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Recently, phylogenomic analyses of two parasitic fungi with amoeboid zoospores and long kinetosomes, the sanchytrids Amoeboradix gromovi and Sanchytrium tribonematis, showed that they formed a clade Sanchytriomycota sister to Blastocladiomycota. Sanchytrid species diversity is still very low and most of the isolates from different places belong to S. tribonematis. Here, we present a new strain X-137 CCPP ZIN RAS of fresh-water S. tribonematis having a peculiar morphology and an unusual stage in the life cycle. Its zoospores have a kinetosome composed of 9 microtubular singlets along its whole length (1.2 μm) with the pseudocilium containing an axoneme of 4 microtubules and enable to form an extremely long posterior filopodium (up to 10 body lengths). The kinetosome develops from a centriole of the centrosomal apparatus in sporangium, while another centriole becomes a non-flagellar kinetosome. Big zoospores with several pseudocilia and many (up to eleven) kinetosomes per cell have been found in S. tribonematis culture. They are probably a result of several zoospore or gamete fusions. These findings expand our still poor knowledge on the cell structure and biology of Sanchytriomycota. [ABSTRACT FROM AUTHOR]

Eriophyoid mites represent a hyperdiverse, phytophagous lineage with an unclear phylogenetic position. These mites have succeeded in colonizing nearly every seed plant species, and this evolutionary success was in part due to the mites' ability to induce galls in plants. A gall is a unique niche that provides the inducer of this modification with vital resources. The exact mechanism of gall formation is still not understood, even as to whether it is endogenic (mites directly cause galls) or exogenic (symbiotic microorganisms are involved). Here we (i) investigate the phylogenetic affinities of eriophyoids and (ii) use comparative metagenomics to test the hypothesis that the endosymbionts of eriophyoid mites are involved in gall formation. Our phylogenomic analysis robustly inferred eriophyoids as closely related to Nematalycidae, a group of deep-soil mites belonging to Endeostigmata. Our comparative metagenomics, fluorescence in situ hybridization, and electron microscopy experiments identified two candidate endosymbiotic bacteria shared across samples, however, it is unlikely that they are gall inducers (morphotype1: novel Wolbachia, morphotype2: possibly Agrobacterium tumefaciens). We also detected an array of plant pathogens associated with galls that may be vectored by the mites, and we determined a mite pathogenic virus (Betabaculovirus) that could be tested for using in biocontrol of agricultural pest mites. [ABSTRACT FROM AUTHOR]

Many fungi have been identified as pathogens of marine algae. Among them, Chytridiomycota have been revealed as relatively highly abundant, but much of the diversity known within these groups is almost entirely based on environmental sequencing data. Here, we present a novel chytridiomycete genus and species, characterized by light microscopical observations, ultrastructure, and molecular phylogenetic analysis of the parasitic chytrid of brackish-water dinoflagellate Kryptoperidinium foliaceum from the Baltic Sea. Phylogenetic analysis of rDNA sequences and the ultrastructure of the strain reveals that it represents a new family in the order Rhizophydiales. Ericiomyces syringoforeus gen. et sp. nov. is a parasitoid with a life cycle composed by zoospores, which attach to the host, encyst, and produce a rhizoidal system (haustorium). Unlike typical Rhizophydiales chytrids, sporangium develops as a lateral outgrowth of the encysted zoospore. The ultrastructural study revealed at least two unique traits: the syringe-like organelle in the cyst, which supposed to paralyze the host, and funnel-shaped structure anchoring sporangium in the host wall. Sporangium matures and produces new zoospores within 3 days. Multiple infections are common and then the life cycle is 1–2 days shorter compared to the duration when a single infection occurred. Cross-infection experiments showed that E. syringoforeus could only infect dinoflagellates, being K. foliaceum highly susceptible to infection by the chytrid parasitoid. The effects of some fungal epidemics on populations of Kryptoperidinium are discussed. [ABSTRACT FROM AUTHOR]

Correction to: I Scientific Reports i https://doi.org/10.1038/s41598-022-07535-3, published online 09 March 2022 The original version of this Article contained errors. In addition, the Acknowledgments, "We thank Dr. Jeff Chang and Dr. Alexandra Weisberg (Oregon State University) for providing all databases used in the Vir-Search web service [http://gall-id.cgrb.oregonstate.edu/vir-finder.html], Sergey Diachkov (Tyumen State University, Russia) for help with the Gall-ID analysis and several GenBank submissions, and D. Hans Klompen (Ohio State University) who provided sequences of the two endeostigmatid mites." now reads: "We thank Dr. Jeff Chang and Dr. Alexandra Weisberg (Oregon State University) for providing all databases used in the Vir-Search web service [http://gall-id.cgrb.oregonstate.edu/vir-finder.html], Sergey Diachkov (Tyumen State University, Russia) for help with the Gall-ID analysis and several GenBank submissions, and Dr. Hans Klompen (Ohio State University) who provided sequences of the two endeostigmatid mites.". [Extracted from the article]