The importance of Pestalotiopsis and Neopestalotiopsis species as pathogens of economically important plants is steadily increasing, while knowledge of their phytotoxic metabolites remains limited. Eighteen new strains of pestalotioid fungi were isolated from various plant samples that showed visible symptoms of disease. These strains were evaluated morphologically, and phylogenetic analyses of the ITS (internal transcribed spacer) and tub2 (beta-tubulin) gene regions were performed for genotyping. The isolated strains from Castanea sativa wood and nut were assigned to the species Neopestalotiopsis clavispora (six strain) and P. chamaeropis (one strain); four strains of Neopestalotiopsis, and one strain of Pestalotiopsis were not identified at the species level. Five strains isolated from coniferous trees, such as cypress and fir, were assigned to the species P. monochaeta, P. verruculosa, P. hollandica, and N. chrysea. A strain isolated from the Vaccinium uliginosum L. shoot was diagnosed as N. megabetaspora. The pathogenicity of strains was confirmed in vitro on coniferous shoots, Granny Smith apples, and leaves of C. sativa. The most pronounced phytopathogenic properties were demonstrated by strains isolated from C. sativa and a blueberry shoot compared to strains from coniferous trees. The dihydropyrans pestalotin and 7-hydroxypestalotin were identified in these strains, except for P. chamaeropis. The strains, isolated from cypress and fir, mainly produced a range of other metabolites. The extracts of the strains exerted a phytotoxic effect on lettuce root growth, suggesting that the metabolites may be involved in the virulence of the phytopathogenic fungi Pestalotiopsis s.l. Using the extract of Pes21 N. megabetaspora—the most active producer of pestalotins—we demonstrated that the necrosis area on the leaves of V. uliginosum L. and Rubus idaeus L. increased consistently with increasing metabolite concentrations. Purified pestalotin and 7-hydroxypestalotin inhibited lettuce root growth at a concentration of 500 μg/mL and stimulated it at a concentration of 100 μg/mL. This work provides important insights into the regulatory role of metabolites in fungus–plant interactions and serves as a basis for developing new strategies for the maintenance of plant resources.

Biodiversity plays a crucial role in maintaining the stability of both ecosystems (biocenoses) and individual trees, as it enhances resistance to biotic and abiotic stressors. This study focuses on the phyllosphere fungal communities of Larix sibirica Ledeb. and their role in host resilience under combined stresses from the root pathogen Porodaedalea niemelaei M. Fisch. and technogenic pollution. Samples were collected from four groups of trees: infected with the root pathogenic fungus P. niemelaei, exposed only to technogenic pollution, subjected to both P. niemelaei infection and technogenic pollution, and control trees, which were neither infected nor affected by pollution. DNA was amplified, sequenced, and analyzed using Illumina sequencing technology, yielding 598,891 raw ITS sequences. Varying degrees of larch needle necrosis were observed across the groups, likely influenced by different microbial genera under specific environmental conditions. In samples infected with P. niemelaei, Fusarium and Alternaria dominated, whereas in the group exposed to both P. niemelaei and technogenic pollution, Valsa and Cytospora were the most represented. Notably, the latter group also exhibited a reduced number of unique taxa compared to others, though further studies are needed to confirm statistical significance. The dominant pathogenic genera detected – Fusarium, Alternaria, Valsa, and Cytospora – likely interact with other fungi such as Exobasidium, Ophiognomonia, Sarocladium, Phomopsis, and Taphrina, exacerbating damage and altering the microbiome, particularly under pollution-induced stress.

