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Ergot alkaloid synthesis (eas) gene clusters found in several fungi encode biosynthesis of agriculturally and pharmaceutically important ergot alkaloids. Although the biosynthetic genes of the ergot alkaloid pathway have been well characterized, regulation of those genes is unknown. We characterized a gene with sequence similarity to a putative transcription factor and that was found adjacent to the eas cluster of Metarhizium brunneum, a plant symbiont and insect pathogen. Function of the novel gene, easR, was explored by CRISPR-Cas9-derived gene knockouts. To maximize potential for ergot alkaloid accumulation, strains of M. brunneum were injected into larvae of the insect Galleria mellonella. Larvae infected with the wild type contained abundant ergot alkaloids, but those infected with easR knockouts lacked detectable ergot alkaloids. The easR knockout strains had significantly reduced or no detectable mRNA from eas cluster genes in RNAseq and qualitative RT-PCR analyses, whereas the wild-type strain contained abundant mRNA from all eas genes. These data demonstrate that the product of easR is required for ergot alkaloid accumulation and provide evidence that it has a role in the expression of ergot alkaloid biosynthesis genes. Larvae infected with an easR knockout survived significantly longer than those infected with the wild type (P < 0.0001), indicating a role for EasR, and indirectly confirming a role for ergot alkaloids, in the virulence of M. brunneum to insects. Homologs of easR were found associated with eas clusters of at least 15 other ergot alkaloid-producing fungi, indicating that EasR homologs may contribute to regulation of ergot alkaloid synthesis in additional fungi. IMPORTANCE Ergot alkaloids produced by several species of fungi are important as contaminants of food and feed in agriculture and also as the foundation of numerous pharmaceuticals prescribed for dementia, migraines, hyperprolactinemia, and several other disorders. Information on control of the ergot alkaloid pathway may contribute to strategies to limit their production in agricultural settings or increase their yield for pharmaceutical production. Our results demonstrate that a previously uncharacterized gene clustered with the ergot alkaloid synthesis genes is required for the sufficient transcription of the ergot alkaloid biosynthesis genes. This observation suggests the gene encodes a factor regulating transcription of those biosynthetic genes. [ABSTRACT FROM AUTHOR]

Background: As a genus within the Clavicipitaceae, Metarhizium exhibits rich morphological and ecological diversity, with a wide distribution and a variety of hosts. Currently, sixty-eight species of Metarhizium have been described. New information: A new species of Metarhizium, M. puerense (Hong Yu bis), was described in Pu'er City, Yunnan Province, south-western China. Based on morphological characteristics and multilocus phylogenetic analyses, Metarhizium puerense was confirmed to be phylogenetically related to M. album, but was clearly separated and formed a distinct branch. In contrast, the host of Metarhizium album was plants and leafhoppers and that lepidopteran larvae were the host of M. puerense. The diagnostic features of M. puerense were solitary to multiple stromata and smooth-walled, cylindrical with rounded apices conidia. [ABSTRACT FROM AUTHOR]

Plants face many environmental challenges and have evolved different strategies to defend against stress. One strategy is the establishment of mutualistic associations with endophytic microorganisms which contribute to plant defense and promote plant growth. The fungal entomopathogen Metarhizium robertsii is also an endophyte that can provide plant-protective and growth-promoting benefits to the host plant. We conducted a greenhouse experiment in which we imposed stress from deficit and excess soil moisture and feeding by larval black cutworm (BCW), Agrotis ipsilon, to maize plants that were either inoculated or not inoculated with M. robertsii (Mr). We evaluated plant growth and defense indicators to determine the effects of the interaction between Mr, maize, BCW feeding, and water stress. There was a significant effect of water treatment, but no effect of Mr treatment, on plant chlorophyl, height, and dry biomass. There was no effect of water or Mr treatment on damage caused by BCW feeding. There was a significant effect of water treatment, but not Mr treatment, on the expression of bx7 and rip2 genes and on foliar content of abscisic acid (ABA), 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA), and gibberellin 19 (GA19), whereas GA53 was modulated by Mr treatment. Foliar content of GA19 and cis-Zeatin (cZ) was modulated by BCW feeding. In a redundancy analysis, plant phenology, plant nutrient content, and foliar DIMBOA and ABA content were most closely associated with water treatments. This study contributes toward understanding the sophisticated stress response signaling and endophytic mutualisms in crops. [ABSTRACT FROM AUTHOR]

AbstractIn this study, the complete mitogenome of the entomopathogenic fungus Metarhizium pinghaense 15 R, which is highly virulent to aphids and was isolated from Korean soil, was assembled and annotated for three ATP synthase subunits (atp6, atp8, and atp9), three cytochrome oxidase subunits (cox1, cox2, and cox3), apocytochrome b (cob), seven subunits of NADH dehydrogenase (nad1, nad2, nad3, nad4, nad4L, nad5, and nad6), two ribosomal RNAs (rnl and rns), and 19 tRNA genes. Five genes were carrying a total of eight introns, and they may encode ribosomal protein S3, LAGLIDADG and GIY-YIG endonucleases. Phylogenetic analysis based on the mitochondrial nucleotide sequence confirmed that the M. pinghaense 15 R is a member of the Clavicipitaceae, and is closely related to the species M. anisopliae, M. robertsii, and M. brunneum. The mtDNA base sequence of the M. pinghaense 15 R strain reported in this study is thought to be useful for biological resource genetic data.

