32 results match your criteria biflagellate zoospores


The hop downy mildew pathogen Pseudoperonospora humuli.

Mol Plant Pathol 2021 May 4. Epub 2021 May 4.

Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, North Carolina, USA.

Pseudoperonospora humuli is an obligate biotrophic oomycete that causes downy mildew, one of the most devastating diseases of cultivated hop, Humulus lupulus. Downy mildew occurs in all production areas of the crop in the Northern Hemisphere and Argentina. The pathogen overwinters in hop crowns and roots, and causes considerable crop loss. Read More

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Erection of a New Genus and Species for the Pathogen of Hard Clams 'Quahog Parasite Unknown' (QPX): Mucochytrium quahogii gen. nov., sp. nov.

Protist 2021 02 29;172(1):125793. Epub 2021 Jan 29.

School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY 11794-5000, USA. Electronic address:

Quahog Parasite Unknown (QPX) is a facultative parasite of the hard clam, Mercenaria mercenaria. Although it has been observed in clams since the 1960's and cultivated since the 1990's, conflicting reports on important aspects of its biology have prevented its formal description. 18S rRNA gene sequences identify QPX as a thraustochytrid, but its production of copious mucus is atypical for this group. Read More

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February 2021

zoospores: From perception of environmental signals to inoculum formation on the host-root surface.

Comput Struct Biotechnol J 2020 21;18:3766-3773. Epub 2020 Nov 21.

Université Côte d'Azur, INRAE, CNRS, ISA, Sophia Antipolis 06903, France.

To explore moist soils and to target host plants, phytopathogenic species utilize the sensory and propulsion capabilities of the biflagellate unicellular zoospores they produce. Zoospore motion and interactions with the microenvironment are of primary importance for physiology. These are also of critical significance for plant pathology in early infection sequential events and their regulation: the directed zoospore migration toward the host, the local aggregation and adhesion at the host penetration site. Read More

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November 2020

Occurrence of stem blight and fruit rot caused by on Chinese cucumber () in China.

Plant Dis 2020 Jul 30. Epub 2020 Jul 30.

Ahui Academy of Agricultural Sciences, Institute of Plant Protection and Agro-products Safety, No. 40 Nongkenan Rd., Hefei, China, 230031.

Chinese cucumber, Maxim, is a perennial liana plant belonging to the Cucurbitaceae family and is an important traditional medicine in Chinese herbalism. The root, fruit and seed possess the medicinal value, and also the seeds are edible (Zhang et al. 2019). Read More

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A Widely Distributed Thraustochytrid Parasite of Diatoms Isolated from the Arctic Represents a gen. and sp. nov.

J Eukaryot Microbiol 2020 07 29;67(4):480-490. Epub 2020 Apr 29.

UiT Norges arktiske universtiet, BFE, NFH bygget, Framstredet 6, 9019, Tromsø, Norway.

A unicellular, heterotrophic, eukaryotic parasite was isolated from nearshore Arctic marine sediment in association with the diatom Pleurosigma sp. The parasite possessed ectoplasmic threads that could penetrate diatom frustules. Healthy and reproducing Pleurosigma cultures would begin to collapse within a week following the introduction of this parasite. Read More

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Guidance of zoospores by potassium gradient sensing mediates aggregation.

J R Soc Interface 2019 08 7;16(157):20190367. Epub 2019 Aug 7.

Université Côte d'Azur, CNRS, UMR 7010, Institut de Physique de Nice, Parc Valrose, 06108 Nice, France.

The biflagellate zoospores of some phytopathogenic Phytophthora species spontaneously aggregate within minutes in suspension. We show here that Phytophthora parasitica zoospores can form aggregates in response to a K gradient with a particular geometric arrangement. Using time-lapse live imaging in macro- and microfluidic devices, we defined (i) spatio-temporal and concentration-scale changes in the gradient, correlated with (ii) the cell distribution and (iii) the metrics of zoospore motion (velocity, trajectory). Read More

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A Novel Phagomyxid Parasite Produces Sporangia in Root Hair Galls of Eelgrass (Zostera marina).

