Category: 7. Science

A rare chemical reversion in Galápagos tomatoes is challenging how we think about bitterness, toxicity and crop resilience.

On the rocky western shores of the Galápagos Islands, wild tomatoes are doing something evolutionary theory once considered nearly impossible: they’re going backward. Scientists call it a rare case of “reverse evolution,” but what matters most to the future of agriculture is the chemistry behind the change—and what it could mean for breeders, seed companies, and farmers trying to build more resilient crops.

At the center of this breakthrough is Solanum cheesmaniae, a wild tomato species native to the archipelago. On newer islands formed by volcanic activity, this plant has developed a molecular profile that closely resembles its ancient ancestors. According to University of California-Riverside assistant professor of molecular biochemistry Adam Jozwiak, it’s not just an oddity, it’s a potential roadmap for strengthening tomato defenses in an era of mounting pest pressure and reduced pesticide use.

Unlocking Ancestral Chemistry

“Commercial tomato varieties could easily be screened for the presence of both stereoisomeric forms of steroidal glycoalkaloids using standard metabolite profiling techniques such as LC-MS,” Jozwiak explains. “That’s straightforward. However, detecting whether a variety is ‘primed’ to revert to ancestral chemistry is a different story.”

And that story is complicated. Tomatoes, like many crops in the Solanaceae family, produce steroidal glycoalkaloids (SGAs) — bitter-tasting, toxic compounds that protect the plant from insects, fungi and pathogens. In modern breeding, those compounds have been systematically reduced in ripe fruit to satisfy consumer preferences for sweeter, milder tomatoes.

“Tomato breeders have worked to reduce bitterness in cultivated varieties for decades,” Jozwiak says. “But by reducing these compounds for the sake of flavor, we may have unintentionally compromised the plant’s natural ‘immune system.’”

The Four-Amino-Acid Switch

That’s where the Galápagos tomatoes come in. On newer islands like Fernandina and Isabela, S. cheesmaniae plants produce alkaloids with a stereochemistry not seen in cultivated tomatoes for millions of years. These compounds resemble the bitter, bioactive chemicals found in eggplants, and they’re synthesized through an altered version of the GAME8 enzyme.

The kicker? It only takes four amino acid substitutions in that enzyme to flip the chemical signature from modern to ancestral.

“The fact that just four amino acid changes in the GAME8 enzyme can flip the stereochemistry of these compounds shows how precise and targeted this kind of trait manipulation could be,” Jozwiak says. “In theory, we could use CRISPR gene editing to introduce specific mutations that shift the chemical profiles.”

His team didn’t stop at tomatoes. They introduced the modified GAME8 gene into tobacco plants, which then produced the same ancestral alkaloids. It was a rare, clear demonstration that evolution doesn’t always move in one direction, and that reversing a major plant chemistry pathway is both possible and predictable.

A New Frontier for Crop Defense

That level of biochemical control opens the door for what Jozwiak calls “designer plant chemistry,” where breeders and biotech firms could tailor alkaloid profiles to balance pest resistance, flavor, safety, and shelf life.

“If the goal were to make plants more resistant to pests, then a logical approach would be to upregulate key biosynthetic enzymes, particularly GAME8, GAME6 and GAME15,” he says. “But do so in a tissue-specific or developmental-stage-specific way.”

For example, boosting SGAs in leaves and stems (the parts of the plant that aren’t consumed) could increase pest deterrence without compromising fruit quality. Alternatively, delaying the natural conversion of α-tomatine (a bitter, toxic compound) into its non-toxic form, esculeoside A, might allow for better protection during early fruit development while preserving taste at harvest.

“Another approach could involve fine-tuning the timing of alkaloid conversion during ripening, to maximize pest resistance early in fruit development while ensuring a palatable product at harvest,” Jozwiak explains.

Balancing Flavor and Function

But any strategy involving increased SGAs would need careful testing and regulatory scrutiny. These compounds, while natural, can be toxic to humans and animals at high doses. In modern tomatoes, they’re typically present in unripe fruit and vegetative tissue—but the ripe fruit contains little to none.

“Yes, I think targeted alkaloid manipulation has real potential to reduce pesticide use, but it would require a careful, science-based approach,” Jozwiak says. “Any commercial application would need to be precisely controlled and subjected to rigorous regulatory safety assessments, especially if the edible parts of the plant are affected.”

