Search results for "oomycete"
showing 10 items of 37 documents
TheMedicago truncatulahypermycorrhizal B9 mutant displays an altered response to phosphate and is more susceptible toAphanomyces euteiches
2014
Inorganic phosphate (Pi) plays a key role in the development of arbuscular mycorrhizal (AM) symbiosis, which is favoured when Pi is limiting in the environment. We have characterized the Medicago truncatula hypermycorrhizal B9 mutant for its response to limiting (P/10) and replete (P2) Pi. On P2, mycorrhization was significantly higher in B9 plants than in wild-type (WT). The B9 mutant displayed hallmarks of Pi-limited plants, including higher levels of anthocyanins and lower concentrations of Pi in shoots than WT plants. Transcriptome analyses of roots of WT and B9 plants cultivated on P2 or on P/10 confirmed the Pi-limited profile of the mutant on P2 and highlighted its altered response t…
Achlya spiralis, a new aquatic oomycete with bent oogonial stalks, isolated from the Burgundian region of France
2008
Achlya spiralis sp. nov. was isolated from water samples collected in the river Tille in the Burgundian region of France. The new oomycete is described, illustrated and compared with related species of the genus Achlya. It is characterized by the presence of smooth-walled oogonia that are usually borne on bent or twisted oogonial stalks; mainly monoclinous, androgynous and diclinous antheridial branches and eccentric oospores which generally do not mature or mature after a long period of time. The internal transcribed spacer (ITS) region of its rRNA is comprised of 671 bases. The taxonomic description of this new species, its comparison with related oomycetes and the sequence of the ITS reg…
Assessing the effectiveness of Byssochlamys nivea and Scopulariopsis brumptii in pentachlorophenol removal and biological control of two Phytophthora…
2016
Bioremediation and biological-control by fungi have made tremendous strides in numerous biotechnology applications. The aim of this study was to test Byssochlamys nivea and Scopulariopsis brumptii in sensitivity and degradation to pentachlorophenol (PCP) and in biological-control of Phytophthora cinnamomi and Phytophthora cambivora. B. nivea and S. brumptii were tested in PCP sensitivity and degradation in microbiological media while the experiments of biological-control were carried out in microbiological media and soil. The fungal strains showed low PCP sensitivity at 12.5 and 25 mg PCP L(-1) although the hyphal size, fungal mat, patulin, and spore production decreased with increasing PCP…
An ethoxylated surfactant enhances the penetration of the sulfated laminarin through leaf cuticle and stomata, leading to increased induced resistanc…
2016
International audience; Some β-1,3-glucans and particularly sulfated laminarin (PS3) are known as resistance inducers (RIs) in grapevine against the downy mildew. However, their efficacy in vineyard is still often too low, which might be caused by a limited penetration through the leaf cuticle following spray application. We used (14) C-sucrose uptake experiments with grapevine leaves in order to select a surfactant as saccharide penetration enhancer. Our results showed that though sucrose foliar uptake was low, it was strongly enhanced by Dehscofix CO125 (DE), a highly ethoxylated surfactant. Fluorescent saccharides were then produced and laser scanning microscopy was used to analyze their…
Inhibitory Activity of Shrimp Waste Extracts on Fungal and Oomycete Plant Pathogens
2021
(1) Background: This study was aimed at determining the in vitro inhibitory effect of new natural substances obtained by minimal processing from shrimp wastes on fungi and oomycetes in the genera Alternaria, Colletotrichum, Fusarium, Penicillium, Plenodomus and Phytophthora
Characterisation of a new species of Pythium isolated from a wheat field in northern France and its antagonism towards Botrytis cinerea causing the g…
2003
A new species, Pythium bifurcatum, isolated from soil samples taken from a wheat field in Lille in northern France is described here. The oomycete occurred thrice out of 50 samples. The type specimen is F-91, which is a slow-growing saprophyte living on vegetable debris and which can be recognised by its antheridial as well as oogonial characteristics, which are different from other known species of Pythium. When grown together with Botrytis cinerea, the causal agent of the grey mould disease of the grapevine, Pythium bifurcatum shows a pronounced antagonism and suppresses its growth. Morphological features of this new species, its antagonism to B. cinerea, the sequences of the ITS region o…
Pythium burgundicum sp. nov. isolated from soil samples taken in French vineyards.
2009
During the course of investigation on pythiaceous fungi occurring in the Burgundian vineyards, a new species of Pythium has been isolated. This oomycete is characterized by its nonproliferating and nonsporulating, spherical to cylindrical type of sporangia (hyphal bodies) germinating through germ tubes, smooth-walled oogonia that are supplied with hypogynous, monoclinous or rarely diclinous antheridia, and smooth-walled oospores. The antheridial cells are very prominent and are reminiscent of Pythium bifurcatum, Pythium segnitium and Pythium longandrum described previously by the author. The internal transcribed spacer region of the rRNA of this new species is composed of 883 bases, which i…
Isolation frequency and efficiency of mycoparasitic Pythium species in the West Mediterranean region of Turkey
2021
Abstract A total of 132 mycoparasitic Pythium isolates were obtained from the soil samples taken from fruit orchards, vegetable fields, carnation greenhouses, sugarbeet fields and cereal fields in the West Mediterranean region of Turkey. The Oomycetes were isolated by using; surface soil dilution plate, sclerotia bait and precolonised plate methods. Isolates were identified as P. acanthophoron, P. amasculinum, P. lycopersicum, P. oligandrum, P. periplocum and P. paroecandrum, according to their morphological and molecular characteristics. The most commonly isolated mycoparasitic species were P. amasculinum and P. lycopersicum. The majority of the mycoparasites came from soil samples taken f…
Corrigendum: Species Richness, rRNA Gene Abundance, and Seasonal Dynamics of Airborne Plant-Pathogenic Oomycetes
2019
The 1.45 A resolution structure of the cryptogein-cholesterol complex: a close-up view of a sterol carrier protein (SCP) active site.
2002
Cryptogein is a small 10 kDa elicitor produced by the phytoparasitic oomycete Phytophthora cryptogea. The protein also displays a sterol carrier activity. The native protein crystallizes in space group P4(1)22, with unit-cell parameters a = b = 46.51, c = 134.9 A (diffraction limit: 2.1 A). Its complex with cholesterol crystallizes in space group C222(1), with unit-cell parameters a = 30.96, b = 94.8, c = 65.3 A and a resolution enhanced to 1.45 A. The large inner non-specific hydrophobic cavity is able to accommodate a large variety of 3-beta-hydroxy sterols. Cryptogein probably acts as a sterol shuttle helping the pathogen to grow and complete its life cycle.