Strains of Cryphonectria parasitica (Murrill) M.E. Barr were isolated from the bark of Castanea sativa Mill. with visual signs of weakening in Krasnodar Krai and Abkhazia. Strains demonstrated varying degrees of phytopathogenicity in vitro towards two plant test objects. Extensive (on C. sativa shoots) and deep (on Granny Smith apples) necrosis was observed in 67

The Hymenochaetales is an order with most species as wood-inhabiting fungi that have high phylogenetic complexity and morphological diversity. Species in this order play important roles in forest ecosystems and include wood decomposers, pathogens, and those that form ectomycorrhizal associations. However, we have limited knowledge of the patterns of large-scale evolutionary history of the order. In this study, using 171 genomes, including 113 newly assembled, we reconstructed the phylogenomic relationships, divergence times, biogeographic patterns, morphological evolution of basidiomata, and patterns of speciation/extinction in the Hymenochaetales. The phylogenomic relationships of 12 families within the Hymenochaetales suggested that 10 families can be accepted, and 2 families rejected. Molecular clock dating analyses suggested that the Hymenochaetales possibly started a rapid family-wide and genus-wide radiation during the early Cretaceous to late Jurassic and Cretaceous, respectively. Reconstruction of the ancestral state implied that Hymenochaetales probably originated from the temperate regions of Asia, with the basidiomata of the common ancestor likely being a corticioid species that rapidly transformed between the early Cretaceous and late Jurassic, coinciding with radiations at the family level. Furthermore, we detected a gradually increasing trend of speciation, extinction, and net diversification rates. We provided large-scale genomes of the Hymenochaetales and revealed evolutionary history patterns, which are key to understanding the evolution of fungi.

On Pinus sylvestris L. trees of different ages with different phytopathological conditions, we have identified the invasive species Diplodia sapinea (Fr.) P. Karst., which is a dangerous pathogen of coniferous trees, for the first time in Central Siberia (in the parks of Krasnoyarsk). Pure cultures are isolated from pycnidia on cones; their morphological and molecular genetic characteristics correspond to the species D. sapinea. Siberian isolates are characterized by a high radial growth rate on nutrient media and are phytopathogenic against shoots of P. sylvestris and fruits of Granny Smith apples in vitro. They cause rapid and extensive necrotic lesions of the bark, shoot cambium, and fruit pulp and exhibit high peroxidase and protease enzymatic activity. Siberian D. sapinea isolates do not exceed the parameters of southern isolates in terms of morphological characteristics, enzyme activity, and phytopathogenicity. Significant differences are shown with the Dp1-23 strain of Diplodia seriata De Not isolated from pycnidia on the cones of Cupressus sempervirens L. For Siberian D. sapinea isolates, high resistance to cold stress is established in the temperature range from –8 to –31°C in a series of experiments on freezing-thawing of the mycelium. After activation, the radial growth rate of isolates on potato dextrose agar (PDA) at 24°C turn out to be higher than that of strains that were not subjected to freezing; relatively slow activation is noted at –16°C compared to other temperatures. The presence of a long endophytic phase in the species, which was discovered in Central Siberia for the first time; high adaptive capabilities; and phytopathogenicity pose a particular danger to its spread to a new territory and host plants. This requires special attention and study.

Areal, location, species, host, source, origin and pathogenicity of Siberian and Far Eastern strains of Armillaria used in the study.

Ascomycete fungi isolated in Central Siberia from canker lesions of Abies sibirica Ledeb. were assigned to the genus Corinectria Gonzalez Chaverri. Our earlier research has shown four Corinectria Siberian strains to be significantly different genetically from the known Corinectria spp. This work investigated the secondary metabolites of 23 morphologically similar Corinectria Siberian strains and their phytotoxicity. The strains were divided into two types by their morphological and cultural traits, MCT1 and MCT2. The MCT1 strains synthesized the meroterpenoids ilicicolins A and B, ilicicolin A epoxide and chlorocylindrocarpol; the MCT2 strains produced ilicicolins C, D (ascochlorin), F and ascofuranol. The phytotoxicity of the Corinectria strains showed a significant heterogeneity to Picea obovata seeds and was exhibited by 31

