The Innate Potato is a GMO that was recently approved for cultivation in the US. It is made by Simplot (or J.R Simplot Company). According to their website, they are a “food and agribusiness empire”. They do everything from seeds and fertilizer, to frozen foods. Apparently, they made billions by “commercializing frozen french fries“, and later became one of McDonald’s major suppliers. So I think it’s safe to say that they know their spuds.
The Innate Potato uses RNAi to silence 4 different proteins. RNAi is the same methodology that is used to make the non-browning Arctic Apple. Here’s the entry for RNAi from Wikipedia (it’s actually a pretty decent overview), but very briefly, RNAi or RNA interference is a naturally occurring process in cells that can turn off or silence specific RNA molecules, and consequently, the proteins that they make. In the past few decades, scientists have harnessed RNAi to turn off genes that they’re studying. If you add a properly-designed sequence of DNA corresponding to the gene you’re interested in silencing, it will produce an RNA molecule that will trigger RNAi and then, wham!!! The protein gets shut-down.
In the context of our discussion on the Innate Potato, it’s important to note that a protein from a different organism has not been added. It’s not like the mythical “fish genes in a tomato”. The DNA sequence that has been added is from the potato itself, which is why they’ve called it the “Innate Potato”. Thus, this isn’t a transgenic crop, where the gene added is from a species distant to the potato. It is a cisgenic crop, where the genes came from closely related species; in this case, either from the potato itself or from a wild potato native to Mexico (Solanum verrucosum).
So what proteins are silenced in the Innate Potato and why? Four different proteins are silenced and these are involved in three different traits:
The first trait is prevention of potato bruising (again, this is very similar to the non-browning Arctic Apple). Potato bruising is caused when damaged cells release an enzyme known as polyphenol oxidase (PPO) which interacts with different compounds creating the black or dark grey color. In the Innate Potato, the PPO enzyme is “turned off” only in the tuber and remains on in the leaves. Currently, many steps are taken in potato farming and handling to prevent bruising, but it doesn’t seem to be enough. Potato bruising costs the industry “at least $298 million annually”. Keep in mind that those bruised potatoes don’t make their way to the store, so that translates to a lot of food waste, too.
The company claims that the potatoes will not turn brown for several days, compared to just 10 minutes with a normal potato.
The second trait is reduction in the amount of acrylamide produced in the potato. Acrylamide is a chemical compound which is also a known carcinogen at high doses. We use it in the lab fairly frequently. When I started doing lab work, I had the annoying task of making our acrylamide solutions, since I was the lowly undergrad… Fear not, spouse! I took heavy precautions: a full mask, a full lab coat, etc. Once I got into my PhD, our lab had more funding, so we’d buy the acrylamide solutions pre-disolved. Now that I’m in industry, we buy our acrylamide lab items ready-to-use. Such is the nuisance of acrylamide that no-one wants to deal with it.
So what’s acrylamide doing in potatoes? When potatoes are heated, a chemical reaction (known as the Maillard reaction) occurs between the amino acid asparagine and sugars (such as the naturally occurring sugars in the potato). When I was discussing this article with the spouse, he knew all about the Maillard reaction because it’s what causes browning in food such as meats or bread, and is not to be confused with caramelizing. He had read about it when doing research on how to cook the perfect steak (He’s Texan… It’s the only explanation I have). At high temperatures, such as when potatoes are put in a fryer, acrylamide also forms in the reaction. In the Innate potato, the amount of the enzyme that synthesizes asparagine has been reduced, so consequently, less acrylamide is made. The company’s website claims that the Innate potato produces up to 70% less acrylamide than other potatoes cooked at the same temperature.
The final trait is improvement in starch quality and potato color. I had a tough time finding a decent description of this trait and relied on information from a Q&A with one of Simplot’s VPs over on Biofortified. Basically, they’ve reduced the amount of sugar in the potato, which can result in “consistent golden color”. Their website and the Q&A say “under certain conditions”, but do not explain what those conditions are so I’m a bit skeptical. I wish there was more information about this trait.