In this study, the complete mitogenome of the entomopathogenic fungus Metarhizium pinghaense 15 R, which is highly virulent to aphids and was isolated from Korean soil, was assembled and annotated for three ATP synthase subunits (atp6, atp8, and atp9), three cytochrome oxidase subunits (cox1, cox2, and cox3), apocytochrome b (cob), seven subunits of NADH dehydrogenase (nad1, nad2, nad3, nad4, nad4L, nad5, and nad6), two ribosomal RNAs (rnl and rns), and 19 tRNA genes. Five genes were carrying a total of eight introns, and they may encode ribosomal protein S3, LAGLIDADG and GIY-YIG endonucleases. Phylogenetic analysis based on the mitochondrial nucleotide sequence confirmed that the M. pinghaense 15 R is a member of the Clavicipitaceae, and is closely related to the species M. anisopliae, M. robertsii, and M. brunneum. The mtDNA base sequence of the M. pinghaense 15 R strain reported in this study is thought to be useful for biological resource genetic data. [ABSTRACT FROM AUTHOR]

Entomogenous fungi are one of the most diverse fungal groups among ascomycetes. During investigations of macro-fungi biodiversity in Kaihua and Putuo in Zhejiang Province, China, in 2021, several entomopathogenic fungal specimens were collected from subtropical forests. After a careful examination of morphology and multi-gene phylogenetic analyses applying nrSSU, nrLSU, tef1, rpb1 and rpb2, two novel species were discovered, described herein as Blackwellomyces kaihuaensis and Metarhizium putuoense, and further compared with other similar species. Detailed descriptions, color photographs of fresh specimen and figures illustrating microscopic features of the two new species are provided. [ABSTRACT FROM AUTHOR]

Claviceps (Clavicipitaceae, Hypocreales) was erected in 1853, although ergotism had been well-known for a much longer time. By 2000, about 70 taxa had been described in Claviceps, of which eight species and six varieties were based on Japanese type or authentic specimens. Most of these Japanese Claviceps taxa are based on lost specimens or have invalid names, which means many species practically exist only in the scientific literature. The ambiguous identities of these species have hindered taxonomic resolution of the genus Claviceps. Consequently, we sought and collected more than 300 fresh specimens in search of the lost Japanese ergots. Multilocus phylogenetic analyses based on DNA sequences from LSU, TEF-1a, TUB2, Mcm7, and RPB2 revealed the phylogenetic relationships between the Japanese specimens and known Claviceps spp., as well as the presence of biogeographic patterns. Based on the phylogenetic analysis, host range and morphology, we re-evaluated Japanese Claviceps and recognised at least 21 species in Japan. Here we characterised 14 previously described taxa and designated neo-, lecto- and epi-types for C. bothriochloae, C. imperatae, C. litoralis, C. microspora, C. panicoidearum and C. yanagawaensis. Two varieties were elevated to species rank with designated neotypes, i.e. C. agropyri and C. kawatanii. Six new species, C. miscanthicola, C. oplismeni, C. palustris, C. phragmitis, C. sasae and C. tandae were proposed and described. [ABSTRACT FROM AUTHOR]

Plants face many environmental challenges and have evolved different strategies to defend against stress. One strategy is the establishment of mutualistic associations with endophytic microorganisms which contribute to plant defense and promote plant growth. The fungal entomopathogen Metarhizium robertsii is also an endophyte that can provide plant-protective and growth-promoting benefits to the host plant. We conducted a greenhouse experiment in which we imposed stress from deficit and excess soil moisture and feeding by larval black cutworm (BCW), Agrotis ipsilon, to maize plants that were either inoculated or not inoculated with M. robertsii (Mr). We evaluated plant growth and defense indicators to determine the effects of the interaction between Mr, maize, BCW feeding, and water stress. There was a significant effect of water treatment, but no effect of Mr treatment, on plant chlorophyl, height, and dry biomass. There was no effect of water or Mr treatment on damage caused by BCW feeding. There was a significant effect of water treatment, but not Mr treatment, on the expression of bx7 and rip2 genes and on foliar content of abscisic acid (ABA), 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA), and gibberellin 19 (GA19), whereas GA53 was modulated by Mr treatment. Foliar content of GA19 and cis-Zeatin (cZ) was modulated by BCW feeding. In a redundancy analysis, plant phenology, plant nutrient content, and foliar DIMBOA and ABA content were most closely associated with water treatments. This study contributes toward understanding the sophisticated stress response signaling and endophytic mutualisms in crops.

Beauveria bassiana and Metarhizium anisopliae are two promising microbial agents for biopesticides development against the banana root borer Cosmopolites sordidus. In this study, germination, mycelial growth, and sporulation of six local Cameroonian isolates of those two species were assessed under seven different thermal conditions (13, 15, 20, 25, 29 33, and 37 °C) to select thermo-tolerant isolates. The Transmission potential of the thermo-tolerant isolates was determined at 25 ± 1 °C by dipping adult weevils in conidial suspensions (3.2 × 108) conidia/ml and mixing these with uninoculated weevils in different proportions (0, 10, 30 and 50%), in groups of 30, and assessing the spread of the mycosis within the group over 35 d of co-incubation. Incubation temperature and isolates significantly affected germination, mycelial growth and conidial production. All isolates had large thermal tolerance ranges (13–33 °C) except MIITAC6.4.2 (20–29 °C). Horizontal transmission resulted in mortality of non-inoculated weevils from 4.63 ± 1.77 to 53.3 ± 11.9%. The isolate BIITAC6.2.2 exhibited high auto-dissemination potential and high conidia yield in cadavers. These results demonstrate the potential use of these isolates for biopesticides development against C. sordidus in Central Africa.

