1
|
Pinchi-Davila XJ, Vargas-Hernández D, Romero-Jiménez MJ, Jumpponen A, Rudgers JA, Herrera J, Hutchinson M, Dunbar JM, Kuske C, Porras-Alfaro A. Pleoardoris graminearum, gen. et sp. nov., a new member of Pleosporales from North American Plains, its biogeography and effects on a foundation grass species. Mycologia 2023; 115:749-767. [PMID: 37874894 DOI: 10.1080/00275514.2023.2258269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Accepted: 09/08/2023] [Indexed: 10/26/2023]
Abstract
Diverse fungi colonize plant roots worldwide and include species from many orders of the phylum Ascomycota. These fungi include taxa with dark septate hyphae that colonize grass roots and may modulate plant responses to stress. We describe a novel group of fungal isolates and evaluate their effects on the grass Bouteloua gracilis in vitro. We isolated fungi from roots of six native grasses from 24 sites spanning replicated latitudinal gradients in the south-central US grasslands and characterized isolates phylogenetically using a genome analysis. We analyzed 14 isolates representing a novel clade within the family Montagnulaceae (order Pleosporales), here typified as Pleoardoris graminearum, closely related to the genera Didymocrea and Bimuria. This novel species produces asexual, light brown pycnidium-like conidioma, hyaline hyphae, and chlamydospores when cultured on quinoa and kiwicha agar. To evaluate its effects on B. gracilis, seeds were inoculated with one of three isolates (DS304, DS334, and DS1613) and incubated at 25 C for 20 d. We also tested the effect of volatile organic compounds (VOCs) produced by the same isolates on B. gracilis root and stem lengths. Isolates had variable effects on plant growth. One isolate increased B. gracilis root length up to 34% compared with uninoculated controls. VOCs produced by two isolates increased root and stem lengths (P < 0.05) compared with controls. Internal transcribed spacer ITS2 metabarcode data revealed that P. graminearum is distributed across a wide range of sites in North America (22 of 24 sites sampled), and its relative abundance is influenced by host species identity and latitude. Host species identity and site were the most important factors determining P. graminearum relative abundance in drought experiments at the Extreme Drought in the Grasslands Experiment (EDGE) sites. Variable responses of B. gracilis to inoculation highlight the potential importance of nonmycorrhizal root-associated fungi on plant survival in arid ecosystems.
Collapse
Affiliation(s)
| | | | | | - Ari Jumpponen
- Division of Biology, Kansas State University, Manhattan, Kansas, 66506
| | - Jennifer A Rudgers
- Department of Biology, University of New Mexico, Albuquerque, New Mexico, 87131
| | - Jose Herrera
- Office of the Provost and Executive Vice President for Academic Affairs, University of Northern Iowa, Cedar Falls, Iowa, 50614
| | | | - John M Dunbar
- Los Alamos National Laboratory, Los Alamos, New Mexico, 87545
| | - Cheryl Kuske
- Los Alamos National Laboratory, Los Alamos, New Mexico, 87545
| | - Andrea Porras-Alfaro
- Institute for Environmental Studies, Western Illinois University, Macomb, Illinois
- Division of Environmental Biology, National Science Foundation, Alexandria, Virginia 22314
| |
Collapse
|
2
|
Nasif SO, Siddique AB, Siddique AB, Islam MM, Hassan O, Deepo DM, Hossain A. Prospects of endophytic fungi as a natural resource for the sustainability of crop production in the modern era of changing climate. Symbiosis 2022. [DOI: 10.1007/s13199-022-00879-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
|
3
|
Johnston-Monje D, Gutiérrez JP, Becerra Lopez-Lavalle LA. Stochastic Inoculum, Biotic Filtering and Species-Specific Seed Transmission Shape the Rare Microbiome of Plants. Life (Basel) 2022; 12:life12091372. [PMID: 36143410 PMCID: PMC9506401 DOI: 10.3390/life12091372] [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: 07/28/2022] [Revised: 08/22/2022] [Accepted: 08/31/2022] [Indexed: 11/17/2022] Open
Abstract