The opportunity goes beyond tomatoes. Other nightshade crops, like potatoes and eggplants, also use steroidal glycoalkaloids for defense. And they use the same family of enzymes — GAME8-like proteins — to build them.

“Because these compounds play important roles in plant defense, manipulating their biosynthesis could be useful for breeding more pest-resistant or disease-tolerant varieties,” he says. “However, efforts to reduce alkaloid content for safety or flavor often come with a trade-off—lower defense capacity. So, there’s a balance to be struck between taste, safety, and resilience.”

Environmental Hurdles and Genetic Drift

That balance could be achieved through gene editing or even marker-assisted breeding, using enzyme structure as a guide.

But there’s another challenge: ecology. In the Galápagos, Jozwiak’s team found the reversion trait to be stable across multiple populations, likely due to strong local selective pressure, whether from herbivores, microbes or climate. In commercial settings, those pressures might not exist.

“It’s unclear whether this trait would remain stable in other environments,” he says. “The expression and retention of these alkaloids could be influenced by many factors: the surrounding ecosystem, the presence or absence of certain pests, soil microbiota and climate conditions.”

Gene flow is another risk. In places like North America or Europe, where tomatoes are grown commercially alongside many varieties, pollination could spread or dilute the trait.

“There’s a chance of gene flow through pollination. This could dilute or disrupt the trait in subsequent generations unless strict breeding controls are maintained,” he explains.

Bitterness with a Purpose

Still, the potential is real. Breeding tomatoes that are better able to fend for themselves, without a chemical crutch, could help reduce reliance on synthetic pesticides, lower input costs and protect pollinators and soil health.

“Instead of eliminating SGAs altogether, we could explore strategic reintroduction or modulation,” Jozwiak says. “This could pave the way for a more nuanced, defense-aware approach to tomato breeding, where bitterness is not viewed solely as a defect but as a tool.”

As researchers continue to explore the precise effects of SGA stereochemistry on taste receptors, insect deterrence, and microbial interactions, the path forward may depend on looking back.

Sensory heritage is the study of how we connect with historical objects using senses beyond just sight, like smell or touch.

Ancient Egyptians used special oils, waxes, and balms to preserve bodies for the afterlife through a process called mummification. Until now, most studies of mummies have focused on collections in European museums.

But a new study, led by researchers from the University of Ljubljana, the University of Krakow, and the Egyptian Museum in Cairo, explored mummies in Cairo’s collection.

The goal: To determine what mummified bodies smell like.

Scientists digitally unwrapped the almost 2,300-year-old undisturbed mummy of a teenage boy

Researchers wanted to know if today’s mummies still carry traces of the original embalming materials. And if so, could those scents help museums better preserve and explain these ancient remains?

To find out, they studied nine mummies at the Egyptian Museum in Cairo. Some were on display while others were tucked away in storage. These mummies came from different periods (the oldest is 3,500 years old) and had been preserved and stored in various ways.

Because the mummies are so fragile, the team followed strict non-destructive methods to protect them while gathering scent data.

To explore the scents of ancient mummies, researchers used a mix of sensory testing, chemical analysis (GC-MS-O), microbiology, and historical research. But first, they had to make sure it was safe.

Sound of a mummy heard again for the first time in 3,000 years

Many mummies had been treated with synthetic pesticides decades ago, which can be harmful. So, any bodies with high levels of these chemicals were excluded from the study.

For the remaining nine mummies, the team gently opened their sarcophagi just enough to insert tiny pipes and collect air samples. These samples were sealed in special bags and taken to a separate room, where researchers could smell them directly, a rare, nose-to-nose encounter with the past.

To dig deeper into what ancient mummies smell like, researchers captured more air samples using metal tubes filled with a special material that traps scent molecules.

These samples were taken to a lab, where scientists used chromatography to separate the smells into individual components, so trained sniffers could describe each one in detail.

Despite differences in how strong the smells were, most mummies shared a familiar scent palette: woody, floral, sweet, spicy, stale, and resin-like.

Scientists revealed the faces of 3 Egyptian mummies

Chemical tests also revealed traces of ancient embalming ingredients like conifer oils, frankincense, myrrh, and cinnamon. All of these were used by the museum recently for preservation.

They also detected degraded animal fats used in the mummification process, the scent of the human remains themselves, and both modern synthetic pesticides and natural plant-based oils used by the museum for preservation.

Mummies on display gave off stronger scents than those kept in storage. Although none were overpowering like modern perfumes. One mummy even surprised researchers with a smell that reminded them of black tea. The likely culprit? A natural compound called caryophyllene, also found in cloves and cinnamon.

