Tag Archives: Tomato

Is the tomato a fruit or a vegetable? Why not both?

Credit: Pixabay.

Supermarkets place tomatoes in the vegetable aisles, but botanically speaking tomatoes are ripened flower ovaries and contain seeds, which technically makes them fruit.

This segues into the age-old question: are tomatoes fruit or vegetables? Here’s an answer you can try the next time this comes up with friends over drinks, which is sure to raise some eyebrows: they’re both!

What’s the difference between fruits and vegetables, anyway?

Fruits and vegetables have more things in common than differences. For instance, both are rich sources of vitamins, minerals, and fiber.

Botanically speaking, all fruits have seeds and grow from the flower of a plant. For the purpose of simplification, vegetables are all other plant parts, such as roots, leaves, and stems.

By this classification, it’s rather clear that seedy outgrowths such as apples, squash, and, of course, tomatoes are all fruits. It also makes cucumbers, green beans, and pumpkins all fruits.

Meanwhile, roots such as beets, potatoes, and turnips, leaves such as spinach, kale, and lettuce, and stems such as celery and broccoli are all vegetables.

However, people don’t eat or cook with a botanical atlas in hand. They might use a recipe book, though, where ingredients are mixed based on their culinary characteristics, such as texture, flavor, and taste.

So, if you ask a restaurant chef, rather than a botanist, what constitutes a fruit, he will come up with a totally different classification. He would tell you that fruits must have a soft texture and are generally sweet, while vegetables are blander, sometimes bitter, and have a tougher texture.

Fruits are considered deserts, whereas vegetables are suited for savory dishes like stews, salads, and stir-fries.

Tomato: both fruit and vegetables

So, scientifically speaking tomatoes are fruit, while in the kitchen most sensible people use them as vegetables.

Which weighs more, though? I guess if you want to be a wise guy, you can go ahead and insist that tomatoes are vegetables. In everyday language, however, people prefer to refer to things by their common usage.

The USDA, for instance, agrees that tomatoes are vegetables in its official listing. Legally speaking, the US Supreme Court also classed tomatoes as vegetables in 1893 when it ruled that imported tomatoes should be taxed under the Tariff Act of 1883, which does not apply to fruit.

“Botanically speaking, tomatoes are the fruit of a vine, just as are cucumbers, squashes, beans, and peas,” Justice Horace Grey wrote in the court’s opinion at the end of the 19th century.

“But in the common language of the people … all these are vegetables which are grown in kitchen gardens, and which, whether eaten cooked or raw, are, like potatoes, carrots, parsnips, turnips, beets, cauliflower, cabbage, celery, and lettuce, usually served at dinner in, with, or after the soup, fish, or meats which constitute the principal part of the repast, and not, like fruits generally, as dessert.”

Are you confused?

You came reading this article in hopes of settling this debate once for all. I’m sorry if you’re still confused. At least you’re not alone — the tomato is the official “vegetable” of New Jersey and the official “fruit” of Arkansas. Talk about a disagreement.

Bottom line: according to science tomatoes are fruits because they form a flower and contain seeds. Common culinary sense says that tomatoes are vegetables, though. For all intents and purposes, one can say the tomato is both a fruit and vegetable.

I think this line by Miles Kington from a century ago sums up this debate nicely:

“Knowledge is knowing that a tomato is a fruit. Wisdom is not putting it in a fruit salad.”


Team sequences the pan-genome of tomatoes in a bid to make them tasty again

Researchers at the Agricultural Research Service (ARS) and the Boyce Thompson Institute (BTI) want to bring back the tasty tomato of yore.


Image credits Mauro Borghesi.

Sadly, it seems that store-bought tomatoes just aren’t very tasty. An international research team thinks they have the way to fix this tasteless problem, though. They have finished constructing the pan-genome for the cultivated tomato and its wild relatives, mapping almost 5,000 previously undocumented genes. Armed with this knowledge, researchers might be able to bring the flavor back.

They don’t make them like they used to

“These novel genes discovered from the tomato pan-genome added substantial information to the tomato genome repertoire and provide additional opportunities for tomato improvement,” says co-author Zhangjun Fei, a bioinformatics scientist at the Boyce Thompson Institute.

“The presence and absence profiles of these genes in different tomato populations have shed important lights on how human selection of desired traits have reshaped the tomato genomes.”

A genome is the map of an organism’s genes and their functions. Genomes are, unsurprisingly, sequenced for individual organisms, and these are in turn used to create a kind of reference genome for the rest of the species. The team’s pan-genome, on the other hand, includes all of the genes from 725 different cultivated and closely related wild tomatoes, which revealed 4,873 genes that were absent from the original reference genome.