Protist 2019 02 10;170(1):64-81. Epub 2018 Dec 10.

Department of Plant Pathology, Washington State University Research & Extension Center, Puyallup, WA 98371, USA.

The objective of this study was to identify the parasite causing the formation of root hair galls on eelgrass (Zostera marina) in Puget Sound, WA. Microscopic and molecular analyses revealed that a novel protist formed plasmodia that developed into sporangia in root hair tip galls and released biflagellate swimming zoospores. Root hair galls were also observed in the basal section of root hairs, and contained plasmodia or formed thick-walled structures filled with cells (resting spores). Read More

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February 2019

Canker and decline diseases caused by soil- and airborne species in forests and woodlands.

Persoonia 2018 Dec 30;40:182-220. Epub 2018 Apr 30.

Dipartimento di Agraria, Sezione di Patologia vegetale ed Entomologia, Università degli Studi di Sassari, 07100 Sassari, Italy.

Most members of the oomycete genus are primary plant pathogens. Both soil- and airborne species are able to survive adverse environmental conditions with enduring resting structures, mainly sexual oospores, vegetative chlamydospores and hyphal aggregations. Soilborne species infect fine roots and the bark of suberized roots and the collar region with motile biflagellate zoospores released from sporangia during wet soil conditions. Read More

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December 2018

Pythium insidiosum isolated from infected mosquito larvae in central Brazil.

Acta Trop 2018 Sep 18;185:344-348. Epub 2018 Jun 18.

Biomedical Laboratory Diagnostics, Michigan State University, East Lansing, Michigan, USA; Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, USA. Electronic address:

Pythium insidiosum is a straminopilan pathogen causing life threatening infections in mammals inhabiting temperate, tropical and subtropical areas of the world. The concept that P. insidiosum could also infect mosquitoes was mentioned earlier by investigators conducting phylogenetic analysis on available P. Read More

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September 2018

Transport and Retention of Phytophthora capsici Zoospores in Saturated Porous Media.

Environ Sci Technol 2016 09 24;50(17):9270-8. Epub 2016 Aug 24.

Crop Protection Discovery, Dow AgroSciences , Indianapolis, Indiana 46268, United States.

Phytophthora capsici is an important plant pathogen capable of infecting several major vegetable crops. Water-induced P. capsici transport is considered to be a significant contributor to disease outbreaks and subsequent crop loss. Read More

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September 2016

Investigations of cell morphology and reproduction in Ettl & Gärtner (Stephano-sphaerinia, Chlorophyta) by light- and WUDQVPLVVLRQ electron microscopy.

Algol Stud (2007) 2014 Apr;144:95-104

University of Innsbruck, Institute of Botany, Plant Evolution and Diversity, Sternwartestraße 15, 6020 Innsbruck, Austria.

Cell division and reproduction of a cultivated strain of (Stephanosphaerinia clade) were studied by light- and transmission electron microscopy. Multinucleate cells were frequently observed allowing description of the cell structure and details of the reproduction process. Nuclear staining revealed the position of the multiple polymorphic nuclei between the chloroplast lobes. Read More

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PnPMA1, an atypical plasma membrane H(+)-ATPase, is required for zoospore development in Phytophthora parasitica.

Fungal Biol 2012 Sep 27;116(9):1013-23. Epub 2012 Jul 27.

State Key Laboratory of Crop Stress Biology in Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, PR China.

Biflagellate zoospores are the major infective agents that initiate plant infection for most Phytophthora species. Once released from sporangia, zoospores swim and use a number of tactic responses to actively target host tissues. However, the molecular mechanisms controlling zoospore development and behaviour are largely unknown. Read More

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September 2012

The cucurbit downy mildew pathogen Pseudoperonospora cubensis.

Mol Plant Pathol 2011 Apr 10;12(3):217-26. Epub 2010 Nov 10.

Department of Plant Pathology, Michigan State University, East Lansing, MI 48824, USA.