Fungal strains isolated in the Krasnoyarsk Territory from dead caterpillars of the Siberian silkworm Dendrolimus sibiricus Tschetverikov, found in the litter and crown of Abies sibirica Ledeb., were assigned to the species Cordyceps militaris (L.) Fr., based on morphological and genetic methods. The strains were highly active producers of such bioactive compounds as polysaccharides (PS), adenosine, and cordysinin B. Cordysinin B has not been previously reported in the species C. militaris. It was found that PS production was more influenced by the method of fungal cultivation than by the carbon substrate. The highest production of PS (6.0–6.7 g/L) and nucleosides (390 mg/L) by C. militaris 11-5 was observed during submerged cultivation on sucrose using abiopeptide. When studying the biosynthesis of PS during growth of the fungus, it was found that the synthesized PSs were consumed by the culture when the concentration of the carbon substrate in the medium decreased and apparently served as reserve sources of carbon.

Fusarium crown rot (FCR), caused by Fusarium pseudograminearum , significantly impacts wheat yield and quality in China’s Huanghuai region. The rapid F. pseudograminearum epidemic and FCR outbreak within a decade remain unexplained. In this study, two high-quality, chromosome-level genomes of F. pseudograminearum strains producing 3-acetyl-deoxynivalenol (3AcDON) and 15-acetyl-deoxynivalenol (15AcDON) toxins were assembled. Additionally, 38 related strains were resequenced. Genomic differences such as single nucleotide polymorphisms (SNPs), insertions/deletions (indels), and structural variations (SVs) among F. pseudograminearum strains were analyzed. The whole-genome SNP locus based population classification mirrored the toxin chenotype (3AcDON and 15AcDON)-based classification, indicating the presence of genes associated with the trichothecene toxin gene cluster. Further analysis of differential SNP, indel, and SV loci between the 3AcDON and 15AcDON populations revealed a predominant connection to secondary metabolite synthesis genes. Notably, the majority of the secondary metabolite biosynthesis gene cluster (SMGC) loci were located in SNP-dense genomic regions, suggesting high mutability and a possible contribution to F. pseudograminearum population structure and environmental adaptability. This study provides insightful perspectives on the distribution and evolution of F. pseudograminearum , and for forecasting the spread of wheat FCR, thereby aiding in the development of preventive measures and control strategies.

To date, the taxonomy of fusarioid fungi has undergone significant changes due to a clarification of their taxonomic status by molecular genetic methods. As a result, new species/genera have appeared, whereas some old ones have been abolished. Information on the diversity and distribution of Fusarium species do not always correspond to the modern taxonomy and requires a thorough revision. In this study we have systematized some long-term data on the species composition and specialization of fungi associated with woody plants in Russia (Far East, Siberia, the Northwestern region, and Crimea). The molecular genetic identification of 53 isolates earlier identified as Fusarium spp. has been carried out. According to morphological characteristics, phylogenetic analysis, and ecological preferences, five species complexes of Fusarium fungi have been identified. Eleven Fusarium species ( F. acuminatum, F. avenaceum, F. equiseti, F. oxysporum, F. redolens, F. reticulatum, F. sambucinum, F. sporotrichioides, F. torulosum, F. tricinctum, and F. venenatum ) and 1 closely related species from the genus Neocosmospora ( N. solani ) have been identified. In the case of woody plants, the Fusarium tricinctum species complex has been represented by the largest number of species ( F. acuminatum, F. avenaceum, F. reticulatum, F. torulosum , and F. tricinctum ). The maximum number of the studied isolates (17) belongs to F. avenaceum associated with various plants growing in the whole studied areas. Seven Fusarium species and N. solani have been identified on juvenile plants characterized by the signs of tracheomycotic wilt and growing in the forest nurseries of Central and Southern Siberia; species such as F. oxysporum, F. equiseti, and N. solani have been revealed only on first-year conifer seedlings. In forest and park stands, where fusarioid fungi belong mainly to saprotrophs and endophytes, nine Fusarium species have been revealed, among which F. tricinctum, F. torulosum, F. venenatum , and F. reticulatum have not been found in pathological or seed material from the forest nurseries.

