AP Biology class blog for discussing current research in Biology

Tag: tomatoes

Genetically Engineering the Food We Eat to Increase Consumer Desire

Solanaceae is an order of classification for a group of plants known as nightshades. The Solanaceae are a family of plants that ranges from annual and perennial herbs to vines, shrubs, and trees. Included in this family of variety are also a number of agricultural crops like tomatoes, medicinal plants like jimson weed, spices, weeds, and ornamentals. This group of plants are given the term “nightshade” because some of these plants prefer to grow in shady areas, and some flowers at night.Solanum americanum, fruits

The Solanaceae is one of humankind’s most utilized and important families. It contains some of the world’s most important vegetables as well as some of the most deadly toxic plants. Foods like potato, tomato, peppers, ground cherries, and eggplant all hail from this incredible plant. With the benefits of this plant family also comes the dangerous variety of plants. The belladonna, mandrake, Jimson weed, and tobacco also come from this family. Solanum trilobatum flowersNot only does this family of plants produce important vegetables and deadly plants, various chemicals and drugs can be harvested. Some of these include nicotine, solanine, capsaicin, atropine, scopolamine, and hyoscyamine.

CRISPR stands for Clustered Regularly Interspaced Short Palindromic Repeats. It is a gene editing tool that can be used to edit DNA in cells. It used a specific enzyme called Cas9, which stands for CRISPR associated nuclease 9, and a specific RNA guide to either disrupt host genes or insert sequences of interest. CRISPR was initially used in bacteria as an adaptive immunity response but is now being used as an alternative in genome engineering.CRISPR illustration gif animation 1

In the agricultural world, plant breeding has always been the way to improve the traits wanted in a plant. With technological improvements, increased production has been vastly upgraded. Recent advances in gene editing have revolutionized the field of plant breeding. The process of genetic engineering has allowed people to target specific genes to improve rather than continuous breeding to produce the desired trait. 

Consumers choose the type of foods they want to eat by the traits of the fruit/vegetable, and in response, it leads the path to ensure that plant breeding will produce that trait again. In the horticulture industry, fruits are an important food that many people buy. Fruits are known to have a crucial source of energy, vitamins, fibers, and mineral components. The larger the fruit, the less sour and more nutrients it tends to store, influencing consumers to buy fruits that are bigger in size and shape. As a plant family with various crops, Solanaceae crops have a variety of fruit sizes and shape features. With advancing gene editing technology, Solanaceae fruit crops have been on the receiving end of being genetically modified to increase desirable traits of fruit size, fruit weight, fruit quality, and plant architecture.Maduración del tomate (Solanum lycopersicum)

Many of the vegetables and fruits we eat today are slowly being improved with CRISPR. For instance, in tomatoes, the ARGONAUTE7 (SlAGO7) gene function in leaf shape development was one of the first edits done with CRISPR Cas9. Tomatoes have been at the forefront of CRISPR Cas9 gene editing on plants because it is a model crop that is able to grow variability. Many more plants of the Solanaceae family, like the goji berry and groundcherry, have been engineered to produce the best product and CRISPR gene editing will continue to enhance the fruit and plant.

This CRISPR gene editing research on the order of Solanaceae plants is relevant to AP Biology because of gene editing. In the first year of biology, we learned about the taxonomy of species and the order of specificity. The order of Solanaceae plants indicates that it isn’t a particular family of plants that includes the different genus and species. Instead, it is a broader classification. We didn’t specifically learn about CRISPR gene editing in class this year, but we learned about DNA and RNA and their replication process. In a way, we learned about CRISPR because it relies on a strand of RNA with the preferred traits that is then transcribed into DNA.

CRISPR Tomatoes Help You De-Stress

Tomato jeFor the first time, genome-edited food is being sold on the open market. A recent article published on December 14th, 2021 outlines how CRISPR-Cas9 technology has been used to create genome-edited food. Consumers in Japan have been able to purchase genetically edited Sicilian Rouge tomatoes through the Tokyo-based company, Sanatech Seed. These genetically edited tomatoes have been altered to have high amounts of y-aminobutyric, aka GABA. 

In Japan, consuming GABA is very popular. It is supposed to lower blood pressure and promote relaxation. It does so through reducing the excitement of neurons in the nervous system. GABA is an inhibition neurotransmitter in the nervous system.

