatty-acids, organic-acids, and amino-acids. Polysaccharides and fatty acids showed a significant positive correlation with Rhizobiales, Burkholderiales, Bacillales, and Lactobacillales, respectively (p < 0.05). The PCZ and W9 treated plant's metabolic status significantly affected their resistance to non-target, bacterial pathogen P. syringae. Compared to PCZ and control, W9 treatment reduced the ROS deposition and expression of antioxidants gene GPx, PO (~0.1-1.7fold). It enhanced the genes related to the Phenylpropanoid pathway (∼1.6-5.2 fold), PR protein (~1.2-3.4 fold), and JA biosynthesis (~1.7-4.3 fold), resulting in reduced disease incidence. The results provide novel insights into the effects of endophytic biofungicide and chemical fungicides on the plant's metabolic status, its relation to the endophytes, and role in altering the plant's immune system.
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Affiliation(s)
- Udit Yadav
- Microbial Technology Division, CSIR-National Botanical Research Institute, Rana Pratap Marg, Lucknow, 226 001, India; Academy of Scientific and Innovative Research (AcSIR) CSIR-HRDC, Kamla Nehru Nagar, Ghaziabad, Uttar Pradesh, 201 002, India
| | - Vandana Anand
- Microbial Technology Division, CSIR-National Botanical Research Institute, Rana Pratap Marg, Lucknow, 226 001, India; Academy of Scientific and Innovative Research (AcSIR) CSIR-HRDC, Kamla Nehru Nagar, Ghaziabad, Uttar Pradesh, 201 002, India
| | - Sanjeev Kumar
- Microbial Technology Division, CSIR-National Botanical Research Institute, Rana Pratap Marg, Lucknow, 226 001, India; Academy of Scientific and Innovative Research (AcSIR) CSIR-HRDC, Kamla Nehru Nagar, Ghaziabad, Uttar Pradesh, 201 002, India
| | - Suchi Srivastava
- Microbial Technology Division, CSIR-National Botanical Research Institute, Rana Pratap Marg, Lucknow, 226 001, India; Academy of Scientific and Innovative Research (AcSIR) CSIR-HRDC, Kamla Nehru Nagar, Ghaziabad, Uttar Pradesh, 201 002, India
| | - Shashank K Mishra
- Microbial Technology Division, CSIR-National Botanical Research Institute, Rana Pratap Marg, Lucknow, 226 001, India
| | - Puneet Singh Chauhan
- Microbial Technology Division, CSIR-National Botanical Research Institute, Rana Pratap Marg, Lucknow, 226 001, India; Academy of Scientific and Innovative Research (AcSIR) CSIR-HRDC, Kamla Nehru Nagar, Ghaziabad, Uttar Pradesh, 201 002, India
| | - Poonam C Singh
- Microbial Technology Division, CSIR-National Botanical Research Institute, Rana Pratap Marg, Lucknow, 226 001, India; Academy of Scientific and Innovative Research (AcSIR) CSIR-HRDC, Kamla Nehru Nagar, Ghaziabad, Uttar Pradesh, 201 002, India.
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Pandey P, Tripathi A, Dwivedi S, Lal K, Jhang T. Deciphering the mechanisms, hormonal signaling, and potential applications of endophytic microbes to mediate stress tolerance in medicinal plants. FRONTIERS IN PLANT SCIENCE 2023; 14:1250020. [PMID: 38034581 PMCID: PMC10684941 DOI: 10.3389/fpls.2023.1250020] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 10/30/2023] [Indexed: 12/02/2023]
Abstract
The global healthcare market in the post-pandemic era emphasizes a constant pursuit of therapeutic, adaptogenic, and immune booster drugs. Medicinal plants are the only natural resource to meet this by supplying an array of bioactive secondary metabolites in an economic, greener and sustainable manner. Driven by the thrust in demand for natural immunity imparting nutraceutical and life-saving plant-derived drugs, the acreage for commercial cultivation of medicinal plants has dramatically increased in recent years. Limited resources of land and water, low productivity, poor soil fertility coupled with climate change, and biotic (bacteria, fungi, insects, viruses, nematodes) and abiotic (temperature, drought, salinity, waterlogging, and metal toxicity) stress necessitate medicinal plant productivity enhancement through sustainable strategies. Plants evolved intricate physiological (membrane integrity, organelle structural changes, osmotic adjustments, cell and tissue survival, reclamation, increased root-shoot ratio, antibiosis, hypersensitivity, etc.), biochemical (phytohormones synthesis, proline, protein levels, antioxidant enzymes accumulation, ion exclusion, generation of heat-shock proteins, synthesis of allelochemicals. etc.), and cellular (sensing of stress signals, signaling pathways, modulating expression of stress-responsive genes and proteins, etc.) mechanisms to combat stresses. Endophytes, colonizing in different plant tissues, synthesize novel bioactive compounds that medicinal plants can harness to mitigate environmental cues, thus making the agroecosystems self-sufficient toward green and sustainable approaches. Medicinal plants with a host set of metabolites and endophytes with another set of secondary metabolites interact in a highly complex manner involving adaptive mechanisms, including appropriate cellular responses triggered by stimuli received from the sensors situated on the cytoplasm and transmitting signals to the transcriptional machinery in the nucleus to withstand a stressful environment effectively. Signaling pathways serve as a crucial nexus for sensing stress and establishing plants' proper molecular and cellular responses. However, the underlying mechanisms and critical signaling pathways triggered by endophytic microbes are meager. This review comprehends the diversity of endophytes in medicinal plants and endophyte-mediated plant-microbe interactions for biotic and abiotic stress tolerance in medicinal plants by understanding complex adaptive physiological mechanisms and signaling cascades involving defined molecular and cellular responses. Leveraging this knowledge, researchers can design specific microbial formulations that optimize plant health, increase nutrient uptake, boost crop yields, and support a resilient, sustainable agricultural system.
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Affiliation(s)
- Praveen Pandey
- Microbial Technology Department, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow, India
- Division of Plant Breeding and Genetic Resource Conservation, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow, India
| | - Arpita Tripathi
- Microbial Technology Department, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow, India
- Faculty of Education, Teerthanker Mahaveer University, Moradabad, India
| | - Shweta Dwivedi
- Division of Plant Breeding and Genetic Resource Conservation, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Kanhaiya Lal
- Division of Plant Breeding and Genetic Resource Conservation, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Tripta Jhang
- Division of Plant Breeding and Genetic Resource Conservation, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow, India
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Bilous S, Likhanov A, Boroday V, Marchuk Y, Zelena L, Subin O, Bilous A. Antifungal Activity and Effect of Plant-Associated Bacteria on Phenolic Synthesis of Quercus robur L. PLANTS (BASEL, SWITZERLAND) 2023; 12:1352. [PMID: 36987039 PMCID: PMC10059881 DOI: 10.3390/plants12061352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 03/09/2023] [Accepted: 03/10/2023] [Indexed: 06/19/2023]
Abstract
Europe's forests, particularly in Ukraine, are highly vulnerable to climate change. The maintenance and improvement of forest health are high-priority issues, and various stakeholders have shown an interest in understanding and utilizing ecological interactions between trees and their associated microorganisms. Endophyte microbes can influence the health of trees either by directly interacting with the damaging agents or modulating host responses to infection. In the framework of this work, ten morphotypes of endophytic bacteria from the tissues of unripe acorns of Quercus robur L. were isolated. Based on the results of the sequenced 16S rRNA genes, four species of endophytic bacteria were identified: Bacillus amyloliquefaciens, Bacillus subtilis, Delftia acidovorans, and Lelliottia amnigena. Determining the activity of pectolytic enzymes showed that the isolates B. subtilis and B. amyloliquefaciens could not cause maceration of plant tissues. Screening for these isolates revealed their fungistatic effect against phytopathogenic micromycetes, namely Fusarium tricinctum, Botrytis cinerea, and Sclerotinia sclerotiorum. Inoculation of B. subtilis, B. amyloliquefaciens, and their complex in oak leaves, in contrast to phytopathogenic bacteria, contributed to the complete restoration of the epidermis at the sites of damage. The phytopathogenic bacteria Pectobacterium and Pseudomonas caused a 2.0 and 2.2 times increase in polyphenol concentration in the plants, respectively, while the ratio of antioxidant activity to total phenolic content decreased. Inoculation of Bacillus amyloliquefaciens and Bacillus subtilis isolates into oak leaf tissue were accompanied by a decrease in the total pool of phenolic compounds. The ratio of antioxidant activity to total phenolic content increased. This indicates a qualitative improvement in the overall balance of the oak leaf antioxidant system induced by potential PGPB. Thus, endophytic bacteria of the genus Bacillus isolated from the internal tissues of unripe oak acorns have the ability of growth biocontrol and spread of phytopathogens, indicating their promise for use as biopesticides.
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Affiliation(s)
- Svitlana Bilous
- Education and Research Institute of Forestry and Landscape-Park Management, National University of Life and Environmental Sciences of Ukraine, 03041 Kyiv, Ukraine (Y.M.)
- Institute for Evolutionary Ecology NAS of Ukraine, 37 Lebedeva Str., 03143 Kiev, Ukraine
- Forestry Department, Weihenstephan-Triesdorf University of Applied Sciences, Germany, Hans-Carl-von-Carlowitz-Platz 3, 85354 Freising, Germany
| | - Artur Likhanov
- Education and Research Institute of Forestry and Landscape-Park Management, National University of Life and Environmental Sciences of Ukraine, 03041 Kyiv, Ukraine (Y.M.)
- Institute for Evolutionary Ecology NAS of Ukraine, 37 Lebedeva Str., 03143 Kiev, Ukraine
| | - Vira Boroday
- Education and Research Institute of Forestry and Landscape-Park Management, National University of Life and Environmental Sciences of Ukraine, 03041 Kyiv, Ukraine (Y.M.)
| | - Yurii Marchuk
- Education and Research Institute of Forestry and Landscape-Park Management, National University of Life and Environmental Sciences of Ukraine, 03041 Kyiv, Ukraine (Y.M.)
| | - Liubov Zelena
- Danylo Zabolotny Institute of Microbiology and Virology National Academy of Sciences of Ukraine, 154 Zabolotnogo Str., 03143 Kyiv, Ukraine
| | - Oleksandr Subin
- State Enterprise “State Centre of Agricultural Products Certification and Examination”, Janusha Korchaka Str. 9/12, 03143 Kyiv, Ukraine
| | - Andrii Bilous
- Education and Research Institute of Forestry and Landscape-Park Management, National University of Life and Environmental Sciences of Ukraine, 03041 Kyiv, Ukraine (Y.M.)
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Tripathi A, Pandey P, Tripathi SN, Kalra A. Perspectives and potential applications of endophytic microorganisms in cultivation of medicinal and aromatic plants. FRONTIERS IN PLANT SCIENCE 2022; 13:985429. [PMID: 36247631 PMCID: PMC9560770 DOI: 10.3389/fpls.2022.985429] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Accepted: 09/07/2022] [Indexed: 06/16/2023]
Abstract
Ensuring food and nutritional security, it is crucial to use chemicals in agriculture to boost yields and protect the crops against biotic and abiotic perturbations. Conversely, excessive use of chemicals has led to many deleterious effects on the environment like pollution of soil, water, and air; loss of soil fertility; and development of pest resistance, and is now posing serious threats to biodiversity. Therefore, farming systems need to be upgraded towards the use of biological agents to retain agricultural and environmental sustainability. Plants exhibit a huge and varied niche for endophytic microorganisms inside the planta, resulting in a closer association between them. Endophytic microorganisms play pivotal roles in plant physiological and morphological characteristics, including growth promotion, survival, and fitness. Their mechanism of action includes both direct and indirect, such as mineral phosphate solubilization, fixating nitrogen, synthesis of auxins, production of siderophore, and various phytohormones. Medicinal and aromatic plants (MAPs) hold a crucial position worldwide for their valued essential oils and several phytopharmaceutically important bioactive compounds since ancient times; conversely, owing to the high demand for natural products, commercial cultivation of MAPs is on the upswing. Furthermore, the vulnerability to various pests and diseases enforces noteworthy production restraints that affect both crop yield and quality. Efforts have been made towards enhancing yields of plant crude drugs by improving crop varieties, cell cultures, transgenic plants, etc., but these are highly cost-demanding and time-consuming measures. Thus, it is essential to evolve efficient, eco-friendly, cost-effective simpler approaches for improvement in the yield and health of the plants. Harnessing endophytic microorganisms as biostimulants can be an effective and alternative step. This review summarizes the concept of endophytes, their multidimensional interaction inside the host plant, and the salient benefits associated with endophytic microorganisms in MAPs.
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Affiliation(s)
- Arpita Tripathi
- Microbial Technology Department, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
- Faculty of Education, Teerthanker Mahaveer University, Moradabad, India
| | - Praveen Pandey
- Microbial Technology Department, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow, India
- Division of Plant Breeding and Genetic Resource Conservation, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow, India
| | - Shakti Nath Tripathi
- Department of Botany, Nehru Gram Bharati Deemed to be University, Prayagraj, India
| | - Alok Kalra
- Microbial Technology Department, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow, India
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Mathur V, Ulanova D. Microbial Metabolites Beneficial to Plant Hosts Across Ecosystems. MICROBIAL ECOLOGY 2022:10.1007/s00248-022-02073-x. [PMID: 35867138 DOI: 10.1007/s00248-022-02073-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 07/05/2022] [Indexed: 06/15/2023]
Abstract
Plants are intimately connected with their associated microorganisms. Chemical interactions via natural products between plants and their microbial symbionts form an important aspect in host health and development, both in aquatic and terrestrial ecosystems. These interactions range from negative to beneficial for microbial symbionts as well as their hosts. Symbiotic microbes synchronize their metabolism with their hosts, thus suggesting a possible coevolution among them. Metabolites, synthesized from plants and microbes due to their association and coaction, supplement the already present metabolites, thus promoting plant growth, maintaining physiological status, and countering various biotic and abiotic stress factors. However, environmental changes, such as pollution and temperature variations, as well as anthropogenic-induced monoculture settings, have a significant influence on plant-associated microbial community and its interaction with the host. In this review, we put the prominent microbial metabolites participating in plant-microbe interactions in the natural terrestrial and aquatic ecosystems in a single perspective and have discussed commonalities and differences in these interactions for adaptation to surrounding environment and how environmental changes can alter the same. We also present the status and further possibilities of employing chemical interactions for environment remediation. Our review thus underlines the importance of ecosystem-driven functional adaptations of plant-microbe interactions in natural and anthropogenically influenced ecosystems and their possible applications.
