The mass-produced tomatoes we buy at the grocery store tend to taste more like cardboard than fruit. Now researchers have discovered one reason why: a genetic mutation, common in store-bought tomatoes, that reduces the amount of sugar and other tasty compounds in the fruit.
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.
