DOCSLIB.ORG

Drought Consistently Alters the Composition of Soil Fungal and Bacterial Communities in Grasslands from Two Continents

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Drought Consistently Alters the Composition of Soil Fungal and Bacterial Communities in Grasslands from Two Continents Received: 17 November 2017 | Accepted: 15 January 2018 DOI: 10.1111/gcb.14113 PRIMARY RESEARCH ARTICLE Drought consistently alters the composition of soil fungal and bacterial communities in grasslands from two continents Raul Ochoa-Hueso1 | Scott L. Collins2 | Manuel Delgado-Baquerizo3 | Kelly Hamonts4 | William T. Pockman2 | Robert L. Sinsabaugh2 | Melinda D. Smith5 | Alan K. Knapp5 | Sally A. Power4 1Department of Ecology, Autonomous University of Madrid, Madrid, Spain Abstract 2Department of Biology, University of New The effects of short-term drought on soil microbial communities remain largely Mexico, Albuquerque, NM, USA unexplored, particularly at large scales and under field conditions. We used seven 3Cooperative Institute for Research in Environmental Sciences, University of experimental sites from two continents (North America and Australia) to evaluate Colorado, Boulder, CO, USA the impacts of imposed extreme drought on the abundance, community composi- 4 Hawkesbury Institute for the Environment, tion, richness, and function of soil bacterial and fungal communities. The sites Western Sydney University, Penrith, New South Wales, Australia encompassed different grassland ecosystems spanning a wide range of climatic and 5Department of Biology and Graduate soil properties. Drought significantly altered the community composition of soil bac- Degree Program in Ecology, Colorado State University, Fort Collins, CO, USA teria and, to a lesser extent, fungi in grasslands from two continents. The magnitude of the fungal community change was directly proportional to the precipitation gradi- Correspondence Raul Ochoa-Hueso, Department of Ecology, ent. This greater fungal sensitivity to drought at more mesic sites contrasts with the Autonomous University of Madrid, Madrid, generally observed pattern of greater drought sensitivity of plant communities in Spain. Email: [email protected] more arid grasslands, suggesting that plant and microbial communities may respond differently along precipitation gradients. Actinobateria, and Chloroflexi, bacterial Funding information Western Sydney University; Hermon Slade phyla typically dominant in dry environments, increased their relative abundance in Foundation, Grant/Award Number: response to drought, whereas Glomeromycetes, a fungal class regarded as widely P00021516; NSF Macrosystems Biology, Grant/Award Number: EF-1137378, symbiotic, decreased in relative abundance. The response of Chlamydiae and Teneri- EF-1137363, EF-1137342, EF-1137293 cutes, two phyla of mostly pathogenic species, decreased and increased along the precipitation gradient, respectively. Soil enzyme activity consistently increased under drought, a response that was attributed to drought-induced changes in microbial community structure rather than to changes in abundance and diversity. Our results provide evidence that drought has a widespread effect on the assembly of microbial communities, one of the major drivers of soil function in terrestrial ecosystems. Such responses may have important implications for the provision of key ecosystem services, including nutrient cycling, and may result in the weakening of plant–micro- bial interactions and a greater incidence of certain soil-borne diseases. KEYWORDS drought, enzyme activities, microbial community, rainfall manipulation, soil-borne pathogens 2818 | © 2018 John Wiley & Sons Ltd wileyonlinelibrary.com/journal/gcb Glob Change Biol. 2018;24:2818–2827. OCHOA-HUESO ET AL. | 2819 1 | INTRODUCTION and, therefore, understanding how microbial community structure and functioning in grasslands respond to drought is essential for pre- Microorganisms play fundamental roles as primary producers and dicting impacts of climate change on the global C cycle. Climate decomposers and provide important ecosystem services such as models for the Central and Southwest US, where grasslands domi- organic matter decomposition and nutrient cycling and storage nate the landscape, predict an intensification of the hydrological (Bardgett & van der Putten, 2014; van der Heijden, Bardgett, & van cycle, with high interannual precipitation variability and fewer but Straalen, 2008). The structure and activity of microbial communities larger rain events (Cook et al., 