The phenomenon of fluorescence is widely used in molecular biology for studying the interaction of light with biological objects. In this article, we present an experimental investigation of the enhancement of laser-induced fluorescence of Clytia gregaria green fluorescent protein. The laser-induced fluorescence method applied in our work combines the advantages of femtosecond laser pulses and a photonic crystal cavity, with the time dependence of the fluorescence signal studied. It is shown that a green fluorescent protein solution placed in a microcavity and excited by femtosecond laser pulses leads to an increase in fluorescence on the microcavity modes, which can be estimated by two orders of magnitude. The dependences of fluorescence signal saturation on the average integrated optical pump power are demonstrated and analyzed. The results obtained are of interest for the development of potential applications of biophotonics and extension of convenient methods of laser-induced fluorescence.

Areal, location, species, host, source, origin and pathogenicity of Siberian and Far Eastern strains of Armillaria used in the study.

In 2019, the bark beetle Ips amitinus (native to central Europe) was identified in south-western Siberia at a distance exceeding 2500 km east of its previously known easternmost location in the European part of Russia. In Siberia, its invasive populations are characterised by high abundance and harmfulness. Here, I. amitinus accomplishes primary attacks on standing vital trees of Pinus sibirica with a lethal outcome. This invasion has already resulted in massive dieback in stands of pine over a large geographic territory. By, 2021, the invaded area was estimated to cover at least 31,200 km2. The objectives of this study were to investigate fungi associated with/vectored by I. amitinus in its invasive area in south-western Siberia and wood decay fungi that cause root and butt rots to P. sibirica. This led to the following conclusions: (i) DNA analysis of sixty adult beetles of Ips amitinus collected from P. sibirica in south-west Siberia revealed the presence of 143 fungal taxa; (ii) species richness was significantly higher in beetles collected from dead branches than from (more recently infested) dying branches; (iii) fungal communities were >90% dominated by yeasts, among which the most common were Nakazawaea holstii, Kuraishia molischiana, and N. ambrosiae; (iv) entomopathogenic Beauveria bassiana s.l. was the most common fungus isolated from dead/mycosed beetles of I. amitinus, followed by Lophium arboricola and four Ophiostoma spp.; and (v) Heterobasidion parviporum was the most common decay fungus detected, which was causing heart rot in stems of P. sibirica.

To elucidate the genomic traits of ecological diversification in the Hymenochaetales, we sequenced 15 new genomes, with attention to ectomycorrhizal (EcM) Coltricia species. Together with published data, 32 genomes, including 31 Hymenochaetales and one outgroup, were comparatively analyzed in total. Compared with those of parasitic and saprophytic members, EcM species have significantly reduced number of plant cell wall degrading enzyme genes, and expanded transposable elements, genome sizes, small secreted proteins, and secreted proteases. EcM species still retain some of secreted carbohydrate-active enzymes (CAZymes) and have lost the key secreted CAZymes to degrade lignin and cellulose, while possess a strong capacity to degrade a microbial cell wall containing chitin and peptidoglycan. There were no significant differences in secreted CAZymes between fungi growing on gymnosperms and angiosperms, suggesting that the secreted CAZymes in the Hymenochaetales evolved before differentiation of host trees into gymnosperms and angiosperms. Nevertheless, parasitic and saprophytic species of the Hymenochaetales are very similar in many genome features, which reflect their close phylogenetic relationships both being white rot fungi. Phylogenomic and molecular clock analyses showed that the EcM genus Coltricia formed a clade located at the base of the Hymenochaetaceae and divergence time later than saprophytic species. And Coltricia remains one to two genes of AA2 family. These indicate that the ancestors of Coltricia appear to have originated from saprophytic ancestor with the ability to cause a white rot. This study provides new genomic data for EcM species and insights into the ecological diversification within the Hymenochaetales based on comparative genomics and phylogenomics analyses.