Control measures of stored grain pests include the excessive utilization of chemical insecticides that generate negative environmental impact. Current trends in integrated pest management are oriented towards the preservation of the environment using natural biopesticides, among these products arise entomopathogenic fungi. This study aimed to test the efficacy of a native strain of Beauveria bassiana to control two main stored grain pests such as Sitophilus oryzae and Rhyzopertha dominica and also evaluate the persistence of the fungus on wheat grains. The B. bassiana strain controlled 89%±0.07 of R. dominica adults and 80% ±0.14 of S. oryzae. The survival analysis showed that MST was 4.27 ±0.19 days for R. dominica adults and 4.27 ±0.20 days for S. oryzae. Furthermore, results of long rank test for the comparison of the Kaplan-Meier curves did not present significant differences between the survival of both stored grain pests. Dual choice tests demonstrated that B. bassiana LPSc1227 presented a repellent action against both stored grain pests. The seed persistence of conidia was 100% in treated seeds after 45 days. Further research will contribute to elucidate more insecticidal features of the B. bassiana LPSc 1227 strain against S. oryzae and R. dominica, two main stored grain insect pests. [ABSTRACT FROM AUTHOR]

The fungal taxa belonging to the Clavicipitaceae (Hypocreales, Ascomycota) are widely distributed and include diverse saprophytic, symbiotic and pathogenic species that are associated with soils, insects, plants, fungi and invertebrates. In this study, we identified two new fungal taxa belonging to the family Clavicipitaceae that were isolated from soils collected in China. Morphological characterisation and phylogenetic analyses showed that the two species belong to Pochonia (Pochonia sinensis sp. nov.) and a new genus for which we propose Paraneoaraneomyces gen. nov. in Clavicipitaceae. [ABSTRACT FROM AUTHOR]

Ergot fungi produce toxic sclerotia that have significant impacts on the agricultural, food and pharmaceutical industries. These fungi were classified in various genera (such as Sclerotium clavus, or Spermoedia clavus) before Tulasne, in 1853, erected Claviceps and described three species based on variations in morphology and host ranges, viz. C. purpurea, C. microcephala, and C. nigricans. Since then, knowledge regarding the biological, clinical, and pharmaceutical perspectives of ergot has accumulated rapidly. However, a serious taxonomic examination was lacking until Langdon's revision accepted 25 species in 1952. That was followed by intensive regional studies by Loveless in the 1960s for Rhodesia (now Zimbabwe, Africa), and Tanda in Japan (1970s–1990s). More species names were reported and currently over 90 named taxa (species, varieties) are recorded in fungal name repositories (Mycobank and Index Fungorum). Most species were described based on morphological characteristics (sclerotia, ascomata and conidia) and host ranges. Some were characterized by their alkaloid profiles. Recently, DNA multi-locus sequence analyses (MLSA) were applied to resolve species complexes. For instance, the C. purpurea complex was separated into four species, and additional new species were recognized from South Africa and Canada. Infra- and supra-specific level genetic variations were identified via multi-locus and genomic studies. Based on five-locus phylogenies, Píchová and colleagues separated Claviceps into four sections: C. sect. Claviceps, C. sect. Citrinae, C. sect. Paspalorum and C. sect. Pusillae, for 60 species. Among these sections, several doubtful species names require clarification. Careful research on type specimens combined with molecular analyses is essential for clarifying these names. [ABSTRACT FROM AUTHOR]

Periglandula is a fungal genus that is associated with plants in the family Convolvulaceae. They produce medicinally important constituents called ergot alkaloids, which are stored in their host plants. Previously, the fungi were reported to mainly interact with young leaves and seeds of Convolvulaceae species. However, knowledge about how ergot alkaloid-producing fungi interact with their host plants is still lacking. Therefore, we investigated the interaction of Periglandula fungus with different plant parts of Ipomoea asarifolia, using molecular, histochemical, anatomical and micromorphological techniques. Our findings confirm the presence of Periglandula ipomoeae on six out of the eight plant parts examined (young folded leaves, mature leaves, flower buds, mature flowers, young seeds and mature seeds). The fungus was mostly distributed along external plant surfaces, and particularly on areas that were relatively unexposed. Our results suggest that the density of fungal mycelium varies depending on glandular trichome density and the growth stage of the host plant. Detection of the fungus in the flowers of its host plant, for the first time, fills a missing link in understanding how vertical transmission of Periglandula species occurs. [ABSTRACT FROM AUTHOR]

A new compound, 3-O-(4-O-methyl-β-D-glucopyranosyl) xanthone (1) was isolated from the culture of Conoideocrella luteorostrata NBRC106950. The structure of 1 was mainly determined by 1H, 13C, 2D-NMR and HREIMS spectral analyses. The absolute configuration of 4-O-methylglucopyranosyl moiety was determined by the optical rotation of aqueous layer of hydrolyzed 1 as D-configuration. [ABSTRACT FROM AUTHOR]

Clavicipitaceous fungi are pathogenic to scale insects, white flies and other insect orders. However, a few species are spider-associated. Two new genera from China, Neoaraneomyces and Pseudometarhizium, are described based on phylogenetic, ecological and morphological characteristics. Two spider-associated species, Neoaraneomyces araneicola, Pseudometarhizium araneogenum, and an insect-associated species Pseudometarhizium lepidopterorum are included. The morphological characteristics of paecilomyces-like conidiogenous structures, present in many insect/spiders associated species make species-level identifications difficult. A phylogenetic analysis of the combined dataset (ITS, LSU, RPB2 and TEF), placed the two new genera in Clavicipitaceae. The new spider-associated species may be the result of convergent evolution to adapt to the ecological environment and may have undergone host jumping or altered their nutritional preferences. [ABSTRACT FROM AUTHOR]

A single cordycipitoid fungus on a bark louse in Baltic amber and the scars of a death-grip from an ant infected by cordycipitoid fungus on a leaf from Messel, are known from the Eocene. Findings of cordycipitoid fungi on a tiger beetle in Rovno amber and on a "Camponotus" ant in Baltic amber were not confirmed. Ants of the genus Camponotus s. l. are not known from the early and middle Eocene; therefore, the taxonomic position of the Ypresian ant hosts of cordycipitoid fungi cannot be determined with confidence. This paper discusses some aspects of the evolution of entomopathogenic fungi of the order Hypocreales. [ABSTRACT FROM AUTHOR]

