Why are Phytophthora and Other Oomycota not True Fungi?

Outlooks on Pest Management 10/2006; 17(5). DOI: 10.1564/17oct08
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    • "Data are available without restriction. Sample source location Northern Ireland, United Kingdom Members of the genus Phytophthora, like other oomycetes, superficially resemble fungi but are completely distinct from true fungi both phylogenetically [1] and in their phenotypic characteristics; for example, unlike true fungi, the oomycetes are usually diploid [2]. The genus includes numerous important pathogens of plants, including trees and food crops [3]. "
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    ABSTRACT: Here we present draft-quality genome sequence assemblies for the oomycete Phytophthora ramorum genetic lineage EU2. We sequenced genomes of seven isolates collected in Northern Ireland between 2010 and 2012. Multiple genome sequences from P. ramorum EU2 will be valuable for identifying genetic variation within the clonal lineage that can be useful for tracking its spread.
    Genomics Data 09/2015; 6. DOI:10.1016/j.gdata.2015.09.009
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    • "It remains unclear whether pathogen PCD, especially apoptosis, is involved in development of pathogenicity. Many economically important eukaryotic plant pathogens, such as Phytophthora sojae, belong to the oomycetes, which are distinct from fungi and classified in the kingdom Stramenopiles , although exhibiting many morphological and physiological similarities to fungi attributable to convergent evolution (Rossman and Palm 2006). Phytophthora plant pathogens attack a wide variety of plants, causing great losses in agriculture, forestry, and natural ecosystems worldwide (Erwin and Ribiero 1996). "
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    ABSTRACT: During pathogenic interactions, both the host and pathogen are exposed to conditions that induce programmed cell death (PCD). Certain aspects of PCD have been recently examined in eukaryotic microbes, but not in oomycetes. Here, we identified conserved TatD proteins in Phytophthora sojae; the proteins are key components of DNA degradation in apoptosis. We selected PsTatD4 for further investigation because the enzyme is unique to the oomycete branch of the phylogenetic tree. The purified protein exhibited DNase activity in vitro. Its expression was upregulated in sporangia and later infective stages, but downregulated in cysts and during early infection. Functional analysis revealed that the gene was required for sporulation and zoospore production, and the expression levels were associated with the numbers of H2O2-induced TUNEL-positive cells. Furthermore, overexpression of PsTatD4 gene reduced the virulence in a susceptible soybean cultivar. Together, these data suggest that apoptosis may play different roles in the early and late infective stages of P. sojae, and that PsTatD4 is a key regulator of infection. The association of PsTatD4 and apoptosis will lay a fundament to understand the basic biology of apoptosis and its roles in P. sojae disease cycle.
    Molecular Plant-Microbe Interactions 06/2014; 27(10). DOI:10.1094/MPMI-05-14-0153-R · 3.94 Impact Factor
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    • "Traditionally, due to their filamentous growth habit, oomycetes have been classified in the kingdom Fungi. However, modern molecular and biochemical analyses suggest that oomycetes have little taxonomic affinity with filamentous fungi but are more closely related to brown algae (heterokonts) in the stramenopiles , one of several major eukaryotic kingdoms [20] [21] [22]. In a series of initial screening experiments of the factors investigated , only medium pH and nitrogen concentration particular strongly affected the extracellular proteinase activities. "
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    ABSTRACT: Proteinases secreted by the oomycete Phytophthora infestans (Mont.) de Bary, Rhizoctonia solani, and Fusarium culmorum belonging to different families of fungi have been studied to determine if the exoenzyme secretion depends on the environmental conditions and the phylogenetic position of the pathogen. The substrate specificity of the extracellular proteinases of F. culmorum, R. solani, and P. infestans and their sensitivity to the action of synthetic and protein inhibitors suggest that they contain trypsin-like and subtilisin-like enzymes regardless of culture medium composition. The relation of trypsin-like and subtilisin-like enzymes is dependent on the culture medium composition, especially on the form of nitrogen nutrition, particularly in the case of the exoenzymes secreted by R. solani. Phylogenetic analyses have shown that the exoproteinase set of ascomycetes and oomycetes has more similarities than basidiomycetes although they are more distant relatives. Our data suggests that the multiple proteinases secreted by pathogenic fungi could play different roles in pathogenesis, increasing the adaptability and host range, or could have different functions in survival in various ecological habitats outside the host.
    12/2011; 2011:947218. DOI:10.4061/2011/947218
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