2015). Similarly, for south-eastern in soils is influenced by substrate properties, particularly soil pH and Australia, where land conversion has transformed more than 90% of organic matter content, and vegetation type (Delgado-Baquerizo native woodlands into seminatural grasslands, the most recent cli- et al., 2016a; Fierer & Jackson, 2006); at larger spatial and temporal mate models predict an increase in the occurrence of extreme pre- scales long-term climatic phenomena such as increasing aridity have cipitation events interspersed with longer droughts and shifts in also been associated with lower bacterial and fungal abundance and precipitation seasonality but little change in total precipitation lower microbial diversity (Maestre et al., 2015). However, much less (McLaughlin, 2014). is known about how short-term climatic processes, including the In this study, we evaluated the impacts of comparable extreme more extreme drought events forecast (Cook, Ault, & Smerdon, drought simulation experiments (50% precipitation reduction) con- 2015), will affect microbial communities and the ecosystem services ducted at seven grasslands located in two continents, North America they mediate. and Australia (Table 1; Figure 1). We sampled each site during the Climate models forecast widespread changes in precipitation 2nd or 3rd year of imposed drought and measured (i) soil microbial regimes, including longer, more intense droughts (McLaughlin, 2014), community richness (number of phylotypes) and composition (rela- causing desertification and promoting the expansion of drylands tive abundance of phylotypes), (ii) microbial abundance, and (iii) the globally (Huang, Yu, Guan, Wang, & Guo, 2016). Field-based climate potential activities of enzymes associated with decomposition and change studies have traditionally focused on aboveground responses nutrient cycling by soil microbial communities. The consistency of (e.g., plant productivity, biomass, and community composition) of treatment types between sites in the USA (66% precipitation reduc- local studies, whereas belowground responses, particularly those of tion during the growing season, equivalent to an annual reduction of microbial communities, have received much less attention (Wilcox, 50%) and Australia (50% year-round reduction; Power et al., 2016) von Fischer, Muscha, Petersen, & Knapp, 2015; Wilcox et al., 2017). allows for evaluation of responses to experimental drought across Experimental approaches across multiple sites and continents, where continents. We hypothesized that, at both intercontinental and local contrasting climatic and edaphic conditions may mediate the impacts scales, experimental drought will significantly alter the assembly of of changing precipitation regimes, are equally needed to accurately microbial communities in grasslands, with bacterial communities predict the response of microbial communities to extreme drought being more sensitive than fungi to water limitation (Austin et al., (Fridley, Grime, Askew, Moser, & Stevens, 2011; Grime et al., 2008). 2004; Clark, Campbell, Grizzle, Acosta-Martınez, & Zak, 2009). Drought experiments and meta-analyses consistently predict nega- Specifically, we predicted that the relative abundance of bacterial tive impacts of drought on the diversity and abundance of soil microbial communities (Wu, Dijkstra, Koch, Penuelas,~ & Hungate, TABLE 1 Environmental characteristics of study sites 2011), with bacteria typically considered more sensitive than fungi Grassland MAP MAT (Evans & Wallenstein, 2012; Fry et al., 2016). Given the strong link Site name Code type (mm) (°C) pH between microbial communities and soil functioning, any alteration Sevilleta National SEV Desert 242 13.3 8.5 in the composition of microbial communities due to climate change Wildlife Refuge Black might disrupt the functioning of soil, and thus the supply of ecosys- Sevilleta National SEV Shortgrass 242 13.3 8.8 tem services (Bellard, Bertelsmeier, Leadley, Thuiller, & Courchamp, Wildlife Refuge Blue 2012; McLaughlin, 2014). Because of this, improving our under- Central Plains SGS Shortgrass 342 8.6 6.2 standing of the role of altered precipitation regimes in the regulation Experimental Range of soil microbial communities is of paramount importance to accu- High Plains WYO Mixed 384 7.6 7.1 rately predict changes in terrestrial ecosystem processes linked to Grasslands Research future climate change scenarios (Delgado-Baquerizo et al., 2016b; Center Maestre et al., 2015). Hays Agricultural HAYS Mixed 577 12.0 7.2 Research Center Grasslands are critically important components of terrestrial ecosystem feedbacks to climate change. They represent ca. 40% of Konza Prairie KNZ Tallgrass 860 12.9 6.4 Biological Station the total land surface, store ca. 3.4 t C haÀ1 yearÀ1 and provide DRI-Grass DG Australian 800 17.0 6.6 multiple ecosystem services (McLaughlin, 2014). Grasslands also Experimental Site grassland greatly contribute to regulate the interannual variability in the soil C sink at the global scale (Ahlstrom€ et al., 2015; Poulter et al., 2014) MAP, mean annual precipitation; MAT, mean annual temperature. 