You’ll be glad you did, too. It might be a good idea to start carefully checking the pedigrees of apples in the grocery store now. The latest food to be genetically modified (and only for aesthetic reasons) is the apple and it is USDA/APHIS (United States Department of Agriculture/Animal and Plant Health Inspection Service) approved. The two new varieties (genetically modified Granny Smith and Yellow Delicious) created by gene tampering are called “Arctic®Apples“. The new varieties have a polyphenol oxidase (PPO) suppressing gene that will keep sliced apples from turning brown. This was achieved by inserting a type of double stranded RNA (dsRNA) that interferes with PPO gene expression. The genes are said to be “silenced” (see here and here).
So what’s wrong with that? Possibly a lot. Polyphenols, which include flavonoids, are plant compounds with documented healthful properties. PPO converts polyphenols into brownish compounds called phytomelanins which are types of quinones. Unaltered polyphenolic compounds protect plants from UV radiation and some diseases. When polyphenols are altered by PPO into phytomelanins they protect plants from insect pests although there are still many unanswered questions about its role in plant protection. PPO itself has functions in the plant apart from those mentioned already including playing a role in the biosynthetic pathway that creates polyphenols. The suppression of PPO is probably detrimental to some aspects of plant health.
Apple trees (the fruit isn’t the only place where this gene works) with impaired or reduced PPO production will probably be less resistant to insect pests and diseases and might require more insecticide and other pesticide applications to bring the fruit to maturity. The approval of just one part of the apple tree, its fruit in this case, is a serious neglect on the part of the USDA/APHIS as it “ignores potential consequences and uncertainties” and fails to fulfill the requirements of the National Environmental Policy Act (NEPA).
The notion that browning apples are somehow less nutritious and contain less protective polyphenols seems a bit of stretch. Not every single cell in the apple is damaged when you slice it with a knife or take a bite. Besides, as you chew it up and swallow the apple what happens then? In addition, the reaction time from injury to browning varies a lot from apple variety to apple variety. Even apple sauce sold in grocery stores before this new GMO apple was created is white not brown. The argument that the new GMO apples are healthier for us is suspect to say the least. This is more of an instance of aesthetic appeal than human health. PPOs are known to improve nutritional quality in forage crops for ruminants. I wonder if the same is true for monogastric organisms like humans who eat browned apples.
There is also the real possibility that this gene will get into other apples. How? Because in order to produce fruit apples must outcross, that is, receive pollen from another apple variety. Apples are insect pollinated so it is very likely that this gene will appear in new apple trees as seeds from the crosses get into the wild through discarded apple cores. And seeds from discarded GMO apple cores will find their way into the wild as well further spreading the silencing dsRNA. But we are stuck with this now because the USDA/APHIS has approved the new genetically modified fruit. Right now the new apple varieties have been released for commercial growers but I suspect that it won’t be long before it becomes available to the backyard orchardist.
I have four apple trees that are “spontaneous” which means they did not come from a nursery or plant breeder but are from seeds that sprouted from discarded apple cores. Three are regular apples and the fourth is a crab apple. The first three produce medium-sized fruit and look and taste like ordinary apples. One of them is sweet-tart with soft pink flesh and reddish skin with some green. It was found in 1976. Its fruit is pictured above and its flowers below. The other two are sweet-tart with crisp yellow-white flesh and red skin with yellow markings. They were found about 1980 and are the product of a random crossings between unknown but probably heirloom varieties from an old orchard in eastern Minnesota. The crab apple was found here about 1990 and has some Dolgo crab and another variety of crabapple in its background. This one is bittersharp and is red through and through and the size of a small plum. All four apples are no doubt high in polyphenols and because they originated between 1976 and 1990 they obviously do not have any dsRNA polyphenolic oxidase silencing genes. I also have several traditional named apple varieties in my orchard and none are contaminated with GMO technology.