Scientists Engineer Supercharged Tomatoes Packed With Amino Acids And Flavonoids


In a recent research paper featured in the Plant Biotechnology Journal, Spanish scientists employed a cisgenic technique to enhance the metabolic profile of tomatoes by introducing additional flavonoids and branched-chain amino acids (BCAAs). These enhanced tomatoes exhibited a substantial elevation in key amino acids like valine, leucine, and isoleucine, alongside increased flavonoid content, including kaempferol and quercetin, when compared to their wild-type counterparts. The feasibility of assessing the safety of consuming these genetically engineered tomatoes through metabolomic and transcriptomic analyses may be explored in future studies.


Background of the Study

Ensuring proper and sufficient nutrition is essential for healthcare, and tailoring our food sources to meet specific dietary needs is imperative. Plant biotechnology methods, such as gene editing and cisgenesis, enable the precise adjustment of crops, vegetables, and fruits to enhance their nutritional value. Consuming these customized foods could aid in preventing deficiencies and enhancing health outcomes, particularly for older adults and vegetarians.

Flavonoids, plant compounds thought to contribute to preventing cardiovascular diseases and colon cancer, are vital. Branched-Chain Amino Acids (BCAAs) – valine, leucine, and isoleucine – make up 18% of muscle protein and are crucial for muscle growth. Although BCAA supplements are commonly used to treat conditions like sarcopenia, they have been linked to increased body mass index (BMI). In this study, scientists aimed to elevate these nutrients in tomatoes using a cisgenic approach. This research benefits individuals primarily following plant-based diets.


All About the study

Cisgenesis, a genetic modification technique, taps into a plant’s own or cross-compatible gene pool to enhance desirable traits in crops. Unlike transgenesis, which involves introducing foreign DNA into modified food crops and carries inherent risks, cisgenesis poses fewer potential hazards. In a recent study, researchers employed a sophisticated approach that combined cisgenesis with metabolomics and transcriptomics to enhance and assess the flavonoid and BCAA (Branched-Chain Amino Acid) content in tomatoes.

This research involved the insertion of two specific genes into the tomato genome: the herbicide-resistant form of an acetolactate synthase gene (mSlALS) and an MYB12-like transcription factor (SlMYB12). These genes were placed under the control of a fruit-specific promoter, ensuring their activity in the tomato fruit. The SlMYB12 gene played a crucial role in activating genes involved in the flavonoid synthesis pathway, enhancing the production of these beneficial compounds. Simultaneously, the mSlALS gene served a dual purpose – it acted as a selectable marker for the modified tomatoes and played a key role in boosting the synthesis of BCAAs, essential amino acids important for human health.

To evaluate the impact of these genetic modifications, the researchers utilized advanced techniques such as liquid chromatography-mass spectrometry (LC-MS) for metabolic analysis. This method allowed them to precisely quantify the flavonoid and BCAA content in the genetically modified tomatoes, comparing them with their wild-type counterparts. Additionally, the scientists employed reverse transcription-quantitative polymerase chain reaction (RT-qPCR) to study gene expression patterns in the modified fruits. This meticulous analysis provided valuable insights into how the simultaneous overexpression of mSlALS and SlMYB12 influenced the metabolic profile of the tomatoes.

By harnessing the power of cisgenesis and combining it with cutting-edge analytical methods, this study not only enhanced our understanding of plant genetics but also paved the way for developing nutritionally enriched crops with improved metabolite profiles. These biofortified fruits could potentially offer enhanced health benefits, all achieved through precise and targeted genetic modifications guided by a deep understanding of plant molecular biology.


Results and Discussions Following

In this study, a significant advancement in agricultural science was achieved through the development of biofortified tomatoes using a novel cisgenic breeding strategy. These biofortified tomatoes exhibited remarkable differences in their nutritional composition compared to wild-type tomatoes. Specifically, they showed substantial increases in essential amino acids, Leucine being 21 times higher, Valine being 9 times higher, and Isoleucine being 3 times higher. Furthermore, the biofortified fruits displayed significant elevations in important flavonoids, with kaempferol being 64 times higher and quercetin being 45 times higher than their wild-type counterparts.

What’s particularly noteworthy is that the degree of nutrient enrichment achieved through this cisgenic approach was comparable to that achieved through transgenesis, a conventional genetic engineering method. Moreover, the introduction of mSIALS, a specific gene, not only enhanced the nutritional content but also imparted resistance against chlorsulfuron, an herbicide, ensuring the plant’s health and vitality.

Interestingly, the study found that the organic acid levels remained consistent between the cisgenic and wild-type fruits. However, there was a notable increase in glucose and fructose levels in the cisgenic tomatoes. While these enhanced tomatoes proved to be a significant source of antioxidants, they could only fulfill up to 5% of the daily requirement for Branched-Chain Amino Acids (BCAAs).

The researchers employed advanced analytical techniques, such as Liquid Chromatography-Mass Spectrometry (LC-MS), to delve deeper into the metabolic profiles of these biofortified tomatoes. Their findings revealed distinct differences in the composition of the peel and fruit flesh, particularly during the later stages of ripening. Moreover, the leaves of cisgenic plants exhibited an accumulation of BCAA-derived volatiles, indicating comprehensive metabolic alterations resulting from the modification of just two genes. These findings underscore the powerful impact of gene expression modification on the overall composition of fruits.

Significantly, this study introduced a pioneering cisgenic breeding strategy based on acetolactate synthase (ALS). Unlike traditional genetic modification methods, cisgenic plants are developed without introducing foreign DNA, making them more likely to bypass regulatory concerns in countries where genetically modified crops face stringent regulations. Additionally, survey data revealed an increased public acceptance for consuming cisgenic food crops, making this approach not only scientifically innovative but also socially viable, bridging the gap between scientific progress and public acceptance.


In summary, the research findings underscore the viability and potential of cisgenesis as a viable method for enhancing the flavonoid and BCAA (Branched-Chain Amino Acid) levels in tomatoes. What sets cisgenesis apart is its ability to achieve these improvements without the inherent safety concerns typically linked to traditional genetic modification techniques. The study’s success not only opens doors for enhancing the nutritional quality of tomatoes but also carries profound implications for global food production.

By employing in-depth metabolomic and genomic analyses, this approach stands on solid scientific ground. These rigorous analyses not only validate the safety aspects but also provide a comprehensive understanding of the underlying biological processes. Armed with this knowledge, researchers can confidently explore the extension of this technique to a myriad of other food crops. This expansion holds significant promise in elevating the nutritional profiles of various staple foods.

Perhaps the most impactful aspect of this research lies in its potential to address critical issues related to malnutrition and deficiency-related health problems. Vulnerable populations, particularly in regions with limited access to diverse and nutritious food, stand to benefit immensely. By fortifying crops with essential nutrients, cisgenesis becomes a powerful tool in the fight against dietary deficiencies.

In essence, this study marks a pivotal step toward a future where agricultural innovation not only addresses the global demand for food but also ensures that this food is rich in essential nutrients. Through the careful application of cisgenesis and its accompanying analytical techniques, we are not only revolutionizing agriculture but also advancing the cause of public health, making strides toward a world where nutritious and safe food is accessible to all.