To test its audience, in May 2021 Sanatech first sent seedlings for genome-edited tomatoes to 4,200 home gardeners in Japan. Because of the positive feedback and high demand, Sanatech started selling tomatoes to the general public.

The tomatoes are altered through CRISPR-Cas9 genome editing. CRISPR has successfully been used to alter foods, such as making mushrooms that don’t brown, or soybeans that are tolerant to drought. Although many foods have been regulated, these tomatoes by Sanatech are the first to be commercialized.

CRISPR Cas9 technologyCRISPR is a technology that can be used to edit the genes of prokaryotic organisms like archea and bacteria. CRISPR is a way of finding a specific sequence of DNA in a cell, and then altering that DNA. CRISPR-Cas9 (pictured to the right) is the enzyme which finds and binds with specific DNA strands complementary to the CRISPR sequence.

DNA simple2DNA is a polymer which carries the genetic instructions for an organism. It is made up of two strands of bases (two polynucleotide chains) which compliment each other. Each base in a strand of bases can be one of four nucleotides, adenine, thymine, guanine, and cytosine. One nucleotide, or base, on one side of the DNA double helix matches with the corresponding base on the other side of the DNA to form a base pair. Adenine nucleotides must match with thymine, and guanine must match with cytosine.

GRNA-Cas9Sanatech increased GABA in the tomatoes by altering GABA’s metabolic pathway, aka the GABA shunt. They first inserted a strand of guide RNA along with the enzyme CRISPR-Cas9. This guide RNA is a strand that compliments the part of the DNA strand Sanatech wishes to disable: the gene that encodes CaMBD (calmodulin binding dominant). The RNA strand attaches, and the enzyme CRISPR-Cas9 cuts the DNA sequence Sanatech wishes to remove out. Disabling the gene that encodes CaMBD increases the enzyme glutamic acid decarboxylase’s activity. This enzyme catalyzes the decarboxylation of glutamate to GABA, raising GABA levels.

Increasing GABA levels is said to be a healthy way to decrease stress and lower blood pressure, and people around the world love being able to do so through eating everyday foods, such as tomatoes. People are also more accepting of these genome altered tomatoes because they have been edited specifically by CRISPR, which is a pretty trusted and well known form of gene editing technology. CRISPR technology has, and will, change the world by giving humans the power to alter and change DNA.

CRISPR Gene Editing: The Future of Food?

Biology class has taught me a lot about genes and DNA – I know genes code for certain traits, DNA is the code that makes up genes, and that genes are found on chromosomes. I could even tell two parents, with enough information, the probabilities of different eye colors in their children! However, even with all this information, when I first heard “gene editing technology,” I thought, “parents editing what their children will look like,” and while this may be encapsulated in the CRISPR gene editing technology, it is far from its purpose! So, if you’re like me when I first started my CRISPR research, you have a lot to learn! Let’s dive right in!


Firstly, what is CRISPR Gene Editing? It is a genetic engineering technique that “edits genes by precisely cutting DNA and then letting natural DNA repair processes to take over” (  Depending on the cut of DNA, three different genetic edits can occur: if a single cut in the DNA is made, a gene can be inactivated; if two separate DNA sites are cut, the middle part of DNA will be deleted, and the separate cuts will join together; and if the same two separate pieces of DNA are cut, but a DNA template is added, the middle part of DNA that would have been deleted can either be corrected or completely replaced. This technology allows for endless possibilities of advancements, from reducing toxic protein to fighting cancer, due to the countless ways it can be applied. Check out this link for some other incredible ways to apply CRISPR technology!

In this blog post however, we will focus on my favorite topic, food! Just a few months ago, the first CRISPR gene-edited food went on the market! In Japan, Sicilian Rouge tomatoes are now being sold after the Tokyo-based company, Sanatech Seed, edited them to contain an increased amount of y-aminobutyric acid (GABA). “GABA is an amino acid and neurotransmitter that blocks impulses between nerve cells in the brain” ( It supposedly (there is scarce scientific evidence of its role as a health supplement) lowers blood pressure and promotes relaxation. In the past, bioengineers have used CRISPR technology to “develop non-browning mushrooms, drought-tolerant soybeans and a host of other creative traits in plants,” but this is the first time the creation is being sold to consumers on the market (!