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Affiliation(s)
- Vartika Mathur
- Animal Plant Interactions Lab, Department of Zoology, Sri Venkateswara College, Benito Juarez Marg, Dhaula Kuan, New Delhi-110021, India.
| | - Dana Ulanova
- Department of Marine Resource Sciences, Faculty of Agriculture and Marine Science, Kochi University, Monobe, Nankoku city, Kochi, 783-8502, Japan.
- Center for Advanced Marine Core Research, Kochi University, Monobe, Nankoku city, Kochi, 783-8502, Japan.
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Que Y, Huang D, Gong S, Zhang X, Yuan B, Xue M, Shi W, Zeng F, Liu M, Chen T, Yu D, Yan X, Wang Z, Yang L, Xiang L. Indole-3-Carboxylic Acid From the Endophytic Fungus Lasiodiplodia pseudotheobromae LPS-1 as a Synergist Enhancing the Antagonism of Jasmonic Acid Against Blumeria graminis on Wheat. Front Cell Infect Microbiol 2022; 12:898500. [PMID: 35860382 PMCID: PMC9289256 DOI: 10.3389/fcimb.2022.898500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 06/06/2022] [Indexed: 11/17/2022] Open
Abstract
The discovery of natural bioactive compounds from endophytes or medicinal plants against plant diseases is an attractive option for reducing the use of chemical fungicides. In this study, three compounds, indole-3-carbaldehyde, indole-3-carboxylic acid (3-ICA), and jasmonic acid (JA), were isolated from the EtOAc extract of the culture filtrate of the endophytic fungus Lasiodiplodia pseudotheobromae LPS-1, which was previously isolated from the medicinal plant, Ilex cornuta. Some experiments were conducted to further determine the antifungal activity of these compounds on wheat powdery mildew. The results showed that JA was much more bioactive than indole-3-carbaldehyde and 3-ICA against Blumeria graminis, and the disease severity caused by B. graminis decreased significantly with the concentration increase of JA treatment. The assay of the interaction of 3-ICA and JA indicated that there was a significant synergistic effect between the two compounds on B. graminis in each of the ratios of 3-ICA to JA (3-ICA:JA) ranging from 1:9 to 9:1. When the compound ratio of 3-ICA to JA was 2:8, the synergistic coefficient was the highest as 22.95. Meanwhile, a histological investigation indicated that, under the treatment of JA at 500 μg/ml or 3-ICA:JA (2:8) at 40 μg/ml, the appressorium development and haustorium formation of B. graminis were significantly inhibited. Taken together, we concluded that JA plays an important role in the infection process of B. graminis and that 3-ICA as a synergist of JA enhances the antagonism against wheat powdery mildew.
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Affiliation(s)
- Yawei Que
- Key Laboratory of Integrated Pest Management of Crop in Central China, Ministry of Agriculture, Hubei Key Laboratory of Crop Diseases, Insect Pests and Weeds Control, Institute of Plant Protection and Soil Fertility, Hubei Academy of Agricultural Sciences, Wuhan, China
| | - Donghai Huang
- Institute of Chinese Herbal Medicines, Hubei Academy of Agricultural Sciences, Enshi, China
| | - Shuangjun Gong
- Key Laboratory of Integrated Pest Management of Crop in Central China, Ministry of Agriculture, Hubei Key Laboratory of Crop Diseases, Insect Pests and Weeds Control, Institute of Plant Protection and Soil Fertility, Hubei Academy of Agricultural Sciences, Wuhan, China
| | - Xuejiang Zhang
- Key Laboratory of Integrated Pest Management of Crop in Central China, Ministry of Agriculture, Hubei Key Laboratory of Crop Diseases, Insect Pests and Weeds Control, Institute of Plant Protection and Soil Fertility, Hubei Academy of Agricultural Sciences, Wuhan, China
| | - Bin Yuan
- Key Laboratory of Integrated Pest Management of Crop in Central China, Ministry of Agriculture, Hubei Key Laboratory of Crop Diseases, Insect Pests and Weeds Control, Institute of Plant Protection and Soil Fertility, Hubei Academy of Agricultural Sciences, Wuhan, China
| | - Minfeng Xue
- Key Laboratory of Integrated Pest Management of Crop in Central China, Ministry of Agriculture, Hubei Key Laboratory of Crop Diseases, Insect Pests and Weeds Control, Institute of Plant Protection and Soil Fertility, Hubei Academy of Agricultural Sciences, Wuhan, China
| | - Wenqi Shi
- Key Laboratory of Integrated Pest Management of Crop in Central China, Ministry of Agriculture, Hubei Key Laboratory of Crop Diseases, Insect Pests and Weeds Control, Institute of Plant Protection and Soil Fertility, Hubei Academy of Agricultural Sciences, Wuhan, China
| | - Fansong Zeng
- Key Laboratory of Integrated Pest Management of Crop in Central China, Ministry of Agriculture, Hubei Key Laboratory of Crop Diseases, Insect Pests and Weeds Control, Institute of Plant Protection and Soil Fertility, Hubei Academy of Agricultural Sciences, Wuhan, China
| | - Meilin Liu
- Key Laboratory of Integrated Pest Management of Crop in Central China, Ministry of Agriculture, Hubei Key Laboratory of Crop Diseases, Insect Pests and Weeds Control, Institute of Plant Protection and Soil Fertility, Hubei Academy of Agricultural Sciences, Wuhan, China
| | - Tingting Chen
- Key Laboratory of Integrated Pest Management of Crop in Central China, Ministry of Agriculture, Hubei Key Laboratory of Crop Diseases, Insect Pests and Weeds Control, Institute of Plant Protection and Soil Fertility, Hubei Academy of Agricultural Sciences, Wuhan, China
| | - Dazhao Yu
- Key Laboratory of Integrated Pest Management of Crop in Central China, Ministry of Agriculture, Hubei Key Laboratory of Crop Diseases, Insect Pests and Weeds Control, Institute of Plant Protection and Soil Fertility, Hubei Academy of Agricultural Sciences, Wuhan, China
| | - Xia Yan
- The Sainsbury Laboratory, Norwich Research Park, Norwich, United Kingdom
| | - Zhengyi Wang
- State Key Laboratory for Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, China
| | - Lijun Yang
- Key Laboratory of Integrated Pest Management of Crop in Central China, Ministry of Agriculture, Hubei Key Laboratory of Crop Diseases, Insect Pests and Weeds Control, Institute of Plant Protection and Soil Fertility, Hubei Academy of Agricultural Sciences, Wuhan, China
- *Correspondence: Libo Xiang, ; Lijun Yang,
| | - Libo Xiang
- Key Laboratory of Integrated Pest Management of Crop in Central China, Ministry of Agriculture, Hubei Key Laboratory of Crop Diseases, Insect Pests and Weeds Control, Institute of Plant Protection and Soil Fertility, Hubei Academy of Agricultural Sciences, Wuhan, China
- *Correspondence: Libo Xiang, ; Lijun Yang,
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Sedaghatjoo S, Mishra B, Forster MK, Becker Y, Keilwagen J, Killermann B, Thines M, Karlovsky P, Maier W. Comparative genomics reveals low levels of inter- and intraspecies diversity in the causal agents of dwarf and common bunt of wheat and hint at conspecificity of Tilletia caries and T. laevis. IMA Fungus 2022; 13:11. [PMID: 35672841 PMCID: PMC9172201 DOI: 10.1186/s43008-022-00098-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 05/27/2022] [Indexed: 11/10/2022] Open
Abstract
AbstractTilletia caries and T. laevis, which are the causal agents of common bunt, as well as T. controversa, which causes dwarf bunt of wheat, threaten especially organic wheat farming. The three closely related fungal species differ in their teliospore morphology and partially in their physiology and infection biology. The gene content as well as intraspecies variation in these species and the genetic basis of their separation is unknown. We sequenced the genome of four T. caries, five T. controversa, and two T. laevis and extended this dataset with five publicly available ones. The genomes of the three species displayed microsynteny with up to 94.3% pairwise aligned regions excluding repetitive regions. The majority of functionally characterized genes involved in pathogenicity, life cycle, and infection of corn smut, Ustilago maydis, were found to be absent or poorly conserved in the draft genomes and the biosynthetic pathway for trimethylamine in Tilletia spp. could be different from bacteria. Overall, 75% of the identified protein-coding genes comprising 84% of the total predicted carbohydrate utilizing enzymes, 72.5% putatively secreted proteins, and 47.4% of effector-like proteins were conserved and shared across all 16 isolates. We predicted nine highly identical secondary metabolite biosynthesis gene clusters comprising in total 62 genes in all species and none were species-specific. Less than 0.1% of the protein-coding genes were species-specific and their function remained mostly unknown. Tilletia controversa had the highest intraspecies genetic variation, followed by T. caries and the lowest in T. laevis. Although the genomes of the three species are very similar, employing 241 single copy genes T. controversa was phylogenetically distinct from T. caries and T. laevis, however these two could not be resolved as individual monophyletic groups. This was in line with the genome-wide number of single nucleotide polymorphisms and small insertions and deletions. Despite the conspicuously different teliospore ornamentation of T. caries and T. laevis, a high degree of genomic identity and scarcity of species-specific genes indicate that the two species could be conspecific.
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10
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Berry D, Lee K, Winter D, Mace W, Becker Y, Nagabhyru P, Treindl AD, Bogantes EV, Young CA, Leuchtmann A, Johnson LJ, Johnson RD, Cox MP, Schardl CL, Scott B. Cross-species transcriptomics identifies core regulatory changes differentiating the asymptomatic asexual and virulent sexual life cycles of grass-symbiotic Epichloë fungi. G3 (BETHESDA, MD.) 2022; 12:jkac043. [PMID: 35191483 PMCID: PMC8982410 DOI: 10.1093/g3journal/jkac043] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 02/07/2022] [Indexed: 02/04/2023]
Abstract
Fungi from the genus Epichloë form systemic endobiotic infections of cool season grasses, producing a range of host-protective natural products in return for access to nutrients. These infections are asymptomatic during vegetative host growth, with associations between asexual Epichloë spp. and their hosts considered mutualistic. However, the sexual cycle of Epichloë spp. involves virulent growth, characterized by the envelopment and sterilization of a developing host inflorescence by a dense sheath of mycelia known as a stroma. Microscopic analysis of stromata revealed a dramatic increase in hyphal propagation and host degradation compared with asymptomatic tissues. RNAseq was used to identify differentially expressed genes in asymptomatic vs stromatized tissues from 3 diverse Epichloë-host associations. Comparative analysis identified a core set of 135 differentially expressed genes that exhibited conserved transcriptional changes across all 3 associations. The core differentially expressed genes more strongly expressed during virulent growth encode proteins associated with host suppression, digestion, adaptation to the external environment, a biosynthetic gene cluster, and 5 transcription factors that may regulate Epichloë stroma formation. An additional 5 transcription factor encoding differentially expressed genes were suppressed during virulent growth, suggesting they regulate mutualistic processes. Expression of biosynthetic gene clusters for natural products that suppress herbivory was universally suppressed during virulent growth, and additional biosynthetic gene clusters that may encode production of novel host-protective natural products were identified. A comparative analysis of 26 Epichloë genomes found a general decrease in core differentially expressed gene conservation among asexual species, and a specific decrease in conservation for the biosynthetic gene cluster expressed during virulent growth and an unusual uncharacterized gene.
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Affiliation(s)
- Daniel Berry
- Institute of Fundamental Sciences, Massey University, Palmerston North 4442, New Zealand
| | - Kate Lee
- Institute of Fundamental Sciences, Massey University, Palmerston North 4442, New Zealand
| | - David Winter
- Institute of Fundamental Sciences, Massey University, Palmerston North 4442, New Zealand
| | - Wade Mace
- AgResearch Ltd, Grasslands Research Centre, Palmerston North 4442, New Zealand
| | - Yvonne Becker
- Institute for Epidemiology and Pathogen Diagnostics, Julius Kühn Institute, Federal Research Centre for Cultivated Plants, 38104 Braunschweig, Germany
| | - Padmaja Nagabhyru
- Department of Plant Pathology, University of Kentucky, Lexington, KY 40546, USA
| | - Artemis D Treindl
- Institute of Integrative Biology, ETH Zurich, 8092 Zürich, Switzerland
| | | | | | - Adrian Leuchtmann
- Institute of Integrative Biology, ETH Zurich, 8092 Zürich, Switzerland
| | | | | | - Murray P Cox
- Institute of Fundamental Sciences, Massey University, Palmerston North 4442, New Zealand
| | | | - Barry Scott
- Institute of Fundamental Sciences, Massey University, Palmerston North 4442, New Zealand
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11
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Vicente I, Baroncelli R, Hermosa R, Monte E, Vannacci G, Sarrocco S. Role and genetic basis of specialised secondary metabolites in Trichoderma ecophysiology. FUNGAL BIOL REV 2022. [DOI: 10.1016/j.fbr.2021.12.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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12
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Epichloë scottii sp. nov., a new endophyte isolated from Melica uniflora is the missing ancestor of Epichloë disjuncta. IMA Fungus 2022; 13:2. [PMID: 35109929 PMCID: PMC8812020 DOI: 10.1186/s43008-022-00088-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 01/25/2022] [Indexed: 11/13/2022] Open
Abstract
Here we describe a new, haploid and stroma forming species within the genus Epichloë, as Epichloë scottii sp. nov. The fungus was isolated from Melica uniflora growing in Bad Harzburg, Germany. Phylogenetic reconstruction using a combined dataset of the tubB and tefA genes strongly support that E. scottii is a distinct species and the so far unknown ancestor species of the hybrid E. disjuncta. A distribution analysis showed a high infection rate in close vicinity of the initial sampling site and only two more spots with low infection rates. Genetic variations in key genes required for alkaloid production suggested that E. scottii sp. nov. might not be capable of producing any of the major alkaloids including ergot alkaloid, loline, indole-diterpene and peramine. All isolates and individuals found in the distribution analysis were identified as mating-type B explaining the lack of mature stromata during this study. We further release a telomere-to-telomere de novo assembly of all seven chromosomes and the mitogenome of E. scottii sp. nov.
