b'Wild Galpagos tomatoes in flower, producing the biochemical precursors that later influence fruit bitterness and toxicity.PHOTO: UCRRipening wild tomatoes highlight the delicate balance between plant defense chemistry and fruit development.PHOTO: UCRYes, I think targeted alkaloid manipulationIts unclear whether this trait would remain has real potential to reduce pesticide use, but itstable in other environments, he says. The would require a careful, science-based approach,expression and retention of these alkaloids could Jozwiak says. Any commercial application wouldbe influenced by many factors: the surrounding need to be precisely controlled and subjected toecosystem, the presence or absence of certain rigorous regulatory safety assessments, especiallypests, soil microbiota and climate conditions.if the edible parts of the plant are affected. Gene flow is another risk. In places like North The opportunity goes beyond tomatoes. OtherAmerica or Europe, where tomatoes are grown nightshade crops, like potatoes and eggplants, alsocommercially alongside many varieties, pollination use steroidal glycoalkaloids for defense. And theycould spread or dilute the trait.use the same family of enzymesGAME8-likeTheres a chance of gene flow through pollina-proteinsto build them. tion. This could dilute or disrupt the trait in subse-Adam Jozwiak, assistantBecause these compounds play importantquent generations unless strict breeding controls professor of molecularroles in plant defense, manipulating their biosyn- are maintained, he explains.biochemistry at thethesis could be useful for breeding more pest-University of California resistant or disease-tolerant varieties, he says.Bitterness with a PurposeRiverside, led theHowever, efforts to reduce alkaloid content forStill, the potential is real. Breeding tomatoes that research uncovering asafety or flavor often come with a trade-off are better able to fend for themselves, without a rare case of reverselower defense capacity. So, theres a balance to bechemical crutch, could help reduce reliance on evolution in wildstruck between taste, safety and resilience. synthetic pesticides, lower input costs and protect Galpagos tomatoes.pollinators and soil health.PHOTO: UCR Environmental Hurdles and Genetic Drift Instead of eliminating SGAs altogether, we That balance could be achieved through genecould explore strategic reintroduction or modula-editing or even marker-assisted breeding, usingtion, Jozwiak says. This could pave the way for a enzyme structure as a guide. more nuanced, defense-aware approach to tomato But theres another challenge: ecology. In thebreeding, where bitterness is not viewed solely as a Galpagos, Jozwiaks team found the reversiondefect but as a tool.trait to be stable across multiple populations, likelyAs researchers continue to explore the precise due to strong local selective pressure, whethereffects of SGA stereochemistry on taste receptors, from herbivores, microbes or climate. In commer- insect deterrence, and microbial interactions, the cial settings, those pressures might not exist. path forward may depend on looking back.SW26/ SEEDWORLD.COMFEBRUARY 2026'