So, how did Sanatech Seed do it? They took the gene editing approach of disabling a gene with the first method described above, making a single cut in the DNA. By doing so, Sanatech’s researchers inactivated the gene that “encodes calmodulin-binding domain (CaMBD)” in order to increase the “activity of the enzyme glutamic acid decarboxylase, which catalyzes the decarboxylation of glutamate to GABA, thus raising levels of the molecule” ( These may seem like big words, but we know from biology that enzymes speed up reactions and decarboxylation is the removal of carbon dioxide from organic acids so you are already familiar with most of the vocabulary! Essentially, bioengineers made a single cut in DNA inside of the GABA shunt (a metabolic pathway) using CRISPR technology. They were therefore able to disable the gene that encodes the protein CaMBD, and by disabling this gene a certain enzyme (glutamic acid decarboxylase) that helps create GABA from glutamate, was stimulated. Thus, more activity of the enzyme that catalyzes the reaction of glutamate to GABA means more GABA! If you are still a little confused, check out this article to read more about how glutamate becomes GABA which will help you better understand this whole process – I know it can be hard to grasp!

After reading all of this research, I am sure you are wondering if you will soon see more CRISPR-edited food come onto the market! The answer is, it depends on where you are asking from! Bioengineered crops are already hard to sell – many countries have regulations against such food and restrictions about what traits can actually be altered in food. Currently, there are some nutritionally enhanced food on the market like soybeans and canola, and many genetically modified organisms (GMOs), but no other genome-edited ones! The US, Brazil, Argentina, and Australia have “repeatedly ruled that genome-edited crops fall outside of its purview” and “Europe has essentially banned genome-edited foods” ( However, if you are in Japan, where the tomatoes are currently being sold, expect to see many more genome edited foods! I know I am now hoping to take a trip to Japan soon!

Thank you so much for reading! If you have any questions, please ask them below!

Click Here to Learn About the Tomato’s Fancy New Makeover

The sun rose on a dimly light Monday morning when Adriano Nunes-Nesi, Lázaro E.P. Peres, Agustin Zsögön, Lucas de Ávila Silva, Ronan Sulpice, and Emmanuel Rezende Naves published their groundbreaking discovery that could revolutionize the cultivation of chili’s forever.   These insanely talented and well established scientists figured out how to use the CRISPR-Cas9 editing tool to turn a tomato into    a chili.

Capsaicinoids are what give peppers their heat and when these scholars of science mapped the tomato’s and chili’s genomes, they saw that the tomato has genes that, when transcribed, produce these spicy and hot capsaicinoids.

The reason why this is important is because the chili’s cultivation process is extremely tedious and requires many specific conditions, not to mention it having a small yield.  Since the yield of tomatoes is 30x that of the chili, using the CRISPR-Cas9 tool, they could change the shape and taste of the tomato to that of a chili. The price of a chili peppers, per kg, compared to tomatoes is roughly 60 cents higher. It may not seem a ton, but in bulk orders, it quickly adds up.

Lázaro E.P. Peres, who is aProfessor of Plant Physiology at the University of São Paulo and one of the scientists on the team, says, “The proof of concept here is that we can transfer the unique thing endemic to a less-produced plant into another plant that is more widely produced”.  The paper states the tomato “is highly amenable to biotechnological manipulation”. This would drive the price of the chili down which would help markets, restaurants, and Gardners worldwide.

The only issue to this is the publics opinion. For years, the already established “organic” companies having been labelling genetically modified food as unhealthy compared to non-GMO foods.  This claim is simply outright false.  “Any plant or animal product is full of DNA that our body readily digests, messing with one or two genes isn’t going to impact human health. The only way GM food could affect human health is if the modification somehow produce a protein product that was actively toxic to humans.”  This quote is from an article by the Genetic Literacy Project, which could be seen as having bias towards GMO foods, however their mission says,”is to aid the public, media and policymakers in understanding the science and societal implications of human and agricultural genetic and biotechnology research and to promote science literacy.”  All they are interested in doing is educating the public because so many people have been lied to by big organic corporations and the media to prevent customers from eating GMO products.  What would they have to gain by saying they are safe when they are not?    If the public can get passed the idea of genetically modifying foods, I believe turning a tomato into a chili pepper would save much money from hundreds of thousands of businesses– big or small.

What do you guys and gals think of GMO products?

For more information, please go check out the primary source of this article and the researchers report



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