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13
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Fernando K, Reddy P, Guthridge KM, Spangenberg GC, Rochfort SJ. A Metabolomic Study of Epichloë Endophytes for Screening Antifungal Metabolites. Metabolites 2022; 12:metabo12010037. [PMID: 35050159 PMCID: PMC8781816 DOI: 10.3390/metabo12010037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Revised: 12/23/2021] [Accepted: 12/29/2021] [Indexed: 11/16/2022] Open
Abstract
Epichloë endophytes, fungal endosymbionts of Pooidae grasses, are commonly utilized in forage and turf industries because they produce beneficial metabolites that enhance resistance against environmental stressors such as insect feeding and disease caused by phytopathogen infection. In pastoral agriculture, phytopathogenic diseases impact both pasture quality and animal production. Recently, bioactive endophyte strains have been reported to secrete compounds that significantly inhibit the growth of phytopathogenic fungi in vitro. A screen of previously described Epichloë-produced antifeedant and toxic alkaloids determined that the antifungal bioactivity observed is not due to the production of these known metabolites, and so there is a need for methods to identify new bioactive metabolites. The process described here is applicable more generally for the identification of antifungals in new endophytes. This study aims to characterize the fungicidal potential of novel, ‘animal friendly’ Epichloë endophyte strains NEA12 and NEA23 that exhibit strong antifungal activity using an in vitro assay. Bioassay-guided fractionation, followed by metabolite analysis, identified 61 metabolites that, either singly or in combination, are responsible for the observed bioactivity. Analysis of the perennial ryegrass-endophyte symbiota confirmed that NEA12 and NEA23 produce the prospective antifungal metabolites in symbiotic association and thus are candidates for compounds that promote disease resistance in planta. The “known unknown” suite of antifungal metabolites identified in this study are potential biomarkers for the selection of strains that enhance pasture and turf production through better disease control.
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Affiliation(s)
- Krishni Fernando
- AgriBio, Centre for AgriBioscience, Agriculture Victoria, Bundoora, VIC 3083, Australia; (K.F.); (P.R.); (K.M.G.); (G.C.S.)
- School of Applied Systems Biology, La Trobe University, Bundoora, VIC 3083, Australia
| | - Priyanka Reddy
- AgriBio, Centre for AgriBioscience, Agriculture Victoria, Bundoora, VIC 3083, Australia; (K.F.); (P.R.); (K.M.G.); (G.C.S.)
| | - Kathryn M. Guthridge
- AgriBio, Centre for AgriBioscience, Agriculture Victoria, Bundoora, VIC 3083, Australia; (K.F.); (P.R.); (K.M.G.); (G.C.S.)
| | - German C. Spangenberg
- AgriBio, Centre for AgriBioscience, Agriculture Victoria, Bundoora, VIC 3083, Australia; (K.F.); (P.R.); (K.M.G.); (G.C.S.)
- School of Applied Systems Biology, La Trobe University, Bundoora, VIC 3083, Australia
| | - Simone J. Rochfort
- AgriBio, Centre for AgriBioscience, Agriculture Victoria, Bundoora, VIC 3083, Australia; (K.F.); (P.R.); (K.M.G.); (G.C.S.)
- School of Applied Systems Biology, La Trobe University, Bundoora, VIC 3083, Australia
- Correspondence: ; Tel.: +61-390327110
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14
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von Cräutlein M, Helander M, Korpelainen H, Leinonen PH, Vázquez de Aldana BR, Young CA, Zabalgogeazcoa I, Saikkonen K. Genetic Diversity of the Symbiotic Fungus Epichloë festucae in Naturally Occurring Host Grass Populations. Front Microbiol 2021; 12:756991. [PMID: 34925265 PMCID: PMC8678516 DOI: 10.3389/fmicb.2021.756991] [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: 08/11/2021] [Accepted: 10/29/2021] [Indexed: 11/20/2022] Open
Abstract
Epichloë festucae is a common symbiont of the perennial and widely distributed cool season grass, Festuca rubra. The symbiosis is highly integrated involving systemic growth of the fungus throughout above-ground host parts and vertical transmission from plant to its offspring via host seeds. However, the nature of symbiosis is labile ranging from antagonistic to mutualistic depending on prevailing selection pressures. Both the loss of fungus in the maternal host lineage and horizontal transmission through sexual spores within the host population may partly explain the detected variation in symbiosis in wild grass populations. Epichloë species are commonly considered as pathogens when they produce sexual spores and partly castrate their host plant. This is the pathogenic end of the continuum from antagonistic to mutualistic interactions. Here we examined the population genetic structure of E. festucae to reveal the gene flow, importance of reproduction modes, and alkaloid potential of the symbiotic fungus in Europe. Epichloë-species are highly dependent on the host in survival and reproduction whilst benefits to the host are largely linked to defensive mutualism attributable to fungal-origin bioactive alkaloids that negatively affect vertebrate and/or invertebrate herbivores. We detected decreased genetic diversity in previously glaciated areas compared to non-glaciated regions during the last glacial maximum period and found three major genetic clusters in E. festucae populations: southern, northeastern and northwestern Europe. Sexual reproduction may have a higher role than expected in Spanish E. festucae populations due to the predominance of unique genotypes and presence of both mating types in the region. In contrast, asexual reproduction via host seeds predominates in the Faroe Island and Finland in northern Europe due to the presence of biased mating-type ratios and large dominant genotypes in the E. festucae populations within the region. A substantially larger variation of alkaloid genotypes was observed in the fungal populations than expected, although the variability of the alkaloid genotypes within populations is considerably lower in northern than Spanish populations in southern Europe. E. festucae populations consist of different combinations of alkaloid classes from the gene clusters of ergot alkaloid and indole-terpenes, and from pyrrolopyrazine alkaloid gene. We suggest that the postglacial distribution history of the host grass, prevailing reproduction strategies of E. festucae, and local selection pressures likely explain a large part of the genetic variation observed in fungal populations among geographic regions. The identified alkaloid genotypes can be used by turfgrass breeders to improve resistance against herbivores in red fescue varieties and to develop new sustainable cultivars in Europe.
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Affiliation(s)
- Maria von Cräutlein
- Department of Agricultural Sciences, Viikki Plant Science Centre, University of Helsinki, Helsinki, Finland.,Management and Production of Renewable Resources, Natural Resources Institute Finland (Luke), Helsinki, Finland.,Biodiversity Unit, University of Turku, Turku, Finland
| | - Marjo Helander
- Department of Biology, University of Turku, Turku, Finland
| | - Helena Korpelainen
- Department of Agricultural Sciences, Viikki Plant Science Centre, University of Helsinki, Helsinki, Finland
| | - Päivi Helena Leinonen
- Management and Production of Renewable Resources, Natural Resources Institute Finland (Luke), Helsinki, Finland.,Biodiversity Unit, University of Turku, Turku, Finland
| | - Beatriz R Vázquez de Aldana
- Institute of Natural Resources and Agrobiology of Salamanca, Spanish National Research Council (CSIC), Salamanca, Spain
| | | | - Iñigo Zabalgogeazcoa
- Institute of Natural Resources and Agrobiology of Salamanca, Spanish National Research Council (CSIC), Salamanca, Spain
| | - Kari Saikkonen
- Biodiversity Unit, University of Turku, Turku, Finland.,Management and Production of Renewable Resources, Natural Resources Institute Finland (Luke), Turku, Finland
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15
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Liu M, Findlay W, Dettman J, Wyka SA, Broders K, Shoukouhi P, Dadej K, Kolařík M, Basnyat A, Menzies JG. Mining Indole Alkaloid Synthesis Gene Clusters from Genomes of 53 Claviceps Strains Revealed Redundant Gene Copies and an Approximate Evolutionary Hourglass Model. Toxins (Basel) 2021; 13:toxins13110799. [PMID: 34822583 PMCID: PMC8625505 DOI: 10.3390/toxins13110799] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 11/09/2021] [Accepted: 11/10/2021] [Indexed: 11/30/2022] Open
Abstract
Ergot fungi (Claviceps spp.) are infamous for producing sclerotia containing a wide spectrum of ergot alkaloids (EA) toxic to humans and animals, making them nefarious villains in the agricultural and food industries, but also treasures for pharmaceuticals. In addition to three classes of EAs, several species also produce paspaline-derived indole diterpenes (IDT) that cause ataxia and staggers in livestock. Furthermore, two other types of alkaloids, i.e., loline (LOL) and peramine (PER), found in Epichloë spp., close relatives of Claviceps, have shown beneficial effects on host plants without evidence of toxicity to mammals. The gene clusters associated with the production of these alkaloids are known. We examined genomes of 53 strains of 19 Claviceps spp. to screen for these genes, aiming to understand the evolutionary patterns of these genes across the genus through phylogenetic and DNA polymorphism analyses. Our results showed (1) varied numbers of eas genes in C. sect. Claviceps and sect. Pusillae, none in sect. Citrinae, six idt/ltm genes in sect. Claviceps (except four in C. cyperi), zero to one partial (idtG) in sect. Pusillae, and four in sect. Citrinae, (2) two to three copies of dmaW, easE, easF, idt/ltmB, itd/ltmQ in sect. Claviceps, (3) frequent gene gains and losses, and (4) an evolutionary hourglass pattern in the intra-specific eas gene diversity and divergence in C. purpurea.
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Affiliation(s)
- Miao Liu
- Ottawa Research & Development Centre, Agriculture and Agri-Food Canada, Ottawa, ON K1A 0C6, Canada; (W.F.); (J.D.); (P.S.); (K.D.); (A.B.)
- Correspondence: ; Tel.: +1-613-759-1385
| | - Wendy Findlay
- Ottawa Research & Development Centre, Agriculture and Agri-Food Canada, Ottawa, ON K1A 0C6, Canada; (W.F.); (J.D.); (P.S.); (K.D.); (A.B.)
| | - Jeremy Dettman
- Ottawa Research & Development Centre, Agriculture and Agri-Food Canada, Ottawa, ON K1A 0C6, Canada; (W.F.); (J.D.); (P.S.); (K.D.); (A.B.)
| | - Stephen A. Wyka
- Department of Agricultural Biology, Colorado State University, Fort Collins, CO 80523, USA;
| | - Kirk Broders
- USDA, Agricultural Research Service, National Center for Agricultural Utilization Research, Mycotoxin Prevention and Applied Microbiology Research Unit, 1815 N. University St., Peoria, IL 61604, USA;
| | - Parivash Shoukouhi
- Ottawa Research & Development Centre, Agriculture and Agri-Food Canada, Ottawa, ON K1A 0C6, Canada; (W.F.); (J.D.); (P.S.); (K.D.); (A.B.)
| | - Kasia Dadej
- Ottawa Research & Development Centre, Agriculture and Agri-Food Canada, Ottawa, ON K1A 0C6, Canada; (W.F.); (J.D.); (P.S.); (K.D.); (A.B.)
| | - Miroslav Kolařík
- Institute of Microbiology of the Czech Academy of Sciences CAS, 14220 Prague, Czech Republic;
| | - Arpeace Basnyat
- Ottawa Research & Development Centre, Agriculture and Agri-Food Canada, Ottawa, ON K1A 0C6, Canada; (W.F.); (J.D.); (P.S.); (K.D.); (A.B.)
| | - Jim G. Menzies
- Morden Research and Development Centre, Agriculture and Agri-Food Canada, Morden, MB R6M 1Y5, Canada;
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16
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Noorifar N, Savoian MS, Ram A, Lukito Y, Hassing B, Weikert TW, Moerschbacher BM, Scott B. Chitin Deacetylases Are Required for Epichloë festucae Endophytic Cell Wall Remodeling During Establishment of a Mutualistic Symbiotic Interaction with Lolium perenne. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2021; 34:1181-1192. [PMID: 34058838 DOI: 10.1094/mpmi-12-20-0347-r] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Epichloë festucae forms a mutualistic symbiotic association with Lolium perenne. This biotrophic fungus systemically colonizes the intercellular spaces of aerial tissues to form an endophytic hyphal network and also grows as an epiphyte. However, little is known about the cell wall-remodeling mechanisms required to avoid host defense and maintain intercalary growth within the host. Here, we use a suite of molecular probes to show that the E. festucae cell wall is remodeled by conversion of chitin to chitosan during infection of L. perenne seedlings, as the hyphae switch from free-living to endophytic growth. When hyphae transition from endophytic to epiphytic growth, the cell wall is remodeled from predominantly chitosan to chitin. This conversion from chitin to chitosan is catalyzed by chitin deacetylase. The genome of E. festucae encodes three putative chitin deacetylases, two of which (cdaA and cdaB) are expressed in planta. Deletion of either of these genes results in disruption of fungal intercalary growth in the intercellular spaces of plants infected with these mutants. These results establish that these two genes are required for maintenance of the mutualistic symbiotic interaction between E. festucae and L. perenne.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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Affiliation(s)
- Nazanin Noorifar
- School of Fundamental Sciences, Massey University, Palmerston North 4442, New Zealand
| | - Matthew S Savoian
- School of Fundamental Sciences, Massey University, Palmerston North 4442, New Zealand
| | - Arvina Ram
- School of Fundamental Sciences, Massey University, Palmerston North 4442, New Zealand
| | - Yonathan Lukito
- School of Fundamental Sciences, Massey University, Palmerston North 4442, New Zealand
| | - Berit Hassing
- School of Fundamental Sciences, Massey University, Palmerston North 4442, New Zealand
- Bioprotection Research Centre, Massey University, Palmerston North 4442, New Zealand
| | - Tobias W Weikert
- Institute for Biology and Biotechnology of Plants, Westfälische Wilhelms-Universität, Münster, Germany
| | - Bruno M Moerschbacher
- Institute for Biology and Biotechnology of Plants, Westfälische Wilhelms-Universität, Münster, Germany
| | - Barry Scott
- School of Fundamental Sciences, Massey University, Palmerston North 4442, New Zealand
- Bioprotection Research Centre, Massey University, Palmerston North 4442, New Zealand
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17
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Zhang L, Yue Q, Wang C, Xu Y, Molnár I. Secondary metabolites from hypocrealean entomopathogenic fungi: genomics as a tool to elucidate the encoded parvome. Nat Prod Rep 2021; 37:1164-1180. [PMID: 32211677 DOI: 10.1039/d0np00007h] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Covering: 2014 up to the third quarter of 2019 Hypocrealean entomopathogenic fungi (HEF) produce a large variety of secondary metabolites (SMs) that are prominent virulence factors or mediate various interactions in the native niches of these organisms. Many of these SMs show insecticidal, immune system modulatory, antimicrobial, cytotoxic and other bioactivities of clinical or agricultural significance. Recent advances in whole genome sequencing technologies and bioinformatics have revealed many biosynthetic gene clusters (BGCs) potentially involved in SM production in HEF. Some of these BGCs are now well characterized, with the structures of the cognate product congeners elucidated, and the proposed biosynthetic functions of key enzymes validated. However, the vast majority of HEF BGCs are still not linked to SM products ("orphan" BGCs), including many clusters that are not expressed (silent) under routine laboratory conditions. Thus, investigations into the encoded parvome (the secondary metabolome predicted from the genome) of HEF allows the discovery of BGCs for known SMs; uncovers novel metabolites based on the BGCs; and catalogues the predicted SM biosynthetic potential of these fungi. Herein, we summarize new developments of the field, and survey the polyketide, nonribosomal peptide, terpenoid and hybrid SM BGCs encoded in the currently available 40 HEF genome sequences. Studying the encoded parvome of HEF will increase our understanding of the multifaceted roles that SMs play in biotic and abiotic interactions and will also reveal biologically active SMs that can be exploited for the discovery of human and veterinary drugs or crop protection agents.
