Gene-edited mushroom created by Penn State researcher is changing GMO dialogue

The term "genetically modified organism" is almost guaranteed to spark debate in the news and social media, on internet message boards and at the water cooler. Now, the work of a faculty researcher in Penn State's College of Agricultural Sciences has generated a new wave of attention to the ongoing dialogue surrounding GMOs.

In a letter dated April 13, 2016, the U.S. Department of Agriculture's Animal and Plant Health Inspection Service confirmed to Yinong Yang, associate professor of plant pathology, that the anti-browning mushroom he developed using a gene-editing technique known as CRISPR-Cas9 would not be subject to USDA approval. The notification apparently clears the way for the potential commercial development of the mushroom, which is the first CRISPR-Cas9 gene-edited crop deemed to require no regulatory review by USDA.

Why does this anti-browning mushroom not require USDA regulation? Because, Yang explained, unlike most GMO crops, which receive DNA from foreign organisms such as bacteria or other plant species, this mushroom is transgene-free, thanks to the CRISPR-Cas9 tool.

"Our genome-edited mushroom has small deletions in a specific gene but contains no foreign DNA integration in its genome," said Yang, who is also an affiliate of Penn State's Huck Institutes of the Life Sciences. "Therefore, we believed that there was no scientifically valid basis to conclude that the CRISPR-edited mushroom is a regulated article based on the definition described in the regulations."

In this case, the gene editing stops production of a specific enzyme that causes mushrooms to turn brown. The end product is a mushroom with longer shelf life that resists blemishes caused by handling or mechanical harvesting -- but without DNA from a foreign organism.