Unlabelled: Pseudoperonospora cubensis[(Berkeley & M. A. Curtis) Rostovzev], the causal agent of cucurbit downy mildew, is responsible for devastating losses worldwide of cucumber, cantaloupe, pumpkin, watermelon and squash. Read More

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Phytophthora nicotianae transformants lacking dynein light chain 1 produce non-flagellate zoospores.

Fungal Genet Biol 2010 Aug 6;47(8):663-71. Epub 2010 May 6.

Plant Science Division, Research School of Biology, The Australian National University, Canberra, ACT 2601, Australia.

Biflagellate zoospores of the highly destructive plant pathogens in the genus Phytophthora are responsible for the initiation of infection of host plants. Zoospore motility is a critical component of the infection process because it allows zoospores to actively target suitable infection sites on potential hosts. Flagellar assembly and function in eukaryotes depends on a number of dynein-based molecular motors that facilitate retrograde intraflagellar transport and sliding of adjacent microtubule doublets in the flagellar axonemes. Read More

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Proteins related to green algal striated fiber assemblin are present in stramenopiles and alveolates.

Protoplasma 2009 Jul 31;236(1-4):97-101. Epub 2009 Mar 31.

E. H. Graham Center for Agricultural Innovation, Charles Sturt University, Wagga Wagga, New South Wales, 2678, Australia.

In green algae, striated fiber assemblin (SFA) is the major protein of the striated microtubule-associated fibers that are structural elements in the flagellar basal apparatus. Using Basic Local Alignment Search Tool (BLAST) searches of recently established databases, SFA-like sequences were detected in the genomes not only of green algal species but also of a range of other protists. These included species in two alveolate subgroups, the ciliates (Tetrahymena thermophila, Paramecium tetraurelia) and the dinoflagellates (Perkinsus marinus), and two stramenopile subgroups, the oomycetes (Phytophthora sojae, Phytophthora ramorum, Phytophthora infestans) and the diatoms (Thalassiosira pseudonana, Phaeodactylum tricornutum). Read More

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First Report of Downy Mildew Caused by Pseudoperonospora cubensis on Chayote (Sechium edule) in Taiwan.

Plant Dis 2008 Dec;92(12):1706

Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan.

Chayote (Sechium edule) is cultivated on more than 500 ha in Taiwan for its edible shoots and fruit. In August 2005 and later, 40 to 75% of the chayote plants cultivated in the Taichung District Agricultural Improvement Station in Puli developed pale yellow, irregular spots on the upper leaf surfaces with corresponding sporulation on the lower leaf surfaces. The lesions eventually became necrotic and spread over the entire leaf surface, leading to defoliation. Read More

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December 2008

Taxonomy, molecular phylogeny, and ultrastructural morphology of Olpidiopsis porphyrae sp. nov. (Oomycetes, straminipiles), a unicellular obligate endoparasite of Bangia and Porphyra spp. (Bangiales, Rhodophyta).

Mycol Res 2008 Mar 12;112(Pt 3):361-74. Epub 2007 Nov 12.

Graduate School of Natural Science, Konan University, Okamoto, Higashinada, Kobe, Hyogo 658-8501, Japan.

Olpidiopsis porphyrae sp. nov., a marine oomycete endoparasite that infects the commercially cultivated red alga Porphyra yezoensis, is described and its phylogenetic position based on molecular data and ultrastructural morphology is discussed. Read More

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Oomycetes: Lagenidium giganteum.

Authors:
James L Kerwin

J Am Mosq Control Assoc 2007 ;23(2 Suppl):50-7

Department of Biological Chemistry, School of Medicine University of California, Los Angeles, CA 90095, USA.

Lagenidium giganteum is a facultative parasite of mosquito larvae that initiates infection by production of biflagellate zoospores that selectively recognize and attach to larval cuticle. Following penetration of the cuticle, the parasite proliferates within the host, killing it within 24-60 h. Under optimum conditions the mycelia differentiate to produce asexual and/or sexual reproductive structures that produce zoospores within hours (asexual stage) to amplify the initial infection, or remain dormant for days, months or years (sexual stage), until conditions are conducive to mosquito breeding and spore germination. Read More

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October 2007

An ultrastructural study of development and reproduction in the nematode parasite Myzocytiopsis vermicola.