A plant’s health and productivity is influenced by its associated microbes. Although the common/core microbiome is often thought to be the most influential, significant numbers of rare or uncommon microbes (e.g., specialized endosymbionts) may also play an important role in the health and productivity of certain plants in certain environments. To help identify rare/specialized bacteria and fungi in the most important angiosperm plants, we contrasted microbiomes of the seeds, spermospheres, shoots, roots and rhizospheres of Arabidopsis, Brachypodium, maize, wheat, sugarcane, rice, tomato, coffee, common bean, cassava, soybean, switchgrass, sunflower, Brachiaria, barley, sorghum and pea. Plants were grown inside sealed jars on sterile sand or farm soil. Seeds and spermospheres contained some uncommon bacteria and many fungi, suggesting at least some of the rare microbiome is vertically transmitted. About 95% and 86% of fungal and bacterial diversity inside plants was uncommon; however, judging by read abundance, uncommon fungal cells are about half of the mycobiome, while uncommon bacterial cells make up less than 11% of the microbiome. Uncommon-seed-transmitted microbiomes consisted mostly of Proteobacteria, Firmicutes, Bacteriodetes, Ascomycetes and Basidiomycetes, which most heavily colonized shoots, to a lesser extent roots, and least of all, rhizospheres. Soil served as a more diverse source of rare microbes than seeds, replacing or excluding the majority of the uncommon-seed-transmitted microbiome. With the rarest microbes, their colonization pattern could either be the result of stringent biotic filtering by most plants, or uneven/stochastic inoculum distribution in seeds or soil. Several strong plant–microbe associations were observed, such as seed transmission to shoots, roots and/or rhizospheres of Sarocladium zeae (maize), Penicillium (pea and Phaseolus), and Curvularia (sugarcane), while robust bacterial colonization from cassava field soil occurred with the cyanobacteria Leptolyngbya into Arabidopsis and Panicum roots, and Streptomyces into cassava roots. Some abundant microbes such as Sakaguchia in rice shoots or Vermispora in Arabidopsis roots appeared in no other samples, suggesting that they were infrequent, stochastically deposited propagules from either soil or seed (impossible to know based on the available data). Future experiments with culturing and cross-inoculation of these microbes between plants may help us better understand host preferences and their role in plant productivity, perhaps leading to their use in crop microbiome engineering and enhancement of agricultural production.
Collapse
Affiliation(s)
- David Johnston-Monje
- Max Planck Tandem Group in Plant Microbial Ecology, Universidad del Valle, Cali 76001, Colombia
- International Center for Tropical Agriculture (CIAT), Cali 763537, Colombia
- Department of Plant Microbe Interactions, Max Planck Institute for Plant Breeding Research, 50829 Cologne, Germany
- Correspondence: ; Tel.: +57-315-545-6227
| | | | | |
Collapse
|
4
|
El-Hasan A, Ngatia G, Link TI, Voegele RT. Isolation, Identification, and Biocontrol Potential of Root Fungal Endophytes Associated with Solanaceous Plants against Potato Late Blight (Phytophthora infestans). PLANTS 2022; 11:plants11121605. [PMID: 35736756 PMCID: PMC9229062 DOI: 10.3390/plants11121605] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 06/10/2022] [Accepted: 06/14/2022] [Indexed: 12/31/2022]
Abstract
Late blight of potato caused by Phytophthora infestans is one of the most damaging diseases affecting potato production worldwide. We screened 357 root fungal endophytes isolated from four solanaceous plant species obtained from Kenya regarding their in vitro antagonistic activity against the potato late blight pathogen and evaluated their performance in planta. Preliminary in vitro tests revealed that 46 of these isolates showed potential activity against the pathogen. Based on their ITS-sequences, 37 out of 46 endophytes were identified to species level, three isolates were connected to higher taxa (phylum or genus), while two remained unidentified. Confrontation assays, as well as assays for volatile or diffusible organic compounds, resulted in the selection of three endophytes (KB1S1-4, KA2S1-42, and KB2S2-15) with a pronounced inhibitory activity against P. infestans. All three isolates produce volatile organic compounds that inhibit mycelial growth of P. infestans by up to 48.9%. The addition of 5% extracts obtained from KB2S2-15 or KA2S1-42 to P. infestans sporangia entirely suppressed their germination. A slightly lower inhibition (69%) was achieved using extract from KB1S1-4. Moreover, late blight symptoms and the mycelial growth of P. infestans were completely suppressed when leaflets were pre-treated with a 5% extract from these endophytes. This might suggest the implementation of such biocontrol candidates or their fungicidal compounds in late blight control strategies.
