126 research outputs found

    Biophysical analysis of the plant-specific GIPC sphingolipids reveals multiple modes of membrane regulation

    Get PDF
    The plant plasma membrane (PM) is an essential barrier between the cell and the external environment, controlling signal perception and transmission. It consists of an asymmetrical lipid bilayer made up of three different lipid classes: sphingolipids, sterols, and phospholipids. The glycosyl inositol phosphoryl ceramides (GIPCs), representing up to 40% of total sphingolipids, are assumed to be almost exclusively in the outer leaflet of the PM. However, their biological role and properties are poorly defined. In this study, we investigated the role of GIPCs in membrane organization. Because GIPCs are not commercially available, we developed a protocol to extract and isolate GIPC-enriched fractions from eudicots (cauliflower and tobacco) and monocots (leek and rice). Lipidomic analysis confirmed the presence of trihydroxylated long chain bases and 2-hydroxylated very long-chain fatty acids up to 26 carbon atoms. The glycan head groups of the GIPCs from monocots and dicots were analyzed by gas chromatograph–mass spectrometry, revealing different sugar moieties. Multiple biophysics tools, namely Langmuir monolayer, ζ-Potential, light scattering, neutron reflectivity, solid state 2H-NMR, and molecular modeling, were used to investigate the physical properties of the GIPCs, as well as their interaction with free and conjugated phytosterols. We showed that GIPCs increase the thickness and electronegativity of model membranes, interact differentially with the different phytosterols species, and regulate the gel-to-fluid phase transition during temperature variations. These results unveil the multiple roles played by GIPCs in the plant PM.Vers un modèle intégratif de la bicouche lipidique de la membrane plasmique végétaleDéveloppement d’une infrastructure française distribuée pour la métabolomique dédiée à l’innovatio

    Lignin deconstruction by anaerobic fungi

    Get PDF
    Lignocellulose forms plant cell walls, and its three constituent polymers, cellulose, hemicellulose and lignin, represent the largest renewable organic carbon pool in the terrestrial biosphere. Insights into biological lignocellulose deconstruction inform understandings of global carbon sequestration dynamics and provide inspiration for biotechnologies seeking to address the current climate crisis by producing renewable chemicals from plant biomass. Organisms in diverse environments disassemble lignocellulose, and carbohydrate degradation processes are well defined, but biological lignin deconstruction is described only in aerobic systems. It is currently unclear whether anaerobic lignin deconstruction is impossible because of biochemical constraints or, alternatively, has not yet been measured. We applied whole cell-wall nuclear magnetic resonance, gel-permeation chromatography and transcriptome sequencing to interrogate the apparent paradox that anaerobic fungi (Neocallimastigomycetes), well-documented lignocellulose degradation specialists, are unable to modify lignin. We find that Neocallimastigomycetes anaerobically break chemical bonds in grass and hardwood lignins, and we further associate upregulated gene products with the observed lignocellulose deconstruction. These findings alter perceptions of lignin deconstruction by anaerobes and provide opportunities to advance decarbonization biotechnologies that depend on depolymerizing lignocellulose

    Fungal diversity notes 253–366: taxonomic and phylogenetic contributions to fungal taxa

