Bigger and tastier tomatoes and eggplants may soon become a reality, thanks to groundbreaking research conducted by scientists at Johns Hopkins University. Researchers have discovered key genes within the plants' DNA that control fruit size, revealing that precise genetic modifications could lead to juicier, more marketable produce while transforming how these crops are grown around the world.
The study, published in the journal Nature, highlights how gene duplication and evolution have influenced fruit size and shape over millions of years. Researchers utilized CRISPR-Cas9 gene-editing technology to show that targeted genetic modifications could enhance heirloom tomato and eggplant varieties. These advancements could improve heirloom varieties while also enabling the development of larger-fruited strains suited for large-scale agriculture.
Michael Schatz, a geneticist at Johns Hopkins University and co-lead author of the research, emphasized the potential impact of these findings, stating that a single engineered seed could transform agricultural markets worldwide. With proper approvals, these seeds could be distributed across different regions, opening new opportunities for farmers and consumers alike.
The research, which has been conducted in collaboration with Cold Spring Harbor Laboratory, is part of a larger initiative to map the complete genomes of 22 nightshade crops, including tomatoes, potatoes, and eggplants. Using advanced computational analysis, scientists compared these genome maps and traced how genes evolved over time. They found that more than half of the genes had undergone duplication, a process that plays a critical role in determining traits like fruit size, shape, and flowering time.
To test these findings, researchers at the Boyce Thompson Institute used CRISPR-Cas9 to modify specific genetic duplicates, known as paralogs, to observe their impact on plant growth. The results were significant—when both copies of the CLV3 gene paralogs were turned off in the forest nightshade plant native to Australia, the resulting fruits grew in weird, bubbly, disorganized shapes, making them unsuitable for commercial sale. However, by carefully editing just one copy of the gene, the researchers successfully produced larger, more marketable fruits without deformities.
One of the most promising breakthroughs came from studying the African eggplant, a widely cultivated crop across Africa and Brazil. Scientists identified a gene, SaetSCPL25-like, which controls the number of seed cavities (locules) inside the fruit. When this gene was modified in tomato plants, the researchers found they could increase the number of locules, a key factor in fruit size—resulting in larger tomatoes. This discovery could lead to higher crop yields and more flavorful produce, offering economic and nutritional benefits.
Michael Schatz highlighted the real-world implications of these findings, explaining that by having full genome sequences, scientists can unlock genetic pathways that were previously overlooked. This approach could provide unprecedented opportunities to improve crop quality and develop resilient plant varieties tailored to different environments.
The research also introduces a concept called "pan-genetics", where genetic insights from one species help advance another. Scientists leveraged decades of tomato genetics research to make rapid advancements in African eggplants, and in the process, discovered new genes in eggplants that, in turn, can enhance tomatoes. This cross-species approach could transform plant breeding, leading to the development of novel fruit varieties with improved traits for global agriculture.
This pioneering research was supported by funding from the National Institutes of Health, the National Science Foundation, and the Howard Hughes Medical Institute.
(Source: Johns Hopkins University)