Collapse
|
5
|
Mesny F, Miyauchi S, Thiergart T, Pickel B, Atanasova L, Karlsson M, Hüttel B, Barry KW, Haridas S, Chen C, Bauer D, Andreopoulos W, Pangilinan J, LaButti K, Riley R, Lipzen A, Clum A, Drula E, Henrissat B, Kohler A, Grigoriev IV, Martin FM, Hacquard S. Genetic determinants of endophytism in the Arabidopsis root mycobiome. Nat Commun 2021; 12:7227. [PMID: 34893598 PMCID: PMC8664821 DOI: 10.1038/s41467-021-27479-y] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 11/11/2021] [Indexed: 02/03/2023] Open
Abstract
The roots of Arabidopsis thaliana host diverse fungal communities that affect plant health and disease states. Here, we sequence the genomes of 41 fungal isolates representative of the A. thaliana root mycobiota for comparative analysis with other 79 plant-associated fungi. Our analyses indicate that root mycobiota members evolved from ancestors with diverse lifestyles and retain large repertoires of plant cell wall-degrading enzymes (PCWDEs) and effector-like small secreted proteins. We identify a set of 84 gene families associated with endophytism, including genes encoding PCWDEs acting on xylan (family GH10) and cellulose (family AA9). Transcripts encoding these enzymes are also part of a conserved transcriptional program activated by phylogenetically-distant mycobiota members upon host contact. Recolonization experiments with individual fungi indicate that strains with detrimental effects in mono-association with the host colonize roots more aggressively than those with beneficial activities, and dominate in natural root samples. Furthermore, we show that the pectin-degrading enzyme family PL1_7 links aggressiveness of endophytic colonization to plant health.
Collapse
Affiliation(s)
- Fantin Mesny
- Max Planck Institute for Plant Breeding Research, 50829, Cologne, Germany
| | - Shingo Miyauchi
- Max Planck Institute for Plant Breeding Research, 50829, Cologne, Germany
- Université de Lorraine, Institut national de recherche pour l'agriculture, l'alimentation et l'environnement, UMR Interactions Arbres/Microorganismes, Centre INRAE Grand Est-Nancy, 54280, Champenoux, France
| | - Thorsten Thiergart
- Max Planck Institute for Plant Breeding Research, 50829, Cologne, Germany
| | - Brigitte Pickel
- Max Planck Institute for Plant Breeding Research, 50829, Cologne, Germany
| | - Lea Atanasova
- Research division of Biochemical Technology, Institute of Chemical, Environmental and Biological Engineering, Vienna University of Technology, Vienna, Austria
- Institute of Food Technology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Magnus Karlsson
- Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, SE-75007, Uppsala, Sweden
| | - Bruno Hüttel
- Max Planck Genome Centre Cologne, Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Kerrie W Barry
- U.S. Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Sajeet Haridas
- U.S. Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Cindy Chen
- U.S. Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Diane Bauer
- U.S. Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - William Andreopoulos
- U.S. Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Jasmyn Pangilinan
- U.S. Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Kurt LaButti
- U.S. Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Robert Riley
- U.S. Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Anna Lipzen
- U.S. Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Alicia Clum
- U.S. Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Elodie Drula
- INRAE, USC1408 Architecture et Fonction des Macromolécules Biologiques, 13009, Marseille, France
- Architecture et Fonction des Macromolécules Biologiques (AFMB), CNRS, Aix-Marseille Univ., 13009, Marseille, France
| | - Bernard Henrissat
- Department of Biological Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Annegret Kohler
- Université de Lorraine, Institut national de recherche pour l'agriculture, l'alimentation et l'environnement, UMR Interactions Arbres/Microorganismes, Centre INRAE Grand Est-Nancy, 54280, Champenoux, France
| | - Igor V Grigoriev
- U.S. Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, CA, USA
| | - Francis M Martin
- Université de Lorraine, Institut national de recherche pour l'agriculture, l'alimentation et l'environnement, UMR Interactions Arbres/Microorganismes, Centre INRAE Grand Est-Nancy, 54280, Champenoux, France.
- Beijing Advanced Innovation Centre for Tree Breeding by Molecular Design (BAIC-TBMD), Institute of Microbiology, Beijing Forestry University, Tsinghua East Road Haidian District, Beijing, China.
| | - Stéphane Hacquard
- Max Planck Institute for Plant Breeding Research, 50829, Cologne, Germany.
