Fig 4 - uploaded by Reuel M. Bennett
Content may be subject to copyright.
Salisapilia elongata NBRC 100786. Colony patterns on A. Vegetable juice agar. B. Potato carrot agar. C. Mature sporangium; hyaline apical plug (inset). D. Mature sporangium releasing zoospores through a tubular vesicle. Scale bars: A, B = 30 mm, C, D. = 20 µm.
Source publication
Of the diverse lineages of the Phylum Oomycota, saprotrophic oomycetes from the salt marsh and mangrove habitats are still understudied, despite their ecological importance. Salisapiliaceae, a monophyletic and monogeneric taxon of the marine and estuarine oomycetes, was introduced to accommodate species with a protruding hyaline apical plug, small...
Context in source publication
Context 1
... to the phylogeny based on concatenated sequences of ITS and LSU in this study ( Fig. 1), strains Halophytophthora bahamensis NBRC 32556 (Fig. 2), the strain NBRC 32557 (Fig. 4), which was named as H. bahamensis, but is not conspecific with the ex-type strain, H. elongata NBRC 100786 ( Fig. 3 7) clustered with other members of the Salisapiliaceae with strong to maximum support ( Fig. 1). Further, these strains were distinct from S. nakagirii LT6456 (= CBS 127947) (Fig. 8), S. sapeloensis LT6440 (= CBS 127946) ...
Similar publications
As a part of an ongoing revision of Sri
Lankan scincid lizards, I review the genus Lankascincus Greer on the basis of their morphology and morphometric data. I demonstrate that the long-disputed Sphenomorphus megalops (Annandale) is in fact a Lankascincus species, and a neotype is designated. Lankascincus deraniyagalae Greer and L. munindradasai Wi...
Citations
... Oomycetes are eukaryotic, fungus-like, heterotrophic microorganisms that are ubiquitous in marine, brackish, freshwater, as well as terrestrial habitats, and comprise both saprotrophs and pathogens of various hosts (Sparrow 1960, Howard & Johnson 1969, Choi et al. 2008, Thines 2014, Bennett et al. 2018, Bennett & Thines 2019, Hassett et al. 2021. Destructive oomycete pathogens are responsible for several devastating diseases (Erwin & Ribeiro 1996, Bruno et al. 2011, the most notorious being Phytophthora infestans, which causes potato late blight and led to the historical Great Famine in Ireland (Yuen 2021). ...
Oomycetes are a group of fungus-like organisms, which phylogenetically comprise early diverging lineages that are mostly holocarpic, and two crown classes, the Peronosporomycetes and Saprolegniomycetes, including many well-investigated pathogens of plants and animals. However, there is a poorly studied group, the Rhipidiales, which placement amongst the crown oomycetes is ambiguous. It accommodates several taxa with a sophisticated vegetative and reproductive cycle, as well as structural organisation, that is arguably the most complex in the oomycete lineage. Despite the remarkable morphological complexity and their notable perseverance in the face of faster-growing saprotrophic oomycetes and fungi, the knowledge on Rhipidiales is limited to date, as the most complex members are not easily cultured, even by targeted approaches. This also leads to inadequate sequence data for the order, which was sourced from only the two least complex out of seven introduced genera, i.e. Sapromyces and Salispina. In the present study, ex-situ baiting was done using various fruit substrates, and naturally-shed twigs or fruits acquired from water bodies were examined. As a result of these efforts, the species Rhipidium interruptum was obtained and gross cultivation was accomplished using poplar (Populus nigra) twigs as substrate, which allowed further documentation of both asexual and sexual reproduction. This enabled phylogenetic and detailed morphological study, as well as an epitypification of the species. Phylogenetic analyses based on cox2 and nrLSU sequences revealed Rhipidium as the sister genus of Sapromyces. The morphological studies done support a conspecificity of R. interruptum and R. continuum, which might in turn be conspecific with R. americanum. Though several further studies will be required to fit the scattered missing pieces of knowledge on Rhipidiales together revealing a more complete picture of oomycete evolution, we hope that the current study can serve as a cornerstone for future investigations in the group.