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Affiliation(s)
- Liwen Zhang
- Biotechnology Research Institute, The Chinese Academy of Agricultural Sciences, 12 Zhongguancun South Street, Beijing 100081, P. R. China.
| | - Qun Yue
- Biotechnology Research Institute, The Chinese Academy of Agricultural Sciences, 12 Zhongguancun South Street, Beijing 100081, P. R. China.
| | - Chen Wang
- Biotechnology Research Institute, The Chinese Academy of Agricultural Sciences, 12 Zhongguancun South Street, Beijing 100081, P. R. China.
| | - Yuquan Xu
- Biotechnology Research Institute, The Chinese Academy of Agricultural Sciences, 12 Zhongguancun South Street, Beijing 100081, P. R. China.
| | - István Molnár
- Southwest Center for Natural Products Research, University of Arizona, 250 E. Valencia Rd., Tucson, AZ 85706, USA.
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18
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Opposing Effects of Ceanothus velutinus Phytochemistry on Herbivore Communities at Multiple Scales. Metabolites 2021; 11:metabo11060361. [PMID: 34200295 PMCID: PMC8227664 DOI: 10.3390/metabo11060361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2021] [Revised: 05/28/2021] [Accepted: 06/02/2021] [Indexed: 11/26/2022] Open
Abstract
Identifying the interactions of functional, biotic, and abiotic factors that define plant–insect communities has long been a goal of community ecologists. Metabolomics approaches facilitate a broader understanding of how phytochemistry mediates the functional interactions among ecological factors. Ceanothus velutinus communities are a relatively unstudied system for investigating chemically mediated interactions. Ceanothus are nitrogen-fixing, fire-adapted plants that establish early post-fire, and produce antimicrobial cyclic peptides, linear peptides, and flavonoids. This study takes a metabolomic approach to understanding how the diversity and variation of C. velutinus phytochemistry influences associated herbivore and parasitoid communities at multiple spatiotemporal scales. Herbivores and foliar samples were collected over three collection times at two sites on the east slope of the Sierra Nevada Mountain range. Foliar tissue was subjected to LC-MS metabolomic analysis, and several novel statistical analyses were applied to summarize, quantify, and annotate variation in the C. velutinus metabolome. We found that phytochemistry played an important role in plant–insect community structure across an elevational gradient. Flavonoids were found to mediate biotic and abiotic influences on herbivores and associated parasitoids, while foliar oligopeptides played a significant positive role in herbivore abundance, even more than abundance of host plants and leaf abundance. The importance of nutritional and defense chemistry in mediating ecological interactions in C. velutinus plant–herbivore communities was established, justifying larger scale studies of this plant system that incorporate other mediators of phytochemistry such as genetic and metageomic contributions.
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19
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Hettiarachchige IK, Vander Jagt CJ, Mann RC, Sawbridge TI, Spangenberg GC, Guthridge KM. Global Changes in Asexual Epichloë Transcriptomes during the Early Stages, from Seed to Seedling, of Symbiotum Establishment. Microorganisms 2021; 9:microorganisms9050991. [PMID: 34064362 PMCID: PMC8147782 DOI: 10.3390/microorganisms9050991] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 04/30/2021] [Accepted: 04/30/2021] [Indexed: 11/16/2022] Open
Abstract
Asexual Epichloë fungi are strictly seed-transmitted endophytic symbionts of cool-season grasses and spend their entire life cycle within the host plant. Endophyte infection can confer protective benefits to its host through the production of bioprotective compounds. Inversely, plants provide nourishment and shelter to the resident endophyte in return. Current understanding of the changes in global gene expression of asexual Epichloë endophytes during the early stages of host-endophyte symbiotum is limited. A time-course study using a deep RNA-sequencing approach was performed at six stages of germination, using seeds infected with one of three endophyte strains belonging to different representative taxa. Analysis of the most abundantly expressed endophyte genes identified that most were predicted to have a role in stress and defence responses. The number of differentially expressed genes observed at early time points was greater than those detected at later time points, suggesting an active transcriptional reprogramming of endophytes at the onset of seed germination. Gene ontology enrichment analysis revealed dynamic changes in global gene expression consistent with the developmental processes of symbiotic relationships. Expression of pathway genes for biosynthesis of key secondary metabolites was studied comprehensively and fuzzy clustering identified some unique expression patterns. Furthermore, comparisons of the transcriptomes from three endophyte strains in planta identified genes unique to each strain, including genes predicted to be associated with secondary metabolism. Findings from this study highlight the importance of better understanding the unique properties of individual endophyte strains and will serve as an excellent resource for future studies of host-endophyte interactions.
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Affiliation(s)
- Inoka K. Hettiarachchige
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, Bundoora, VIC 3083, Australia; (I.K.H.); (C.J.V.J.); (R.C.M.); (T.I.S.); (G.C.S.)
| | - Christy J. Vander Jagt
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, Bundoora, VIC 3083, Australia; (I.K.H.); (C.J.V.J.); (R.C.M.); (T.I.S.); (G.C.S.)
| | - Ross C. Mann
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, Bundoora, VIC 3083, Australia; (I.K.H.); (C.J.V.J.); (R.C.M.); (T.I.S.); (G.C.S.)
| | - Timothy I. Sawbridge
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, Bundoora, VIC 3083, Australia; (I.K.H.); (C.J.V.J.); (R.C.M.); (T.I.S.); (G.C.S.)
- School of Applied Systems Biology, La Trobe University, Bundoora, VIC 3086, Australia
| | - German C. Spangenberg
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, Bundoora, VIC 3083, Australia; (I.K.H.); (C.J.V.J.); (R.C.M.); (T.I.S.); (G.C.S.)
- School of Applied Systems Biology, La Trobe University, Bundoora, VIC 3086, Australia
| | - Kathryn M. Guthridge
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, Bundoora, VIC 3083, Australia; (I.K.H.); (C.J.V.J.); (R.C.M.); (T.I.S.); (G.C.S.)
- Correspondence:
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20
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Lofgren LA, Nguyen NH, Vilgalys R, Ruytinx J, Liao HL, Branco S, Kuo A, LaButti K, Lipzen A, Andreopoulos W, Pangilinan J, Riley R, Hundley H, Na H, Barry K, Grigoriev IV, Stajich JE, Kennedy PG. Comparative genomics reveals dynamic genome evolution in host specialist ectomycorrhizal fungi. THE NEW PHYTOLOGIST 2021; 230:774-792. [PMID: 33355923 PMCID: PMC7969408 DOI: 10.1111/nph.17160] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 12/16/2020] [Indexed: 05/24/2023]
Abstract
While there has been significant progress characterizing the 'symbiotic toolkit' of ectomycorrhizal (ECM) fungi, how host specificity may be encoded into ECM fungal genomes remains poorly understood. We conducted a comparative genomic analysis of ECM fungal host specialists and generalists, focusing on the specialist genus Suillus. Global analyses of genome dynamics across 46 species were assessed, along with targeted analyses of three classes of molecules previously identified as important determinants of host specificity: small secreted proteins (SSPs), secondary metabolites (SMs) and G-protein coupled receptors (GPCRs). Relative to other ECM fungi, including other host specialists, Suillus had highly dynamic genomes including numerous rapidly evolving gene families and many domain expansions and contractions. Targeted analyses supported a role for SMs but not SSPs or GPCRs in Suillus host specificity. Phylogenomic-based ancestral state reconstruction identified Larix as the ancestral host of Suillus, with multiple independent switches between white and red pine hosts. These results suggest that like other defining characteristics of the ECM lifestyle, host specificity is a dynamic process at the genome level. In the case of Suillus, both SMs and pathways involved in the deactivation of reactive oxygen species appear to be strongly associated with enhanced host specificity.
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Affiliation(s)
- Lotus A Lofgren
- Department of Microbiology and Plant Pathology, University of California Riverside, Riverside, CA, 92507, USA
- Department of Plant and Microbial Biology, University of Minnesota, St Paul, MN, 55108, USA
| | - Nhu H Nguyen
- Department of Tropical Plant and Soil Science, University of Hawaii, Manoa, HI, 96822, USA
| | - Rytas Vilgalys
- Department of Biology, Duke University, Durham, NC, 27708, USA
| | - Joske Ruytinx
- Research group Microbiology, Department of Bio-engineering Sciences, Vrije Universiteit Brussel, Brussel, BE1500, Belgium
| | - Hui-Ling Liao
- Department of Soil Microbial Ecology, University of Florida, Quincy, FL, 32351, USA
| | - Sara Branco
- Department of Integrative Biology, University of Colorado Denver, Denver, CO, 80204, USA
| | - Alan Kuo
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Kurt LaButti
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Anna Lipzen
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - William Andreopoulos
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Jasmyn Pangilinan
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Robert Riley
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Hope Hundley
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Hyunsoo Na
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Kerrie Barry
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Igor V Grigoriev
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720, USA
| | - Jason E Stajich
- Department of Microbiology and Plant Pathology, University of California Riverside, Riverside, CA, 92507, USA
| | - Peter G Kennedy
- Department of Plant and Microbial Biology, University of Minnesota, St Paul, MN, 55108, USA
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21
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Lukito Y, Lee K, Noorifar N, Green KA, Winter DJ, Ram A, Hale TK, Chujo T, Cox MP, Johnson LJ, Scott B. Regulation of host-infection ability in the grass-symbiotic fungus Epichloë festucae by histone H3K9 and H3K36 methyltransferases. Environ Microbiol 2020; 23:2116-2131. [PMID: 33350014 DOI: 10.1111/1462-2920.15370] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2020] [Revised: 12/02/2020] [Accepted: 12/19/2020] [Indexed: 01/30/2023]
Abstract
Recent studies have identified key genes that control the symbiotic interaction between Epichloë festucae and Lolium perenne. Here we report on the identification of specific E. festucae genes that control host infection. Deletion of setB, which encodes a homologue of the H3K36 histone methyltransferase Set2/KMT3, reduced histone H3K36 trimethylation and led to severe defects in colony growth and hyphal development. The E. festucae ΔclrD mutant, which lacks the gene encoding the homologue of the H3K9 methyltransferase KMT1, displays similar developmental defects. Both mutants are completely defective in their ability to infect L. perenne. Alleles that complement the culture and plant phenotypes of both mutants also complement the histone methylation defects. Co-inoculation of either ΔsetB or ΔclrD with the wild-type strain enables these mutants to colonize the host. However, successful colonization by the mutants resulted in death or stunting of the host plant. Transcriptome analysis at the early infection stage identified four fungal candidate genes, three of which encode small-secreted proteins, that are differentially regulated in these mutants compared to wild type. Deletion of crbA, which encodes a putative carbohydrate binding protein, resulted in significantly reduced host infection rates by E. festucae.
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Affiliation(s)
- Yonathan Lukito
- School of Fundamental Sciences, Massey University, Palmerston North, New Zealand.,AgResearch Limited, Grasslands Research Centre, Palmerston North, New Zealand.,Bio-Protection Research Centre, Massey University, Palmerston North, New Zealand.,Ferrier Research Institute, Victoria University of Wellington, Wellington, New Zealand
| | - Kate Lee
- School of Fundamental Sciences, Massey University, Palmerston North, New Zealand.,Bio-Protection Research Centre, Massey University, Palmerston North, New Zealand
| | - Nazanin Noorifar
- School of Fundamental Sciences, Massey University, Palmerston North, New Zealand
| | - Kimberly A Green
- School of Fundamental Sciences, Massey University, Palmerston North, New Zealand
| | - David J Winter
- School of Fundamental Sciences, Massey University, Palmerston North, New Zealand
| | - Arvina Ram
- School of Fundamental Sciences, Massey University, Palmerston North, New Zealand
| | - Tracy K Hale
- School of Fundamental Sciences, Massey University, Palmerston North, New Zealand
| | - Tetsuya Chujo
- Research and Development Center, Mayekawa Mfg. Co., Ltd, Tokyo, Japan
| | - Murray P Cox
- School of Fundamental Sciences, Massey University, Palmerston North, New Zealand.,Bio-Protection Research Centre, Massey University, Palmerston North, New Zealand
| | - Linda J Johnson
- AgResearch Limited, Grasslands Research Centre, Palmerston North, New Zealand
| | - Barry Scott
- School of Fundamental Sciences, Massey University, Palmerston North, New Zealand.,Bio-Protection Research Centre, Massey University, Palmerston North, New Zealand
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22
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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] [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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23
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Tian P, Xu W, Li C, Song H, Wang M, Schardl CL, Nan Z. Phylogenetic relationship and taxonomy of a hybrid Epichloë species symbiotic with Festuca sinensis. Mycol Prog 2020. [DOI: 10.1007/s11557-020-01618-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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24
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Iqbal M, Broberg M, Haarith D, Broberg A, Bushley KE, Brandström Durling M, Viketoft M, Funck Jensen D, Dubey M, Karlsson M. Natural variation of root lesion nematode antagonism in the biocontrol fungus Clonostachys rosea and identification of biocontrol factors through genome-wide association mapping. Evol Appl 2020; 13:2264-2283. [PMID: 33005223 PMCID: PMC7513725 DOI: 10.1111/eva.13001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Revised: 05/09/2020] [Accepted: 05/13/2020] [Indexed: 01/28/2023] Open
Abstract
Biological control is a promising approach to reduce plant diseases caused by nematodes to ensure high productivity in agricultural production. Large-scale analyses of genetic variation in fungal species used for biocontrol can generate knowledge regarding interaction mechanisms that can improve efficacy of biocontrol applications. In this study, we performed a genome-wide association study (GWAS) for in vitro antagonism against the root lesion nematode Pratylenchus penetrans in 53 previously genome re-sequenced strains of the biocontrol fungus Clonostachys rosea. Nematode mortality in C. rosea potato dextrose broth (PDB) culture filtrates was highly variable and showed continuous variation (p < .001) between strains, indicating a polygenic inheritance. Twenty-one strains produced culture filtrates with higher (p ≤ .05) nematode mortality compared with the PDB control treatment, while ten strains lowered (p ≤ .05) the mortality. The difference in in vitro antagonism against P. penetrans correlated with antagonism against the soybean cyst nematode Heterodera glycines, indicating lack of host specificity in C. rosea. An empirical Bayesian multiple hypothesis testing approach identified 279 single nucleotide polymorphism markers significantly (local false sign rate < 10-10) associated with the trait. Genes present in the genomic regions associated with nematicidal activity included several membrane transporters, a chitinase and genes encoding proteins predicted to biosynthesize secondary metabolites. Gene deletion strains of the predicted nonribosomal peptide synthetase genes nps4 and nps5 were generated and showed increased (p ≤ .001) fungal growth and conidiation rates compared to the wild type. Deletion strains also exhibited reduced (p < .001) nematicidal activity and reduced (p ≤ .05) biocontrol efficacy against nematode root disease and against fusarium foot rot on wheat. In summary, we show that the GWAS approach can be used to identify biocontrol factors in C. rosea, specifically the putative nonribosomal peptide synthetases NPS4 and NPS5.
