Characterization of an Indonesian isolate of Paecilomyces reniformis

Revisiting Metarhizium and the description of new species from Thailand

Over the last two decades the molecular phylogeny and classification of Metarhizium has been widely studied. Despite these efforts to understand this enigmatic genus, the basal lineages in Metarhizium are still poorly resolved. In this study, a phylogenetic framework is reconstructed for the Clavicipitaceae focusing on Metarhizium through increased taxon-sampling using five genomic loci (SSU, LSU, tef, rpb1, rpb2) and the barcode marker ITS rDNA. Multi-gene phylogenetic analyses and morphological characterisation of green-spored entomopathogenic Metarhizium isolates from Thailand and soil isolates of M. carneum and M. marquandii reveal their ecological, genetic and species diversity. Nineteen new species are recognised in the Metarhizium clade with narrow host ranges: two new species are found in the M. anisopliae complex - M. clavatum on Coleoptera larvae and M. sulphureum on Lepidoptera larvae; four new species are found in the M. flavoviride complex - M. biotecense and M. fusoideum on brown plant hoppers (Hemiptera), M. culicidarum on mosquitoes, M. nornnoi on Lepidoptera larvae; three new species M. megapomponiae, M. cicadae, M. niveum occur on cicadas; five new species M. candelabrum, M. cercopidarum, M. ellipsoideum, M. huainamdangense M. ovoidosporum occur on planthoppers, leafhoppers and froghoppers (Hemiptera); one new species M. eburneum on Lepidoptera pupae; and four new species M. phuwiangense, M. purpureum, M. purpureonigrum, M. flavum on Coleoptera . Of these 19 new species, seven produce a sexual morph (M. clavatum, M. eburneum, M. flavum, M. phuwiangense, M. purpureonigrum, M. purpureum, and M. sulphureum) and asexual morphs are found in the remaining new species and also in M. sulphureum, M. purpureonigrum and M. purpureum. Metarhizium blattodeae, M. koreanum and M. viridulum are new records for Thailand. An alternative neotype for Metarhizium anisopliae is proposed based on multi-gene and 5'tef analyses showing that CBS 130.71 from Ukraine is more suitable, being from a much closer geographical location to Metchnikoff's Metarhizium anisopliae. This isolate is distinct from the neotype of Metarhizium anisopliae var. anisopliae proposed by M. Tulloch from Ethiopia (ARSEF 7487). Six new genera are established for monophyletic clades subtending the core Metarhizium clade, including Keithomyces, Marquandomyces, Papiliomyces, Purpureomyces, Sungia, and Yosiokobayasia. Metarhizium carneum, M. aciculare, and M. neogunnii are combined in Keithomyces and one new combination for M. marquandii in Marquandomyces is proposed. Purpureomyces is introduced for species producing purple stromata including a new combination for M. khaoyaiense and two new species P. maesotensis and P. pyriformis. Papiliomyces contains two new combinations for M. liangshanense and Metacordyceps shibinensis. The genus Sungia is proposed for the Korean species M. yongmunense on Lepidoptera pupa and Yosiokobayasia for the Japanese species M. kusanagiense also on Lepidoptera pupa. A synoptic and dichotomous key to the accepted taxa is provided together with tables listing distinguishing morphological characters between species, host preferences, and geography.

Transcriptome analysis of the entomopathogenic oomycete Lagenidium giganteum reveals putative virulence factors

A combination of 454 pyrosequencing and Sanger sequencing was used to sample and characterize the transcriptome of the entomopathogenic oomycete Lagenidium giganteum. More than 50,000 high-throughput reads were annotated through homology searches. Several selected reads served as seeds for the amplification and sequencing of full-length transcripts. Phylogenetic analyses inferred from full-length cellulose synthase alignments revealed that L giganteum is nested within the peronosporalean galaxy and as such appears to have evolved from a phytopathogenic ancestor. In agreement with the phylogeny reconstructions, full-length L. giganteum oomycete effector orthologs, corresponding to the cellulose-binding elicitor lectin (CBEL), crinkler (CRN), and elicitin proteins, were characterized by domain organizations similar to those of pathogenicity factors of plant-pathogenic oomycetes. Importantly, the L. giganteum effectors provide a basis for detailing the roles of canonical CRN, CBEL, and elicitin proteins in the infectious process of an oomycete known principally as an animal pathogen. Finally, phylogenetic analyses and genome mining identified members of glycoside hydrolase family 5 subfamily 27 (GH5_27) as putative virulence factors active on the host insect cuticle, based in part on the fact that GH5_27 genes are shared by entomopathogenic oomycetes and fungi but are underrepresented in nonentomopathogenic genomes. The genomic resources gathered from the L. giganteum transcriptome analysis strongly suggest that filamentous entomopathogens (oomycetes and fungi) exhibit convergent evolution: they have evolved independently from plant-associated microbes, have retained genes indicative of plant associations, and may share similar cores of virulence factors, such as GH5_27 enzymes, that are absent from the genomes of their plant-pathogenic relatives.