Transcriptional and enzymatic profile of Pleurotus ostreatus multigene family in submerged and solid state fermentation

CASTANERA RAUL; PEREZ, GÚMER; OMARINI ALEJANDRA; PISABARRO, GERARDO; RAMIREZ, LUCIA

Marburg

Congreso; 11th European Conference on Fungal Genetics; 2012

Philipps-Universität Marburg, Germany

The functional differences among the members of multigene families can be analyzed by studying their transcriptional profiles under different environmental conditions and different genotypes. The white rot fungus Pleurotus ostreatus can be a suitable model for genomics and transcriptomics studies in basidiomycetes due to the information available after the sequencing of the two haploid genomes composing the N001 strain. In this work, we have studied the differential regulation of the laccase gene family transcription using a RT‐qPCR approach. The study has been made using different monokaryotic and dikaryotic (isogenic and non‐isogenic for the growth‐rate containing QTL chromosome VIII) strains, cultured in submerged cultures in the presence or in the absence of a laccase inducer, and in solid fermentation. Our results revealed (1) the importance of measuring the amplification efficiency and of carefully selecting the internal standards for the relative quantification of gene expression, (2) that the Lacc2 and Lacc10 genes are the responsible of laccase induction in submerged cultures, (3) that these two genes displayed opposite transcriptional response in PC9 type and PC15 type full‐sibs strains, suggesting that laccase induction in submerged fermentation is linked to vegetative growth rate, (4) that the expression of these two genes increased in solid fermentation with increased water availability in the culture, (5) that the enzymatic activities and intracellular/extracellular isozyme patterns confirmed the differential behaviour of fast growing and slow growing strains, and characterized the intracellular and extracellular laccase fractions in solid and submerged cultures.