A team of scientists has made a groundbreaking discovery in Galápagos tomatoes that challenges traditional views on bitterness, toxicity, and crop resilience. The study found that a rare chemical reversion in the wild tomato species Solanum cheesmaniae can provide valuable insights into strengthening tomato defenses in an era of mounting pest pressure and reduced pesticide use.
According to University of California-Riverside assistant professor Adam Jozwiak, tomatoes have been bred to produce fewer bitter compounds, known as steroidal glycoalkaloids (SGAs), which protect the plant from insects, fungi, and pathogens. However, this reduction in SGAs has unintentionally compromised the plant’s natural “immune system.”
The Galápagos tomatoes, native to the rocky western shores of the archipelago, have developed a molecular profile that closely resembles their ancient ancestors. By analyzing the chemistry behind this reversion, Jozwiak and his team found that it is possible to reverse the production of SGAs in commercial tomato varieties.
“The fact that just four amino acid changes in the GAME8 enzyme can flip the stereochemistry of these compounds shows how precise and targeted this kind of trait manipulation could be,” Jozwiak says. “In theory, we could use CRISPR gene editing to introduce specific mutations that shift the chemical profiles.”
The study’s findings have significant implications for crop breeding and pest management. By introducing the modified GAME8 gene into tobacco plants, Jozwiak’s team demonstrated that evolution doesn’t always move in one direction, and that reversing a major plant chemistry pathway is both possible and predictable.
The research also highlights the importance of balancing flavor and function in crop development. While increasing SGAs could provide pest resistance, it would require careful testing and regulatory scrutiny to ensure safety and palatability.
As researchers continue to explore the precise effects of SGA stereochemistry on taste receptors, insect deterrence, and microbial interactions, the path forward may depend on looking back at the natural chemistry of plants like tomatoes.
Source: https://www.seedworld.com/us/2025/07/01/reverse-evolution-reveals-a-hidden-defense-in-tomatoes