2820 | OCHOA-HUESO ET AL. (a) (b) EDGE WYO SGS 1,600 HAYS KNZ 1,400 1,200 1,000 800 EDGE Latitude 600 SEV 400 200 30 32 34 36 38 40 42 44 –110 –105 –100
Load more

Recommended publications
  • Fungal Evolution: Major Ecological Adaptations and Evolutionary Transitions
    Biol. Rev. (2019), pp. 000–000. 1 doi: 10.1111/brv.12510 Fungal evolution: major ecological adaptations and evolutionary transitions Miguel A. Naranjo-Ortiz1 and Toni Gabaldon´ 1,2,3∗ 1Department of Genomics and Bioinformatics, Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88, Barcelona 08003, Spain 2 Department of Experimental and Health Sciences, Universitat Pompeu Fabra (UPF), 08003 Barcelona, Spain 3ICREA, Pg. Lluís Companys 23, 08010 Barcelona, Spain ABSTRACT Fungi are a highly diverse group of heterotrophic eukaryotes characterized by the absence of phagotrophy and the presence of a chitinous cell wall. While unicellular fungi are far from rare, part of the evolutionary success of the group resides in their ability to grow indefinitely as a cylindrical multinucleated cell (hypha). Armed with these morphological traits and with an extremely high metabolical diversity, fungi have conquered numerous ecological niches and have shaped a whole world of interactions with other living organisms. Herein we survey the main evolutionary and ecological processes that have guided fungal diversity. We will first review the ecology and evolution of the zoosporic lineages and the process of terrestrialization, as one of the major evolutionary transitions in this kingdom. Several plausible scenarios have been proposed for fungal terrestralization and we here propose a new scenario, which considers icy environments as a transitory niche between water and emerged land. We then focus on exploring the main ecological relationships of Fungi with other organisms (other fungi, protozoans, animals and plants), as well as the origin of adaptations to certain specialized ecological niches within the group (lichens, black fungi and yeasts).
    [Show full text]
  • Occurrence of Glomeromycota Species in Aquatic Habitats: a Global Overview
    Occurrence of Glomeromycota species in aquatic habitats: a global overview MARIANA BESSA DE QUEIROZ1, KHADIJA JOBIM1, XOCHITL MARGARITO VISTA1, JULIANA APARECIDA SOUZA LEROY1, STEPHANIA RUTH BASÍLIO SILVA GOMES2, BRUNO TOMIO GOTO3 1 Programa de Pós-Graduação em Sistemática e Evolução, 2 Curso de Ciências Biológicas, and 3 Departamento de Botânica e Zoologia, Universidade Federal do Rio Grande do Norte, Campus Universitário, 59072-970, Natal, RN, Brazil * CORRESPONDENCE TO: [email protected] ABSTRACT — Arbuscular mycorrhizal fungi (AMF) are recognized in terrestrial and aquatic ecosystems. The latter, however, have received little attention from the scientific community and, consequently, are poorly known in terms of occurrence and distribution of this group of fungi. This paper provides a global list on AMF species inhabiting aquatic ecosystems reported so far by scientific community (lotic and lentic freshwater, mangroves, and wetlands). A total of 82 species belonging to 5 orders, 11 families, and 22 genera were reported in 8 countries. Lentic ecosystems have greater species richness. Most studies of the occurrence of AMF in aquatic ecosystems were conducted in the United States and India, which constitute 45% and 78% reports coming from temperate and tropical regions, respectively. KEY WORDS — checklist, flooded areas, mycorrhiza, taxonomy Introduction Aquatic ecosystems comprise about 77% of the planet surface (Rebouças 2006) and encompass a diversity of habitats favorable to many species from marine (ocean), transitional estuaries to continental (wetlands, lentic and lotic) environments (Reddy et al. 2018). Despite this territorial representativeness and biodiversity already recorded, there are gaps when considering certain types of organisms, e.g. fungi. Fungi are considered a common and important component of almost all trophic levels.