Mycologia 2006 Jan-Feb;98(1):1-15

Department of Biological Sciences, Northern Illinois University, DeKalb 60115-2861, USA.

An isolate of Myzocytiopsis vermicola, a holocarpic parasite of Rhabditis nematodes, was studied with transmission electron microscopy (TEM) to follow development during infection, asexual and sexual reproduction. Nematodes became infected after attachment of apical cystospore buds to the nematode cuticle. Apical buds were packed with vesicles with dense fibrillar contents, which were absent from the thallus. Read More

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Isolation and characterization of a novel thraustochytrid-like microorganism that efficiently produces docosahexaenoic acid.

Biotechnol Lett 2006 Feb;28(3):197-202

Laboratory of Environmental Molecular Biology, Graduate School of Environmental Earth Science, Hokkaido University, Sapporo, Kita-ku, 060-0810, Japan.

A thraustochytrid-like microorganism (strain 12B) was isolated from the mangrove area of Okinawa, Japan. On the basis of its ectoplasmic net structure and biflagellate zoospores we determined strain 12B to be a novel member of the phylum Labyrinthulomycota in the kingdom Protoctista. When grown on glucose/seawater at 28 degrees C, it had a lipid content of 58% with docosahexaenoic acid (DHA; 22:6 n-3) at 43% of the total fatty acids. Read More

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February 2006

Thraustochytrium gaertnerium sp. nov.: a new thraustochytrid stramenopilan protist from mangroves of Goa, India.

Protist 2005 Nov 2;156(3):303-15. Epub 2005 Aug 2.

National Institute of Oceanography, Dona Paula, Goa - 403 004, India.

Thraustochytrids are ubiquitous, chemo-organotrophic, marine stramenipilan protists belonging to the class Labyrinthulomycetes. Their taxonomy is largely based on life cycle development stages. We describe here a new species of thraustochytrid isolated from mangroves of Goa, India. Read More

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November 2005

Phytophthora cinnamomi.

Mol Plant Pathol 2005 11;6(6):589-604

Plant Cell Biology Group, Research School of Biological Sciences, The Australian National University, Canberra, ACT 2601, Australia.

Summary: Phytophthora cinnamomi Rands was first isolated from cinnamon trees in Sumatra in 1922. The pathogen is believed to have originated near Papua New Guinea but now has a worldwide distribution. P. Read More

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November 2005

Genes expressed in zoospores of Phytophthora nicotianae.

Mol Genet Genomics 2004 Jan 3;270(6):549-57. Epub 2003 Dec 3.

Cooperative Research Centre for Tropical Plant Protection and Plant Cell Biology Group, Research School of Biological Sciences, Australian National University, ACT 2601, Canberra, Australia.

The genus Phytophthora includes many highly destructive plant pathogens. In many Phytophthora species, pathogen dispersal and initiation of plant infection are achieved by motile, biflagellate zoospores that are chemotactically attracted to suitable infection sites. In order to study gene expression in zoospores, we have constructed a cDNA library using mRNA from zoospores of Phytophthora nicotianae. Read More

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January 2004

Clinicopathologic findings associated with Lagenidium sp. infection in 6 dogs: initial description of an emerging oomycosis.

J Vet Intern Med 2003 Sep-Oct;17(5):637-46

Department of Veterinary Clinical Sciences, Louisiana State University, Baton Rouge, LA 70803-8410, USA.

