Trehalose in the bicoloured deceiver (Laccaria bicolor)

The disaccharide trehalose is a key regulator of glycolysis in higher plants, animals, and certain fungi. Based on gene expression and metabolite analysis, trehalose is also supposed to be a storage carbohydrate in ectomycorrhizal basidiomycotic fungi. Under symbiotic conditions, a crucial function of trehalose biosynthesis is carbohydrate sink formation, which is thought to enable a continuous fungal sugar support by a plant host. In this work manipulation of trehalose biosynthesis was initiated and a first glance of the impact of reduced trehalose formation on ectomycorrhizal fungal physiology will be given. Successful gene knock out by homologous recombination has not been archived for higher basidiomycetes yet. Therefore, an RNAi strategy was followed to suppress genes involved in trehalose formation and break down using the ectomycorrhizal model fungus Laccaria bicolor. Laccaria transformation was performed using an Agrobacterium-based strategy. Monocaryotic mycelia were used to increase RNAi efficiency and the manipulation was performed with two different strains to compare the impact of the genetic background on fungal physiology.