Hyphochytriomycota and Oomycota

Beakes, Gordon W.; Thines, Marco

doi:10.1007/978-3-319-32669-6_26-1

Cited by 29 publications

(35 citation statements)

References 289 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This is an interesting relationship, since Phytopythium is morphologically intermediate between Pythium and Phytophthora: Phytop. vexans shares an extrasporangial zoospore cleavage with Pythiales but has other characteristics such as papillate sporangia that support its inclusion in the Peronosporales . Ascunce et al suggested that, because of both Phytop.…”

Section: Discussionmentioning

confidence: 99%

“…Oomycetes comprise microorganisms of the Peronosporomycete and Saprolegniomycetes classes, together with several early‐diverging classes presenting distinct lifestyles and host preferences. Among Peronosporomycete, some orders include pathogens of agronomic, veterinary or medical importance like Peronosporales (downy mildews of Phytophthora and Phytopythium ), Pythiales ( Pythium species) and Albuginales ( Albugo and other white rust) . Albuginales encompasses the sister group to Peronosporales + Pythiales clades, and these genera constitute the peronosporaleans lineage, which diverged from the Saprolegniomycetes in the early Mesozoic …”

Section: Introductionmentioning

confidence: 99%

“…Molecular evolution and systematic analyses have been used to reconstruct the phylogenetic relationships of oomycetes, which is important due to the need to understand the evolution of pathogenesis. In fact, several studies have provided phylogenetic frameworks that allow thorough comparisons among some oomycetes species . Nevertheless, to date, most of these studies were performed using a limited set of traditional genetic markers, such as nuclear ribosomal DNA and/or mitochondrial markers .…”

Section: Introductionmentioning

confidence: 99%

“…Moreover, based on morphological evidence, Phytopythium was recently reclassified from Pythium clade K to its own genus of Peronosporales . Even so, Pythium sensu lato currently encompasses over a hundred species, most of which are phytopathogens or pathogens of algae, fishes, insects and mammals, although some species have been reported to be parasitic to fungi and a few have been evaluated for biological control against other oomycete plant pathogens . Pythium species are genetically diverse, exhibiting significant variation in terms of virulence, host range and distribution …”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

New insights on evolutionary aspects of Pythium insidiosum and other peronosporaleans

Weiblen

Robe

Azevedo

et al. 2020

Mycoses

View full text Add to dashboard Cite

Summary Background The evolution of pathogenic mechanisms is a major challenge, which requires a thorough comprehension of the phylogenetic relationships of pathogens. Peronosporaleans encompasses a heterogeneous group of oomycetes that includes some animal/human pathogens, like Pythium insidiosum. Objective We analysed here the phylogenetic positioning and other evolutionary aspects related to this species and other peronosporaleans, using a multi‐locus approach with one mitochondrial and three nuclear genes. Methodology Phylogenetic patterns of 55 oomycetes were inferred by maximum likelihood and Bayesian analysis, and a relaxed molecular clock method was applied to infer the divergence time of some peronosporaleans branches. Results Pythium insidiosum was monophyletic with a major and polytomous clade of American isolates; however, Pythium spp. was found to be paraphyletic with Phytopythium sp. and Phytophthora spp. In general, peronosporaleans subdivided into four lineages, one of which evidenced a close relationship of P insidiosum, P aphanidermatum and P arrhenomanes. This lineage diverged about 63 million years ago (Mya), whereas P insidiosum diversified at approximately 24 Mya. The divergence of American and Thai isolates seems to have occurred at approximately 17 Mya, with further American diversification at 2.4 Mya. Conclusion Overall, this study clarifies the phylogenetic relationships of P insidiosum regarding other peronosporaleans in a multi‐locus perspective, despite previous claims that phylogenomic analyses are needed to accurately infer the patterns and processes related to the evolution of different lineages in this group. Additionally, this is the first time that a molecular clock was applied to study the evolution of P insidiosum.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