Ustiloxins I–M (1 – 5), five undescribed cyclopeptides bearing a 15-membered macrocyclic skeleton, were isolated from Cordyceps militaris. The structures of 1 and 5 were identified by spectroscopic and crystallographic methods, whereas the structures of 2 – 4 were assigned by spectroscopic and computational approaches. Biological evaluation of all the compounds toward human triple-negative breast cancer cells revealed that compounds 4 and 5 are toxic with IC 50 values of 64.29 μM and 28.89 μM, respectively. Five undescribed cyclopeptides were isolated from the fungus Cordyceps militaris. Compounds 45 and exhibit moderate cell toxic activity toward MDA-MB-231 cells. [Display omitted] • Five undescribed cyclopeptides were isolated from Cordyceps militaris. • 1 – 5 both consist of four amino acids and possess a 15-membered ring system. • Compounds 4 and 5 show potential cytotoxic activity. [ABSTRACT FROM AUTHOR]

Nine Metarhizium anisopliae (Hypocreales: Clavicipitaceae) isolates were evaluated for efficacy against Melolontha melolontha (Coleoptera: Scarabaeidae) larvae, stability in culture, and the superior isolate used to produce an oil-in-water mycoinsecticide. The phenotypic and genotypic characters of four isolates with high virulence were evaluated for their stability after repeating 12 cycles of in vitro subculture. Repeated subculture did not affect the germination of conidia; however, the morphology of some isolates changed significantly. Three isolates lost their virulence, whereas the KTU-2 isolate remained highly pathogenic. Therefore, KTU-2 was selected as the superior isolate for mycoinsecticide production. After the conidia of KTU-2 were produced by solid-state fermentation using cracked rice as the substrate, the conidia were formulated as an oil-in-water emulsion and its efficacy was assessed. The formulation caused 80% mortality on Me. melolontha larvae even at the lowest application rate (1 × 105 conidia/mL) in pot experiments, and complete mortality was obtained with the concentration of 1 × 107 conidia/mL. Lethal concentrations that kill 50% and 95% of Me. melolontha larvae present were estimated as 9.29 × 103 and 2.1 × 106 conidia/mL, respectively. Oil-in-water mycoinsecticide could be a potential candidate for the commercial control of Me. melolontha and other white grubs. [ABSTRACT FROM AUTHOR]

Ustilaginoidea virens is the causal agent of rice false smut, which can be a highly destructive disease of rice. The plasma membrane phosphatase Psr1 proteins, which act as a regulator of the salinity stress response in yeast, are widely distributed across fungi, but their functional characterization is sketchy. In this study, we characterized the functions of Psr1 protein, UvPsr1, in U. virens. Analyses of the ΔUvpsr1 and its complementation strain showed that UvPsr1 is required for normal mycelial growth, conidiation and tolerance to oxidative, osmotic and cell wall stresses. When rice panicles were inoculated with the ΔUvpsr1 strains, no symptoms of false smut disease developed, showing that UvPSR1 also contributes to the pathogenicity of the fungus. The deletion mutant of UvPSR1 also appeared to produce a smaller titer of toxic compounds able to inhibit elongation of the germinated seeds. In conclusion, our results indicated that UvPsr1 is a new pathogenic factor of U. virens.

Ophiocordyceps sinensis and Cordyceps militaris both contain many bioactive compounds that confer potential therapeutic benefits. This review discusses the possible use of cultivated C. militaris as an effective substitute for native O. sinensis in the face of ever-increasing prices of O. sinensis because of its short supply. On the one hand, cultivated C. militaris contains higher levels of cordycepin when compared with that of wild-type O. sinensis and cultivation of C. militaris has been shown to be capable of reducing the risk of heavy metal contamination. On the other hand, there is a paucity of robust in vivo studies and randomized controlled tests comparing the pharmacology and use of C. militaris and O. sinensis. For extraction of cordycepin as western-style tablets, the use of cultivated C. militaris rather than O. sinensis represents the most appropriate future approach. For many other purposes, comparative pharmacology and clinical trials are in urgent needs. [ABSTRACT FROM AUTHOR]

Since the discovery of the Pleurocordyceps/ "Polycephalomyces" clade unaffiliated with the clades of Clavicipitaceae s. str., Ophiocordycipitaceae, and Cordycipitaceae of clavicipitaceous fungi, some taxa have been published and more fungal material relevant to the group have become available for further study. Here, a multigene phylogeny using nrSSU, nrLSU, tef1, rpb1, and rpb2 was constructed with some of the recently discovered additional taxa using maximum likelihood and Bayesian analyses (BI) to test and refine the current phylogenetic framework for Cordyceps s. lat. and other clavicipitaceous fungi. In addition to the well supported major Pleurocordyceps/"Polycephalomyces" clade revealed previously, another clade with newly added taxa referred to as "Polycephalomyces formosus‐like" from Japan was found to be sister to the Pleurocordyceps/"Polycephalomyces" clade. Extensive investigation revealed that strains named "P. formosus‐like" grouped in this new clade and do indeed represent the true P. formosus and that species previously included in the genus Polycephalomyces required a new generic name. Based on the phylogenetic analyses and morphological characteristics, including both sexual and asexual morphs when available, the new generic name Pleurocordyceps is introduced and relevant new combinations are made. A newly designated lectotype and a supporting epitype for P. formosus is selected and the circumscription of Polycephalomyces is discussed. [ABSTRACT FROM AUTHOR]

