Location: Crop Bioprotection Research
Title: CRISPR-Cas9-mediated enhancement of Beauveria bassiana virulence with overproduction of oosporeinAuthor
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MASCARIN, GABRIEL - Embrapa |
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SHRESTHA, SOMRAJ - Auburn University |
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CORTES, MARCIO - Embrapa |
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Ramirez, Jose |
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Dunlap, Christopher |
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COLEMAN, JEFFREY - Auburn University |
Submitted to: Fungal Biology and Biotechnology
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 11/11/2024 Publication Date: 11/21/2024 Citation: Mascarin, G.M., Shrestha, S., Cortes, M.V., Ramirez, J.L., Dunlap, C.A., Coleman, J.J. 2024. CRISPR-Cas9-mediated enhancement of Beauveria bassiana virulence with overproduction of oosporein. Fungal Biology and Biotechnology. https://doi.org/10.1186/s40694-024-00190-5. DOI: https://doi.org/10.1186/s40694-024-00190-5 Interpretive Summary: Arthropod pests, such as insects and mites, exert a severe impact on food security and agricultural productivity worldwide, leading to substantial economic losses. Biological control offers an opportunity to manage these pests in a more sustainable manner using their natural pathogens. The insect-killing fungus Beauveria bassiana, is widely used as a biological control agent for managing insect pests. A drawback of using this fungus is the slow rate of killing the insect. In this study, genetic engineering was utilized to increase production of a virulence compound produced by Beauveria, which enhanced the killing rate of the insect. The research demonstrates a method to increase the rate of insect killing by a biocontrol fungus. This research benefits producers and consumers by developing new methods to control insect pests. Technical Abstract: Biocontrol agents play a pivotal role in managing pests and contribute to sustainable agriculture. Recent advancements in genetic engineering can facilitate the development of entomopathogenic fungi with desired traits to enhance biocontrol efficacy. In this study, a CRISPR-Cas9 ribonucleoprotein system was utilized to genetically improve the virulence of Beauveria bassiana, a broad-spectrum insect pathogen used in biocontrol of arthropod pests worldwide. CRISPR-Cas9-based disruption of the transcription factor-encoding gene Bbsmr1 led to derepression of the oosporein biosynthetic gene cluster unlocking the hyperproduction of the red-pigmented dibenzoquinone oosporein involved in the host immune evasion, thus increasing host susceptibility to fungal infection. Mutant phenotypes defective for Bbsmr1 displayed a remarkable increase in insecticide activity against greater wax moth larvae (Galleria mellonella), with reduced lethal times and concentrations, while at the same time presenting negligible or minor pleiotropic effects. In addition, these mutants displayed faster germination on the insect cuticle and early overproduction of oosporein in the insect host following infection. These findings emphasize the utility of genetic engineering in developing enhanced biocontrol agents with customized phenotypic traits and provide an efficient and versatile genetic transformation tool for applications in other beneficial entomopathogenic fungi. |