Basidiomycetes Armillaria infect deciduous, coniferous and fruit trees, causing enormous economic damage. The role of secondary metabolites (tricyclic sesquiterpene aryl esters - melleolides) in the life cycle and pathogenesis of Armillaria is under active investigation. To date, not all species of Armillaria have been tested for the biosynthesis of melleolides. We investigated the secondary metabolite profiles of six root-pathogenic species of the genus Armillaria (A. borealis Marxmüller & Korhonen, A. cepistipes Velenovský, A. gallica Marxm, A. mellea (Vahl) P. Kummer, A. sinapina Bérubé & Dessur, A. ostoyae (Romagn.) Herink) distributed in Siberia (South Krasnoyarsk Krai, Republic of Tyva, Republic of Khakassia, Taimyr Peninsula), Russian Far East (Sikhote-Alin) and Crimea (Krymsky National Park, Chatyr-Dag Mountain Lower Plateau). A total of 15 compounds were identified in the metabolome profile. Two compounds (melleolide D and melledonal C) are synthesized by all investigated strains irrespective of their geographic location and host plant. The maximum spectrum of melleolides (7-8 compounds) was found in isolates of A. borealis, A. gallica, A. sinapina, A. ostoyae. In submerged culture, the maximum accumulation of melleolides varied from 2 up to 239 mg l-1. A mixture of melleolide D and melledonal C (1:1) synthesized by the most productive strain A. mellea Cr2-17 was first found to have a phytotoxic action on the growth parameters of the callus culture Populus balsamifera and 10-day-old conifer seedlings. A 0.5% concentration of melleolides caused a credible decrease of P. balsamifera callus raw biomass; a decrease of the viability of Larix sibirica and, which is especially significant, Pinus sylvestris seedlings; inhibition of stem and root growth processes; dechromation of foliage; loss of turgor. The occurrence of a broad range of melleolides in the metabolome profile and two common compounds in all investigated strains, with a phytotoxic action at their sufficiently high concentration, enables considering the synthesis of melleolides by Armillaria fungi as one of the possible mechanisms of their pathogenicity efficiently realized in strains characterized by overproduction of melleolides under natural conditions.

Dictyostelid cellular slime molds (dictyostelids) are protists that are common inhabitants of most soils, where they feed upon bacteria. Changbai Mountain is the highest mountain in northeast China. Soil samples collected on Changbai Mountain yielded 11 isolates representing six species of dictyostelid samples. Two of these species (Dictyostelium robusticaule and Heterostelium recretum) were found to be new to science, based on morphology, SSU rDNA sequences, and an ATPase subunit 1 gene (atp1) phylogeny. The present study also demonstrated that the increased accuracy and lower costs associated with the use of atp1 sequences make them a complement of SSU rDNA sequences for identifying dictyostelids. Changbai Mountain is characterized by a higher diversity of dictyostelids than indicated by the few previous reports. Moreover, the data for Changbai Mountain, compared with comparable data for Taiwan, suggest that differences in diversity at the family level are possibly related to latitude. Mixed broadleaf-conifer forests produced more isolates and species than broadleaf forests at the same elevation and also had the highest species richness, which indicates an effect of vegetation on dictyostelids. However, the pattern of slightly decreasing diversity with increasing elevation in dictyostelids was also apparent. IMPORTANCE Dictyostelium robusticaule and Heterostelium recretum are two new species of dictyostelids reported in this study. The potential use of atp1 sequences is a complement of SSU rDNA sequences for the identifying dictyostelids. A pattern of slightly decreasing diversity with increasing elevation in dictyostelids was observed, with the conditions that exist at lower elevations apparently more suitable for dictyostelids, whereas differences of diversity observed at the family level are possibly related to latitude.

