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The entomopathogenic fungus Beauveria bassiana produces microsclerotia‐like pellets mediated by oxidative stress and peroxisome biogenesis
Author(s) -
HuarteBonnet Carla,
Paixão Flávia R. S.,
Mascarin Gabriel M.,
Santana Marianela,
Fernandes Éverton K. K.,
Pedrini Nicolás
Publication year - 2019
Publication title -
environmental microbiology reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.229
H-Index - 69
ISSN - 1758-2229
DOI - 10.1111/1758-2229.12742
Subject(s) - conidium , beauveria bassiana , entomopathogenic fungus , hypha , propagule , biology , fungus , bassiana , germination , metarhizium anisopliae , botany , germ tube , microbiology and biotechnology , biological pest control , food science
Summary Several filamentous fungi are known to produce macroscopic pigmented hyphal aggregates named sclerotia. In recent years, some entomopathogenic fungi were reported to produce small sclerotia termed ‘microsclerotia’, becoming new potential propagules for biocontrol strategies. In this study, we described the production of microsclerotia‐like pellets by the entomopathogenic fungus Beauveria bassiana . The carbon: nitrogen ratio equal to or higher than 12.5:1 amended with Fe 2+ induced the germination of conidia, producing hyphal aggregate that formed sclerotial structures in submerged liquid cultures. These aggregates were able to tolerate desiccation as they germinated and subsequently produced viable conidia. Conidia derived from microsclerotial aggregates formulated with diatomaceous earth effectively kill Tribolium castaneum larvae. Optical and transmission microscopical imaging, qPCR and spectrophotometric analysis revealed that an oxidative stress scenario is involved in conidial differentiation into microsclerotia‐like pellets, inducing fungal antioxidant response with high peroxidase activity – mainly detected in peroxisomes and mitochondria – and progress with active peroxisome proliferation. The results provide clues about B. bassiana microsclerotial differentiation and indicate that these pigmented aggregates are promising propagules for production, formulation and potentially application in the control of soil‐inhabiting arthropod pests.