We all know it intuitively. Fresh fruits and veggies you pick from your backyard garden (or get from the Farmer’s Market) taste loads more delicious than produce you purchase from the grocery store. But researchers at UC Davis have finally been able to pinpoint why. Apparently, in our quest to produce mass quantities of tomatoes, we’ve inadvertently engineered a genetic mutation that reduces the amount of sugar and other tasty compounds in the fruit.
More from the LA Times:
For the last 70-odd years, tomato breeders have been selecting for fruits that are uniform in color. Consumers prefer those tomatoes over ones with splotches, and the uniformity makes it easier for producers to know when it’s time to harvest.
But the new study, published this week in Science, found that the mutation that leads to the uniform appearance of most store-bought tomatoes has an unintended consequence: It disrupts the production of a protein responsible for the fruit’s production of sugar.
Mass-produced tomato varieties carrying this genetic change are light green all over before they ripen. Tomatoes without the mutation — including heirloom and most small-farm tomatoes — have dark-green tops before they ripen. There is also a significant difference in flavor between the two types of tomatoes, but researchers had not previously known the two traits had the same root cause.
The study authors set out to pin down the genetic change that makes tomatoes lose their dark-green top. They focused their attention on two genes — GLK1 and GLK2 — both known to be crucial for harvesting energy from sunlight in plant leaves.
They found that GLK2 is active in fruit as well as leaves — but that in uniformly colored tomatoes, it is inactivated.
That’s one more reason to dig your hands in your dirt!