Researchers from China and Australia have presented the world's first tomato sample that smells like freshly popped popcorn. The development was made possible by CRISPR/Cas9 gene-editing technology, which scientists used to specifically deactivate two genes responsible for the breakdown of aromatic molecules in the fruit. The result has been published in the peer-reviewed scientific journal Journal of Integrative Agriculture and, according to the authors, opens up a fundamentally new path to enriching the taste and aroma qualities of vegetable crops without sacrificing yield.
Why Modern Tomatoes Have Almost No Scent
The tomato (Solanum lycopersicum) remains one of the most widely grown and consumed vegetables in the world. However, over recent decades, breeding work has focused primarily on increasing yield, disease resistance, and standardizing the appearance of the fruit. As a result, the natural aromatic potential of tomatoes has noticeably declined: modern hybrids lag behind older varieties, which were grown in home gardens not so long ago, in scent intensity. This is precisely the problem that scientists from the Xianhu Laboratory (China) and their Australian colleagues set out to tackle.
The 2-Acetyl-1-Pyrroline Molecule and Brake Genes
The key to success was the 2-acetyl-1-pyrroline (2-AP) molecule—a compound that gives popcorn and aromatic rice their characteristic scent. Scientists analyzed the tomato genome and identified two genes, SlBADH1 and SlBADH2, whose products are involved in 2-AP metabolism. Essentially, these genes act as "brakes," limiting the accumulation of the aromatic molecule in the fruit. Using CRISPR/Cas9, the researchers knocked out both genes in the Alice Craig tomato variety and evaluated the result both individually and combined.
Fourfold Aroma Enhancement Without Yield Loss
Experiments showed that the mutation in the SlBADH2 gene alone significantly increased the 2-AP content in the fruit. However, the most impressive result was achieved when both genes were simultaneously deactivated: the amount of the aromatic molecule increased more than fourfold compared to control plants. This indicates an interaction between SlBADH1 and SlBADH2 in regulating the tomato's aroma profile. At the same time, the genetic modifications had no negative impact on key agronomic indicators: flowering time, plant height, fruit weight, and the content of soluble sugars, organic acids, and vitamin C remained within normal limits.
From Laboratory to Commercial Varieties
Professor Shenchun Xu, lead researcher at the Xianhu Laboratory, emphasized that the current result is an important step toward creating tomatoes with enhanced aroma without reducing productivity. According to co-author Associate Professor Peng Zheng, work is currently underway to transfer the aromatic trait to commercial tomato varieties. Experts compare this approach to the experience of developing aromatic rice varieties, where the similar 2-AP molecule became the basis for an entire breeding direction. The scientists expect that in the future, consumers will be able to choose vegetables with a unique smell and taste, and the market value of such products will be higher due to increased consumer appeal.
Prospects and Limitations of the Technology
Despite impressive laboratory results, the path from experimental sample to mass product remains challenging. Popcorn-scented tomatoes may not appeal to all consumers, and regulatory requirements for genetically modified products vary across countries. Nevertheless, as the study's authors note, CRISPR/Cas9 technology allows for targeted correction of the aroma profile without introducing foreign genes, simplifying the approval process in a number of jurisdictions. In the long term, similar approaches could be extended to other vegetable crops—from peppers to cucumbers—creating a new generation of products with an enriched flavor profile.