Now, the team is taking things a step further. They plan to recreate these ancient aromas so that visitors to the Egyptian Museum in Cairo can experience the scent of history, literally.

Authors noted, “The results also revealed close similarities between mummified bodies from the Late Period, indicating that with a larger set with more detailed information on the mummified bodies, it may be possible to differentiate by the period (or at least by the mummification practice) based on chemical and olfactory profiles and to achieve a better understanding of the different practices.”

Journal Reference

1. Emma Paolin, Cecilia Bembibre, Fabiana Di Gianvincenzo, Julio Cesar Torres-Elguera, Randa Deraz, Ida Kraševec, Ahmed Abdellah, Asmaa Ahmed, Irena Kralj Cigić, Abdelrazek Elnaggar, Ali Abdelhalim, Tomasz Sawoszczuk, and Matija Strlič. Ancient Egyptian Mummified Bodies: Cross-Disciplinary Analysis of Their Smell. Journal of the American Chemical Society. DOI: 10.1021/jacs.4c15769

A second “new star” has unexpectedly appeared in the night sky, less than two weeks after a near-identical point of light first burst into view without warning.

These never-before-seen “stars” are made of light coming from rare stellar explosions known as classical novas. Scientists believe this may be the first time in recorded history that more than one of these luminous outbursts have been visible with the naked eye at the same time.

WASHINGTON, July 1, 2025 /PRNewswire/ — Media accreditation is open for the launch of NASA’s 11th rotational mission of a SpaceX Falcon 9 rocket and Dragon spacecraft carrying astronauts to the International Space Station for a science expedition. NASA’s SpaceX Crew-11 mission is targeted to launch in the late July/early August timeframe from Launch Complex 39A at the agency’s Kennedy Space Center in Florida.

The mission includes NASA astronauts Zena Cardman, serving as commander; Mike Fincke, pilot; JAXA (Japan Aerospace Exploration Agency) astronaut Kimiya Yui, mission specialist; and Roscosmos cosmonaut Oleg Platonov, mission specialist. This is the first spaceflight for Cardman and Platonov, the fourth trip for Fincke, and the second for Yui, to the orbiting laboratory.

Media accreditation deadlines for the Crew-11 launch as part of NASA’s Commercial Crew Program are as follows:

• International media without U.S. citizenship must apply by 11:59 p.m. EDT on Sunday, July 6.
• U.S. media and U.S. citizens representing international media organizations must apply by 11:59 p.m. on Monday, July 14.

All accreditation requests must be submitted online at:

https://media.ksc.nasa.gov

NASA’s media accreditation policy is online. For questions about accreditation or special logistical requests, email: [email protected]. Requests for space for satellite trucks, tents, or electrical connections are due by Monday, July 14.

For other questions, please contact NASA Kennedy’s newsroom at: 321-867-2468.

Para obtener información sobre cobertura en español en el Centro Espacial Kennedy o si desea solicitar entrevistas en español, comuníquese con Antonia Jaramillo: 321-501-8425, o Messod Bendayan: 256-930-1371.

For launch coverage and more information about the mission, visit:

https://www.nasa.gov/commercialcrew 

SOURCE NASA

AMES, Iowa – Plant scientists have used a standard “gene gun” since 1988 to genetically modify crops for better yield, nutrition, pest resistance and other valuable traits.

That technology, which loads genetic materials on tiny particles and uses high pressure to shoot them into plant cells, has presented challenges to plant scientists, including inefficiency, inconsistency and even tissue damage caused by high-velocity particles.

But that was just the way these experiments worked, and plant scientists worked around the challenges.

“We didn’t even know we had a problem,” said Kan Wang, an Iowa State University agronomist and Charles F. Curtiss Distinguished Professor in Agriculture and Life Sciences.

Shan Jiang, an Iowa State associate professor of materials science and engineering, wondered if his research group could do something to improve that basic tool of plant research. Ultimately, he and the group determined plant scientists had been “shooting a bullet without a barrel” for 40 years.

A paper just published by the journal Nature Communications details the research team’s search for a solution, its subsequent findings and the invention that launched a startup company.

The project was more than solving a single engineering problem, though. Jiang, because of his research resume, really wanted to use his engineering approach to improve plant science and, potentially, human lives.

Post-doc lessons

After earning his doctorate from the University of Illinois Urbana-Champaign, Jiang went to work as a post-doctoral researcher in the Langer Lab at the Massachusetts Institute of Technology.