The genus Moelleriella mostly occur on scale insects and whiteflies. It is characterized by producing brightly colored stromata, obpyriform to subglobose perithecia, cylindrical asci, disarticulating ascospores inside the ascus, and fusiform conidia, predominantly found in tropical and occasionally subtropical regions. Scale insects and whiteflies' pathogens were found during our surveys and collections of entomopathogenic fungi. Investigations of morphological characters and multi-locus phylogenetic analyses based on partial sequences of LSU, TEF, and RPB1 were made. Five new species of Moelleriella are described here, including M. chiangmaiensis, M. flava, M. kanchanaburiensis, M. nanensis, and M. nivea. They were found on scale insects, mostly forming flat to thin, umbonate, whitish stromata. Their anamorphic and teleomorphic states were mostly often on the same stroma, possessing obpyriform perithecia, cylindrical asci with disarticulating ascospores. Their conidiomata are widely open with several locules per stroma, containing cylindrical phialides and fusiform conidia. However, M. flava has yellow stromata with one conidioma per stroma, and M. kanchanaburiensis was found only in its anamorphic state. Furthermore, the perithecia of M. nanensis were completely embedded in stromata as opposed to other species with semi-immersed perithecia. We also found a teleomorph link to M. sinensis, a species described based on anamorphic stage previously reported from southeastern China. [ABSTRACT FROM AUTHOR]

Periglandula is a fungal genus that is associated with plants in the family Convolvulaceae. They produce medicinally important constituents called ergot alkaloids, which are stored in their host plants. Previously, the fungi were reported to mainly interact with young leaves and seeds of Convolvulaceae species. However, knowledge about how ergot alkaloid-producing fungi interact with their host plants is still lacking. Therefore, we investigated the interaction of Periglandula fungus with different plant parts of Ipomoea asarifolia, using molecular, histochemical, anatomical and micromorphological techniques. Our findings confirm the presence of Periglandula ipomoeae on six out of the eight plant parts examined (young folded leaves, mature leaves, flower buds, mature flowers, young seeds and mature seeds). The fungus was mostly distributed along external plant surfaces, and particularly on areas that were relatively unexposed. Our results suggest that the density of fungal mycelium varies depending on glandular trichome density and the growth stage of the host plant. Detection of the fungus in the flowers of its host plant, for the first time, fills a missing link in understanding how vertical transmission of Periglandula species occurs.

Bubonic plague is a lethal bacterial disease of great historical importance. The plague organism, Yersinia pestis , is primarily transmitted by fleas (Siphonaptera). In natural settings, where its range expands, Y. pestis resides in association with wild rodents and their fleas (sylvatic plague). While chemical insecticides are used against plague vector fleas, biological approaches have not been as critically evaluated. Benign and cost-effective control methods are sorely needed, particularly where imperiled species are at risk. Here we explore the potential of two representative insect pathogenic fungi, Beauveria bassiana Vuillemin 1912 (Hypocreales: Cordycipitaceae) and Metarhizium anisopliae Metschnikoff 1879 (Hypocreales: Clavicipitaceae), each already used commercially worldwide in large-scale agricultural applications, as candidate biopesticides for application against fleas. We review the life cycles, flea virulence, commercial production, and field application of these fungi, and ecological and safety considerations. Pathogenic fungi infections among natural flea populations suggest that conditions within at least some rodent burrows are favorable, and laboratory studies demonstrate lethality of these fungi to at least some representative flea species. Continued study and advancements with these fungi, under appropriate safety measures, may allow for effective biocontrol of plague vector fleas to protect imperiled species, decrease plague outbreaks in key rodent species, and limit plague in humans. [ABSTRACT FROM AUTHOR]

The present investigation aimed to determine the fungal toxicity of Isaria tenuipes (My-It) against the dengue mosquito vector Aedes aegypti L. and its non-target impact against the aquatic predator Toxorhynchites splendens. Lethal concentrations (LC50 and LC90) of My-It were observed in 2.27 and 2.93 log ppm dosages, respectively. The sub-lethal dosage (My-It-1 x 104 conidia/mL) displayed a significant oviposition deterrence index and also blocked the fecundity rate of dengue mosquitos in a dose-dependent manner. The level of major detoxifying enzymes, such as carboxylesterase (α-and β-) and SOD, significantly declined in both third and fourth instar larvae at the maximum dosage of My-It 1 x 105 conidia/mL. However, the level of glutathione S-transferase (GST) and cytochrome P-450 (CYP450) declined steadily when the sub-lethal dosage was increased and attained maximum reduction in the enzyme level at the dosage of My-It (1 x 105 conidia/mL). Correspondingly, the gut-histology and photomicrography results made evident that My-It (1 x 105 conidia/mL) heavily damaged the internal gut cells and external physiology of the dengue larvae compared to the control. Moreover, the non-target toxicity against the beneficial predator revealed that My-It at the maximum dosage (1 x 1020 conidia/mL) was found to be less toxic with <45% larval toxicity against Tx. splendens. Thus, the present toxicological research on Isaria tenuipes showed that it is target-specific and a potential agent for managing medically threatening arthropods. [ABSTRACT FROM AUTHOR]

Metarhizium album, with a narrow host range, is an entomopathogenic fungus in the family Clavicipitaceae. Its nuclear genome has been sequenced, whereas its mitogenome is still unknown. In this study, the complete mitogenome of M. album was assembled and annotated. This circular mitogenome was 68,425 bp in length and encodes two rRNA genes, 26 tRNA genes, 14 standard protein-coding genes of the oxidative phosphorylation system, and seven intergenic ORFs. A total of 23 introns invaded ten genes, including atp9 (1 intron), cob (2), cox1 (9), cox2 (1), nad1 (1), nad2 (2), nad3 (1), nad4 (1), nad5 (2), and rnl (3). Except for one group II intron (i.e. mL2060), others were all group I introns and involved four subgroups (i.e. IA, IB, IC2 and ID). Phylogenetic analysis based on mitochondrial nucleotide sequences confirmed M. album in the family Clavicipitaceae, being closely related to its congeneric Metarhizium rileyi.