    [Show full text]
  • The Threads That Bind: Symbiotic Fungi in the Garden
    veryone knows that a plant they formed a symbiosis with fungi, has leaves and flowers, and whose growing network of threads (the below ground its roots mycelium) allowed them to explore branch and explore the soil. the soil and forage for phosphate. In Yet that picture misses an return the plant provided the fungus essential component as with organic compounds. EEvirtually all plants live with a fungus in Three lines of evidence support this a symbiosis called a mycorrhiza (from story: first, molecular evidence shows the Greek, meaning ‘fungus root’) that that this group of fungi originated at or is essential to both partners. The plants before that distant time; second, we get phosphate and some other nutrients find plants that form this type of mycor- from the fungus, and the fungus gets all rhiza in all branches of the evolutionary its sugars from the plant. Plants gain tree of land plants, showing that they The threads other benefits too from the symbiosis must all have shared a common mycor- and sustainable farming, forestry and rhizal ancestor; and most convincingly, gardening will all increasingly rely on there are fossils from Devonian rocks understanding how it behaves. nearly 400 million years old that contain the fungal structures (Fig. 1a) that bind: Meet the ancestors and older Ordovician spores that are To explain why they are mycorrhizal, unequivocally from the group. This we need to go back to when plants first ancestral type is known as an arbus- colonized the land more than 400 cular mycorrhiza, after the tiny struct- million years ago, in the Ordovician ures called arbuscules that develop symbiotic fungi and Devonian periods.
    [Show full text]
  • Microbial Community Structure in Rice, Crops, and Pastures Rotation Systems with Different Intensification Levels in the Temperate Region of Uruguay
    Supplementary Material Microbial community structure in rice, crops, and pastures rotation systems with different intensification levels in the temperate region of Uruguay Sebastián Martínez Table S1. Relative abundance of the 20 most abundant bacterial taxa of classified sequences. Relative Taxa Phylum abundance 4,90 _Bacillus Firmicutes 3,21 _Bacillus aryabhattai Firmicutes 2,76 _uncultured Prosthecobacter sp. Verrucomicrobia 2,75 _uncultured Conexibacteraceae bacterium Actinobacteria 2,64 _uncultured Conexibacter sp. Actinobacteria 2,14 _Nocardioides sp. Actinobacteria 2,13 _Acidothermus Actinobacteria 1,50 _Bradyrhizobium Proteobacteria 1,23 _Bacillus Firmicutes 1,10 _Pseudolabrys_uncultured bacterium Proteobacteria 1,03 _Bacillus Firmicutes 1,02 _Nocardioidaceae Actinobacteria 0,99 _Candidatus Solibacter Acidobacteria 0,97 _uncultured Sphingomonadaceae bacterium Proteobacteria 0,94 _Streptomyces Actinobacteria 0,91 _Terrabacter_uncultured bacterium Actinobacteria 0,81 _Mycobacterium Actinobacteria 0,81 _uncultured Rubrobacteria Actinobacteria 0,77 _Xanthobacteraceae_uncultured forest soil bacterium Proteobacteria 0,76 _Streptomyces Actinobacteria Table S2. Relative abundance of the 20 most abundant fungal taxa of classified sequences. Relative Taxa Orden abundance. 20,99 _Fusarium oxysporum Ascomycota 11,97 _Aspergillaceae Ascomycota 11,14 _Chaetomium globosum Ascomycota 10,03 _Fungi 5,40 _Cucurbitariaceae; uncultured fungus Ascomycota 5,29 _Talaromyces purpureogenus Ascomycota 3,87 _Neophaeosphaeria; uncultured fungus Ascomycota
    [Show full text]
  • Fungal Phyla