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Affiliation(s)
- Mudassir Iqbal
- Department of Forest Mycology and Plant Pathology Uppsala BioCenter Swedish University of Agricultural Sciences Uppsala Sweden
| | - Martin Broberg
- Department of Forest Mycology and Plant Pathology Uppsala BioCenter Swedish University of Agricultural Sciences Uppsala Sweden
| | - Deepak Haarith
- Department of Plant and Microbial Biology University of Minnesota St. Paul MN USA
| | - Anders Broberg
- Department of Molecular Sciences Uppsala BioCenter Swedish University of Agricultural Sciences Uppsala Sweden
| | - Kathryn E Bushley
- Department of Plant and Microbial Biology University of Minnesota St. Paul MN USA
| | - Mikael Brandström Durling
- Department of Forest Mycology and Plant Pathology Uppsala BioCenter Swedish University of Agricultural Sciences Uppsala Sweden
| | - Maria Viketoft
- Department of Ecology Swedish University of Agricultural Sciences Uppsala Sweden
| | - Dan Funck Jensen
- Department of Forest Mycology and Plant Pathology Uppsala BioCenter Swedish University of Agricultural Sciences Uppsala Sweden
| | - Mukesh Dubey
- Department of Forest Mycology and Plant Pathology Uppsala BioCenter Swedish University of Agricultural Sciences Uppsala Sweden
| | - Magnus Karlsson
- Department of Forest Mycology and Plant Pathology Uppsala BioCenter Swedish University of Agricultural Sciences Uppsala Sweden
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25
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Tanaka A, Kamiya S, Ozaki Y, Kameoka S, Kayano Y, Saikia S, Akano F, Uemura A, Takagi H, Terauchi R, Maruyama J, Hammadeh HH, Fleissner A, Scott B, Takemoto D. A nuclear protein NsiA from
Epichloë festucae
interacts with a MAP kinase MpkB and regulates the expression of genes required for symbiotic infection and hyphal cell fusion. Mol Microbiol 2020; 114:626-640. [DOI: 10.1111/mmi.14568] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 06/20/2020] [Accepted: 06/29/2020] [Indexed: 12/29/2022]
Affiliation(s)
- Aiko Tanaka
- Graduate School of Bioagricultural Sciences Nagoya University Nagoya Japan
- School of Fundamental Sciences Massey University Palmerston North New Zealand
| | - Shota Kamiya
- Graduate School of Bioagricultural Sciences Nagoya University Nagoya Japan
| | - Yoshino Ozaki
- Graduate School of Bioagricultural Sciences Nagoya University Nagoya Japan
| | - Shinichi Kameoka
- Graduate School of Bioagricultural Sciences Nagoya University Nagoya Japan
| | - Yuka Kayano
- Graduate School of Bioagricultural Sciences Nagoya University Nagoya Japan
| | - Sanjay Saikia
- School of Fundamental Sciences Massey University Palmerston North New Zealand
| | - Fumitake Akano
- Graduate School of Bioagricultural Sciences Nagoya University Nagoya Japan
| | - Aiko Uemura
- Iwate Biotechnology Research Center Kitakami Japan
| | | | | | | | - Hamzeh Haj Hammadeh
- Institut für Genetik Technische Universität Braunschweig Braunschweig Germany
| | - André Fleissner
- Institut für Genetik Technische Universität Braunschweig Braunschweig Germany
| | - Barry Scott
- School of Fundamental Sciences Massey University Palmerston North New Zealand
| | - Daigo Takemoto
- Graduate School of Bioagricultural Sciences Nagoya University Nagoya Japan
- School of Fundamental Sciences Massey University Palmerston North New Zealand
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26
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Shi X, Qin T, Liu H, Wu M, Li J, Shi Y, Gao Y, Ren A. Endophytic Fungi Activated Similar Defense Strategies of Achnatherum sibiricum Host to Different Trophic Types of Pathogens. Front Microbiol 2020; 11:1607. [PMID: 32793143 PMCID: PMC7393327 DOI: 10.3389/fmicb.2020.01607] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 06/19/2020] [Indexed: 12/17/2022] Open
Abstract
It is well documented that Epichloë endophytes can enhance the resistance of grasses to herbivory. However, reports on resistance to pathogenic fungi are limited, and their conclusions are variable. In this study, we chose pathogenic fungi with different trophic types, namely, the biotrophic pathogen Erysiphales species and the necrotrophic pathogen Curvularia lunata, to test the effects of Epichloë on the pathogen resistance of Achnatherum sibiricum. The results showed that, compared to Erysiphales species, C. lunata caused a higher degree of damage and lower photochemical efficiency (Fv/Fm) in endophyte−free (E−) leaves. Endophytes significantly alleviated the damage caused by these two pathogens. The leaf damaged area and Fv/Fm of endophyte−infected (E+) leaves were similar between the two pathogen treatments, indicating that the beneficial effects of endophytes were more significant when hosts were exposed to C. lunata than when they were exposed to Erysiphales species. We found that A. sibiricum initiated jasmonic acid (JA)−related pathways to resist C. lunata but salicylic acid (SA)–related pathways to resist Erysiphales species. Endophytic fungi had no effect on the content of SA but increased the content of JA and total phenolic compounds, which suggest that endophyte infection might enhance the resistance of A. sibiricum to these two different trophic types of pathogens through similar pathways.
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27
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Green KA, Berry D, Feussner K, Eaton CJ, Ram A, Mesarich CH, Solomon P, Feussner I, Scott B. Lolium perenne apoplast metabolomics for identification of novel metabolites produced by the symbiotic fungus Epichloë festucae. THE NEW PHYTOLOGIST 2020; 227:559-571. [PMID: 32155669 PMCID: PMC7317419 DOI: 10.1111/nph.16528] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Accepted: 02/28/2020] [Indexed: 05/05/2023]
Abstract
Epichloë festucae is an endophytic fungus that forms a symbiotic association with Lolium perenne. Here we analysed how the metabolome of the ryegrass apoplast changed upon infection of this host with sexual and asexual isolates of E. festucae. A metabolite fingerprinting approach was used to analyse the metabolite composition of apoplastic wash fluid from uninfected and infected L. perenne. Metabolites enriched or depleted in one or both of these treatments were identified using a set of interactive tools. A genetic approach in combination with tandem MS was used to identify a novel product of a secondary metabolite gene cluster. Metabolites likely to be present in the apoplast were identified using MarVis in combination with the BioCyc and KEGG databases, and an in-house Epichloë metabolite database. We were able to identify the known endophyte-specific metabolites, peramine and epichloëcyclins, as well as a large number of unknown markers. To determine whether these methods can be applied to the identification of novel Epichloë-derived metabolites, we deleted a gene encoding a NRPS (lgsA) that is highly expressed in planta. Comparative MS analysis of apoplastic wash fluid from wild-type- vs mutant-infected plants identified a novel Leu/Ile glycoside metabolite present in the former.
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Affiliation(s)
- Kimberly A. Green
- School of Fundamental SciencesMassey UniversityPalmerston North4442New Zealand
- Bioprotection Research CentreMassey UniversityPalmerston North4442New Zealand
| | - Daniel Berry
- School of Fundamental SciencesMassey UniversityPalmerston North4442New Zealand
- Bioprotection Research CentreMassey UniversityPalmerston North4442New Zealand
| | - Kirstin Feussner
- Department of Plant BiochemistryAlbrecht von Haller Institute for Plant SciencesUniversity of GoettingenD‐37077GoettingenGermany
- Service Unit for Metabolomics and LipidomicsGoettingen Center for Molecular Biosciences (GZMB)University of GoettingenD‐37077GoettingenGermany
| | - Carla J. Eaton
- School of Fundamental SciencesMassey UniversityPalmerston North4442New Zealand
- Bioprotection Research CentreMassey UniversityPalmerston North4442New Zealand
| | - Arvina Ram
- School of Fundamental SciencesMassey UniversityPalmerston North4442New Zealand
| | - Carl H. Mesarich
- Bioprotection Research CentreMassey UniversityPalmerston North4442New Zealand
- School of Agriculture and EnvironmentMassey UniversityPalmerston North4442New Zealand
| | - Peter Solomon
- Research School of BiologyAustralian National UniversityCanberraACT0200Australia
| | - Ivo Feussner
- Department of Plant BiochemistryAlbrecht von Haller Institute for Plant SciencesUniversity of GoettingenD‐37077GoettingenGermany
- Service Unit for Metabolomics and LipidomicsGoettingen Center for Molecular Biosciences (GZMB)University of GoettingenD‐37077GoettingenGermany
- Department of Plant BiochemistryGoettingen Center for Molecular Biosciences (GZMB)University of GoettingenD‐37077GoettingenGermany
| | - Barry Scott
- School of Fundamental SciencesMassey UniversityPalmerston North4442New Zealand
- Bioprotection Research CentreMassey UniversityPalmerston North4442New Zealand
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28
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Bharadwaj R, Jagadeesan H, Kumar SR, Ramalingam S. Molecular mechanisms in grass-Epichloë interactions: towards endophyte driven farming to improve plant fitness and immunity. World J Microbiol Biotechnol 2020; 36:92. [PMID: 32562008 DOI: 10.1007/s11274-020-02868-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2020] [Accepted: 06/10/2020] [Indexed: 11/26/2022]
Abstract
All plants harbor many microbial species including bacteria and fungi in their tissues. The interactions between the plant and these microbes could be symbiotic, mutualistic, parasitic or commensalistic. Mutualistic microorganisms are endophytic in nature and are known to play a role in plant growth, development and fitness. Endophytes display complex diversity depending upon the agro-climatic conditions and this diversity could be exploited for crop improvement and sustainable agriculture. Plant-endophyte partnerships are highly specific, several genetic and molecular cascades play a key role in colonization of endophytes in host plants leading to rapid changes in host and endophyte metabolism. This results in the accumulation of secondary metabolites, which play an important role in plant defense against biotic and abiotic stress conditions. Alkaloids are one of the important class of metabolites produced by Epichloë genus and other related classes of endophytes and confer protection against insect and mammalian herbivory. In this context, this review discusses the evolutionary aspects of the Epichloë genus along with key molecular mechanisms determining the lifestyle of Epichloë endophytes in host system. Novel hypothesis is proposed to outline the initial cellular signaling events during colonization of Epichloë in cool season grasses. Complex clustering of alkaloid biosynthetic genes and molecular mechanisms involved in the production of alkaloids have been elaborated in detail. The natural defense and advantages of the endophyte derived metabolites have also been extensively discussed. Finally, this review highlights the importance of endophyte-arbitrated plant immunity to develop novel approaches for eco-friendly agriculture.
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Affiliation(s)
- R Bharadwaj
- Plant Genetic Engineering Laboratory, Department of Biotechnology, Bharathiar University, Coimbatore, Tamil Nadu, 641046, India
| | - H Jagadeesan
- Department of Biotechnology, PSG College of Technology, Coimbatore, Tamil Nadu, India
| | - S R Kumar
- Plant Genetic Engineering Laboratory, Department of Biotechnology, Bharathiar University, Coimbatore, Tamil Nadu, 641046, India
| | - S Ramalingam
- Plant Genetic Engineering Laboratory, Department of Biotechnology, Bharathiar University, Coimbatore, Tamil Nadu, 641046, India.
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29
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Impact of endophyte inoculation on the morphological identity of cultivars of Lolium perenne (L) and Festuca arundinacea (Schreb.). Sci Rep 2020; 10:7729. [PMID: 32382099 PMCID: PMC7205862 DOI: 10.1038/s41598-020-64474-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 04/09/2020] [Indexed: 11/08/2022] Open
Abstract
Grass endophytes have been shown to confer enhanced environmental resilience to symbiont cultivars with reports of modified growth. If inoculating with an endophyte (E+) made an accession morphologically distinct from its registered endophyte free (E−) accession, there could be protection and ownership issues for testing authorities and breeders. This study investigated if, in official Plant Breeders Rights (PBR) field trials, the morphological characteristics of E+and E− accessions of perennial ryegrass and tall fescue cultivars were sufficiently modified to designate them as mutually distinct and also distinct from their definitive accessions (Def), held by the testing authorities. Testing perennial ryegrass on 17 characters at 2 sites generated 48,960 observations and for tall fescue on 9 characters at 1 site, 12,960 observations (each for 3 accessions of 4 cultivars × 60 plants × 2 growing cycles). Distinctness required a p < 0.01 difference in a single character from the combined over years analysis (COYD). A few significant differences were recorded between E− and E+accessions. Cultivar Carn E+ was smaller than Carn E− for Infloresence Length (p < 0.01) in both years but COYD analysis (p < 0.05) was insufficient to declare distinctiveness. Overall, the number of observed differences between E−/E+ accessions was less or similar to the number expected purely by chance. In contrast, comparisons between Def and E− or E+ accessions showed a number of significant differences that were substantially more numerous than expected by chance. These results showed no conclusive evidence of endophyte inclusion creating false PBR distinctions but unexpectedly, several E− and E+ accessions were distinguished from their official definitive stock.