... Since phylogenetic studies demonstrated that the genus was polyphyletic, numerous species were transferred to other genera, i.e., Calycofera, Phytopythium, Salisapilia, Salispina, leaving H. vesicula (the type species), H. avicennae, H. batemanensis, H. fluviatilis, H. insularis, H. polymorphica, H. souzae and eight newly described species from Portugal (H. brevisporangia, H. celeris, H. frigida, H. lateralis, H. lusitanica, H. macrosporangia, H. sinuata, H. thermoambigua) in the genus Halophytophthora sensu stricto [12][13][14][15][16][17][18]. ...
In this study, mycelia of eight recently described species of Halophytophthora and H. avicennae collected in Southern Portugal were analysed for lipids and fatty acids (FA) content to evaluate their possible use as alternative sources of FAs and understand how each species FAs profile relates to their phylogenetic position. All species had a low lipid percentage (0.06% in H. avicennae to 0.28% in H. frigida). Subclade 6b species contained more lipids. All species produced monounsaturated (MUFA), polyunsaturated (PUFA) and saturated (SFA) FAs, the latter being most abundant in all species. H. avicennae had the highest FA variety and was the only producer of γ-linolenic acid, while H. brevisporangia produced the lowest number of FAs. The best producer of arachidonic acid (ARA) and eicosapentaenoic acid (EPA) was H. thermoambigua with 3.89% and 9.09% of total FAs, respectively. In all species, palmitic acid (SFA) was most abundant and among the MUFAs produced oleic acid had the highest relative percentage. Principal component analysis (PCA) showed partial segregation of species by phylogenetic clade and subclade based on their FA profile. H. avicennae (Clade 4) differed from all other Clade 6 species due to the production of γ-linolenic and lauric acids. Our results disclosed interesting FA profiles in the tested species, adequate for energy (biodiesel), pharmaceutical and food industries (bioactive FAs). Despite the low amounts of lipids produced, this can be boosted by manipulating culture growth conditions. The observed interspecific variations in FA production provide preliminary insights into an evolutionary background of its production.
... They are thought to have evolved from marine environments and adapted to a wide range of niches and lifestyles [4]. Oomycetes were proposed to encompass three crown orders (Saprolegniales, Albuginales, and Peronosporales [5]), as well as several orders that are still poorly documented, despite potential ecological impact [4,[6][7][8]. Saprolegniales mainly consist of animal parasites, but also few plant pathogens and free-living saprophytes [4]. Albuginales group the obligate, biotrophic parasites of plants that exclusively survive on living tissues. ...
... This large order includes several thousands of both formal and provisional species. Among them are some of the most devastating plant pathogens worldwide, including the genera Phytophthora, Pythium and the intermediate Phytopythium genus [9,10], as well as downy mildews, whose taxonomy was recently revised [6,11], and newly discovered organisms that are not known to be pathogenic, such as Halophytophthora [12], Nothophytophthora [13], and Calycofera [7], as well as Salisipiliaceae [8]. Pathogenic species have highly contrasting lifestyles, ranging from a biotrophic, obligate parasitism to necrotrophy, while most Phytophthora spp. ...
Oomycetes, of the genus Phytophthora, comprise of some of the most devastating plant pathogens. Parasitism of Phytophthora results from evolution from an autotrophic ancestor and adaptation to a wide range of environments, involving metabolic adaptation. Sequence mining showed that Phytophthora spp. display an unusual repertoire of glycolytic enzymes, made of multigene families and enzyme replacements. To investigate the impact of these gene duplications on the biology of Phytophthora and, eventually, identify novel functions associated to gene expansion, we focused our study on the first glycolytic step on P. nicotianae, a broad host range pathogen. We reveal that this step is committed by a set of three glucokinase types that differ by their structure, enzymatic properties, and evolutionary histories. In addition, they are expressed differentially during the P. nicotianae life cycle, including plant infection. Last, we show that there is a strong association between the expression of a glucokinase member in planta and extent of plant infection. Together, these results suggest that metabolic adaptation is a component of the processes underlying evolution of parasitism in Phytophthora, which may possibly involve the neofunctionalization of metabolic enzymes.