That’s the lab of Robert Langer, once called the “smartest man in Boston” by the Boston Globe and co-founder and, until last August, a board member for Moderna, Inc., a leader in the creation of mRNA medicine, including vaccines for COVID-19.

Jiang was one of 15 post-docs working on new ideas to deliver genetic materials for medical therapies.

“It was such difficult research,” he said.

But one outcome, even after research funding dried up, was the use of messenger RNA to produce proteins that could help the body fight off disease.

“That research had a profound impact in my life,” Jiang said. “When I arrived at Iowa State, I thought about what I wanted to do.”

But there was no research hospital and limited opportunities for medical research.

He looked around in the scientific literature and read about delivering DNA into plant cells to introduce or boost particular traits, including high crop yields, resistance to insects or tolerance of heat.

He picked up the phone and made a cold call.

Wang answered and was surprised to be talking to a materials engineer but was interested enough to schedule a lunch and talk about the challenges of plant science research, particularly the challenge of delivering genetic materials through a plant’s tough cell walls.

“It was such an overlooked area,” Jiang said. “Very few materials scientists were working on plant cell delivery. Agriculture is always overlooked – people want to cure cancer.”

From losing patience to a shock discovery

The decades-old “gene gun” used by plant scientists for what’s known as “biolistic” delivery of genetic information works by coating gold or tungsten microparticles, just a few millionths of a meter in size, with genetic material and then shooting particle and cargo into plant cells.

Some of those cells survive the particle bombardment, take up the introduced DNA and express the corresponding traits. Whole plants can then be grown from the transformed cells.

“However, biolistic delivery faces notable challenges with efficiency, consistency, and tissue damage caused by high-velocity microprojectiles, which hinder regeneration and transformation,” Jiang and co-authors wrote in their paper about the project (see team and paper details below). “Additionally, it often leads to fragmented and multiple transgene insertions in the genome, resulting in unpredictable gene expression.”

Jiang and his research collaborators began looking for solutions – “We tried to minimize the error bar,” he said.

The researchers tried everything they could think of, but Jiang said they made little progress. After four years, it was time to reconsider the time and effort spent on the project.

“We were losing hope and patience,” Jiang said.

In one last push for a solution, the research team ran computational fluid dynamics models of gene gun particle flows and discovered a bottleneck within an internal barrel. It seemed too narrow and restrictive, leading to particle loss, disrupted flow, decreased pressures, slower speeds, and uneven distribution at the target cells.

“These findings pinpoint critical limitations in the gene gun design and led us to hypothesize that engineering the flow dynamics within the gene gun could significantly improve its efficiency and consistency,” Jiang and his collaborators wrote.

To do that, the researchers designed a new internal barrel for the gene gun – they call it a “Flow Guiding Barrel” – and Connor Thorpe, a doctoral student and 3D-printing hobbyist, printed one for testing.

“It improved performance by 50%, then two, three, five, ten, twenty times,” Jiang said. “I was very shocked, to be honest with you.”

Easier plant transformations

The computer modeling shows a conventional gene gun directs about 21% of loaded particles toward its plant cell targets while a gene gun modified with the Flow Guiding Barrel delivers nearly 100%.

Subsequent tests by plant scientists found, for example, a 22-fold increase in transient transfection efficiency in tests with onions, a 17-fold improvement in viral infection efficiency in maize seedlings and double the efficiency of experiments using CRISPR genome editing tools in wheat.

“No previous device has achieved such improvements, offering substantial potential for advancing genotype independent transformation and genome editing for plants,” paper co-authors wrote.

Wang, the Iowa State plant scientist originally approached by Jiang, noted laboratory “improvements of 10-fold and sometimes 20-fold. We’re able to work far more efficiently.”

Yiping Qi, a professor of plant science and landscape architecture at the University of Maryland and a project collaborator, said the Flow Guiding Barrel “will make plant transformation and genome editing easier with improved efficiency.”

In one test, for example, he said the Flow Guiding Barrel allowed CRISPR reagents to penetrate deeper into the shoot apical meristem of bread wheat, the part of the plant where cell and leaf production occur.

“This translated to the higher efficiency of heritable genome editing in the next generation of wheat,” Qi said. “While this demonstration was done in wheat, one can envision such improvement can also benefit other crops, like barley, sorghum, etc.”

