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ARS Home » Midwest Area » Peoria, Illinois » National Center for Agricultural Utilization Research » Crop Bioprotection Research » Research » Publications at this Location » Publication #380875

Research Project: Discovery and Production of Beneficial Microbes for Control of Agricultural Pests through Integration into Sustainable Agricultural Production Systems

Location: Crop Bioprotection Research

Title: Transcriptional responses of Beauveria bassiana blastospores cultured under varying glucose concentrations

item MASCARIN, GABRIEL - Embrapa
item IWANICKI, NATASHA S A - Sao Paulo State University (UNESP)
item Ramirez, Jose
item DELALIBERA, JR, ITALO - Sao Paulo State University (UNESP)
item Dunlap, Christopher

Submitted to: Frontiers in Cellular and Infection Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/9/2021
Publication Date: 3/24/2021
Citation: Mascarin, G.M., Iwanicki, N.S., Ramirez, J.L., Delalibera, Jr, I., Dunlap, C.A. 2021. Transcriptional responses of Beauveria bassiana blastospores cultured under varying glucose concentrations. Frontiers in Cellular and Infection Microbiology. 11. Article 644372.

Interpretive Summary: ARS researchers from Peoria, IL collaborated with scientists from Brazil to determine the genes expressed in a biopesticide fungus during large scale production. The large scale economical production of biopesticidal fungi is a key step in developing them as crop protection products. Understanding how these fungi respond to different culturing conditions allows us to develop better methods of producing these fungi. The goal of this study was to identify the genes associated with the development of a specific fungal propagule known as a blastospore. Blastospores are the desired product when producing these fungi for pest control application. This research benefits agricultural producers and consumers by promoting the development of crop protection products to support sustainable agriculture.

Technical Abstract: Culturing the entomopathogenic fungus Beauveria bassiana under high glucose concentrations coupled with high aeration results in a fungal developmental shift from hyphae growth to mostly blastospores (yeast-like cells). The underlying molecular mechanisms involved in this shift remains elusive. Therefore, this has motivated us to realize a systematic analysis of the differential gene expression to uncover the fungal transcriptomic response to osmotic and oxidative stresses associated with the resulting high blastospores yield. Differential gene expression was compared under moderate glucose concentration (10% w/v) and high glucose concentration (20% w/v) daily for the three-day culturing. The RNAseq-based transcriptomic results underpinned a higher proportion of down- than up-regulated genes when the fungus was grown under 20% glucose than at 10%. A follow-up study explored a broader glucose range (4, 8, 12, 16, 20% w/v) with phenotype assessment and qRT-PCR of selected genes. Antioxidant, calcium transport, conidiation, and osmosensor related genes were highly up-regulated in higher glucose titers (18-20%) than at lower titers. These findings improved the knowledge of the molecular mechanisms during blastospore development and may help the large scale blastospores industrial production.