Comparative Transcriptome Analysis of Thitarodes Armoricanus in Response to the Entomopathogenic Fungi Paecilomyces Hepiali and Ophiocordyceps Sinensis

Abstract

Thitarodes armoricanus is a medicinal and economically important Lepidopteran insect species. The larvae infected by Paecilomyces hepiali survive no more than four days, while those infected by Ophiocordyceps sinensis can survive for several months before mummification. This provides a valuable comparative system to study interactions between an insect host and different pathogenic fungi. By using the T. armoricanus genome, a time-course transcriptome analysis of the whole larvae without guts was performed to explore the larvae response to P. hepiali and O. sinensis infection. A total of 3106 differentially expressed genes in five clusters were identified. The genes involved in coagulation and multiple metabolisms were both suppressed after P. hepiali or O. sinensis infection, whereas those related to environmental information responses, cell processes, biotic stimulus, and immunity (such as cecropin (CEC)) were elevated. The rapid death of T. armoricanus after P. hepiali infection might be caused by osmotic imbalance, immunocompromise (such as DEFs and GLVs), and nervous system dysfunction (glutamatergic synapse). Up-regulation of the genes related to cuticle structure, nervous system (such as neurotrophin signal pathway and dopaminergic synapse) and immune effectors (such as attacin (ATT) and proline-rich antimicrobial peptide 1 (PRAMP1)) in T. armoricanus, may contribute to the co-existence of T. armoricanus and O. sinensis. This study provides a global view and potential key genes of the interaction between T. armoricanus and two fungal entomopathogens.

Secondary metabolites from hypocrealean entomopathogenic fungi: genomics as a tool to elucidate the encoded parvome

“…However, SM producer strains that had been claimed to belong to Metarhizium anisopliae in the original chemical or biosynthetic papers referenced here may have now been separated from M. anisopliae (sensu stricto) and transferred to M. robertsii. 38 Similarly, an entomopathogenic 39 fungus isolated from an insect/Cordyceps sinensis natural complex 39 remains described as Paecilomyces hepiali even after its genome sequence has been published. 40 However, the genus name Paecilomyces is now restricted for fungi in the Eurotiales 41-43 thus P. hepiali is classified in Mycobank (www.mycobank.org) under that order.…”

Infection of Ophiocordyceps sinensis Fungus Causes Dramatic Changes in the Microbiota of Its Thitarodes Host

“…A high diversity of fungal communities, with the dominant fungal phylum Ascomycota (such as Ophiocordyceps, Verticillium, larvae post infection is still an unresolved problem and an obstacle for commercial production of Chinese cordyceps (Li et al, 2016;Qin et al, 2018;Han et al, 2019). The living infected larvae might harbor the spindle blastospores in the hemolymph for several months, contrary to other entomopathogenic fungi such as Metarhizium anisopliae and Beauveria bassiana which cause the death of their host larvae within a few days (Meng et al, 2015;Rao et al, 2019).…”

Stage- and Rearing-Dependent Metabolomics Profiling of Ophiocordyceps sinensis and Its Pipeline Products

“…This exhibited a difference between volatile and non-volatile molecules over the development of O. sinensis products. Meanwhile, we have also found that gene expressions and microbial compositions were changed during the infection process in Thitarodes [57,58]. So far it is agreed that the parasitism process of O. sinensis fungus to its host ghost moth has involved complex chemical changes.…”