- Cluster of Excellence on Plant Sciences (CEPLAS), Max Planck Institute for Plant Breeding Research, 50829, Cologne, Germany.
| |
Collapse
|
6
|
Araujo R, Dunlap C, Franco CM. Analogous wheat root rhizosphere microbial successions in field and greenhouse trials in the presence of biocontrol agents Paenibacillus peoriae SP9 and Streptomyces fulvissimus FU14. MOLECULAR PLANT PATHOLOGY 2020; 21:622-635. [PMID: 32056349 PMCID: PMC7170773 DOI: 10.1111/mpp.12918] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Revised: 12/26/2019] [Accepted: 01/21/2020] [Indexed: 05/05/2023]
Abstract
Two Pythium-infested soils were used to compare the wheat root and rhizosphere soil microbial communities from plants grown in the field or in greenhouse trials and their stability in the presence of biocontrol agents. Bacteria showed the highest diversity at early stages of wheat growth in both field and greenhouse trials, while fungal diversity increased later on, at 12 weeks of the crop cycle. The microbial communities were stable in roots and rhizosphere samples across both soil types used in this study. Such stability was also observed irrespective of the cultivation system (field or greenhouse) or addition of biocontrol coatings to wheat seeds to control Pythium disease (in this study soil infected with Pythium sp. clade F was tested). In greenhouse plant roots, Archaeorhizomyces, Debaryomyces, Delftia, and unclassified Pseudeurotiaceae were significantly reduced when compared to plant roots obtained from the field trials. Some operational taxonomic units (OTUs) represented genetic determinants clearly transmitted vertically by seed endophytes (specific OTUs were found in plant roots) and the plant microbiota was enriched over time by OTUs from the rhizosphere soil. This study provided key information regarding the microbial communities associated with wheat roots and rhizosphere soils at different stages of plant growth and the role that Paenibacillus and Streptomyces strains play as biocontrol agents in supporting plant growth in infested soils.
Collapse
Affiliation(s)
- Ricardo Araujo
- Department Medical BiotechnologyFlinders UniversitySouth Australia
- i3S, Institute of Research and Innovation in HealthUniversity of PortoPortugal
| | - Christopher Dunlap
- Crop Bioprotection ResearchThe United States Department of AgriculturePeoriaILUSA
| | | |
Collapse
|
7
|
Strom N, Hu W, Haarith D, Chen S, Bushley K. Corn and Soybean Host Root Endophytic Fungi with Toxicity Toward the Soybean Cyst Nematode. PHYTOPATHOLOGY 2020; 110:603-614. [PMID: 31631807 DOI: 10.1094/phyto-07-19-0243-r] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Although fungal endophytes are commonly investigated for their ability to deter microbial plant pathogens, few studies have examined the activity of fungal root endophytes against nematodes. The soybean cyst nematode (SCN; Heterodera glycines), the most severe yield-limiting pathogen of soybean (Glycine max), is commonly managed through rotation of soybean with corn (Zea mays), a nonhost of the SCN. A total of 626 fungal endophytes were isolated from surface-sterilized corn and soybean roots from experimental plots in which soybean and corn had been grown under annual rotation and under 1, 3, 5, and 35 years of continuous monoculture. Fungal isolates were grouped into 401 morphotypes, which were clustered into 108 operational taxonomic units (OTUs) based on 99% sequence similarity of the full internal transcribed spacer region. Morphotype representatives within each OTU were grown in malt extract broth and in a secondary metabolite-inducing medium buffered with ammonium tartrate, and their culture filtrates were tested for nematicidal activity against SCN juveniles. A majority of OTUs containing isolates with nematicidal culture filtrates were in the order Hypocreales, with the genus Fusarium being the most commonly isolated nematicidal genus from corn and soybean roots. Less commonly isolated taxa from soybean roots included the nematophagous fungi Hirsutella rhossiliensis, Metacordyceps chlamydosporia, and Arthrobotrys iridis. Root endophytic fungal diversity in soybean was positively correlated with SCN density, suggesting that the SCN plays a role in shaping the soybean root endophytic community.