New insights on evolutionary aspects of Pythium insidiosum and other peronosporaleans

Weiblen

Robe

Azevedo

et al. 2020

Mycoses

View full text Add to dashboard Cite

show abstract

“…Downy mildews of the genus Peronospora are obligate biotrophs, which means that they are dependent on living host cells for nutrition (Thines and Choi, 2016). They belong to the Peronosporaceae within the phylum Oomycota of the kingdom Straminipila (Beakes and Thines, 2017). The cell walls of oomycetes mainly contain β‐(1,3)‐glucan, β‐(1,6)‐glucan, and cellulose (Sietsma et al , 1969; Blaschek et al , 1992).…”

Section: Introductionmentioning

confidence: 99%

Tracking host infection and reproduction of Peronospora salviae‐officinalis using an improved method for confocal laser scanning microscopy

et al. 2020

Self Cite

View full text Add to dashboard Cite

Peronospora salviae-officinalis, the causal agent of downy mildew on common sage, is an obligate biotrophic pathogen. It grows in the intercellular spaces of the leaf tissue of sage and forms intracellular haustoria to interface with host cells. Although P. salviae-officinalis was described as a species of its own 10 years ago, the infection process remains obscure. To address this, a histological study of various infection events, from the adhesion of conidia on the leaf surface to de novo sporulation is presented here. As histological studies of oomycetes are challenging due to the lack of chitin in their cell wall, we also present an improved method for staining downy mildews for confocal laser scanning microscopy as well as evaluating the potential of autofluorescence of fixed nonstained samples. For staining, a 1:1 mixture of aniline blue and trypan blue was found most suitable and was used for staining of oomycete and plant structures, allowing discrimination between them as well as the visualization of plant immune responses. The method was also used to examine samples of Peronospora lamii on Lamium purpureum and Peronospora belbahrii on Ocimum basilicum, demonstrating the potential of the presented histological method for studying the infection processes of downy mildews in general. K E Y W O R D Saniline blue, confocal laser scanning microscopy, Peronospora belbahrii, Peronospora lamii, Peronospora salviae-officinalis, trypan blueThis is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

show abstract

Different community compositions between obligate and facultative oomycete plant parasites in a landscape-scale metabarcoding survey

Fiore-Donno

Bonkowski

2020

Biol Fertil Soils

View full text Add to dashboard Cite

Oomycetes are a ubiquitous protistan lineage including devastating crop parasites. Although their ecology in agrosystems has been widely studied, little is known of their distribution in natural and semi-natural ecosystems and how they respond to edaphic and environmental factors. We provide here a baseline of the diversity and distribution of soil oomycetes, classified by lifestyles (biotrophy, hemibiotrophy and saprotrophy), at the landscape scale in temperate grassland and forest. From 600 soil samples, we obtained 1148 operational taxonomy units representing ~ 20 million Illumina reads (region V4, 18S rRNA gene). We found a majority of hemibiotrophic plant pathogens, which are parasites spending part of their life cycle as saprotrophs after the death of the host. Overall both grassland and forest constitute an important reservoir of plant pathogens. Distance-based RDA models identified soil type and mineral soil C/N ratio as the most influential factors in shaping oomycete communities in grassland and forest. Edaphic conditions and human-induced management intensification in forest triggered opposite responses in the relative abundances of obligate biotrophs and hemibiotrophs, suggesting different ecological requirements of these two lifestyles.

show abstract

Hyphochytriomycota and Oomycota

Cited by 29 publications

References 289 publications

New insights on evolutionary aspects of Pythium insidiosum and other peronosporaleans

New insights on evolutionary aspects of Pythium insidiosum and other peronosporaleans

Tracking host infection and reproduction of Peronospora salviae‐officinalis using an improved method for confocal laser scanning microscopy

Different community compositions between obligate and facultative oomycete plant parasites in a landscape-scale metabarcoding survey

Contact Info

Product

Resources

About