The above article explains a discovery. They now know how to use genetic engineering to change tomato traits, such as fruit size. They figure it'll work for other plants, too, such as ground cherries.
How many copies of that gene can they give a tomato, I wonder. I also wonder if they taste like typically larger tomatoes, or if they taste just like the smaller ones. Now maybe we'll get watermelon-sized alpine strawberries, house-sized pumpkins, boat-sized bananas, and James and the Giant Peach.
They could genetically engineer weeds to make them commercially viable fruit crops. I mean, like the common mallow found in the USA, for instance. The fruit is tiny, but good (it's not sweet; it's kind of a green bean like flavor). Imagine if it were huge.
They could probably give the gene to plants that don't even really produce much of a fruit. Maybe they would.
Cherry trees and bushes could get substantial fruits. Elderberries could be big. Cornelian Cherries could be enormous.
One problem is that GMO plants tend to have utility patents (not just plant patents), which means most plant breeders may not have the legal right to breed with the results. Home gardeners may never see them, legally. Of course, many would consider that a good thing, considering the fight against GMOs.