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30
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Purev E, Kondo T, Takemoto D, Niones JT, Ojika M. Identification of ε-Poly-L-lysine as an Antimicrobial Product from an Epichloë Endophyte and Isolation of Fungal ε-PL Synthetase Gene. Molecules 2020; 25:molecules25051032. [PMID: 32106587 PMCID: PMC7179176 DOI: 10.3390/molecules25051032] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 02/20/2020] [Accepted: 02/23/2020] [Indexed: 12/18/2022] Open
Abstract
The endophytic fungus Epichloë festucae is known to produce bioactive metabolites, which consequently protect the host plants from biotic and abiotic stresses. We previously found that the overexpression of vibA (a gene for transcription factor) in E. festucae strain E437 resulted in the secretion of an unknown fungicide. In the present study, the active substance was purified and chemically identified as ε-poly-L-lysine (ε-PL), which consisted of 28–34 lysine units. The productivity was 3.7-fold compared with that of the wild type strain E437. The isolated ε-PL showed inhibitory activity against the spore germination of the plant pathogens Drechslera erythrospila, Botrytis cinerea, and Phytophthora infestans at 1–10 μg/mL. We also isolated the fungal gene “epls” encoding ε-PL synthetase Epls. Overexpression of epls in the wild type strain E437 resulted in the enhanced production of ε-PL by 6.7-fold. Interestingly, overexpression of epls in the different strain E. festucae Fl1 resulted in the production of shorter ε-PL with 8–20 lysine, which exhibited a comparable antifungal activity to the longer one. The results demonstrate the first example of ε-PL synthetase gene from the eukaryotic genomes and suggest the potential of enhanced expression of vibA or/and epls genes in the Epichloë endophyte for constructing pest-tolerant plants.
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Affiliation(s)
- Enkhee Purev
- Department of Applied Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa-ku, Nagoya 464-8601, Japan; (E.P.); (T.K.)
| | - Tatsuhiko Kondo
- Department of Applied Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa-ku, Nagoya 464-8601, Japan; (E.P.); (T.K.)
| | - Daigo Takemoto
- Department of Plant Production Sciences, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa-ku, Nagoya 464-8601, Japan; (D.T.); (J.T.N.)
| | - Jennifer T. Niones
- Department of Plant Production Sciences, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa-ku, Nagoya 464-8601, Japan; (D.T.); (J.T.N.)
- Philippine Rice Research Institute, Science City of Munoz, Nueva Ecija 3119, Philippines
| | - Makoto Ojika
- Department of Applied Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa-ku, Nagoya 464-8601, Japan; (E.P.); (T.K.)
- Correspondence: ; Tel.: +81-52-789-4116; Fax: +81-52-789-4118
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Stroe MC, Netzker T, Scherlach K, Krüger T, Hertweck C, Valiante V, Brakhage AA. Targeted induction of a silent fungal gene cluster encoding the bacteria-specific germination inhibitor fumigermin. eLife 2020; 9:52541. [PMID: 32083553 PMCID: PMC7034978 DOI: 10.7554/elife.52541] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Accepted: 02/09/2020] [Indexed: 12/29/2022] Open
Abstract
Microorganisms produce numerous secondary metabolites (SMs) with various biological activities. Many of their encoding gene clusters are silent under standard laboratory conditions because for their activation they need the ecological context, such as the presence of other microorganisms. The true ecological function of most SMs remains obscure, but understanding of both the activation of silent gene clusters and the ecological function of the produced compounds is of importance to reveal functional interactions in microbiomes. Here, we report the identification of an as-yet uncharacterized silent gene cluster of the fungus Aspergillus fumigatus, which is activated by the bacterium Streptomyces rapamycinicus during the bacterial-fungal interaction. The resulting natural product is the novel fungal metabolite fumigermin, the biosynthesis of which requires the polyketide synthase FgnA. Fumigermin inhibits germination of spores of the inducing S. rapamycinicus, and thus helps the fungus to defend resources in the shared habitat against a bacterial competitor.
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Affiliation(s)
- Maria Cristina Stroe
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Jena, Germany.,Institute of Microbiology, Friedrich Schiller University Jena, Jena, Germany
| | - Tina Netzker
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Jena, Germany
| | | | - Thomas Krüger
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Jena, Germany
| | - Christian Hertweck
- Institute of Microbiology, Friedrich Schiller University Jena, Jena, Germany.,Department of Biomolecular Chemistry, HKI, Jena, Germany
| | - Vito Valiante
- Leibniz Research Group - Biobricks of Microbial Natural Product Syntheses, HKI, Jena, Germany
| | - Axel A Brakhage
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Jena, Germany.,Institute of Microbiology, Friedrich Schiller University Jena, Jena, Germany
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32
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Selvasekaran P, Chidambaram R. Agriculturally Important Fungi for Crop Protection. Fungal Biol 2020. [DOI: 10.1007/978-3-030-48474-3_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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33
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Berry D, Mace W, Grage K, Wesche F, Gore S, Schardl CL, Young CA, Dijkwel PP, Leuchtmann A, Bode HB, Scott B. Efficient nonenzymatic cyclization and domain shuffling drive pyrrolopyrazine diversity from truncated variants of a fungal NRPS. Proc Natl Acad Sci U S A 2019; 116:25614-25623. [PMID: 31801877 PMCID: PMC6926027 DOI: 10.1073/pnas.1913080116] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Nonribosomal peptide synthetases (NRPSs) generate the core peptide scaffolds of many natural products. These include small cyclic dipeptides such as the insect feeding deterrent peramine, which is a pyrrolopyrazine (PPZ) produced by grass-endophytic Epichloë fungi. Biosynthesis of peramine is catalyzed by the 2-module NRPS, PpzA-1, which has a C-terminal reductase (R) domain that is required for reductive release and cyclization of the NRPS-tethered dipeptidyl-thioester intermediate. However, some PpzA variants lack this R domain due to insertion of a transposable element into the 3' end of ppzA We demonstrate here that these truncated PpzA variants utilize nonenzymatic cyclization of the dipeptidyl thioester to a 2,5-diketopiperazine (DKP) to synthesize a range of novel PPZ products. Truncation of the R domain is sufficient to subfunctionalize PpzA-1 into a dedicated DKP synthetase, exemplified by the truncated variant, PpzA-2, which has also evolved altered substrate specificity and reduced N-methyltransferase activity relative to PpzA-1. Further allelic diversity has been generated by recombination-mediated domain shuffling between ppzA-1 and ppzA-2, resulting in the ppzA-3 and ppzA-4 alleles, each of which encodes synthesis of a unique PPZ metabolite. This research establishes that efficient NRPS-catalyzed DKP biosynthesis can occur in vivo through nonenzymatic dipeptidyl cyclization and presents a remarkably clean example of NRPS evolution through recombinant exchange of functionally divergent domains. This work highlights that allelic variants of a single NRPS can result in a surprising level of secondary metabolite diversity comparable to that observed for some gene clusters.
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Affiliation(s)
- Daniel Berry
- School of Fundamental Sciences, Massey University, Palmerston North 4442, New Zealand
- Bioprotection Research Centre, Massey University, Palmerston North 4442, New Zealand
| | - Wade Mace
- Grasslands Research Centre, AgResearch Ltd., Palmerston North 4442, New Zealand
| | - Katrin Grage
- School of Fundamental Sciences, Massey University, Palmerston North 4442, New Zealand
| | - Frank Wesche
- Fachbereich Biowissenschaften, Molekulare Biotechnologie, Goethe Universität Frankfurt, 60438 Frankfurt am Main, Germany
| | - Sagar Gore
- Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute, 07745 Jena, Germany
| | | | | | - Paul P Dijkwel
- School of Fundamental Sciences, Massey University, Palmerston North 4442, New Zealand
- Bioprotection Research Centre, Massey University, Palmerston North 4442, New Zealand
| | - Adrian Leuchtmann
- Institute of Integrative Biology, ETH Zürich, CH-8092 Zürich, Switzerland
| | - Helge B Bode
- Fachbereich Biowissenschaften, Molekulare Biotechnologie, Goethe Universität Frankfurt, 60438 Frankfurt am Main, Germany;
- Buchmann Institute for Molecular Life Sciences, Goethe-Universität, 60438 Frankfurt am Main, Germany
- Landes-Offensive zur Entwicklung Wissenschaftlich-Ökonomischer Exzellenz (LOEWE) Centre for Translational Biodiversity Genomics, 60325 Frankfurt am Main, Germany
| | - Barry Scott
- School of Fundamental Sciences, Massey University, Palmerston North 4442, New Zealand;
- Bioprotection Research Centre, Massey University, Palmerston North 4442, New Zealand
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Antimicrobial secondary metabolites from agriculturally important fungi as next biocontrol agents. Appl Microbiol Biotechnol 2019; 103:9287-9303. [DOI: 10.1007/s00253-019-10209-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 10/15/2019] [Accepted: 10/19/2019] [Indexed: 10/25/2022]
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35
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Forester NT, Lane GA, McKenzie CM, Lamont IL, Johnson LJ. The Role of SreA-Mediated Iron Regulation in Maintaining Epichloë festucae- Lolium perenne Symbioses. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2019; 32:1324-1335. [PMID: 31107632 DOI: 10.1094/mpmi-03-19-0060-r] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In ascomycetes and basidiomycetes, iron-responsive GATA-type transcriptional repressors are involved in regulating iron homeostasis, notably to prevent iron toxicity through control of iron uptake. To date, it has been unknown whether this iron regulator contributes toward mutualistic endosymbiosis of microbes with plants, a system where the endophyte must function within the constraints of an in-host existence, including a dependency on the host for nutrient acquisition. Functional characterization of one such protein, SreA from Epichloë festucae, a fungal endosymbiont of cool-season grasses, indicates that regulation of iron homeostasis processes is important for symbiotic maintenance. The deletion of the sreA gene (ΔsreA) led to iron-dependent aberrant hyphal growth and the gradual loss of endophyte hyphae from perennial ryegrass. SreA negatively regulates the siderophore biosynthesis and high-affinity iron uptake systems of E. festucae, similar to other fungi, resulting in iron accumulation in mutants. Our evidence suggests that SreA is involved in the processes that moderate Epichloë iron acquisition from the plant apoplast, because overharvesting of iron in ΔsreA mutants was detected as premature chlorosis of the host using a hydroponic plant growth assay. E. festucae appears to have a tightly regulated iron management system, involving SreA that balances endophyte growth with its survival and prevents overcompetition with the host for iron in the intercellular niche, thus promoting mutualistic associations. Mutations that interfere with Epichloë iron management negatively affect iron-dependent fungal growth and destabilize mutualistic Epichloë -ryegrass associations.
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Affiliation(s)
- Natasha T Forester
- AgResearch Ltd., Grasslands Research Centre, Tennent Drive, Private Bag 11008, Palmerston North 4442, New Zealand
| | - Geoffrey A Lane
- AgResearch Ltd., Grasslands Research Centre, Tennent Drive, Private Bag 11008, Palmerston North 4442, New Zealand
| | - Catherine M McKenzie
- AgResearch Ltd., Grasslands Research Centre, Tennent Drive, Private Bag 11008, Palmerston North 4442, New Zealand
| | - Iain L Lamont
- Department of Biochemistry, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand
| | - Linda J Johnson
- AgResearch Ltd., Grasslands Research Centre, Tennent Drive, Private Bag 11008, Palmerston North 4442, New Zealand
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Infection Rates and Alkaloid Patterns of Different Grass Species with Systemic Epichloë Endophytes. Appl Environ Microbiol 2019; 85:AEM.00465-19. [PMID: 31227553 DOI: 10.1128/aem.00465-19] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Accepted: 06/14/2019] [Indexed: 01/05/2023] Open
Abstract
Symbiotic Epichloë species are fungal endophytes of cool-season grasses that can produce alkaloids with toxicity to vertebrates and/or invertebrates. Monitoring infections and presence of alkaloids in grasses infected with Epichloë species can provide an estimate of possible intoxication risks for livestock. We sampled 3,046 individuals of 13 different grass species in three regions on 150 study sites in Germany. We determined infection rates and used PCR to identify Epichloë species diversity based on the presence of different alkaloid biosynthesis genes, then confirmed the possible chemotypes with high-performance liquid chromatography (HPLC)/ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) and gas chromatography-mass spectrometry (GC-MS) measurements. Infections of Epichloë spp. were found in Festuca pratensis Huds. (81%), Festuca ovina L. aggregate (agg.) (73%), Lolium perenne L. (15%), Festuca rubra L. (15%) and Dactylis glomerata L. (8%). The other eight grass species did not appear to be infected. For the majority of Epichloë-infected L. perenne samples (98%), the alkaloids lolitrem B and peramine were present, but ergovaline was not detected, which was consistent with the genetic evaluation, as dmaW, the gene encoding the first step of the ergot alkaloid biosynthesis pathway, was absent. Epichloë uncinata in F. pratensis produced anti-insect loline compounds. The Epichloë spp. observed in the F. ovina agg. samples showed the greatest level of diversity, and different intermediates of the indole-diterpene pathway could be detected. Epichloë infection rates alone are insufficient to estimate intoxication risks for livestock, as other factors, like the ability of the endophyte to produce the alkaloids, also need to be assessed.IMPORTANCE Severe problems of livestock intoxication from Epichloë-infected forage grasses have been reported from New Zealand, Australia, and the United States, but much less frequently from Europe, and particularly not from Germany. Nevertheless, it is important to monitor infection rates and alkaloids of grasses with Epichloë fungi to estimate possible intoxication risks. Most studies focus on agricultural grass species like Lolium perenne and Festuca arundinacea, but other cool-season grass species can also be infected. We show that in Germany, infection rates and alkaloids differ between grass species and that some of the alkaloids can be toxic to livestock. Changes in grassland management due to changing climate, especially with a shift toward grasslands dominated with Epichloë-infected species such as Lolium perenne, may result in greater numbers of intoxicated livestock in the near future. We therefore suggest regular monitoring of grass species for infections and alkaloids and call for maintaining heterogenous grasslands for livestock.
