Gene expression and nutrient utilization in the basideomycete Moniliophthora perniciosa suggest the existence of regulatory mechanisms of catabolite repression

I.S. Ganda

Moniliophthora perniciosa, a hemibiotrophic fungus (characterized by biotrophic and saprotrophic phases in its life cycle), is the causal agent of witches’ broom disease (WBD), which negatively affects the Latin American cocoa (Theobroma cacao) production. The southern region of Bahia, in Brazil, had the first occurrence of WBD in 1989, which led to a great drop in cacao production in the following years. During the biotrophic phase, the infecting fungus promotes stem enlargement, hyperplasic and hypertrophic tissue growth, loss of apical dominance, and green broom formation in T. cacao. During the saprotrophic phase of fungal infection, the green broom turns into a dry one, due to an intense programmed cell death that leads to necrosis of infected parts of the plant. Studies have suggested the presence of a carbon repression (CR) mechanism in M. perniciosa. CR is well characterized in the yeast Saccharomyces cerevisiae and consists in the repression or induction of a set of genes according to the type of carbon source present in the environment. MIG1 and SNF1 genes encode transcription factors that are involved in the regulation of the CR process. Read More….

Key words: Carbon repression; Energy metabolism; Glucose; Glycerol; Peptone

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