Collapse
Affiliation(s)
- Noah Strom
- Department of Plant and Microbial Biology, University of Minnesota, Saint Paul, MN
| | - Weiming Hu
- Entomology and Nematology Department, University of Florida, Gainesville, FL
| | - Deepak Haarith
- Department of Plant Pathology, University of Minnesota, Saint Paul, MN
| | - Senyu Chen
- Southern Research and Outreach Center, University of Minnesota, Waseca, MN
| | - Kathryn Bushley
- Department of Plant and Microbial Biology, University of Minnesota, Saint Paul, MN
| |
Collapse
|
8
|
Challacombe JF, Hesse CN, Bramer LM, McCue LA, Lipton M, Purvine S, Nicora C, Gallegos-Graves LV, Porras-Alfaro A, Kuske CR. Genomes and secretomes of Ascomycota fungi reveal diverse functions in plant biomass decomposition and pathogenesis. BMC Genomics 2019; 20:976. [PMID: 31830917 PMCID: PMC6909477 DOI: 10.1186/s12864-019-6358-x] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Accepted: 12/01/2019] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND The dominant fungi in arid grasslands and shrublands are members of the Ascomycota phylum. Ascomycota fungi are important drivers in carbon and nitrogen cycling in arid ecosystems. These fungi play roles in soil stability, plant biomass decomposition, and endophytic interactions with plants. They may also form symbiotic associations with biocrust components or be latent saprotrophs or pathogens that live on plant tissues. However, their functional potential in arid soils, where organic matter, nutrients and water are very low or only periodically available, is poorly characterized. RESULTS Five Ascomycota fungi were isolated from different soil crust microhabitats and rhizosphere soils around the native bunchgrass Pleuraphis jamesii in an arid grassland near Moab, UT, USA. Putative genera were Coniochaeta, isolated from lichen biocrust, Embellisia from cyanobacteria biocrust, Chaetomium from below lichen biocrust, Phoma from a moss microhabitat, and Aspergillus from the soil. The fungi were grown in replicate cultures on different carbon sources (chitin, native bunchgrass or pine wood) relevant to plant biomass and soil carbon sources. Secretomes produced by the fungi on each substrate were characterized. Results demonstrate that these fungi likely interact with primary producers (biocrust or plants) by secreting a wide range of proteins that facilitate symbiotic associations. Each of the fungal isolates secreted enzymes that degrade plant biomass, small secreted effector proteins, and proteins involved in either beneficial plant interactions or virulence. Aspergillus and Phoma expressed more plant biomass degrading enzymes when grown in grass- and pine-containing cultures than in chitin. Coniochaeta and Embellisia expressed similar numbers of these enzymes under all conditions, while Chaetomium secreted more of these enzymes in grass-containing cultures. CONCLUSIONS This study of Ascomycota genomes and secretomes provides important insights about the lifestyles and the roles that Ascomycota fungi likely play in arid grassland, ecosystems. However, the exact nature of those interactions, whether any or all of the isolates are true endophytes, latent saprotrophs or opportunistic phytopathogens, will be the topic of future studies.
Collapse
Affiliation(s)
- Jean F Challacombe
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA.
- Present address: Colorado State University, College of Agricultural Sciences, 301 University Ave, Fort Collins, CO, 80523, USA.
| | - Cedar N Hesse
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
- Horticultural Crops Research, USDA ARS, Corvallis, OR, USA
| | - Lisa M Bramer
- Applied Statistics & Computational Modeling, Pacific Northwest National Laboratory, Richland, Washington, USA
| | - Lee Ann McCue
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington, 99352, USA
| | - Mary Lipton
- Applied Statistics & Computational Modeling, Pacific Northwest National Laboratory, Richland, Washington, USA
| | - Samuel Purvine
- Applied Statistics & Computational Modeling, Pacific Northwest National Laboratory, Richland, Washington, USA
| | - Carrie Nicora
- Applied Statistics & Computational Modeling, Pacific Northwest National Laboratory, Richland, Washington, USA
| | | | | | - Cheryl R Kuske
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
| |
Collapse
|
9
|
Andreo-Jimenez B, Vandenkoornhuyse P, Lê Van A, Heutinck A, Duhamel M, Kadam N, Jagadish K, Ruyter-Spira C, Bouwmeester H. Plant host and drought shape the root associated fungal microbiota in rice. PeerJ 2019; 7:e7463. [PMID: 31565550 PMCID: PMC6744933 DOI: 10.7717/peerj.7463] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 07/11/2019] [Indexed: 11/22/2022] Open
Abstract
Background and Aim Water is an increasingly scarce resource while some crops, such as paddy rice, require large amounts of water to maintain grain production. A better understanding of rice drought adaptation and tolerance mechanisms could help to reduce this problem. There is evidence of a possible role of root-associated fungi in drought adaptation. Here, we analyzed the endospheric fungal microbiota composition in rice and its relation to plant genotype and drought. Methods Fifteen rice genotypes (Oryza sativa ssp. indica) were grown in the field, under well-watered conditions or exposed to a drought period during flowering. The effect of genotype and treatment on the root fungal microbiota composition was analyzed by 18S ribosomal DNA high throughput sequencing. Grain yield was determined after plant maturation. Results There was a host genotype effect on the fungal community composition. Drought altered the composition of the root-associated fungal community and increased fungal biodiversity. The majority of OTUs identified belonged to the Pezizomycotina subphylum and 37 of these significantly correlated with a higher plant yield under drought, one of them being assigned to Arthrinium phaeospermum. Conclusion This study shows that both plant genotype and drought affect the root-associated fungal community in rice and that some fungi correlate with improved drought tolerance. This work opens new opportunities for basic research on the understanding of how the host affects microbiota recruitment as well as the possible use of specific fungi to improve drought tolerance in rice.