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Stringlis IA, Zhang H, Pieterse CMJ, Bolton MD, de Jonge R. Microbial small molecules - weapons of plant subversion. Nat Prod Rep 2019; 35:410-433. [PMID: 29756135 DOI: 10.1039/c7np00062f] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Covering: up to 2018 Plants live in close association with a myriad of microbes that are generally harmless. However, the minority of microbes that are pathogens can severely impact crop quality and yield, thereby endangering food security. By contrast, beneficial microbes provide plants with important services, such as enhanced nutrient uptake and protection against pests and diseases. Like pathogens, beneficial microbes can modulate host immunity to efficiently colonize the nutrient-rich niches within and around the roots and aerial tissues of a plant, a phenomenon mirroring the establishment of commensal microbes in the human gut. Numerous ingenious mechanisms have been described by which pathogenic and beneficial microbes in the plant microbiome communicate with their host, including the delivery of immune-suppressive effector proteins and the production of phytohormones, toxins and other bioactive molecules. Plants signal to their associated microbes via exudation of photosynthetically fixed carbon sources, quorum-sensing mimicry molecules and selective secondary metabolites such as strigolactones and flavonoids. Molecular communication thus forms an integral part of the establishment of both beneficial and pathogenic plant-microbe relations. Here, we review the current knowledge on microbe-derived small molecules that can act as signalling compounds to stimulate plant growth and health by beneficial microbes on the one hand, but also as weapons for plant invasion by pathogens on the other. As an exemplary case, we used comparative genomics to assess the small molecule biosynthetic capabilities of the Pseudomonas genus; a genus rich in both plant pathogenic and beneficial microbes. We highlight the biosynthetic potential of individual microbial genomes and the population at large, providing evidence for the hypothesis that the distinction between detrimental and beneficial microbes is increasingly fading. Knowledge on the biosynthesis and molecular activity of microbial small molecules will aid in the development of successful biological agents boosting crop resiliency in a sustainable manner and could also provide scientific routes to pathogen inhibition or eradication.
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Affiliation(s)
- Ioannis A Stringlis
- Plant-Microbe Interactions, Department of Biology, Science4Life, Utrecht University, Utrecht, The Netherlands.
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38
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Abstract
Endophytic fungi play an important role in balancing the ecosystem and boosting host growth; however, the underpinning mechanisms remain poorly understood. Here, we found that endophytic fungal colonization with P. liquidambaris significantly increased the productivity, nodulation, and N2 fixation of peanuts through the secretion of specific root exudates. We provide a reasonable mechanism explaining how P. liquidambaris promotes peanut nodulation and N2 fixation, whereby the specific root exudates produced by P. liquidambaris colonization decrease rhizosphere soil nitrate (NO3−) and increase the population and biological activities of peanut-nodulating-related Bradyrhizobium strains, which is beneficial to enhancing the peanut-Bradyrhizobium symbiotic interaction. Our study provides reliable empirical evidence to show the mechanism of how an exotic endophytic fungus drives an increase in nodulation and N2 fixation, which will be helpful in erecting a resource-efficient and sustainable agricultural system. Endophytic fungi play important roles in the modification of ecosystem productivity; however, the underlying mechanisms are only partly understood. A 2-year field plot experiment verified that the endophytic fungus Phomopsis liquidambaris increased peanut (Arachis hypogaea L.) yields and significantly increased nodulation and N2 fixation regardless of whether N fertilizers were added. Root exudates collected from P. liquidambaris-colonized plants significantly improved nodulation and N2 fixation. Rhizosphere stimulation experiments further showed that colonized root exudates had significantly decreased soil nitrate (NO3−) concentrations, with decreased abundance and diversity of ammonia oxidizing archaea (AOA). In contrast, the abundance and diversity of diazotrophs significantly increased, and most diazotrophs identified were peanut nodulation-related strains (Bradyrhizobium sp.). P. liquidambaris symbiosis increased the expression of phenolic and flavonoid synthesis-related genes, and the derived phenolics and flavonoids could effectively increase the chemotaxis, biofilm formation, and nodC gene expression (nodulation-related biological processes) of the Bradyrhizobium strain. Metabolic pattern analysis showed that phenolics and flavonoids are more likely to accumulate to higher levels in the rhizosphere soil of peanuts colonized with P. liquidambaris. Finally, a synthetic root exudate experiment further confirmed the underlying mechanisms for the P. liquidambaris-induced improvement in nodulation and N2 fixation, i.e., that the specific root exudates derived from P. liquidambaris colonization decrease nitrate concentration and increase the population and biological activities of peanut nodulation-related Bradyrhizobium species, which beneficially enhance peanut-Bradyrhizobium interactions. Therefore, this study is the first to provide new insight into a positive relationship between an exotic endophytic fungus, crop nodulation, and N2 fixation increase.
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Green KA, Eaton CJ, Savoian MS, Scott B. A homologue of the fungal tetraspanin Pls1 is required for Epichloë festucae expressorium formation and establishment of a mutualistic interaction with Lolium perenne. MOLECULAR PLANT PATHOLOGY 2019; 20:961-975. [PMID: 31008572 PMCID: PMC6589725 DOI: 10.1111/mpp.12805] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Epichloë festucae is an endophytic fungus that forms a mutualistic symbiotic association with the grass host Lolium perenne. Endophytic hyphae exit the host by an appressorium-like structure known as an expressorium. In plant-pathogenic fungi, the tetraspanin Pls1 and the NADPH oxidase component Nox2 are required for appressorium development. Previously we showed that the homologue of Nox2, NoxB, is required for E. festucae expressorium development and establishment of a mutualistic symbiotic interaction with the grass host. Here we used a reverse genetics approach to functionally characterize the role of the E. festucae homologue of Pls1, PlsA. The morphology and growth of ΔplsA in axenic culture was comparable to wild-type. The tiller length of plants infected with ΔplsA was significantly reduced. Hyphae of ΔplsA had a proliferative pattern of growth within the leaves of L. perenne with increased colonization of the intercellular spaces and the vascular bundles. The ΔplsA mutant was also defective in expressorium development although the phenotype was not as severe as for ΔnoxB, highlighting potentially distinct roles for PlsA and NoxB in signalling through the NoxB complex. Hyphae of ΔplsA proliferate below the cuticle surface but still occasionally form an expressorium-like structure that enables the mutant hyphae to exit the leaf to grow on the surface. These expressoria still form a septin ring-like structure at the point of cuticle exit as found in the wild-type strain. These results establish that E. festucae PlsA has an important, but distinct, role to NoxB in expressorium development and plant symbiosis.
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Affiliation(s)
- Kimberly A. Green
- Institute of Fundamental SciencesMassey UniversityPalmerston NorthNew Zealand
| | - Carla J. Eaton
- Institute of Fundamental SciencesMassey UniversityPalmerston NorthNew Zealand
| | - Matthew S. Savoian
- Institute of Fundamental SciencesMassey UniversityPalmerston NorthNew Zealand
| | - Barry Scott
- Institute of Fundamental SciencesMassey UniversityPalmerston NorthNew Zealand
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40
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Lukito Y, Chujo T, Hale TK, Mace W, Johnson LJ, Scott B. Regulation of subtelomeric fungal secondary metabolite genes by H3K4me3 regulators CclA and KdmB. Mol Microbiol 2019; 112:837-853. [DOI: 10.1111/mmi.14320] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/30/2019] [Indexed: 11/28/2022]
Affiliation(s)
- Yonathan Lukito
- Institute of Fundamental Sciences Massey University Palmerston North New Zealand
- Grasslands Research Centre AgResearch Limited Palmerston North New Zealand
| | - Tetsuya Chujo
- Institute of Fundamental Sciences Massey University Palmerston North New Zealand
| | - Tracy K. Hale
- Institute of Fundamental Sciences Massey University Palmerston North New Zealand
| | - Wade Mace
- Grasslands Research Centre AgResearch Limited Palmerston North New Zealand
| | - Linda J. Johnson
- Grasslands Research Centre AgResearch Limited Palmerston North New Zealand
| | - Barry Scott
- Institute of Fundamental Sciences Massey University Palmerston North New Zealand
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Qian X, Li H, Wang Y, Wu B, Wu M, Chen L, Li X, Zhang Y, Wang X, Shi M, Zheng Y, Guo L, Zhang D. Leaf and Root Endospheres Harbor Lower Fungal Diversity and Less Complex Fungal Co-occurrence Patterns Than Rhizosphere. Front Microbiol 2019; 10:1015. [PMID: 31143169 PMCID: PMC6521803 DOI: 10.3389/fmicb.2019.01015] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 04/24/2019] [Indexed: 12/21/2022] Open
Abstract
Plant-associated microbiomes are key determinants of host-plant fitness, productivity, and function. However, compared to bacterial community, we still lack fundamental knowledge concerning the variation in the fungal microbiome at the plant niche level. In this study, we quantified the fungal communities in the rhizosphere soil, as well as leaf and root endosphere compartments of a subtropical island shrub, Mussaenda kwangtungensis, using high-throughput DNA sequencing. We found that fungal microbiomes varied significantly across different plant compartments. Rhizosphere soil exhibited the highest level of fungal diversity, whereas the lowest level was found in the leaf endosphere. Further, the fungal communities inhabiting the root endosphere shared a greater proportion of fungal operational taxonomic units (OTUs) with rhizosphere communities than with leaf fungal endophyte communities, despite significant separation in community structure between the two belowground compartments. The fungal co-occurrence networks in the three compartments of M. kwangtungensis showed scale-free features and non-random co-occurrence patterns and matched the topological properties of small-world and evidently modular structure. Additionally, the rhizosphere network was more complex and showed higher centrality and connectedness than the leaf and root endosphere networks. Overall, our findings provide comprehensive insights into the structural variability, niche differentiation, and co-occurrence patterns in the plant associated fungal microbiome.
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Affiliation(s)
- Xin Qian
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China.,State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Hanzhou Li
- Biomarker Technologies Corporation, Beijing, China
| | - Yonglong Wang
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China.,State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Binwei Wu
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China.,State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Mingsong Wu
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Liang Chen
- Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Xingchun Li
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Ying Zhang
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Xiangping Wang
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
| | - Miaomiao Shi
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
| | - Yong Zheng
- Key Laboratory of Humid Subtropical Eco-geographical Process of Ministry of Education, Fujian Normal University, Fuzhou, China
| | - Liangdong Guo
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Dianxiang Zhang
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
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42
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Rahnama M, Maclean P, Fleetwood DJ, Johnson RD. The LaeA orthologue in Epichloë festucae is required for symbiotic interaction with Lolium perenne. Fungal Genet Biol 2019; 129:74-85. [PMID: 31071427 DOI: 10.1016/j.fgb.2019.05.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 05/02/2019] [Accepted: 05/02/2019] [Indexed: 10/26/2022]
Abstract
LaeA is a conserved global regulator of secondary metabolism and development in fungi. It is often required for successful pathogenic interactions. In this study, the laeA homologue in the fungal grass endophyte E. festucae was deleted and functionally characterised in vitro and its role in the mutualistic E. festucae interaction with Lolium perenne (perennial ryegrass) was determined. We showed that laeA in E. festucae is required for normal hyphal morphology, resistance to oxidative stress, and conidiation under nutrient-limited in vitro conditions. In planta studies revealed that laeA is expressed in a tissue-specific manner and is required to form a compatible plant interaction, with the majority of seedlings inoculated with a laeA deletion mutant either dying or being uninfected. In mature infected plants no difference was observed in the number or morphology of endophytic hyphae. However, the number of epiphyllous hyphae were greatly increased. Comparative transcriptomics analyses suggested roles for plant cell wall degradation, fungal cell wall composition, secondary metabolism and small-secreted proteins in Epichloë foliar symbiosis.
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Affiliation(s)
- M Rahnama
- AgResearch, Grasslands Research Centre, Palmerston North, New Zealand; School of Biological Sciences, University of Auckland, New Zealand
| | - P Maclean
- AgResearch, Grasslands Research Centre, Palmerston North, New Zealand
| | - D J Fleetwood
- AgResearch, Grasslands Research Centre, Palmerston North, New Zealand; Biotelliga Ltd, Auckland, New Zealand.
| | - R D Johnson
- AgResearch, Grasslands Research Centre, Palmerston North, New Zealand.
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Complex epigenetic regulation of alkaloid biosynthesis and host interaction by heterochromatin protein I in a fungal endophyte-plant symbiosis. Fungal Genet Biol 2019; 125:71-83. [DOI: 10.1016/j.fgb.2019.02.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 01/29/2019] [Accepted: 02/03/2019] [Indexed: 01/10/2023]
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44
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Ozturk IK, Dupont PY, Chettri P, McDougal R, Böhl OJ, Cox RJ, Bradshaw RE. Evolutionary relics dominate the small number of secondary metabolism genes in the hemibiotrophic fungus Dothistroma septosporum. Fungal Biol 2019; 123:397-407. [PMID: 31053329 DOI: 10.1016/j.funbio.2019.02.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2018] [Revised: 02/12/2019] [Accepted: 02/21/2019] [Indexed: 10/27/2022]
Abstract
Fungal secondary metabolites have important functions for the fungi that produce them, such as roles in virulence and competition. The hemibiotrophic pine needle pathogen Dothistroma septosporum has one of the lowest complements of secondary metabolite (SM) backbone genes of plant pathogenic fungi, indicating that this fungus produces a limited range of SMs. Amongst these SMs is dothistromin, a well-characterised polyketide toxin and virulence factor that is required for expansion of disease lesions in Dothistroma needle blight disease. Dothistromin genes are dispersed across six loci on one chromosome, rather than being clustered as for most SM genes. We explored other D. septosporum SM genes to determine if they are associated with gene clusters, and to predict what their likely products and functions might be. Of nine functional SM backbone genes in the D. septosporum genome, only four were expressed under a range of in planta and in culture conditions, one of which was the dothistromin PKS backbone gene. Of the other three expressed genes, gene knockout studies suggested that DsPks1 and DsPks2 are not required for virulence and attempts to determine a functional squalestatin-like SM product for DsPks2 were not successful. However preliminary evidence suggested that DsNps3, the only SM backbone gene to be most highly expressed in the early stage of disease, appears to be a virulence factor. Thus, despite the small number of SM backbone genes in D. septosporum, most of them appear to be poorly expressed or dispensable for virulence in planta. This work contributes to a growing body of evidence that many fungal secondary metabolite gene clusters might be non-functional and may be evolutionary relics.
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Affiliation(s)
- I Kutay Ozturk
- Bio-Protection Research Centre, Institute of Fundamental Sciences, Massey University, Palmerston North, 4410, New Zealand
| | - Pierre-Yves Dupont
- Bio-Protection Research Centre, Institute of Fundamental Sciences, Massey University, Palmerston North, 4410, New Zealand; Institute of Environmental Science and Research, Christchurch, 8041, New Zealand
| | - Pranav Chettri
- Bio-Protection Research Centre, Institute of Fundamental Sciences, Massey University, Palmerston North, 4410, New Zealand
| | - Rebecca McDougal
- Scion, NZ Forest Research Institute Ltd, Rotorua, 3010, New Zealand
| | - Ole J Böhl
- Institut für Organische Chemie, Leibniz Universität Hannover, Schneiderberg 1b, Hannover, 30167, Germany
| | - Russell J Cox
- Institut für Organische Chemie, Leibniz Universität Hannover, Schneiderberg 1b, Hannover, 30167, Germany
| | - Rosie E Bradshaw
- Bio-Protection Research Centre, Institute of Fundamental Sciences, Massey University, Palmerston North, 4410, New Zealand.