... The stacked columns are projected onto a cladogram (drawn based on Diéguez-Uribeondo et al., 2009;Hulvey et al., 2010;McCarthy and Fitzpatrick, 2017;Fletcher et al., 2019) that shows the phylogenetic relationship between the oomycete species whose genomes/transcriptome were analyzed here. Note that alternatively, S. sapeloensis may also be placed between the genera Phytophthora and Pythium (Bennett and Thines, 2019). Background shading of the cladogram indicates the taxonomic orders (Albugonales, Peronosporales, and Saprolegniales). ...
Carbohydrate-active enzymes (CAZymes) are a cornerstone in the phytopathogenicity of filamentous microbes. CAZymes are required for every step of a successful infection cycle—from penetration, to nutrient acquisition (during colonization), to exit and dispersal. Yet, CAZymes are not a unique feature of filamentous pathogens. They are found across eukaryotic genomes and including, for example, saprotrophic relatives of major pathogens. Comparative genomics and functional analyses revealed that CAZyme content is shaped by a multitude of factors, including utilized substrate, lifestyle, and host preference. Yet, family size alone says little about usage. Indeed, in a previous study, we found that genes putatively coding for the CAZyme families of carbohydrate esterase (CE)1 and CE10, while not specifically enriched in number, were suggested to have lifestyle-specific gene expression patterns. Here, we used comparative genomics and a clustering approach to understand how the repertoire of the CE1- and CE10-encoding gene families is shaped across oomycete evolution. These data are combined with comparative transcriptomic analyses across homologous clusters within the gene families. We find that CE1 and CE10 have been reduced in number in biotrophic oomycetes independent of the phylogenetic relationship of the biotrophs to each other. The reduction in CE1 is different from that observed for CE10: While in CE10 specific clusters of homologous sequences show convergent reduction, CE1 reduction is caused by species-specific losses. Comparative transcriptomics revealed that some clusters of CE1 or CE10 sequences have a higher expression than others, independent of the species composition within them. Further, we find that CE1- and CE10-encoding genes are mainly induced in plant pathogens and that some homologous genes show lifestyle-specific gene expression levels during infection, with hemibiotrophs showing the highest expression levels.
... In pre-molecular times most marine oomycetes were assigned to the genus Halophytophthora but recent phylogenetic studies demonstrated that Halophytophthora is polyphyletic. Consequently, numerous Halophytophthora species were transferred to several new genera including Calycofera, Phytopythium, and Salisapilia (Marano et al., 2014;Bennett et al., 2017;Jung et al., 2017b;Bennett and Thines, 2019). Currently Halophytophthora sensu stricto contains nine described species. ...
We investigated the incidence of RNA viruses in a collection of Halophytophthora spp. from estuarine ecosystems in southern Portugal. The first approach to detect the presence of viruses was based on the occurrence of dsRNA, typically considered as a viral molecule in plants and fungi. Two dsRNA-banding patterns (∼7 and 9 kb) were observed in seven of 73 Halophytophthora isolates tested (9.6%). Consequently, two dsRNA-hosting isolates were chosen to perform stranded RNA sequencing for de novo virus sequence assembly. A total of eight putative novel virus species with genomic affinities to members of the order Bunyavirales were detected and their full-length RdRp gene characterized by RACE. Based on the direct partial amplification of their RdRp gene by RT-PCR multiple viral infections occur in both isolates selected. Likewise, the screening of those viruses in the whole collection of Halophytophthora isolates showed that their occurrence is limited to one single Halophytophthora species. To our knowledge, this is the first report demonstrating the presence of negative (−) ssRNA viruses in marine oomycetes.
... However, recent phylogenetic studies demonstrated that the genus Halophytophthora is polyphyletic. Consequently numerous Halophytophthora species were transferred to the newly erected genera Calycofera, Phytopythium, Salispina and Salisapilia(Marano et al. 2014;Li et al. 2016;Bennett et al. 2017;Jung et al. 2017b;Bennett & Thines 2019). ...
... In a recent manuscript (Bennett & Thines 2019), an invalid new combination was proposed, which is herewith validated. ...