Support for research and development of the Flow Guiding Barrel came from Iowa State sources, including the Digital and Precision Agriculture Research and Innovation Platform; The Agriculture and Food Research Initiative of the U.S. Department of Agriculture’s National Institute of Food and Agriculture; the National Science Foundation; and the Department of Energy.

A startup for plant science

The Flow Guiding Barrel worked so well, Jiang; Thorpe; Wang; Kyle Miller, a former doctoral student in Jiang’s lab; and Alan Eggenberger, an Iowa State research scientist in materials science and engineering; took steps to investigate the commercial potential of the invention. Jiang and Thorpe also enrolled in Iowa State’s startup programs and later co-founded a company with Jibing Lin, an Iowa State graduate and startup leader. The U.S. Department of Energy’s Small Business Technology Transfer program has supported the company’s development.

“This project would not be possible without close collaboration with plant biologists,” Jiang said. “We believe the best way to give back is to make our tools commercially available so they can be broadly used in the plant science community.”

The Iowa State University Research Foundation filed for patent protection on the innovation and has licensed the commercial rights to the co-founders’ company, Hermes Biomaterials Inc. The company is based at the Iowa State University Research Park and is manufacturing its products in Iowa. The company continues its customer discovery work based on the National Science Foundation’s Innovation Corps program and has started selling products.

With efficiency gains of 10- and 20-fold, Jiang said the Flow Guiding Barrel could save plant scientists and agriculture companies millions of dollars in time and plant or product turnaround.

“This is a small device, and it seems overly simple,” Jiang said. “But the benefits it can bring are invaluable. It enables the development of safer and more effective strategies to improve crops that can better withstand environmental changes, enhance nutritional content, and contribute to sustainable energy production.”

– 30 –

The research team

Iowa State University Materials Science and Engineering: Shan Jiang, Connor Thorpe, Alan Eggenberger, Ritinder Sandhu

Iowa State Agronomy and Crop Bioengineering Center: Kan Wang, Qing Ji, Keunsub Lee, Steven Whitham

Iowa State Plant Pathology, Entomology and Microbiology: Aline Chicowski, Weihui Xu

University of Maryland Plant Science and Landscape Architecture: Yiping Qi, Weifeng Luo

Read the paper

“Enhancing biolistic plant transformation and genome editing with a flow guiding barrel,” Nature Communications, July 1, 2025, https://doi.org/10.1038/s41467-025-60761-x

Private spaceflight continues its upward trajectory.

American companies launched 21 commercial space missions in June 2025, which was a new record for a single month, according to the Federal Aviation Administration (FAA).

We aim to discover whether the stellar multiplicity rate may provide information on the origin of recently discovered planets in the Neptunian Desert.

Using Gaia DR3 astrometry, we search for common proper motion companions to 1779 known exoplanet hosts and 2927 exoplanet candidate hosts from the TESS mission, both within 650 pc.

We find overall stellar multiplicity rates of 16.6±0.9% and 19.8±0.6% for confirmed and candidate exoplanets, respectively. We find stellar multiplicity rates of 16.7±5.8% and 27.5±2.6% for confirmed and candidate exoplanets in the Neptunian Desert, respectively. Hot Jupiter host stars were found to have rates of 25.8±2.1% and 22.9±1.3%.

For the sample of candidate exoplanets, we find higher stellar multiplicity rates for stars hosting both Hot Jupiters and Neptunian Desert planets compared to control samples of similar stars not known to host planets. For the sample of confirmed exoplanets an increased multiplicity rate is seen for Hot Jupiter hosts, but cannot be significantly determined for Neptunian Desert planet hosts due to small sample sizes.

If the candidates from TESS are indeed planets, the increased multiplicity rate observed could indicate that the Neptunian Desert and Hot Jupiter populations share similar formation mechanisms and environmental conditions. Alternatively, the TESS candidate high multiplicity rate could imply a prevalence of false positives related to binary and triple stars in this parameter space.

Fintan Eeles-Nolle, David J. Armstrong

Comments: Accepted for publication in MNRAS. 14 pages, 9 figures, 6 tables
Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)
Cite as: arXiv:2506.22399 [astro-ph.EP] (or arXiv:2506.22399v1 [astro-ph.EP] for this version)
https://doi.org/10.48550/arXiv.2506.22399
Focus to learn more
Submission history
From: Fintan Eeles-Nolle
[v1] Fri, 27 Jun 2025 17:15:41 UTC (862 KB)
https://arxiv.org/abs/2506.22399

Astrobiology,