An oomycotic pathogen in the genus Lagenidium was isolated from tissues obtained from 6 dogs with progressive cutaneous disease. Initial clinical findings in 5 dogs included multifocal cutaneous lesions, subcutaneous lesions, or both associated with regional lymphadenopathy: the 6th dog initially was presented for evaluation of mandibular lymphadenopathy. Cutaneous lesions were ulcerated, exudative regions (often with necrosis and draining tracts) or multiple firm dermal or subcutaneous nodules. Read More

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December 2003

FINE STRUCTURE OF BIFLAGELLATE ZOOSPORES OF ASTEROCOCCUS SUPERBUS (TETRASPORALES, CHLOROPHYCEAE), INCLUDING THE ABSOLUTE CONFIGURATION OF THE FLAGELLAR APPARATUS.

J Phycol 2000 Aug;36(4):714-722

Laboratorio de Ficología y Micología, Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur, 8000 Bahía Blanca, ArgentinaDepartamento de Ciencias Biológicas, Universidad de Buenos Aires, 1428 Buenos Aires, Argentina.

The ultrastructure of zoospores of Asterococcus superbus (Cienk.) Scherffel was studied to provide ultrastructural data relevant to the systematic position of the genus. Our results demonstrated that the motile cells of A. Read More

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PSEUDONEOCHLORIS MARINA (CHLOROPHYTA), A NEW COCCOID ULVOPHYCEAN ALGA, AND ITS PHYLOGENETIC POSITION INFERRED FROM MORPHOLOGICAL AND MOLECULAR DATA.

J Phycol 2000 Jun 25;36(3):596-604. Epub 2001 Dec 25.

Department of Biology, Faculty of Education, Toyama University, Toyama, 930 JapanDepartment of Biology, University of New Mexico, Albuquerque, New Mexico 87131Department of Plant Biology, Ohio State University, Columbus, Ohio 43210Department of Molecular Genetics, Ohio State University, Columbus, Ohio 43210.

Ultrastructural and molecular sequence data were used to assess the phylogenetic position of the coccoid green alga deposited in the culture collection of the University of Texas at Austin under the name of Neochloris sp. (1445). This alga has uninucleate vegetative cells and a parietal chloroplast with pyrenoids; it reproduces by forming naked biflagellate zoospores. Read More

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Life cycle of the human and animal oomycete pathogen Pythium insidiosum.

J Clin Microbiol 1993 Nov;31(11):2967-73

Division of Biological Sciences, University of Texas at Austin 78712-1095.

Pythium insidiosum, the etiologic agent of pythiosis insidiosii, causes life-threatening infections in humans and animals. Previous studies of the epidemiology of this disease hypothesized about the possible life cycle of this oomycete. Details, however, were not provided on the steps required to cause infection. Read More

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November 1993

A method to obtain rapid zoosporogenesis of Pythium insidiosum.

Authors:
L Mendoza J Prendas

Mycopathologia 1988 Oct;104(1):59-62

Mycology Department, School of Veterinary Medicine, Universidad Nacional, Heredia, Costa Rica.

Nine strains of Pythium insidiosum the etiologic agent of pythiosis, were inoculated on 2% water agar plus grass blades and then incubated one day at 25 degrees C, 35 degrees C and 37 degrees C. Sporangium and secondary biflagellate-type zoosporas from the parasitized grass blades were noticed in induction medium after one hour of incubation at 35 degrees C and 37 degrees C. The number of sporangia and zoospores were lower at 25 degrees C, than 35 degrees C and 37 degrees C. Read More

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October 1988

Nematophagous fungi: three new species of Myzocytium.

Authors:
G L Barron

Can J Microbiol 1976 May;22(5):752-62

Three species of Myzocytium parasitic on nematodes are described as new. In M. papillatum the zoospores encyst directly on the host cuticle before penetration. Read More

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Nematophagous fungi: new species of the Lagenidiales endoparasitic on Rhabditis.

Authors:
G L Barron

Antonie Van Leeuwenhoek 1976 ;42(1-2):131-9

Two new species of the Lagenidiales endoparasitic on the nematode Rhabditis are reported from Ontario soils. In Myzocytium lenticulare the biflagellate zoospores encyst at any point on the cuticle of the host and penetrate directly through the wall. Sexual reproduction in this species is by oogamy. Read More

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September 1976