Scientists identify genes that influence tomato and eggplant size
Researchers uncover how genetic changes control fruit size and seed cavities
USA – Scientists from Johns Hopkins University and Cold Spring Harbor Laboratory have identified genes in tomatoes and eggplants that determine the number of seed cavities, a factor that influences fruit size.
This research is part of a broader project aimed at mapping the genomes of 22 nightshade crops, including tomatoes, potatoes, and eggplants.
The team compared genome sequences and traced genetic evolution, revealing that more than half of the genes had been duplicated over time. Researchers at the Boyce Thompson Institute used CRISPR-Cas9 gene editing technology to modify specific genes and assess their impact on plant development.
The results showed that genetic duplicates, known as paralogs, play a key role in characteristics like flowering time, fruit size, and shape.
Turning off both copies of a gene called CLV3 in the forest nightshade resulted in plants unsuitable for commercial sale. However, altering just one copy led to larger fruits.
In the African eggplant, scientists identified a gene called SaetSCPL25-like, which controls seed cavity formation. When they modified this gene in tomatoes, they were able to produce tomatoes with more seed cavities, resulting in larger fruit.
“This work shows the importance of studying many species together,” said researcher Michael Schatz. “We leveraged decades of work in tomato genetics to rapidly advance African eggplants, and along the way we found entirely new genes in African eggplants that reciprocally advance tomatoes. We call this ‘pan-genetics,’ and it opens endless opportunities to bring many new fruits, foods, and flavors to dinner plates around the world.”
Advancements in tomato growth timing
In a separate study, scientists at the University of Lausanne (UNIL) in Switzerland used genome editing technology to adjust a genetic mutation in tomatoes, allowing them to mature earlier.
This method, known as base editing, changes one of the nearly 850 million DNA base pairs in the tomato gene to repair a flaw caused by domestication.
Doctoral researcher Anna Glaus examined 72 modified plants and tracked 4,500 harvested fruits over two days, measuring size, weight, maturity, and sugar content.
By fixing this genetic mutation, researchers developed a tomato variety that produces fruit earlier in the season.
Considering that Switzerland has a moratorium on genetically modified crops, which is set to expire in June 2025, this study has sparked discussions about the future of genome editing in agriculture.
“We show here the varied application of genome editing and its benefit for agriculture,” Glaus stated.
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