    ZOBODAT - www.zobodat.at Zoologisch-Botanische Datenbank/Zoological-Botanical Database Digitale Literatur/Digital Literature Zeitschrift/Journal: Sydowia Jahr/Year: 1984 Band/Volume: 37 Autor(en)/Author(s): Arx Josef Adolf, von Artikel/Article: Fungal phyla. 1-5 ©Verlag Ferdinand Berger & Söhne Ges.m.b.H., Horn, Austria, download unter www.biologiezentrum.at Fungal phyla J. A. von ARX Centraalbureau voor Schimmelcultures, P. O. B. 273, NL-3740 AG Baarn, The Netherlands 40 years ago I learned from my teacher E. GÄUMANN at Zürich, that the fungi represent a monophyletic group of plants which have algal ancestors. The Myxomycetes were excluded from the fungi and grouped with the amoebae. GÄUMANN (1964) and KREISEL (1969) excluded the Oomycetes from the Mycota and connected them with the golden and brown algae. One of the first taxonomist to consider the fungi to represent several phyla (divisions with unknown ancestors) was WHITTAKER (1969). He distinguished phyla such as Myxomycota, Chytridiomycota, Zygomy- cota, Ascomycota and Basidiomycota. He also connected the Oomycota with the Pyrrophyta — Chrysophyta —• Phaeophyta. The classification proposed by WHITTAKER in the meanwhile is accepted, e. g. by MÜLLER & LOEFFLER (1982) in the newest edition of their text-book "Mykologie". The oldest fungal preparation I have seen came from fossil plant material from the Carboniferous Period and was about 300 million years old. The structures could not be identified, and may have been an ascomycete or a basidiomycete. It must have been a parasite, because some deformations had been caused, and it may have been an ancestor of Taphrina (Ascomycota) or of Milesina (Uredinales, Basidiomycota).
    [Show full text]
  • Chytridiomycetes, Chytridiomycota)
    VOLUME 5 JUNE 2020 Fungal Systematics and Evolution PAGES 17–38 doi.org/10.3114/fuse.2020.05.02 Taxonomic revision of the genus Zygorhizidium: Zygorhizidiales and Zygophlyctidales ord. nov. (Chytridiomycetes, Chytridiomycota) K. Seto1,2,3*, S. Van den Wyngaert4, Y. Degawa1, M. Kagami2,3 1Sugadaira Research Station, Mountain Science Center, University of Tsukuba, 1278-294, Sugadaira-Kogen, Ueda, Nagano 386-2204, Japan 2Department of Environmental Science, Faculty of Science, Toho University, 2-2-1, Miyama, Funabashi, Chiba 274-8510, Japan 3Graduate School of Environment and Information Sciences, Yokohama National University, 79-7, Tokiwadai, Hodogaya, Yokohama, Kanagawa 240- 8502, Japan 4Department of Experimental Limnology, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Alte Fischerhuette 2, D-16775 Stechlin, Germany *Corresponding author: [email protected] Key words: Abstract: During the last decade, the classification system of chytrids has dramatically changed based on zoospore Chytridiomycota ultrastructure and molecular phylogeny. In contrast to well-studied saprotrophic chytrids, most parasitic chytrids parasite have thus far been only morphologically described by light microscopy, hence they hold great potential for filling taxonomy some of the existing gaps in the current classification of chytrids. The genus Zygorhizidium is characterized by an zoospore ultrastructure operculate zoosporangium and a resting spore formed as a result of sexual reproduction in which a male thallus Zygophlyctis and female thallus fuse via a conjugation tube. All described species of Zygorhizidium are parasites of algae and Zygorhizidium their taxonomic positions remain to be resolved. Here, we examined morphology, zoospore ultrastructure, host specificity, and molecular phylogeny of seven cultures of Zygorhizidium spp. Based on thallus morphology and host specificity, one culture was identified as Z.