    Get PDF
    Notes on 113 fungal taxa are compiled in this paper, including 11 new genera, 89 new species, one new subspecies, three new combinations and seven reference specimens. A wide geographic and taxonomic range of fungal taxa are detailed. In the Ascomycota the new genera Angustospora (Testudinaceae), Camporesia (Xylariaceae), Clematidis, Crassiparies (Pleosporales genera incertae sedis), Farasanispora, Longiostiolum (Pleosporales genera incertae sedis), Multilocularia (Parabambusicolaceae), Neophaeocryptopus (Dothideaceae), Parameliola (Pleosporales genera incertae sedis), and Towyspora (Lentitheciaceae) are introduced. Newly introduced species are Angustospora nilensis, Aniptodera aquibella, Annulohypoxylon albidiscum, Astrocystis thailandica, Camporesia sambuci, Clematidis italica, Colletotrichum menispermi, C. quinquefoliae, Comoclathris pimpinellae, Crassiparies quadrisporus, Cytospora salicicola, Diatrype thailandica, Dothiorella rhamni, Durotheca macrostroma, Farasanispora avicenniae, Halorosellinia rhizophorae, Humicola koreana, Hypoxylon lilloi, Kirschsteiniothelia tectonae, Lindgomyces okinawaensis, Longiostiolum tectonae, Lophiostoma pseudoarmatisporum, Moelleriella phukhiaoensis, M. pongdueatensis, Mucoharknessia anthoxanthi, Multilocularia bambusae, Multiseptospora thysanolaenae, Neophaeocryptopus cytisi, Ocellularia arachchigei, O. ratnapurensis, Ochronectria thailandica, Ophiocordyceps karstii, Parameliola acaciae, P. dimocarpi, Parastagonospora cumpignensis, Pseudodidymosphaeria phlei, Polyplosphaeria thailandica, Pseudolachnella brevifusiformis, Psiloglonium macrosporum, Rhabdodiscus albodenticulatus, Rosellinia chiangmaiensis, Saccothecium rubi, Seimatosporium pseudocornii, S. pseudorosae, Sigarispora ononidis and Towyspora aestuari. New combinations are provided for Eutiarosporella dactylidis (sexual morph described and illustrated) and Pseudocamarosporium pini. Descriptions, illustrations and / or reference specimens are designated for Aposphaeria corallinolutea, Cryptovalsa ampelina, Dothiorella vidmadera, Ophiocordyceps formosana, Petrakia echinata, Phragmoporthe conformis and Pseudocamarosporium pini. The new species of Basidiomycota are Agaricus coccyginus, A. luteofibrillosus, Amanita atrobrunnea, A. digitosa, A. gleocystidiosa, A. pyriformis, A. strobilipes, Bondarzewia tibetica, Cortinarius albosericeus, C. badioflavidus, C. dentigratus, C. duboisensis, C. fragrantissimus, C. roseobasilis, C. vinaceobrunneus, C. vinaceogrisescens, C. wahkiacus, Cyanoboletus hymenoglutinosus, Fomitiporia atlantica, F. subtilissima, Ganoderma wuzhishanensis, Inonotus shoreicola, Lactifluus armeniacus, L. ramipilosus, Leccinum indoaurantiacum, Musumecia alpina, M. sardoa, Russula amethystina subp. tengii and R. wangii are introduced. Descriptions, illustrations, notes and / or reference specimens are designated for Clarkeinda trachodes, Dentocorticium ussuricum, Galzinia longibasidia, Lentinus stuppeus and Leptocorticium tenellum. The other new genera, species new combinations are Anaeromyces robustus, Neocallimastix californiae and Piromyces finnis from Neocallimastigomycota, Phytophthora estuarina, P. rhizophorae, Salispina, S. intermedia, S. lobata and S. spinosa from Oomycota, and Absidia stercoraria, Gongronella orasabula, Mortierella calciphila, Mucor caatinguensis, M. koreanus, M. merdicola and Rhizopus koreanus in Zygomycota

    One stop shop: backbones trees for important phytopathogenic genera: I (2014)