So what seems to be the problem with our tomatoes? Where’s the taste? The team reports that cultivated tomatoes show a wide range of physical and metabolic variation but, by and large, they’ve all been through several severe bottlenecks during their domestication and later breeding. In effect, this means that today’s tomatoes aren’t very genetically diverse.

Modern breeders, the team explains, have focused on traits such as yield, shelf life, disease resistance, and stress tolerance, which are economically important to growers. However, the pan-genome does point to a few genes we can use to improve the flavor, too.

“One of the most important discoveries from constructing this pan-genome is a rare form of a gene labeled TomLoxC, which mostly differs in the version of its DNA gene promoter,” explained James Giovannoni, a molecular biologist at the Agricultural Research Service (ARS) and paper co-author.

“The gene influences fruit flavor by catalyzing the biosynthesis of a number of lipid (fat)-involved volatiles–compounds that evaporate easily and contribute to aroma.”

TomLoxC also facilitates the production of apocarotenoids — a class of organic chemicals derived from carotenoids including vitamin A precursors — which function as signaling molecules for various responses in plants, including environmental stresses. The compounds also have a variety of floral and fruity odors that are important in tomato taste, the team notes.

The rarer version of TomLoxC was found in only 2% of older or heirloom varieties of large tomato. The common version was present in 91% of currant-sized wild tomatoes, primarily Solanum pimpinellifolium, the wild predecessor of the cultivated tomato. It is becoming more common in newer varieties.

“It appears that there may have been strong selection pressure against or at least no selection for the presence of this version of TomLoxC early in the domestication of tomatoes,” Giovannoni added. “The increase in prevalence of this form in modern tomatoes likely reflects breeders’ renewed interest in improved flavor.”

The team says that with the pan-genome in hand, breeders should be able to quickly increase the flavor of mass-produced tomatoes without sacrificing the traits that make them so economically-viable.

“These novel genes discovered from the tomato pan-genome added substantial information to the tomato genome repertoire and provide additional opportunities for tomato improvement. The presence and absence profiles of these genes in different tomato populations have shed important lights on how human selection of desired traits have reshaped the tomato genomes,” said Fei.

The team also expects that the nearly new tomato 5,000 genes they’ve identified in the pan-genome will help breeders improve it in further ways. Tomatoes, although they are fruits, botanically, are one of the most eaten vegetables worldwide, with a total annual production of 182 million tons (worth more than $60 billion). In the U.S., tomatoes are the second-most consumed vegetable after potatoes. Each American eats an average of 20.3 pounds of fresh tomatoes and an additional 73.3 pounds of processed tomatoes per year (estimated based on 2017 figures).

The paper “The tomato pan-genome uncovers new genes and a rare allele regulating fruit flavor” has been published in the journal Nature Genetics.

Credit: Pixabay.

Why scientists want to engineer spicy tomatoes

It might seem odd, but spicy chili peppers and juicy tomatoes are actually related. The two plant species split off from a common ancestor nearly 19 million years ago, embarking on very different paths. Now, scientists are thinking about engineering tomatoes that are spicy for industrial applications.

Credit: Pixabay.

Credit: Pixabay.

The pungency (or heat) of chili peppers is due to capsaicinoids, which originate from the pith (a tissue in the stems of vascular plants). When you eat chili, the signature heat is not actually a taste — it’s pain. The molecules activate nerve cells in the tongue, which the brain interprets as a burning sensation. In a way, eating chili is like placing a hot object inside your mouth, without having to deal with the thermal damage.

Scientists believe that Capsicum plants evolved this ability in order to ward off predators, such as large mammals. Meanwhile, birds — which are seed dispersers and thus are of great use to chili peppers — show no pain response to capsaicin.

There are 23 different types of capsaicinoids, and some more pungent than others, depending on the environment for which the pepper is adapted for. Previous research has shown that capsaicinoid production is regulated by certain genes, and tomatoes — the distant cousin of chili peppers — also have these genes. They, however, lack the biological machinery to turn them on.

. The expression of the gene (CS) encoding capsaicinoid synthase is directly affected by irradiance, temperature, and wounding. Higher temperatures and wounding also increase this enzyme activity. Credit: Trends in Plant Science.

The expression of the gene (abbreviated CS) encoding capsaicinoid synthase is directly affected by irradiance, temperature, and wounding. Higher temperatures and wounding also increase this enzyme activity. Credit: Trends in Plant Science.

In a new study, researchers at the Federal University of Viçosa in Brazil are investigating the potential genetic pathways that could enable the harvest of spicy tomatoes.

“We have the tools powerful enough to engineer the genome of any species; the challenge is to know which gene to engineer and where,” senior author Agustin Zsögön, a plant biologist at the Federal University of Viçosa in Brazil, said in a statement.

