The circadian clock in Metarhizium: elucidation and its role in virulence and stress tolerance

• Grant number: 19/24298-5
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: January 01, 2020
• End date: December 31, 2020
• Field of knowledge: Biological Sciences - Genetics - Molecular Genetics and Genetics of Microorganisms
• Principal Investigator: Gilberto Úbida Leite Braga
• Grantee: Nathalia Botelho Nunes
• Host Institution: Faculdade de Ciências Farmacêuticas de Ribeirão Preto (FCFRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

Circadian clocks are important biological oscillators capable of marking the passage of time and were initially described in the model organism Neurospora crassa. In this fungus, the clock regulates a variety of biological processes such as conidiogenesis and metabolism. Circadian clocks are important because they allow the organism to both prepare and respond to environmental changes. The oscillator is based on a positive and negative feedback mechanism regulated by transcriptional and translational processes. The main protein responsible for controlling the circadian oscillator is FREQUENCY (FRQ). Fungi of the genus Metarhizium are entomopathogens currently used in the biological control of insect pests and disease vectors. However, environmental stressors such as exposure to ultraviolet radiation and to high temperatures negatively affect fungal development and insect killing. Therefore, there is a constant search for the discovery of biological processes regulating pathogenicity, virulence, and tolerance to abiotic stressors such as high temperatures and ultraviolet solar radiation. Although it potentially plays a role in regulating stress tolerance and virulence, the circadian clock of Metarhizium has never been studied. A recent study from our group reported the photoinduction of the frequency (frq) gene in Metarhizium acridum, which may indicate that a functioning circadian oscillator is present. Therefore, this project aims to study the circadian clocks in M. acridum and Metarhizium robertsii, and their role in regulating ultraviolet radiation tolerance and virulence in these fungi. (AU)