Repairing a domestication mutation in tomato leads to an earlier yield

Genome editing with CRISPR-Cas is often associated with the induction of mutations. However, a team of researchers from the Swiss University of Lausanne now shows that it can also be used to repair natural mutations.

Humans have been domesticating plants for thousands of years, by selecting mutations that lead to favorable characteristics such as larger or more numerous fruits. However, this process often caused the co-selection of other undesirable mutations that can have negative effects on plant growth and development. This phenomenon is called the "cost of domestication."

Researchers in the laboratory of Sebastian Soyk, assistant professor at the DBMV, used a genome editing technology, called base editing, to change one of the ~850 million DNA base pairs in the genome of the tomato to repair an unfavorable domestication mutation. Anna Glaus, doctoral student in the research group, first selected and then investigated the mutated and repaired plants.

"To obtain these results, I characterized 72 plants and harvested during two consecutive days, 4,500 fruits that I sorted by size, weight, and maturity (red or green) and measured their sugar content," explains Anna Glaus.

By repairing the deleterious domestication mutation with genome editing, the Swiss researchers have obtained a tomato variety that is earlier yielding. Considering the Swiss moratorium banning the growth of genetically modified organisms (GMO), which expires in June 2025, this new study is thought-provoking.

Image source: Anna Glaus, UNIL.