Collapse
Affiliation(s)
- Beatriz Andreo-Jimenez
- Laboratory of Plant Physiology, Wageningen University, Wageningen, Netherlands.,Biointeractions & Plant Health Business Unit, Wageningen University & Research, Wageningen, Netherlands
| | | | | | - Arvid Heutinck
- Laboratory of Plant Physiology, Wageningen University, Wageningen, Netherlands
| | - Marie Duhamel
- EcoBio, Université Rennes I, Rennes, France.,IBL Plant Sciences and Natural Products, Leiden University, Leiden, Netherlands
| | - Niteen Kadam
- International Rice Research Institute, Los Baños, Philippines
| | - Krishna Jagadish
- International Rice Research Institute, Los Baños, Philippines.,Department of Agronomy, Kansas State University, Manhattan, KS, United States of America
| | | | - Harro Bouwmeester
- Laboratory of Plant Physiology, Wageningen University, Wageningen, Netherlands.,Plant Hormone Biology group, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, Netherlands
| |
Collapse
|
10
|
Rootstocks Shape the Rhizobiome: Rhizosphere and Endosphere Bacterial Communities in the Grafted Tomato System. Appl Environ Microbiol 2019; 85:AEM.01765-18. [PMID: 30413478 DOI: 10.1128/aem.01765-18] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 10/23/2018] [Indexed: 12/21/2022] Open
Abstract
Root-associated microbes are critical to plant health and performance, although understanding of the factors that structure these microbial communities and the theory to predict microbial assemblages are still limited. Here, we use a grafted tomato system to study the effects of rootstock genotypes and grafting in endosphere and rhizosphere microbiomes that were evaluated by sequencing 16S rRNA. We compared the microbiomes of nongrafted tomato cultivar BHN589, self-grafted BHN589, and BHN589 grafted to Maxifort or RST-04-106 hybrid rootstocks. Operational taxonomic unit (OTU)-based bacterial diversity was greater in Maxifort compared to the nongrafted control, whereas bacterial diversity in the controls (self-grafted and nongrafted) and the other rootstock (RST-04-106) was similar. Grafting itself did not affect bacterial diversity; diversity in the self-graft was similar to that of the nongraft. Bacterial diversity was higher in the rhizosphere than in the endosphere for all treatments. However, despite the lower overall diversity, there was a greater number of differentially abundant OTUs (DAOTUs) in the endosphere, with the greatest number of DAOTUs associated with Maxifort. In a permutational multivariate analysis of variance (PERMANOVA), there was evidence for an effect of rootstock genotype on bacterial communities. The endosphere-rhizosphere compartment and study site explained a high percentage of the differences among bacterial communities. Further analyses identified OTUs responsive to rootstock genotypes in both the endosphere and rhizosphere. Our findings highlight the effects of rootstocks on bacterial diversity and composition. The influence of rootstock and plant compartment on microbial communities indicates opportunities for the development of designer communities and microbiome-based breeding to improve future crop production.IMPORTANCE Understanding factors that control microbial communities is essential for designing and supporting microbiome-based agriculture. In this study, we used a grafted tomato system to study the effect of rootstock genotypes and grafting on bacterial communities colonizing the endosphere and rhizosphere. To compare the bacterial communities in control treatments (nongrafted and self-grafted plants) with the hybrid rootstocks used by farmers, we evaluated the effect of rootstocks on overall bacterial diversity and composition. These findings indicate the potential for using plant genotype to indirectly select bacterial taxa. In addition, we identify taxa responsive to each rootstock treatment, which may represent candidate taxa useful for biocontrol and in biofertilizers.