Ustilaginoidea virens is the causal agent of rice false smut, which can be a highly destructive disease of rice. The plasma membrane phosphatase Psr1 proteins, which act as a regulator of the salinity stress response in yeast, are widely distributed across fungi, but their functional characterization is sketchy. In this study, we characterized the functions of Psr1 protein, UvPsr1, in U. virens. Analyses of the Δ Uvpsr1 and its complementation strain showed that UvPsr1 is required for normal mycelial growth, conidiation and tolerance to oxidative, osmotic and cell wall stresses. When rice panicles were inoculated with the Δ Uvpsr1 strains, no symptoms of false smut disease developed, showing that UvPSR1 also contributes to the pathogenicity of the fungus. The deletion mutant of UvPSR1 also appeared to produce a smaller titer of toxic compounds able to inhibit elongation of the germinated seeds. In conclusion, our results indicated that UvPsr1 is a new pathogenic factor of U. virens. [ABSTRACT FROM AUTHOR]

Our previous study provided correlative evidence that morning glory species harboring endophytic fungi (Periglandula) are resistant to potato psyllid [ Bactericera cockerelli (Šulc)], whereas species free of fungi often allowed psyllid development. In this study, we manipulated levels of ergot alkaloids in host tissues by inoculating clippings from potato plants with extracts from morning glories that harbor Periglandula [ Ipomoea leptophylla Torrey, Ipomoea imperati (Vahl) Grisebach, Ipomoea tricolor Cavanilles, Ipomoea pandurata (L.) G. F. Meyer, and Turbina corymbosa (L.)] and one species (Ipomoea alba L.) that does not harbor the endophyte. Ergot alkaloids (clavines, lysergic acid amides, and ergopeptines) were detected in potato clippings, thus confirming that leaves had taken up compounds from solutions of crude extracts. Psyllid mortality rates on inoculated clippings ranged between 53 and 93% in treatments producing biochemically detectable levels of alkaloids, when compared with 15% mortality in water controls or the alkaloid-free I. alba. We then tested synthetic analogs from each of the three alkaloid classes that had been detected in the crude extracts. Each compound was assayed by inoculating clippings of two host species (potato and tomato) at increasing concentrations (0, 1, 10, and 100 µg/ml in solution). Psyllids exhibited a large and significant increase in mortality rate beginning at the lowest two concentrations, indicating that even very small quantities of these chemicals led to mortality. Feeding by nymphs on artificial diets containing synthetic compounds resulted in 100% mortality within 48 h, irrespective of compound. Further testing of ergot alkaloids to characterize the mode of action that leads to psyllid mortality is warranted. [ABSTRACT FROM AUTHOR]

Four ergot species (Claviceps ripicola, C. quebecensis, C. perihumidiphila, and C. occidentalis) were recognized based on analyses of DNA sequences from multiple loci, including two housekeeping genes, RNA polymerase II second largest subunit (RPB2), and translation elongation factor 1-α (TEF1-α), and a single-copy ergot alkaloid synthesis gene (easE) encoding chanoclavine I synthase oxidoreductase. Morphological features, ergot alkaloid production, and pathogenicity on five common cereal crops of each species were evaluated and presented in taxonomic descriptions. A synoptic key was also provided for identification. [ABSTRACT FROM AUTHOR]

A biopesticide that combines Metarhizium rileyi and nucleopolyhedrovirus (NPV) in an oil dispersion (OD) was developed. Its efficacy against Anticarsia gemmatalis and Chrysodeixis includens was evaluated under laboratory and field conditions. First, each of the two selected fungal strains, combined or not in OD preparations with AgMNPV or ChinNPV, was tested in the laboratory against A. gemmatalis and C. includens, respectively. AgMNPV–fungus combinations had similar effect on overall mortality of A. gemmatalis compared to each pathogen used alone. C. includens was less susceptible to infection by M. rileyi strains, and ChinNPV became the major cause of larval death. The OD formulations with M. rileyi and/or NPV were applied in infested soybean fields. ChinNPV + M. rileyi caused 50.8% of overall mortality six days after spraying in a soybean crop infested by both pests, whereas for treatments with the fungus or the virus alone the percentages were 41.2% and 8.8%, respectively. In another field infested solely by A. gemmatalis, insect mortality was similar for the AgMNPV–fungus combination and the virus used alone. Larval parasitism by wasps and dipterans was not affected following biopesticide spraying. Our results suggest that the performance of a dual‐action biopesticide is related to the NPV and fungal strains that are combined and the proportion of host populations simultaneously infesting the crop. [ABSTRACT FROM AUTHOR]