    Get PDF
    Many fungi are pathogenic on plants and cause significant damage in agriculture and forestry. They are also part of the natural ecosystem and may play a role in regulating plant numbers/density. Morphological identification and analysis of plant pathogenic fungi, while important, is often hampered by the scarcity of discriminatory taxonomic characters and the endophytic or inconspicuous nature of these fungi. Molecular (DNA sequence) data for plant pathogenic fungi have emerged as key information for diagnostic and classification studies, although hampered in part by non-standard laboratory practices and analytical methods. To facilitate current and future research, this study provides phylogenetic synopses for 25 groups of plant pathogenic fungi in the Ascomycota, Basidiomycota, Mucormycotina (Fungi), and Oomycota, using recent molecular data, up-to-date names, and the latest taxonomic insights. Lineage-specific laboratory protocols together with advice on their application, as well as general observations, are also provided. We hope to maintain updated backbone trees of these fungal lineages over time and to publish them jointly as new data emerge. Researchers of plant pathogenic fungi not covered by the present study are invited to join this future effort. Bipolaris, Botryosphaeriaceae, Botryosphaeria, Botrytis, Choanephora, Colletotrichum, Curvularia, Diaporthe, Diplodia, Dothiorella, Fusarium, Gilbertella, Lasiodiplodia, Mucor, Neofusicoccum, Pestalotiopsis, Phyllosticta, Phytophthora, Puccinia, Pyrenophora, Pythium, Rhizopus, Stagonosporopsis, Ustilago and Verticillium are dealt with in this paper

    Does irrigation influence the growth, yield and water use efficiency of the protea hybrid 'Sylvia' (Protea susannae X Protea eximia)?

    No full text
    The response of the protea hybrid 'Sylvia' (Protea susannae X Protea eximia) to irrigation was investigated to determine the water requirements of this commercial floriculture crop. Both field and glasshouse trials were conducted in which plants were exposed to different irrigation levels. The effects of the irrigation regimes were determined by measuring the δ 13C, δ15N, gas exchange characteristics, biomass accumulation, yield and root development. The plants in the glasshouse were exposed to watering regimes maintaining water at 20%, 40% and 60% of field capacity in sand-filled pots. Higher water supply resulted in increased growth of the roots in particular, but also of the shoots, reaching a maximum at 40% of field capacity. There were no significant changes in the gas exchange characteristics of the plants associated with this increased growth. In the field trial the intensity of irrigation (dry-land, normal and double-irrigation) did not influence the vegetative or reproductive biomass accumulation. Although the water content of the upper 30cm of soil was significantly different between treatments, there were no differences in δ 13C, relative water contents or in elemental compositions of the leaves. The gas exchange characteristics of the plants were only slightly influenced by the irrigation intensity maintaining very similar water use efficiencies between treatments, concurring with δ13C results. However, the development of cluster roots was strongly increased by irrigation. Dryland plants had extensive sinker roots penetrating the deeper (>1m) soil layers. It was concluded that the dimorphic and deep roots of 'Sylvia' allow access to water deep in the soil profile once the root system is established. Although maintenance of cluster roots for nutrient uptake is important, management practices should take cognisance of the fact that surface soil water contents only partially determine the availability of water for these deep-rooted perennial shrubs, if at all.Articl

    Cystic fibrosis: what do teenagers really know?

    Get PDF

    Morphology, Phylogeny and Culture Characteristics of Ganoderma gibbosum Collected from Kunming, Yunnan Province, China

    No full text
    Ganoderma is a genus of medicinally and economically important mushrooms in the family Ganodermataceae. Ganoderma species are popular medicinal mushrooms and their health benefits are well-documented. Ganoderma is a cosmopolitan genus that is widely distributed in both tropical and temperate regions. This genus is characterized by its unique laccate or non-laccate species with double-walled basidiospores. Here, we report on eight collections of G. gibbosum collected during surveys in Kunming, Yunnan Province, China. The specimens are described and illustrated based on macro- and micro-morphological characteristics. Total DNA of the eight G. gibbosum strains were extracted using the Biospin Fungal Extraction Kit following manufacturer protocol. Amplification of the Internal Transcribed Spacer (nrITS) region was carried out using ITS5/ITS4 primers and LROR/LR5 for the nuclear ribosomal large subunit 28S rDNA gene (LSU). Phylogenetic analysis with closely related species to G. gibbosum showed that all eight collections grouped with G. gibbosum with 100% bootstrap support. Phylogenetic similarity and morphological variations within the eight collections of G. gibbosum are discussed
    • …
    corecore