Collapse
|
11
|
Araujo R, Dunlap C, Barnett S, Franco CM. Decoding Wheat Endosphere-Rhizosphere Microbiomes in Rhizoctonia solani-Infested Soils Challenged by Streptomyces Biocontrol Agents. FRONTIERS IN PLANT SCIENCE 2019; 10:1038. [PMID: 31507625 PMCID: PMC6718142 DOI: 10.3389/fpls.2019.01038] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Accepted: 07/24/2019] [Indexed: 05/21/2023]
Abstract
The endosphere and the rhizosphere are pertinent milieus with microbial communities that perturb the agronomic traits of crop plants through beneficial or detrimental interactions. In this study, we challenged these communities by adding Streptomyces biocontrol strains to wheat seeds in soils with severe Rhizoctonia solani infestation. Wheat plants were grown in a glasshouse standardized system, and the bacterial and fungal microbiomes of 233 samples of wheat roots (endosphere) and rhizosphere soils were monitored for 20 weeks, from seed to mature plant stage. The results showed highly dynamic and diverse microbial communities that changed over time, with Sphingomonas bacteria and Aspergillus, Dipodascus, and Trichoderma fungi increasing over time. Application of biocontrol Streptomyces strains promoted plant growth and maturation of wheat heads and modulated the root microbiome, decreasing Paenibacillus and increasing other bacterial and fungal OTUs. The soils with the highest levels of R. solani had increased reads of Thanatephorus (Rhizoctonia anamorph) and increased root disease levels and increased Balneimonas, Massilia, Pseudomonas, and unclassified Micrococcaceae. As we enter the era of biologically sustainable agriculture, it may be possible to reduce and limit the effects of serious fungal infestations by promoting a beneficial microbiome through the application of biocontrol agents during different periods of plant development.
Collapse
Affiliation(s)
- Ricardo Araujo
- Department of Medical Biotechnology, Flinders University, Adelaide, SA, Australia
- i3S, University of Porto, Porto, Portugal
- *Correspondence: Ricardo Araujo,
| | - Christopher Dunlap
- Crop Bioprotection Research, The United States Department of Agriculture, Peoria, IL, United States
| | - Steve Barnett
- Department of Medical Biotechnology, Flinders University, Adelaide, SA, Australia
- South Australian Research & Development Institute (SARDI), Adelaide, SA, Australia
| | | |
Collapse
|
12
|
|
13
|
Knapp DG, Kovács GM. Interspecific metabolic diversity of root-colonizing endophytic fungi revealed by enzyme activity tests. FEMS Microbiol Ecol 2016; 92:fiw190. [PMID: 27604257 DOI: 10.1093/femsec/fiw190] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/31/2016] [Indexed: 01/09/2023] Open
Abstract
Although dark septate endophytes (DSE) represent a worldwide dispersed form group of root-colonizing endophytic fungi, our knowledge on their role in ecosystem functioning is far limited. In this study, we aimed to test if functional diversity exists among DSE fungi representing different lineages of root endophytic fungal community of semiarid sandy grasslands. To address this question and to gain general information on function of DSE fungi, we adopted api-ZYM and BioLog FF assays to study those non-sporulating filamentous fungi and characterized the metabolic activity of 15 different DSE species. Although there were striking differences among the species, all of the substrates tested were utilized by the DSE fungi. When endophytes characteristic to grasses and non-grass host plants were separately considered, we found that the whole substrate repertoire was used by both groups. This might illustrate the complementary functional diversity of the communities root endophytic plant-associated fungi. The broad spectra of substrates utilized by these root endophytes illustrate the functional importance of their diversity, which can play role not only in nutrient mobilization and uptake of plants from with nutrient poor soils, but also in general plant performance and ecosystem functioning.
Collapse
Affiliation(s)
- Dániel G Knapp
- Institute of Biology, Department of Plant Anatomy, Eötvös Loránd University, Pázmány Péter sétány 1/C, Budapest 1117, Hungary
| | - Gábor M Kovács
- Institute of Biology, Department of Plant Anatomy, Eötvös Loránd University, Pázmány Péter sétány 1/C, Budapest 1117, Hungary
| |
Collapse
|