Two new fungal genera and six species occurring on insects in the orders Orthoptera and Phasmatodea (superorder Orthopterida) were discovered that are distributed across three families in the Hypocreales. Sixty-seven sequences generated in this study were used in a multi-locus phylogenetic study comprising SSU, LSU, TEF, RPB1 and RPB2 together with the nuclear intergenic region (IGR). These new taxa are introduced as Metarhizium gryllidicola, M. phasmatodeae, Neotorrubiella chinghridicola, Ophiocordyceps kobayasii, O. krachonicola and Petchia siamensis. Petchia siamensis shows resemblance to Cordyceps mantidicola by infecting egg cases (ootheca) of praying mantis (Mantidae) and having obovoid perithecial heads but differs in the size of its perithecia and ascospore shape. Two new species in the Metarhizium cluster belonging to the M. anisopliae complex are described that differ from known species with respect to phialide size, conidia and host. Neotorrubiella chinghridicola resembles Torrubiella in the absence of a stipe and can be distinguished by the production of whole ascospores, which are not commonly found in Torrubiella (except in Torrubiella hemipterigena, which produces multiseptate, whole ascospores). Ophiocordyceps krachonicola is pathogenic to mole crickets and shows resemblance to O. nigrella, O. ravenelii and O. barnesii in having darkly pigmented stromata. Ophiocordyceps kobayasii occurs on small crickets, and is the phylogenetic sister species of taxa in the 'sphecocephala' clade. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate Metarhizium anisopliae (Metschn.) Sorokin (Hypocreales: Clavicipitaceae) persistence in the soil and its impact on Rhipicephalus microplus Canestrini (Acari: Ixodidae) larval recovery in a semifield trial after the treatment of female ticks. Nine strains from the genus Metarhizium Sorokin were isolated from the soil in Brazil and taxonomically classified using the ef1-α gene. The thermotolerance of the strains and their in vitro virulence to tick larvae were tested. One M. anisopliae strain was selected and formulated for the semifield test. The presence of M. anisopliae in the soil ranged from 0.4 × 105 to 1.4 × 105 colony forming units per gram of soil after the treatment during the five months of the survey. The fungus-treated grass pots had significantly fewer larvae than did the control pots. Evidence was gathered about the soil persistence of a native M. anisopliae strain and its efficacy in the biological control of ticks. [ABSTRACT FROM AUTHOR]

Environmental stress conditions compromise the effectiveness of microorganisms for use in biological control. We investigated the thermotolerance of seven Metarhizium isolates from Central Brazil to 32 °C, and the thermotolerance of conidia of Metarhizium anisopliae s.str. IP 119 (Metchnikoff) (Hypocreales: Clavicipitaceae) and M. robertsii formulated in oil-in-water emulsion to 45 °C. We also evaluated the efficacy of oil-formulated conidia of M. anisopliaes.str. IP 119 against the tick Rhipicephalus microplus (Canestrini) (Acari: Ixodidae) under stress conditions (32 °C; 75% RH). The conidial germination on tick's cuticle was assessed by Scanning Electron Microscopy. Conidia of M. anisopliaes.str. IP 119 formulated in oil-in-water emulsion caused significant control (59.4%) of R. microplus, even when treated ticks were incubated under stress (32 °C; 75% RH). Metarhizium spp. incubated at 32 °C had both decreased radial growth and conidial production. Conidia of IP 119 formulated in oil-in-water emulsion were more tolerant to 45 °C than conidia suspended in water. An oil-in-water emulsion protected M. anisopliaes.str. conidia against heat and dry conditions and may enhance its efficacy to control ticks by improving the tolerance of fungi against adverse environmental factors. [ABSTRACT FROM AUTHOR]

A fungus causing false smut in the flowers of Murdannia keisak (Commelinaceae, Commelinales, Monocots) in Japan was morphologically identical to Ustilago aneilematis. The fungus infected ovaries of most flowers of host plants. Infected flowers were filled with yellow to orange thick-walled conidia that became olivaceous green at maturity. However, multilocus phylogenetic analysis of DNA sequences (18S, 28S, translation elongation factor 1α [TEF], the largest [RPB1] and the second largest [RPB2] subunit of RNA polymerase II) showed that the fungus belonged to the tribe Ustilaginoideae (Clavicipitaceae, Hypocreales, Ascomycota). Microscopic examination showed that the fungus developed conidia at the apex of conidiogenous cells, in contrast to other species in the Ustilaginoideae that develop conidia pleurogenously. A new genus, Commelinaceomyces, is formally proposed in the Ustilaginoideae to accommodate this fungus. Four species previously misplaced in Ustilago (Ustilaginales, Basidiomycota) are transferred to Commelinaceomyces, including the type of the genus, C. aneilematis, on Murdannia keisak. This is the first report of a clavicipitaceous species infecting host plants in the Commelinaceae. [ABSTRACT FROM AUTHOR]

The compatibility of microsclerotial granules of the entomopathogenic fungus Metarhizium brunneum (Petch) strain F52 with fungicides (chlorothalonil, iprodione, propiconazole, pyraclostrobin+metconazole, and propiconazole+trifloxystrobin) was determined. In vitro, chlorothalonil was not detrimental to conidial production and viability at all concentrations (1–1000 mg a.i. (active ingredient) l−1). Iprodione reduced conidial production at ≥ 100 mg a.i. l−1 but had no effect on viability. Propiconazole reduced conidial production at ≥ 10 mg a.i. l−1 and reduced viability at 1000 mg a.i. l−1. A pyraclostrobin+metconazole combination reduced conidial production at ≥ 10 mg a.i. l−1 and viability at ≥ 100 mg a.i. l−1. A propiconazole+trifloxystrobin combination reduced conidial production at all concentrations and viability at ≥ 100 mg a.i. l−1. In the greenhouse, propiconazole suppressed colony forming unit (CFU) counts at both low and high rates. Chlorothalonil and iprodione had no inhibitory effect on fungal growth. The number of CFUs recovered did not differ significantly ten, 20 or 30 days after treatment. This study provides baseline information for the potential commercial use of the microsclerotia in pest control. [ABSTRACT FROM AUTHOR]

In this study, the complete mitogenome of an entomopathogenic fungus Orbiocrella petchii (syn. Torrubiella petchii) was assembled and annotated. This circular mitogenome was 23,794 bp in length and consisted of 2 rRNA genes (rnl and rns), 25 tRNA genes, and 14 standard protein-coding genes of the oxidative phosphorylation system. Two group I introns were identified, and they encoded ribosomal protein S3 (in rnl) or a GIY-YIG endonuclease (in nad1). Phylogenetic analysis based on mitochondrial DNA sequences confirms O. petchii in the family of Clavicipitaceae.

