Role of Gene in the Filamentous Fungus .

The (suppressor of four kinase) gene has been mainly studied in , where it was shown to be involved in growth and thermal stress resistance. This gene is widely conserved within the phylum . Despite this, to date has not been studied in any filamentous fungus. Previously, we found that the orthologous of was differentially expressed in a strain of with an altered phenotype. In this work, we have performed a functional characterization of this gene by using RNAi-silencing technology. The silencing of in resulted in decreased apical growth and the promotion of conidial germination, but interesting, it had no effect on conidiation. In addition, the attenuation of the expression sensitized the fungus to osmotic stress, but not to thermal stress. RNA-mediated gene-silencing of also affected cell wall integrity in the fungus. Finally, the silencing of depleted the production of the main secondary metabolites of , namely roquefortine C, andrastin A, and mycophenolic acid. To the best of our knowledge this is the first study of the gene in filamentous fungi.