The shape of tomatoes is determined by the SUN gene
Botanists from Ohio State University have isolated a gene that controls the shape of tomatoes. The work of scientists (A Retrotransposon-Mediated Gene Duplication Underlies Morphological Variation of Tomato Fruit), published in the journal Science, will help in understanding the mechanisms that determine the shape of fruits in plants.
The gene was named SUN after the name of the tomato variety from which it was isolated – "Sun 1642". One of the authors of the work, Esther van der Knaap, said that she drew attention to this variety because of its elongated shape with a pointed tip.
Scientists have managed to determine which part of the genome contains the gene or genes that control the shape of the fetus. Eventually, they identified a specific gene responsible for fetal morphology. SUN is the second gene known to date responsible for the appearance of elongated fruits.
Knaap and colleagues conducted several experiments to check whether the gene found directly affects the shape of the fruit. They "added" SUN to the genome of tomatoes with round fruits. Transgenic plants began to bear elongated fruits. At the next stage of the experiment, the researchers "turned off" the SUN gene in tomatoes with oblong fruits using a method called "knockout". As a result, the plants began to bear wild-type fruits, that is, rounded.
Thus, the detected SUN gene directly affects the shape of tomato fruits, but the mechanism determining morphological changes remains unclear at the moment. In the near future, scientists plan to check whether the SUN gene or genes close to it in sequence affect the shape of fruits of other plants.
All modern varieties of tomatoes have evolved from a small rounded predecessor. Thanks to the increased ability of tomatoes to change, breeders managed to bring out varieties bearing elongated fruits, segmented fruits, fruits in the form of pears or peppers, and so on. However, the genetic basis of such variability remained a mystery.
Portal "Eternal youth" www.vechnayamolodost.ru14.03.2008