Genetically modified mushrooms cleared by the USDA
But before you can buy the white mushrooms with anti-browning properties, they'll need to pass by the FDA first.
While the ethical debate rages on about genetically modified human embryos, the United States Department of Agriculture has cleared its first CRISPR-modified organism. CRISPR, in case you've forgotten, is an editing technique that can alter the genome of almost any organism pretty easily. Penn State University's agriculture department used the method on white button mushrooms to include an anti-browning phenotype that reduced the polyphenol oxidase enzyme (turns produce brown when exposed to air) down to about 70 percent effectiveness. Popular Science notes that because CRISPR doesn't use bacteria or viruses to affect the DNA like previous methods have, these 'shrooms aren't considered "plant pests."
Before you see these longer-lasting mushrooms at the grocery store or on your next salad or steak, though, they'll have to pass through other regulatory bodies first. Meaning, the Food and Drug Administration or Environmental Protection Agency could still put the kibosh down. Even that could take awhile however because of how slow bureaucracy moves: Penn State's Yinong Yang submitted his work October 30th last year and was only given the USDA letter of approval (PDF) this week.