    [Show full text]
  • A Crispy Diet: Grazers of Achromatium Oxaliferum in Lake Stechlin Sediments
    Microbial Ecology https://doi.org/10.1007/s00248-018-1158-4 NOTE A Crispy Diet: Grazers of Achromatium oxaliferum in Lake Stechlin Sediments Sina Schorn1,2 & Heribert Cypionka1 Received: 29 December 2017 /Accepted: 7 February 2018 # The Author(s) 2018. This article is an open access publication Abstract Achromatium is the largest freshwater bacterium known to date and easily recognised by conspicuous calcite bodies filling the cell volume. Members of this genus are highly abundant in diverse aquatic sediments and may account for up to 90% of the bacterial biovolume in the oxic-anoxic interfaces. The high abundance implies that Achromatium is either rapidly growing or hardly prone to predation. As Achromatium is still uncultivated and does not appear to grow fast, one could assume that the cells might escape predation by their unusual shape and composition. However, we observed various members of the meiofauna grazing or parasitizing on Achromatium. By microphotography, we documented amoebae, ciliates, oligochetes and plathelminthes having Achromatium cells ingested. Some Achromatium cells harboured structures resembling sporangia of parasitic fungi (chytrids) that could be stained with the chitin-specific dye Calcofluor White. Many Achromatia carried prokary- otic epibionts in the slime layer surrounding the cells. Their regular distribution over the cell might indicate that they are commensalistic rather than harming their hosts. In conclusion, we report on various interactions of Achromatium with the sediment community and show that although Achromatium cells are a crispy diet, full of calcite bodies, predators do not spare them. Keywords Large sulfur bacteria . Plathelminthes . Ciliates . Amoebae . Oligochetes . Aquatic fungi Introduction are numerous intracellular calcite bodies (CaCO3), which fill major parts of the cell volume [6].
    [Show full text]
  • Compile.Xlsx
    Silva OTU GS1A % PS1B % Taxonomy_Silva_132 otu0001 0 0 2 0.05 Bacteria;Acidobacteria;Acidobacteria_un;Acidobacteria_un;Acidobacteria_un;Acidobacteria_un; otu0002 0 0 1 0.02 Bacteria;Acidobacteria;Acidobacteriia;Solibacterales;Solibacteraceae_(Subgroup_3);PAUC26f; otu0003 49 0.82 5 0.12 Bacteria;Acidobacteria;Aminicenantia;Aminicenantales;Aminicenantales_fa;Aminicenantales_ge; otu0004 1 0.02 7 0.17 Bacteria;Acidobacteria;AT-s3-28;AT-s3-28_or;AT-s3-28_fa;AT-s3-28_ge; otu0005 1 0.02 0 0 Bacteria;Acidobacteria;Blastocatellia_(Subgroup_4);Blastocatellales;Blastocatellaceae;Blastocatella; otu0006 0 0 2 0.05 Bacteria;Acidobacteria;Holophagae;Subgroup_7;Subgroup_7_fa;Subgroup_7_ge; otu0007 1 0.02 0 0 Bacteria;Acidobacteria;ODP1230B23.02;ODP1230B23.02_or;ODP1230B23.02_fa;ODP1230B23.02_ge; otu0008 1 0.02 15 0.36 Bacteria;Acidobacteria;Subgroup_17;Subgroup_17_or;Subgroup_17_fa;Subgroup_17_ge; otu0009 9 0.15 41 0.99 Bacteria;Acidobacteria;Subgroup_21;Subgroup_21_or;Subgroup_21_fa;Subgroup_21_ge; otu0010 5 0.08 50 1.21 Bacteria;Acidobacteria;Subgroup_22;Subgroup_22_or;Subgroup_22_fa;Subgroup_22_ge; otu0011 2 0.03 11 0.27 Bacteria;Acidobacteria;Subgroup_26;Subgroup_26_or;Subgroup_26_fa;Subgroup_26_ge; otu0012 0 0 1 0.02 Bacteria;Acidobacteria;Subgroup_5;Subgroup_5_or;Subgroup_5_fa;Subgroup_5_ge; otu0013 1 0.02 13 0.32 Bacteria;Acidobacteria;Subgroup_6;Subgroup_6_or;Subgroup_6_fa;Subgroup_6_ge; otu0014 0 0 1 0.02 Bacteria;Acidobacteria;Subgroup_6;Subgroup_6_un;Subgroup_6_un;Subgroup_6_un; otu0015 8 0.13 30 0.73 Bacteria;Acidobacteria;Subgroup_9;Subgroup_9_or;Subgroup_9_fa;Subgroup_9_ge;
    [Show full text]
  • BIOL 1030 – TOPIC 3 LECTURE NOTES Topic 3: Fungi (Kingdom Fungi – Ch