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45
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Acuña-Rodríguez IS, Hansen H, Gallardo-Cerda J, Atala C, Molina-Montenegro MA. Antarctic Extremophiles: Biotechnological Alternative to Crop Productivity in Saline Soils. Front Bioeng Biotechnol 2019; 7:22. [PMID: 30838204 PMCID: PMC6389620 DOI: 10.3389/fbioe.2019.00022] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Accepted: 01/29/2019] [Indexed: 01/01/2023] Open
Abstract
Salinization of soils is one of the main sources of soil degradation worldwide, particularly in arid and semiarid ecosystems. High salinity results in osmotic stress and it can negatively impact plant grow and survival. Some plant species, however, can tolerate salinity by accumulating osmolytes like proline and maintaining low Na+ concentrations inside the cells. Another mechanism of saline stress tolerance is the association with symbiotic microorganism, an alternative that can be used as a biotechnological tool in susceptible crops. From the immense diversity of plant symbionts, those found in extreme environments such as Antarctica seems to be the ones with most potential since they (and their host) evolved in harsh and stressful conditions. We evaluated the effect of the inoculation with a consortium of plant growth-promoting rhizobacteria (PGPB) and endosymbiotic fungi isolated from an Antarctic plant on saline stress tolerance in different crops. To test this we established 4 treatments: (i) uninoculated plants with no saline stress, (ii) uninoculated plants subjected to saline stress (200 mM NaCl), (iii) plants inoculated with the microorganism consortium with no saline stress, and (iv) inoculated plants subjected to saline stress. First, we assessed the effect of symbiont consortium on survival of four different crops (cayenne, lettuce, onion, and tomato) in order to obtain a more generalized response of this biological interaction. Second, in order to deeply the mechanisms involved in salt tolerance, in lettuce plants we measured the ecophysiological performance (Fv/Fm) and lipid peroxidation to estimate the impact of saline stress on plants. We also measured proline accumulation and NHX1 antiporter gene expression (involved in Na+ detoxification) to search for possible mechanism of stress tolerance. Additionally, root, shoot, and total biomass was also obtained as an indicator of productivity. Overall, plants inoculated with microorganisms from Antarctica increased the fitness related traits in several crops. In fact, three of four crops selected to assess the general response increased its survival under salt conditions compared with those uninoculated plants. On the other hand, saline stress negatively impacted all measured trait, but inoculated plants were significantly less affected. In control osmotic conditions, there were no differences in proline accumulation and lipid peroxidation between inoculation treatments. Interestingly, even in control salinity, Fv/Fm was higher in inoculated plants after 30 and 60 days. Under osmotic stress, Fv/Fm, proline accumulation and NHX1 expression was significantly higher and lipid peroxidation lower in inoculated plants compared to uninoculated individuals. Moreover, inoculated plants exposed to saline stress had a similar final biomass (whole plant) compared to individuals under no stress. We conclude that Antarctic extremophiles can effectively reduce the physiological impact of saline stress in a salt-susceptible crops and also highlight extreme environments such as Antarctica as a key source of microorganism with high biotechnological potential.
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Affiliation(s)
- Ian S. Acuña-Rodríguez
- Center for Molecular and Functional Ecology (CEMFE), Instituto de Ciencias Biológicas, Universidad de Talca, Talca, Chile
| | - Hermann Hansen
- Facultad de Ciencias Agrarias, Universidad de Talca, Talca, Chile
| | - Jorge Gallardo-Cerda
- Center for Molecular and Functional Ecology (CEMFE), Instituto de Ciencias Biológicas, Universidad de Talca, Talca, Chile
| | - Cristian Atala
- Laboratorio de Anatomía y Ecología Funcional de Plantas (AEF), Instituto de Biología, Pontificia Universidad Católica de Valparaíso, Valparaiso, Chile
| | - Marco A. Molina-Montenegro
- Center for Molecular and Functional Ecology (CEMFE), Instituto de Ciencias Biológicas, Universidad de Talca, Talca, Chile
- Centro de Estudios Avanzados en Zonas Áridas (CEAZA), Facultad de Ciencias del Mar, Universidad Católica del Norte, Coquimbo, Chile
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46
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Pathan EK, Deshpande MV. The puzzle of highly virulent Metarhizium anisopliae
strains from Annona squamosa
fields against Helicoverpa armigera. J Basic Microbiol 2019; 59:392-401. [DOI: 10.1002/jobm.201800631] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Revised: 01/17/2019] [Accepted: 01/25/2019] [Indexed: 01/16/2023]
Affiliation(s)
- Ejaj K. Pathan
- Biochemical Sciences Division; CSIR-National Chemical Laboratory; Pune India
| | - Mukund V. Deshpande
- Biochemical Sciences Division; CSIR-National Chemical Laboratory; Pune India
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47
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Berry D, Mace W, Rehner SA, Grage K, Dijkwel PP, Young CA, Scott B. Orthologous peramine and pyrrolopyrazine-producing biosynthetic gene clusters in Metarhizium rileyi, Metarhizium majus and Cladonia grayi. Environ Microbiol 2018; 21:928-939. [PMID: 30452111 DOI: 10.1111/1462-2920.14483] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 11/09/2018] [Accepted: 11/13/2018] [Indexed: 12/17/2022]
Abstract
Peramine is a non-ribosomal peptide-derived pyrrolopyrazine (PPZ)-containing molecule with anti-insect properties. Peramine is known to be produced by fungi from genus Epichloë, which form mutualistic endophytic associations with cool-season grass hosts. Peramine biosynthesis has been proposed to require only the two-module non-ribosomal peptide synthetase (NRPS) peramine synthetase (PerA), which is encoded by the 8.3 kb gene perA, though this has not been conclusively proven. Until recently, both peramine and perA were thought to be exclusive to fungi of genus Epichloë; however, a putative perA homologue was recently identified in the genome of the insect-pathogenic fungus Metarhizium rileyi. We use a heterologous expression system and a hydrophilic interaction chromatography-based analysis method to confirm that PerA is the only pathway-specific protein required for peramine biosynthesis. The perA homologue from M. rileyi (MR_perA) is shown to encode a functional peramine synthetase, establishing a precedent for distribution of perA orthologs beyond genus Epichloë. Furthermore, perA is part of a larger seven-gene PPZ cluster in M. rileyi, Metarhizium majus and the stalked-cup lichen fungus Cladonia grayi. These PPZ genes encode proteins predicted to derivatize peramine into more complex PPZ metabolites, with the orphaned perA gene of Epichloë spp. representing an example of reductive evolution.
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Affiliation(s)
- Daniel Berry
- Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand.,Bio-Protection Research Centre, Massey University, Palmerston North, New Zealand
| | - Wade Mace
- AgResearch Ltd., Grasslands Research Center, Palmerston North, New Zealand
| | - Stephen A Rehner
- Mycology and Nematology Genetic Diversity and Biology Laboratory, USDA-ARS, Beltsville, MD, USA
| | - Katrin Grage
- Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand
| | - Paul P Dijkwel
- Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand
| | | | - Barry Scott
- Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand.,Bio-Protection Research Centre, Massey University, Palmerston North, New Zealand
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48
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Daru BH, Bowman EA, Pfister DH, Arnold AE. A novel proof of concept for capturing the diversity of endophytic fungi preserved in herbarium specimens. Philos Trans R Soc Lond B Biol Sci 2018; 374:20170395. [PMID: 30455213 PMCID: PMC6282087 DOI: 10.1098/rstb.2017.0395] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/29/2018] [Indexed: 12/22/2022] Open
Abstract
Herbarium specimens represent important records of morphological and genetic diversity of plants that inform questions relevant to global change, including species distributions, phenology and functional traits. It is increasingly appreciated that plant microbiomes can influence these aspects of plant biology, but little is known regarding the historic distribution of microbes associated with plants collected in the pre-molecular age. If microbiomes can be observed reliably in herbarium specimens, researchers will gain a new lens with which to examine microbial ecology, evolution, species interactions. Here, we describe a method for accessing historical plant microbiomes from preserved herbarium specimens, providing a proof of concept using two plant taxa from the imperiled boreal biome (Andromeda polifolia and Ledum palustre subsp. groenlandicum, Ericaceae). We focus on fungal endophytes, which occur within symptomless plant tissues such as leaves. Through a three-part approach (i.e. culturing, cloning and next-generation amplicon sequencing via the Illumina MiSeq platform, with extensive controls), we examined endophyte communities in dried, pressed leaves that had been processed as regular herbarium specimens and stored at room temperature in a herbarium for four years. We retrieved only one endophyte in culture, but cloning and especially the MiSeq analysis revealed a rich community of foliar endophytes. The phylogenetic distribution and diversity of endophyte assemblages, especially among the Ascomycota, resemble endophyte communities from fresh plants collected in the boreal biome. We could distinguish communities of endophytes in each plant species and differentiate likely endophytes from fungi that could be surface contaminants. Taxa found by cloning were observed in the larger MiSeq dataset, but species richness was greater when subsets of the same tissues were evaluated with the MiSeq approach. Our findings provide a proof of concept for capturing endophyte DNA from herbarium specimens, supporting the importance of herbarium records as roadmaps for understanding the dynamics of plant-associated microbial biodiversity in the Anthropocene.This article is part of the theme issue 'Biological collections for understanding biodiversity in the Anthropocene'.
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Affiliation(s)
- Barnabas H Daru
- Department of Life Sciences, Texas A&M University-Corpus Christi, Corpus Christi, TX 78412, USA
| | | | - Donald H Pfister
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
| | - A Elizabeth Arnold
- School of Plant Sciences, University of Arizona, Tucson, AZ 85721, USA
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ 85721, USA
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49
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Hettiarachchige IK, Elkins AC, Reddy P, Mann RC, Guthridge KM, Sawbridge TI, Forster JW, Spangenberg GC. Genetic modification of asexual Epichloë endophytes with the perA gene for peramine biosynthesis. Mol Genet Genomics 2018; 294:315-328. [PMID: 30443676 DOI: 10.1007/s00438-018-1510-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Accepted: 11/08/2018] [Indexed: 10/27/2022]
Abstract
Development of grass-endophyte associations with minimal or no detrimental effects in combination with beneficial characteristics is important for pastoral agriculture. The feasibility of enhancing production of an endophyte-derived beneficial alkaloid through introduction of an additional gene copy was assessed in a proof-of-concept study. Sexual and asexual Epichloë species that form symbiotic associations with cool-season grasses of the Poaceae sub-family Pooideae produce bioactive alkaloids that confer resistance to herbivory by a number of organisms. Of these, peramine is thought to be crucial for protection of perennial ryegrass (Lolium perenne L.) from the Argentinian stem weevil, an economically important exotic pest in New Zealand, contributing significantly to pasture persistence. A single gene (perA) has been identified as solely responsible for peramine biosynthesis and is distributed widely across Epichloë taxa. In the present study, a functional copy of the perA gene was introduced into three recipient endophyte genomes by Agrobacterium tumefaciens-mediated transformation. The target strains included some that do not produce peramine, and others containing different perA gene copies. Mitotically stable transformants generated from all three endophyte strains were able to produce peramine in culture and in planta at variable levels. In summary, this study provides an insight into the potential for artificial combinations of alkaloid biosynthesis in a single endophyte strain through transgenesis, as well as the possibility of using novel genome editing techniques to edit the perA gene of non-peramine producing strains.
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Affiliation(s)
| | - Aaron C Elkins
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, 3083, Bundoora, VIC, Australia
| | - Priyanka Reddy
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, 3083, Bundoora, VIC, Australia
| | - Ross C Mann
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, 3083, Bundoora, VIC, Australia
| | - Kathryn M Guthridge
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, 3083, Bundoora, VIC, Australia
| | - Timothy I Sawbridge
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, 3083, Bundoora, VIC, Australia.,School of Applied Systems Biology, La Trobe University, 3086, Bundoora, VIC, Australia
| | - John W Forster
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, 3083, Bundoora, VIC, Australia.,School of Applied Systems Biology, La Trobe University, 3086, Bundoora, VIC, Australia
| | - German C Spangenberg
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, 3083, Bundoora, VIC, Australia. .,School of Applied Systems Biology, La Trobe University, 3086, Bundoora, VIC, Australia.
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50
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Khare E, Mishra J, Arora NK. Multifaceted Interactions Between Endophytes and Plant: Developments and Prospects. Front Microbiol 2018; 9:2732. [PMID: 30498482 PMCID: PMC6249440 DOI: 10.3389/fmicb.2018.02732] [Citation(s) in RCA: 232] [Impact Index Per Article: 38.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2018] [Accepted: 10/25/2018] [Indexed: 11/13/2022] Open
Abstract
Microbial endophytes are present in all known plant species. The ability to enter and thrive in the plant tissues makes endophytes unique, showing multidimensional interactions within the host plant. Several vital activities of the host plant are known to be influenced by the presence of endophytes. They can promote plant growth, elicit defense response against pathogen attack, and can act as remediators of abiotic stresses. To date, most of the research has been done assuming that the interaction of endophytes with the host plant is similar to the plant growth-promoting (PGP) microbes present in the rhizosphere. However, a new appreciation of the difference of the rhizosphere environment from that of internal plant tissues is gaining attention. It would be interesting to explore the impact of endosymbionts on the host’s gene expression, metabolism, and other physiological aspects essential in conferring resistance against biotic and abiotic stresses. A more intriguing and inexplicable issue with many endophytes that has to be critically evaluated is their ability to produce host metabolites, which can be harnessed on a large scale for potential use in diverse areas. In this review, we discuss the concept of endophytism, looking into the latest insights related to the multifarious interactions beneficial for the host plant and exploring the importance of these associations in agriculture and the environment and in other vital aspects such as human health.
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Affiliation(s)
- Ekta Khare
- Department of Microbiology, Institute of Biosciences and Biotechnology, Chhatrapati Shahu Ji Maharaj University, Kanpur, India
| | - Jitendra Mishra
- Department of Microbiology, Babasaheb Bhimrao Ambedkar University, Lucknow, India
| | - Naveen Kumar Arora
- Department of Environmental Science, Babasaheb Bhimrao Ambedkar University, Lucknow, India
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