SPORELESS · From evolutionary biology to crop mushrooms: constructing sporeless mushroom strains

In our previous ERC project we identified a broad panel of fungal genes that are associated with spore formation, one of the largest problems in industry-scale crop mushroom production. The mushroom market intensely seeks sporeless strains, however, existing ones are used by a small fraction of growers, because, in addition to sporelessness, they show unwanted morphological defects, which reduce crop quality. In preliminary experiments, we demonstrated that CRISPR-based targeting of novel genes we identified can generate sporeless strains in two model mushroom species, without unwanted side effects. In this project, we set out to demonstrate the utility of this gene panel in converting industrial oyster mushroom (Pleurotus spp) strains into sporeless varieties, without the genomic incorporation of exogenous DNA. This will give us a simple and low cost lab-to-farm pipeline for developing novel industrial mushroom strains using a technology that is widely accepted as non-GMO in several regions worldwide. We plan to commercialize such strains through our existing and novel industrial partners in the US, Australia, Japan and potentially several more countries. Overall, this project might provide a lasting solution to a major problem in a well-defined field of biotechnology, that can be used in the ever growing number of countries where marker-free genetic engineering is accepted.