In this study, the complete mitogenome of an entomopathogenic fungus Metarhizium rileyi was assembled and annotated. This circular mitogenome was 62,514 bp in length and consisted of 2 rRNA genes, 25 tRNA genes, 14 standard protein-coding genes of the oxidative phosphorylation system, and seven intergenic ORFs. Seven genes were invaded by a total of 22 introns, including atp9 (1), cob (4), cox1 (8), cox3 (2), nad1 (1), nad5 (3), and rnl (3 introns). These introns all belonged to the group I intron family but fell into four specific subgroups. Phylogenetic analysis based on mitochondrial nucleotide sequences confirmed M. rileyi in the family Clavicipitaceae, being most close to Metarhizium anisopliae.

In this study, the complete mitogenome of the entomopathogenic fungus Metarhizium pinghaense 15 R, which is highly virulent to aphids and was isolated from Korean soil, was assembled and annotated for three ATP synthase subunits ( atp 6, atp 8, and atp 9), three cytochrome oxidase subunits ( cox 1, cox2 , and cox 3), apocytochrome b ( cob ), seven subunits of NADH dehydrogenase ( nad 1 , nad 2 , nad 3 , nad 4 , nad 4L , nad 5, and nad 6), two ribosomal RNAs ( rnl and rns ), and 19 tRNA genes. Five genes were carrying a total of eight introns, and they may encode ribosomal protein S3, LAGLIDADG and GIY-YIG endonucleases. Phylogenetic analysis based on the mitochondrial nucleotide sequence confirmed that the M. pinghaense 15 R is a member of the Clavicipitaceae, and is closely related to the species M. anisopliae, M. robertsii, and M. brunneum. The mtDNA base sequence of the M. pinghaense 15 R strain reported in this study is thought to be useful for biological resource genetic data., Competing Interests: No potential conflict of interest was reported by the authors., (© 2023 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.)

Based on new specimens of Myriogenospora spp. from Costa Rica and Panama, we present morphological analyses, systematic conclusions, additions to host ranges, and geographical distribution data for the two species currently classified in this genus. Myriogenospora atramentosa (Berk. & M.A. Curtis) Diehl differs from Myriogenospora linearis (Rehm) J.F. White & Glenn in the ascus and part-spore morphology, a different position in the molecular phylogeny, and the host range. We conclude that the two species are not congeneric and propose that M. linearis should be called Balansia linearis (Rehm) Diehl. [ABSTRACT FROM AUTHOR]

Chemical investigation on the cultures of the fungus Cordyceps spp., a strain from cell fusion between Cordyceps militaris and Cordyceps cicadae, resulted in the isolation of 13 compounds including 2 new ones named 2-(5-(3-oxobutyl) furan-2-yl) acetic acid (1) and cordycepone (2). Their structures were elucidated from the analysis of 1D/2D NMR and CD data. Among them, compounds 1, 7–9, at a concentration of 50 μg/ml, showed weak inhibitory activity against AChE. Moreover, compounds 6, 9, and 11 showed moderate inhibitory activity against the nematode Panagrellus redivivus with mortality ratio of 79.0, 71.7, and 72.3% at 2.5 mg/ml, respectively. [ABSTRACT FROM AUTHOR]

The aim of this study was to search for entomopathogenic fungi that infect wild cockroaches in forest ecosystems in two protected natural areas of Argentina. Two isolates of Metarhizium argentinense were obtained and identified from wild cockroaches (Blaberidae : Epilamprinae) through the use of morphological characteristics and molecular phylogenetic analyses. This novel species was found in Argentina and is a member of the Metarhizium flavoviride species complex. Phylogenetic analyses, based on sequence similarity analysis using internal transcribed spacer (ITS) and a set of four protein-coding marker sequences (EF1A , RPB1 , RPB2 and BTUB), supported the status of this fungus as a new species. In addition, we tested the biological activity of the new species through assays against Blattella germanica nymphs and found that the two evaluated isolates were pathogenic. However, isolate CEP424 was more virulent and caused a confirmed mortality of 76 % with a median lethal time of 7.2 d. This study reports the southernmost worldwide location of a Metarhizium species that infects cockroaches and will help expand the knowledge of the biodiversity of pathogenic fungi of Argentine cockroaches. [ABSTRACT FROM AUTHOR]

Metarhizium is a genus of entomopathogenic fungi that was initially classified into three species and varieties. More recently, DNA sequencing has improved the phylogenetic resolution of Metarhizium which now includes 30 species. The insect host ranges vary within the genus and some species such as M. robertsii have broad host ranges, while others such as M. acridum show a narrow host range and are restricted to the order Orthoptera. Metarhizium spp. are ubiquitous naturally occurring soil inhabiting fungi, and some are rhizosphere colonisers and their diversity has been attributed to various selective factors (habitat type, climatic conditions, specific associations with plants and insect hosts). Metarhizium have been used for the biological control of insect pests that affect economically important agricultural crops and have been tested under laboratory and field conditions for the control of insect vectors of human disease, showing the effectiveness of the fungus against the target pest. In Mexico, Metarhizium species have been used for the control of insect pests such as the spittlebug (Hemiptera: Cercopidae), and locusts (Orthoptera) that affect crops such as corn, bean and sugarcane. Biosafety studies, such as dermal and intragastric tests in mammalian models have also been carried out to ensure safety to humans and other animals. Metarhizium shows great promise as an alternative to chemical insecticides that has relatively low impact on human health and the environment. Key features of Metarhizium for biocontrol of insects are outlined with special reference to their utility in Mexico. [ABSTRACT FROM AUTHOR]