Why don't we see square vegetables?

Scientists have discovered genes that regulate the shape of fruits and vegetables. Can one day see them in nature?

Along the stalls of a vegetable shop, you will find countless types of tomatoes, as big as fists as small as balls are also. Other vegetables such as squash, potatoes, cucumbers and green vegetables are similar. Their variety of colors, shapes and sizes are not the result of natural selection, but rather come from the hands of human molders.

Over the millennia, farmers, researchers and breeders have discovered beneficial mutations in fruits and vegetables - such as good properties, high productivity, novel shapes - and maintain these characteristics through conventional breeding techniques. This process is slow, but if you can overcome many different lines, you can finally create a new, market-oriented fruit and have its own unique characteristics.

OVATE is what gives the difference between round-shaped tomato and pear-shaped tomato.

Advances made from genetic maps will help speed up the normal breeding process, which is always slow and stable. With the genome of tomatoes or cucumbers in hand, breeders don't need to wait months to wait for it to know what the shape is. Instead, they can look for identifiable signs in the DNA of seedlings that regulate the shape, size and color characteristics.Maker Assisted Selection (Maker Assisted Selection) promises to reduce the number of years of traditional plant breeding.

Esther van der Knaap, a leader in genetics, has done research on the exact way that plant DNA impacts its developmental direction, long and thin examples like cucumbers or rounds. and thick meat like tomato beefsteak. In an article published on November 9, 2018 in the journal Nature Communications , van der Knaap said it was discovered that two families of genes play a major role in forming a round or long shape vegetable. . Fruits and vegetables are the edible organs of plants, and the organism grows and develops through cell division.

"To create a certain shape, like long or round, you will need certain tissue meristems. They will either split horizontally or will split vertically," van der Knaap explained. . That means that the cells of an organ are split horizontally by splitting in the middle, the more horizontal the shape of the fruit will appear rounder and appear fatter.

What van der Knaap and her colleagues discovered in the tomato genome is a gene called OVATE , which seems to be responsible for making proteins that regulate cells vertically. As more and more cells divide next to each other, the growth model will produce a fruit with an elongated shape. OVATE is what gives the difference between round-shaped tomato and pear-shaped tomato.

According to van der Knaap, wild tomatoes, such as native varieties in Peru, Ecuador and Mexico, always have small and round morphology, which means that tomatoes are pear shaped and other long-tailed tomatoes are Mutant varieties appear later. In the 1930s of the last century, biologists called them an elongated OVATE mutation , but they still didn't know the true genetic mechanism behind it.

The shape of fruits and vegetables is completely new but can be accompanied by unpleasant taste.

For now, van der Knaap has identified the OVATE protein , as well as another protein family called TRMs that interacts with OVATE, which provides an alternative for breeders to follow a molecular-based approach. If both OVATE and TRM appear, we can be sure that the fruit will be elongated, if one is missing, the shape will return to a round shape. She said the finding will help speed up the breeding process and growers will be able to focus on more complex characteristics such as yield and pest resistance that are not easily linked to genes.

So will those advances in plant genetics help us create pyramidal or pumpkin-shaped tomatoes? This seems impossible, van der Knaap said, but there are other ways. She thinks that there are tons of mutations in the tomato genome that can lead to amazing results and because these mutations occur naturally, they can be separated and replicated in the laboratory. .

But there are two issues that will happen with square tomatoes and other oddly shaped fruits, van der Knaap said. The first problem is that GMO (genetically modified organisms) , if breeders use modified genes to directly regulate or patch genes in food, then those strains are considered GMOs and many people Don't like my food being transformed like that.

Second, it's a completely new shape of fruits and vegetables, but it can be accompanied by unpleasant flavors."Some mutations are so bizarre that no one decides to use it, because they bring more problems. Each tree will have only a few fruits or a very bad taste, because when you plant something that is periodic This will disrupt hormonal balance, which leads to a pleasant taste , " van der Knaap said.

"If you really want a square tomato, put it in the box you want, like what Japanese people do with their exotic watermelons. Those will be really high-class tomatoes. However, not everyone is willing to pay to buy them, " she said.