There are very practical reasons for engineering a spicy tomato. These juicy berries are a lot easier to grow than chili and would produce more capsaicin per surface area due to the large volume of the fruiting body. Chili has been a prized commodity ever since it was discovered during the voyages of Christopher Columbus, which at the time fetched prices similar to gold. Today, capsaicin has been shown to have therapeutic and nutritional properties. For instance, the molecules can work as antibiotics and painkillers, and research suggests that the chili juice reduces inflammation in the gut and has antidepressant properties. They’re also used in pepper sprays.

Transcriptional profile of genes related to the metabolism of pungency in hot pepper, sweet pepper, and tomato. Credit: Trends in Plant Science.

Transcriptional profile of genes related to the metabolism of pungency in hot pepper, sweet pepper, and tomato. Credit: Trends in Plant Science.

In order to engineer spicy tomatoes, the researchers have identified various genes whose expression can be jump-started. One tool to achieve this is through the use of transcriptional activator-like effectors (TALEs), a suite of proteins secreted by pathogenic Xanthomonas spp. bacteria when they infect plant hosts. The second strategy is the use of genome engineering for targeted replacement of promoters.

“In theory, you could use these genes to produce capsaicinoids in the tomato,” says Zsögön. “Since we don’t have solid data about the expression patterns of the capsaicinoid pathway in the tomato fruit, we have to try alternative approaches. One is to activate candidate genes one at a time and see what happens, which compounds are produced. We are trying this and a few other things.”

While the main focus of such preliminary research is to produce more capsaicin at scale, such endeavors could also result in a new variety of produce in the grocery aisle. I mean, admit it, who wouldn’t try a hot tomato?


New finding could help plants survive drastic droughts

A new finding could prove instrumental for future food security — Australian researchers have found a way to help plants survive for 50% longer during severe droughts.

Dr Su Yin Phua, Dr Kai Xun Chan, Diep Ganguly, and Estee Tee, in the lab. Image credits: Stuary Hay, ANU.

As the climate continues to get hotter and hotter, drought becomes a more likely possibility. Just look at California, for example. The US state underwent its most severe drought in the past 1,200 years, and might be locked in a drought cycle that will last centuries. California is also not an isolated case. Aridity is on the rise and it will threaten crops in many parts of the world. Ensuring that plants can survive these tiring parts will be crucial in this case, and this new finding might just make a difference for millions of people.

The research team, led by Dr Wannarat Pornsiriwong, Dr Gonzalo Estavillo, Dr Kai Chan and Dr Barry Pogson from the Australian National University (ANU) Research School of Biology, found that chloroplasts, more known for their role in photosynthesis, play a role in regulating plant hormone during heat stress.

“This basic scientific research has the potential to be able to improve farming productivity not just in Australia, but potentially in other countries that suffer from drought stress,” Dr Pogson said. “If we can even alleviate drought stress a little it would have a significant impact on our farmers and the economy.”

A chloroplast is a type of organelle strongly influenced by light intensity. They are the agents that conduct photosynthesis, where the pigment chlorophyll captures the energy from sunlight and converts it and stores it in energy-storing molecules. But as researchers found, chloroplasts can sense drought stress, and activate a chemical that closes the plant’s pores (stomata) to conserve water.

Colorized electron microscope image of a stoma on the leaf of a tomato plant. Image credits: Dartmouth University.

“Chloroplasts are actually capable of sensing drought stress and telling the leaves to shut-up and prevent water from being lost during drought stress,” he said. “So the chloroplasts are actually helping the plants to prevent losing too much water.”We know how the drought alarm actually calls for help and we know how help comes in the form of closing pores on the leaves.”

“Boosting the levels of this chloroplast signal also restores tolerance in drought-sensitive plants and extended their drought survival by about 50 per cent,” Dr Chan added.

Boosting the activity of the chloroplasts or stimulating this chemical signal in another way, then plants could store water for a longer period and survive for longer. This could be accomplished through genetic or agronomic ways, and the team is now working on developing the best approach.

Journal Reference: Wannarat Pornsiriwong et al — A chloroplast retrograde signal, 3′-phosphoadenosine 5′-phosphate, acts as a secondary messenger in abscisic acid signaling in stomatal closure and germinationElife. doi: 10.7554/eLife.23361.

Lotus seeds.

German researchers release open-source tomato and wheat seeds to boost research

Breeders from the Göttingen University and Dottenfelderhof agricultural school in Bad Vilbel, Germany, have released new varieties of tomato and wheat seeds. The catch? They’re free for anyone to use, ever, as long as the products of their work remain free to use. In essence, these are open-source seeds.

Lotus seeds.

Image credits Nam Nguyen.