    BIOL 1030 – TOPIC 3 LECTURE NOTES Topic 3: Fungi (Kingdom Fungi – Ch. 31) KINGDOM FUNGI A. General characteristics • Fungi are diverse and widespread. • Ten thousand species of fungi have been described, but it is estimated that there are actually up to 1.5 million species of fungi. • Fungi play an important role in ecosystems, decomposing dead organisms, fallen leaves, feces, and other organic materials. °This decomposition recycles vital chemical elements back to the environment in forms other organisms can assimilate. • Most plants depend on mutualistic fungi to help their roots absorb minerals and water from the soil. • Humans have cultivated fungi for centuries for food, to produce antibiotics and other drugs, to make bread rise, and to ferment beer and wine • Fungi play ecological diverse roles - they are decomposers (saprobes), parasites, and mutualistic symbionts. °Saprobic fungi absorb nutrients from nonliving organisms. °Parasitic fungi absorb nutrients from the cells of living hosts. .Some parasitic fungi, including some that infect humans and plants, are pathogenic. .Fungi cause 80% of plant diseases. °Mutualistic fungi also absorb nutrients from a host organism, but they reciprocate with functions that benefit their partner in some way. • Fungi are a monophyletic group, and all fungi share certain key characteristics. B. Morphology of Fungi 1. heterotrophs - digest food with secreted enzymes “exoenzymes” (external digestion) 2. have cell walls made of chitin 3. most are multicellular, with slender filamentous units called hyphae (Label the diagram below – Use Textbook figure 31.3) 1 of 11 BIOL 1030 – TOPIC 3 LECTURE NOTES Septate hyphae Coenocytic hyphae hyphae may be divided into cells by crosswalls called septa; typically, cytoplasm flows through septa • hyphae can form specialized structures for things such as feeding, and even for food capture 4.
    [Show full text]
  • Phytoplankton Chytridiomycosis: Fungal Parasites of Phytoplankton and Their Imprints on the Food Web Dynamics
    REVIEW ARTICLE published: 12 October 2012 doi: 10.3389/fmicb.2012.00361 Phytoplankton chytridiomycosis: fungal parasites of phytoplankton and their imprints on the food web dynamics Télesphore Sime-Ngando* UMR CNRS 6023, Laboratoire Microorganismes: Génome et Environnement, Clermont Université Blaise Pascal, Clermont-Ferrand, France Edited by: Parasitism is one of the earlier and common ecological interactions in the nature, occurring Hans-Peter Grossart, Leibniz-Institute in almost all environments. Microbial parasites typically are characterized by their small of Freshwater Ecology and Inland Fisheries, Germany size, short generation time, and high rates of reproduction, with simple life cycle occurring Reviewed by: generally within a single host.They are diverse and ubiquitous in aquatic ecosystems, com- Michael R. Twiss, Clarkson University, prising viruses, prokaryotes, and eukaryotes. Recently, environmental 18S rDNA surveys USA of microbial eukaryotes have unveiled major infecting agents in pelagic systems, consisting Hans-Peter Grossart, Leibniz-Institute primarily of the fungal order of Chytridiales (chytrids). Chytrids are considered the earlier of Freshwater Ecology and Inland Fisheries, Germany branch of the Eumycetes and produce motile, flagellated zoospores, characterized by a *Correspondence: small size (2–6 mm), and a single, posterior flagellum. The existence of these dispersal Télesphore Sime-Ngando, UMR CNRS propagules includes chytrids within the so-called group of zoosporic fungi, which are par- 6023, Laboratoire Microorganismes: ticularly adapted to the plankton lifestyle where they infect a wide variety of hosts, including Génome et Environnement, Clermont fishes, eggs, zooplankton, algae, and other aquatic fungi but primarily freshwater phyto- Université Blaise Pascal, BP 80026, 63171 Aubière Cedex, plankton. Related ecological implications are huge because chytrids can killed their hosts, Clermont-Ferrand, France.