Olpidiopsis is a genus of obligate holocarpic endobiotic oomycetes. Most of the species classified in the genus are known only from their morphology and life cycle, and a few have been examined for their ultrastructure or molecular phylogeny. However, the taxonomic placement of all sequenced species is provisional, as no sequence data are available for the type species, O. saprolegniae, to consolidate the taxonomy of species currently placed in the genus. Thus, efforts were undertaken to isolate O. saprolegniae from its type host, Saprolegnia parasitica and to infer its phylogenetic placement based on 18S rDNA sequences. As most species of Olpidiopsis for which sequence data are available are from rhodophyte hosts, we have also isolated the type species of the rhodophyte-parasitic genus Pontisma, P. lagenidioides and obtained partial 18S rDNA sequences. Phylogenetic reconstructions in the current study revealed that O. saprolegniae from Saprolegnia parasitica forms a monophyletic group with a morphologically similar isolate from S. ferax, and a morphologically and phylogenetically more divergent species from S. terrestris. However, they were widely separated from a monophyletic, yet unsupported clade containing P. lagenidioides and red algal parasites previously classified in Olpidiopsis. Consequently, all holocarpic parasites in red algae should be considered to be members of the genus Pontisma as previously suggested by some researchers. In addition, a new species of Olpidiopsis, O. parthenogenetica is introduced to accommodate the pathogen of S. terrestris.
During an oomycete survey in December 2015, 10 previously unknown Halophytophthora taxa were isolated from marine and brackish water of tidal ponds and channels in saltmarshes, lagoon ecosystems and river estuaries at seven sites along the Algarve coast in the South of Portugal. Phylogenetic analyses of LSU and ITS datasets, comprising all described Halophytophthora species, the 10 new Halophytophthora taxa and all relevant and distinctive sequences available from GenBank, provided an updated phylogeny of the genus Halophytophthora s.str. showing for the first time a structure of 10 clades designated as Clades 1–10. Nine of the 10 new Halophytophthora taxa resided in Clade 6 together with H. polymorphica and H. vesicula. Based on differences in morphology and temperature-growth relations and a multigene (LSU, ITS, Btub, hsp90, rpl10, tigA, cox1, nadh1, rps10) phylo-geny, eight new Halophytophthora taxa from Portugal are described here as H. brevisporangia, H. celeris, H. frigida, H. lateralis, H. lusitanica, H. macrosporangia, H. sinuata and H. thermoambigua. Three species, H. frigida, H. macrosporangia and H. sinuata, have a homothallic breeding system while the remaining five species are sterile. Pathogenicity and litter decomposition tests are underway to clarify their pathological and ecological role in the marine and brackish-water ecosystems. More oomycete surveys in yet undersurveyed regions of the world and population genetic or phylogenomic analyses of global populations are needed to clarify the origin of the new Halophytophthora species.
Citation: Maia C, Horta Jung M, Carella G, et al. 2022. Eight new Halophytophthora species from marine and brackish-water ecosystems in Portugal and an updated phylogeny for the genus. Persoonia 48: 54 – 90. https://doi.org/10.3767/persoonia.2022.48.02..
Downy mildews are the most species-rich group of oomycetes, with more than 700 known species. The relationships within the main downy mildew lineages (i.e. the downy mildews with pyriform haustoria, the downy mildews with coloured conidia, and the brassicolous downy mildews) are increasingly well resolved, and 20 well-characterised monophyletic genera have been described. However, their relationships to each other, the various lineages of graminicolous downy mildews, and to the species subsumed in Phytophthora are still unresolved. Recent phylogenomic studies have suggested a polyphyly of the downy mildews, but with a limited taxon sampling within Phytophthora . As taxon sampling is crucial for inferring relationships between large groups, we have conducted a multigene analysis with a set of 72 Phytophthora species and included all known downy mildew lineages. In addition, we performed approximately unbiased (AU) testing as an additional approach to evaluate major nodes. Our analyses resolve the downy mildews as a monophyletic assemblage in all phylogenetic algorithms used. We thus conclude that the evolution of the obligate biotrophy characteristic of downy mildews was a singular event and that all downy mildew pathogens can be traced to a single ancestor.
