Scientists have discovered in the genomes of plants hitherto unknown mechanisms. This opens a new path for genetic modification, in order to grow giant fruits and vegetables in the future.
Human has been genetically changing crops for thousands of years. But while the process simply consisted in selecting larger or more fruitful plants to cultivate them the following year, scientists ended up managing the genomes of cultivated plants and modifying specific genes in order to improve size, yield, rusticity, taste or texture.
It was within the framework of a study conducted jointly by the Cold Spring Harbor Laboratory and the Johns-Hopkins University, in the United States, and published in the journal Nature, that scientists have pierced a genetic mystery of several million years. By leaning on the solanaceae – a vegetable family including tomatoes, eggplant and peppers -, researchers have identified a natural mechanism which makes it possible to considerably increase the size of the fruit.
The key to this advance is in a gene named Clv3 (for Clavata3), which plays a crucial role in the size and shape of fruits and vegetables. This gene controls the proliferation of cells in the meristem, an area at the end of the stems where a large part of the plant tissues forms. More specifically, in fruits such as tomatoes, clv3 determines the number of lodges – these internal cavities containing the seeds. However, the more a tomato has lodges, the bigger it can be. Ditto in the black morrelle (Solanum Nigrum), a wild cousin of the tomato, and the African eggplant (Solanum macrocarpon), which has a similar gene.
The researchers noticed that many genetic sequences seemed to duplicate themselves over long periods. They realized that by slightly modifying only one of these copies using precision genetic publishing techniques (CRISPR type), they managed to deactivate its limitation effect without disturbing the overall balance of the plant. Result: tomatoes and eggplant producing larger fruits and vegetables, with more lodges, without loss of quality or malformations. On the other hand, by deactivating the two copies of the gene, the fruits and vegetables produced were distorted and not marketable.
Unlike conventional transgenic approaches, this so-called pan-genetic approach is based on the modification of existing genes-and not on the introduction of a foreign gene-, which makes it closer to natural evolution and therefore potentially more acceptable to the general public and the health authorities.
But then, will we soon see these giant vegetables on our plates? Not so fast. The work is still at an experimental stage, although very promising. But the idea of growing naturally larger fruits and vegetables, without having to use chemical inputs, already arouses a strong interest in the agricultural sector.
Especially since by adjusting the expression of certain genes, it would be possible to obtain fruits and vegetables not only larger, but also more resistant to diseases and better suited to changing climatic conditions. This has something to make you dream … and salivate!