A non-browning mushroom developed by a Penn State University researcher is demonstrating the versatility of new gene-editing techniques and posing new challenges for regulators and already fuzzy consumer understanding of genetically modified food.
Eventually, the so-called CRISPR technology — discovered about three years ago — could be used to bring fruits, vegetables and other crops to the market with improvements in yield, disease resistance, shelf life improvement, nutrition and other attributes, researchers say.
Yinong Yang, the Penn State professor who developed the anti-browning mushroom using the gene-editing tool called CRISPR, has asked the U.S. Department of Agriculture for clarity on their regulatory position on the mushroom, though he admits the mushroom isn’t necessarily bound for the commercial market. The non-browning mushroom is a test case, the first CRISPR developed that has been submitted to USDA for approval, he said.
Yang was featured in an lengthy feature in the March issue of Scientific American called “Editing the Mushroom.”
Mark Wach, of mushroom spawn manufacturer Sylvan Inc. and chairman of the American Mushroom Institute Research Committee, said CRISPR — short for clustered regularly-interspaced short palindromic repeats — is a gene editing tool that allows a researcher to disable a gene or add a desirable trait by modifying a gene in a specific place in a genome.
“What makes the technique different from transgenic methods is the relative ease that “foreign” DNA can be removed from the cell by conventional breeding,” he said. 
He said CRISPR is a research tool, and not used for product development at this point. “Mushrooms were used because they grow indoors in a controlled environment and relatively quickly compared to field crops,” he said in the statement. Wach said research using the technology will continue for a number of crops. Whether growers will grow varieties developed CRISPR on a commercial basis will be up to consumers, he said.
Yang said Feb. 23 that USDA has not made a decision yet on how they will handle the CRISPR-developed mushroom. 
“Certainly what we hope, that based on current USDA regulations, our (expectation) is that they should not regulate,” he said. “We asked them to confirm this particular genome-edited mushroom as a non-regulated article.” That means growers could grow the mushroom without regulation.
“Whether (growers) want to market it is another other issue,” he said. Yang said researchers may look at other attributes of the mushroom beyond anti-browning. 
Beyond the USDA’s decision, Yang said FDA approval — though not required — may also be requested if the product has commercial potential.
The commercial future of the CRISPR anti-browning mushroom is yet to be determined, said David Carroll, president of Avondale, Pa.-based Giorgi Mushroom Co.
“Whether something that is a non-traditional (bred) mushroom is marketable is really in the hands of the consumer,” he said. He noted that some buyers want assurances the mushrooms they receive are non-GMO and currently non-GMO mushrooms are the only kind Giorgi Mushroom Co. sells.
The White House Office of Science and Technology has enlisted the National Academies of Science to evaluate regulatory issues, and that document may be released fairly soon, Yang said. In addition, USDA has indicated they are revamping their regulatory approach to genetically modified crops in light of the new generation of tools to genetically edit crops.
Amit Dhingra, associate scientist/associate professor at Washington State University, Pullman, said that the CRISPR technology is a tool that is being used in research to improve various fruit crops. For example, the gene-editing technology is being used on strawberries to help edit the fruit’s genes to prevent the development of powdery mildew.
Compared with traditional breeding and previous versions of genetic modification technology, Dhingra said that CRISPR gives researchers surgical precision. “In the end, you don’t have transgenic or foreign DNA at all,” he said. “It is just like random mutation but it happened in the right gene.”
Joyce Van Eck, assistant professor and director of the New York-based Center for Plant Biotechnology Research for Boyce Thompson Institute, is using CRISPR technology on tomatoes for exploration of traits like higher yields.
“We’re using tomatoes as a model species to work with,” she said. CRISPR gives researchers more precision in where DNA is integrated, she said.
Rodolphe Barrangou, associate professor of food science, North Carolina State University. said in a statement that the mushroom is likely to be the first of an ongoing pipeline. “I would be surprised if the number of labs looking to develop CRISPR food products wasn’t well into the hundreds,” he said in the statement. “Everyone I talk to who is doing any genetics research is using CRISPR. The first instance is always compelling, but in six months the number will be much higher.”
If the USDA decides CRISPR edited food does not require special regulation, Barrangou said that will hasten the use of the technology. While consumer perception is still unknown, he said in the statement that it appears momentum seems in favor of CRISPR edited commodities entering the commercial market in the years ahead.
Van Eck said some consumers may resist any type of technology-driven genetic modification, even though traditional plant breeding has also modified plant genetics over the centuries. Removing allergens from food, boosting nutrition, and saving crops like citrus from decline could make the case to consumers.  “When consumers start to see benefits, they will see why those of us in the field are so excited about it,” she said.
While calling the research “interesting,” Carroll said the anti-browning mushroom is “not ready for prime time.”
Whether consumers will make distinctions between non-transgenic (not from another organism) crop improvement as different from genetic engineering that moves a gene from one organism to another is uncertain, he said. “It is up to  the market place,” he said. “Farmers aren’t going to make (the decision) for consumers,” Carroll said.