Species of Abies trees are considered susceptible to the effects of diseases and pests. As a result of the complex biotic impact of the Ussuri Polygraph (Polygraphus proximus Blandford) the area of potential drying of Siberian fir (Abies sibirica Ledeb) stands up to 10 million hectares. Trees corrupted by root pathogens are a center of desiccation, from where pathological decay spreads, so also there arise an urgent issue of disposal of corrupted bark and wood waste. A promising solution to this problem is the extractive processing of wood-bark wastes aimed to obtain a wide range of high-valued substances. Fractions of resinous substances, tannins and pectins were isolated from the corrupted A. sibirica bark using the sequential extraction method. The optimization of the process of pectin extraction - one of the most valuable secondary extractive components was carried out. The optimal experimental conditions were established with the highest yield of pectins up to 8.4 wt.%, which is achieved by treating the A. sibirica bark, corrupted by P. proximus, with a HCl solution at pH = 1.71 and the process duration 48 min. The isolated extractive substances (tannins, pectins) from the A. sibirica bark characterized by IR spectroscopy and gel permeation chromatography. The antioxidant activity of tannins and pectins studied using compounds imitated free radicals (1,1-diphenyl-2-picrylhydrazyl), which amounted to 97% and 89%, respectively.

Extended cultivation with multiple removal of BC pellicles is proposed herein as a new biosynthetic process for bacterial cellulose (BC). This method enhances the BC surface area by 5–11 times per unit volume of the growth medium, improving the economic efficiency of biosynthesis. The resultant BC gel-films were thin, transparent, and congruent. The degree of polymerization (DP) and elastic modulus (EM) depended on the number of BC pellicle removals, vessel shape, and volume. The quality of BC from removals II–III to VII was better than from removal I. The process scale-up of 1:40 by volume increased DP by 1.5 times and EM by 5 times. A fact was established that the symbiotic Medusomyces gisevii Sa-12 was adaptable to exhausted growth medium: the medium was able to biosynthesize BC for 60 days, while glucose ran low at 24 days. On extended cultivation, DP and EM were found to decline by 39–64% and 57–65%, respectively. The BC gel-films obtained upon removals I–VI were successfully trialed in experimental tension-free hernioplasty.

A phytopathogenic complex of the genus Fusarium, common on 19 wheat varieties cultivated in Siberia, was investigated. It was found eleven fungal species in wheat grain (Fusarium avenaceum, F. culmorum, F. diversisporum, F. heterosporum, F. oxysporum, F.poae, F. sambucinum, F. incarnatum, F. sporotrichioides, F. tricinctum, Neocosmospora solani), with the dominant one being F. sporotrichioides (from 23 to 68 % of the total number of species). Seven species were found in the rhizosphere of wheat (F. avenaceum, F.incarnatum, F. oxysporum, F. sambucinum, F. sporotrichioides, F. tricinctum, N. solani), with the most common being F. oxysporum (up to 39 %) and F. sporotrichioides (up to 35%). Biotesting a mixture of metabolites in wheat seeds and seedlings revealed highly toxic species, namely F. sporotrichioides and F. oxysporum (a decrease of in vitro seed germination by more than 55 % and a prolonged inhibitory effect on seedling development). F. avenaceum, N.solani and F. culmorum are moderately toxic species. The greatest danger for the development of wheat fusariosis in Siberia in terms of the total frequency of occurrence, phytotoxic and phytopathogenic properties is represented by F. sporotrichioides.

Species of Armillaria are distributed globally and include some of the most important pathogens of forest and ornamental trees. Some of them form large long-living clones that are considered as one of the largest organisms on earth and are capable of long-range spore-mediated transfer as well as vegetative spread by drought-resistant hyphal cords called rhizomorphs. However, the virus community infecting these species has remained unknown. In this study we used dsRNA screening and high-throughput sequencing to search for possible virus infections in a collection of Armillaria isolates representing three different species: Armillaria mellea from South Africa , A. borealis from Finland and Russia (Siberia) and A. cepistipes from Finland. Our analysis revealed the presence of both negative-sense RNA viruses and positive-sense RNA viruses, while no dsRNA viruses were detected. The viruses included putative new members of virus families Mymonaviridae , Botourmiaviridae and Virgaviridae and members of a recently discovered virus group tentatively named “ambiviruses” with ambisense bicistronic genomic organization. We demonstrated that Armillaria isolates can be cured of viruses by thermal treatment, which enables the examination of virus effects on host growth and phenotype using isogenic virus-infected and virus-free strains.