I think we’ve all, at one point or another, had to bump heads with the sprawling world of intelectual property and copyright licensing. That being said, I don’t think many of us imagined that licensing is a problem farmers and plant breeders also have to face — but they do. Feeling that this practice has gone beyond doing good and is actually stifling progress (both scientifically and morally in areas where food insecurity is still high,) German scientists have created new varieties of tomato and wheat plants, whose seeds are now freely available for use under an open-source license.

The move follows similar initiatives to share plant material in India and the United States, but it’s the first to actually extend the legal framework to all future descendants of the varieties.

So why would you make seeds open source? Well, the idea is that scientists and breeders can experiment with these seeds to improve the varieties or create new ones altogether without having to worry about the legal department suing them back into the stone age. And in that respect, it’s a gift that keeps on giving. According to Johannes Kotschi, an agricultural scientist who helped write the license last year, the license “says that you can use the seed in multiple ways but you are not allowed to put a plant variety protection or patent on this seed and all the successive developments of this seed.” Kotschi manages OpenSourceSeeds for the nonprofit Agrecol in Marburg, Germany, which announced the tomato and wheat licensing in Berlin back in April.

The open source seeds have had a very positive reception. Since their announcement, other universities, nonprofits, as well as organic breeders have expressed an interest in releasing open-source licenses for their hop, potato, and tomato varieties, and Kotschi’s tomato seeds have been in great demand.

Why open-source

For the majority of human history, seeds have, obviously, been open-source. Without any system in place to enforce copyright claim or to penalize copyright infringements in place, farmers could use and improve on any variety of plant to suit his needs. This freedom allowed for the crops we know today — those with ample yields, drought- and pest-resistance, better taste and growing times, so on. Or they just got lucky.

But in the 1930s the United States began applying patent law to plants and soon everyone was doing it — so farmers and breeders couldn’t claim a variety as their own, and even risked legal action for working with a claimed crop. The problem further deepened as a sleuth of additional measures including patents and a special intellectual property system for crops called “plant variety protection” made it into legislature. As companies merge, these patents and plant intellectual property become increasingly concentrated to an ever-smaller number of legal entities.

Some progress was done on plant variety protection, with international agreements allowing an exception from the intellectual property for research and breeding. But there’s no such system in place for patents, and scientists aren’t allowed to use patented plants for breeding or research purposes.

The Geman open-source seeds solve these problems by allowing anyone to use the varieties as long as any derivatives (offspring) remain in the common, public domain. However, there is some concern that a complete shift to an open-source system would harm innovation, as commercial breeders (who are the main source of new varieties) and universities wouldn’t be able to cash in royalties off their work. As with most areas of life, balance is key to solving the issue.

For now, governments will likely keep an eye on how the seeds impact existing systems.

This is Tomatan, and he will power you through a marathon — with tomatoes

Ever felt like there was something missing while you go for a jog? Like an unsatisfied yearning, a hungering left unanswered?

If you did, you’re not alone. Japanese vegetable juice company Kagome thinks they have the answer in the shape of a wearable robot that feeds you tomatoes while you run. Weighing in at 18 pounds / 8kg, Tomatan can be worn as a tomato-headed-backpack.

At the flip of a switch Tomatan will grab a tomato with its metal arms then swing them over your head and feed the juicy treat to you. Japan-based artistic studios Maywa Denki, well known for their unusual musical instruments and other devices, designed the robot — and an inexplicably large amount of the berries were involved in the process.

“We used about 100 tomatoes to complete this machine,” said Novmichi Tosa, one of the founders of Meiwa Denki. “We focused mostly on its visual design.”

Now, I really like Tomatan. It looks awesome and seems like a great conversation starter with the mademoiselles. But there is one thing that’s still beyond my grasp…Why? Why would anyone want to bite into a tomato while he’s running?

Awesome? Undoubtedly. Useful? Well, according to Kagome, which claims to be Japan’s largest supplier of ketchup and tomato juice, people taking part in the Tokyo marathon really need this.

“Tomatoes have lots of nutrition that combats fatigue,” said Kagome employee Shigenori Suzuki.

Suzuki intends to wear Tomatan on Saturday 21st, when he will be representing Kagome in the Tokyo Marathon. During the 5km long fun run, Tosa will be running beside him with tools just in case the robot needs fixing or Suzuki encounters a problem.

Then on Sunday 22 February during the full Tokyo Marathon, a professional runner from Kagome will take part using a lighter version of the tomato robot known as Petit-Tomatan.

Petit-Tomatan weighs just 3kg and features a mini tomato holster that is worn on the back.
Image via klepa.ru

As this robot is much smaller, the runner will need to hold a delivery tube up to their mouth through which the tomatoes will be delivered. Petit-Tomatan also features a timer so the runner isn’t fed too many tomatoes in one go.