    [Show full text]
  • Clade (Kingdom Fungi, Phylum Chytridiomycota)
    TAXONOMIC STATUS OF GENERA IN THE “NOWAKOWSKIELLA” CLADE (KINGDOM FUNGI, PHYLUM CHYTRIDIOMYCOTA): PHYLOGENETIC ANALYSIS OF MOLECULAR CHARACTERS WITH A REVIEW OF DESCRIBED SPECIES by SHARON ELIZABETH MOZLEY (Under the Direction of David Porter) ABSTRACT Chytrid fungi represent the earliest group of fungi to have emerged within the Kingdom Fungi. Unfortunately despite the importance of chytrids to understanding fungal evolution, the systematics of the group is in disarray and in desperate need of revision. Funding by the NSF PEET program has provided an opportunity to revise the systematics of chytrid fungi with an initial focus on four specific clades in the order Chytridiales. The “Nowakowskiella” clade was chosen as a test group for comparing molecular methods of phylogenetic reconstruction with the more traditional morphological and developmental character system used for classification in determining generic limits for chytrid genera. Portions of the 18S and 28S nrDNA genes were sequenced for isolates identified to genus level based on morphology to seven genera in the “Nowakowskiella” clade: Allochytridium, Catenochytridium, Cladochytrium, Endochytrium, Nephrochytrium, Nowakowskiella, and Septochytrium. Bayesian, parsimony, and maximum likelihood methods of phylogenetic inference were used to produce trees based on one (18S or 28S alone) and two-gene datasets in order to see if there would be a difference depending on which optimality criterion was used and the number of genes included. In addition to the molecular analysis, taxonomic summaries of all seven genera covering all validly published species with a listing of synonyms and questionable species is provided to give a better idea of what has been described and the morphological and developmental characters used to circumscribe each genus.
    [Show full text]
  • Potential Use of High-Throughput Sequencing of Soil Microbial Communities for Estimating the Adverse Effects of Continuous Cropping on Ramie (Boehmeria Nivea L
    RESEARCH ARTICLE Potential use of high-throughput sequencing of soil microbial communities for estimating the adverse effects of continuous cropping on ramie (Boehmeria nivea L. Gaud) Siyuan Zhu*, Yanzhou Wang, Xiaomin Xu, Touming Liu, Duanqing Wu, Xia Zheng, Shouwei Tang, Qiuzhong Dai* a1111111111 Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, Changsha, Hunan, P.R. China a1111111111 * [email protected] (SZ); [email protected] (QD) a1111111111 a1111111111 a1111111111 Abstract Ramie (Boehmeria nivea L. Gaud) fiber, one of the most important natural fibers, is extracted from stem bark. Continuous cropping is the main obstacle to ramie stem growth OPEN ACCESS and a major cause of reduced yields. Root-associated microbes play crucial roles in plant Citation: Zhu S, Wang Y, Xu X, Liu T, Wu D, Zheng growth and health. In this study, we investigated differences between microbial communities X, et al. (2018) Potential use of high-throughput in the soil of healthy and continuously cropped ramie plants, and sought to identify potential sequencing of soil microbial communities for mechanisms whereby these communities could counteract the problems posed by continu- estimating the adverse effects of continuous cropping on ramie (Boehmeria nivea L. Gaud). ous cropping. Paired-end Illumina MiSeq analysis of 16S rRNA and ITS gene amplicons PLoS ONE 13(5): e0197095. https://doi.org/ was employed to study bacterial and fungal communities. Long-term monoculture of ramie 10.1371/journal.pone.0197095 significantly decreased fiber yields and altered soil microbial communities. Our findings Editor: Raffaella Balestrini, Institute for Sustainable revealed how microbial communities and functional diversity varied according to the planting Plant Protection, C.N.R., ITALY year and plant health status.
    [Show full text]