Category: 7. Science

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
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Submission history
From: Fintan Eeles-Nolle
[v1] Fri, 27 Jun 2025 17:15:41 UTC (862 KB)
https://arxiv.org/abs/2506.22399

Astrobiology,

It’s the first moon in July, and with each passing night, we’re seeing more and more of the moon lit up, signaling our journey through the lunar cycle.

The lunar cycle is a series of eight unique phases of the moon’s visibility. The whole cycle takes about 29.5 days, according to NASA, and these different phases happen as the Sun lights up different parts of the moon whilst it orbits Earth. 

See what’s happening with the moon tonight, July 1.

What is today’s moon phase?

As of Tuesday, July 1, the moon phase is Waxing Crescent. 38% of the moon will be lit up and visible to us on Earth (according to NASA’s Daily Moon Observation).

This is the sixth day of the lunar cycle, and let’s hope for a clear sky tonight because there’s plenty to spot on the moon’s surface.

With just the naked eye, you’ll be able to spot the Mare Crisium, the Mare Tranquillitatis, and the Mare Fecunditatis. If you’re in the Northern Hemisphere, these will be positioned in the top right of the moon. If you’re in the Southern Hemisphere, direct your gaze to the bottom left.

If you have binoculars, you’ll see a little more. Both the Endymion Crater and the Posidonius Crater are visible, as well as the Mare Nectaris.

And that’s not all, if you’re one of the lucky few with a telescope, there’s even more for you to spot tonight. Both Apollo 11 and Apollo 17 can be seen, marking two of the most famous moon landings: the first and the last human missions to the Moon.

Slightly south of these spots (north if you’re in the Southern Hemisphere), you’ll also get a glimpse of the Rupes Altai, a circular cliff.

When is the next full moon?

This month’s full moon will take place on July 10. The last full moon was on June 11.

What are moon phases?

Moon phases are caused by the 29.5-day cycle of the moon’s orbit, which changes the angles between the Sun, Moon, and Earth. Moon phases are how the moon looks from Earth as it goes around us. We always see the same side of the moon, but how much of it is lit up by the Sun changes depending on where it is in its orbit. This is how we get full moons, half moons, and moons that appear completely invisible. There are eight main moon phases, and they follow a repeating cycle:

New Moon – The moon is between Earth and the sun, so the side we see is dark (in other words, it’s invisible to the eye).

Waxing Crescent – A small sliver of light appears on the right side (Northern Hemisphere).

First Quarter – Half of the moon is lit on the right side. It looks like a half-moon.

Waxing Gibbous – More than half is lit up, but it’s not quite full yet.

Full Moon – The whole face of the moon is illuminated and fully visible.

Waning Gibbous – The moon starts losing light on the right side.

Last Quarter (or Third Quarter) – Another half-moon, but now the left side is lit.

Waning Crescent – A thin sliver of light remains on the left side before going dark again.

The ubiquitous, evolutionarily oldest RNAs and proteins exclusively use rather rare zinc as transition metal cofactor and potassium as alkali metal cofactor, which implies their abundance in the habitats of the first organisms.

Intriguingly, lunar rocks contain a hundred times less zinc and ten times less potassium than the Earth’s crust; the Moon is also depleted in other moderately volatile elements (MVEs). Current theories of impact formation of the Moon attribute this depletion to the MVEs still being in a gaseous state when the hot post-impact disk contracted and separated from the nascent Moon.

The MVEs then fell out onto juvenile Earth’s protocrust; zinc, as the most volatile metal, precipitated last, just after potassium. According to our calculations, the top layer of the protocrust must have contained up to 1019 kg of metallic zinc, a powerful reductant.

The venting of hot geothermal fluids through this MVE-fallout layer, rich in metallic zinc and radioactive potassium, both capable of reducing carbon dioxide and dinitrogen, must have yielded a plethora of organic molecules released with the geothermal vapor.

n the pools of vapor condensate, the RNA-like molecules may have emerged through a pre-Darwinian selection for low-volatile, associative, mineral-affine, radiation-resistant, nitrogen-rich, and polymerizable molecules.

Origin of the RNA World in Cold Hadean Geothermal Fields Enriched in Zinc and Potassium: Abiogenesis as a Positive Fallout from the Moon-Forming Impact?, Life via PubMed (open access)

Astrobiology, Astrochemistry,

The search for life outside our solar system is at the forefront of modern astronomy, and telescopes such as the Habitable Worlds Observatory (HWO) are being designed to identify biosignatures.

Molecular oxygen, O₂, is considered a promising indication of life, yet substantial abiotic O₂ may accumulate from H₂O photolysis and hydrogen escape on a lifeless, fully (100%) ocean-covered terrestrial planet when surface O₂ sinks are suppressed.

This so-called waterworld false positive scenario could be ruled out with land detection because exposed land precludes extremely deep oceans (~50 Earth oceans) given topographic limits set by the crushing strength of rocks.

Land detection is possible because plausible geologic surfaces exhibit increasing reflectance with wavelength in the visible, whereas liquid water and ice/snow have flat or decreasing reflectance, respectively.

Here, we present reflected light retrievals to demonstrate that HWO could detect land on an exo-Earth in the disk-averaged spectrum. Given a signal-to-noise ratio of 20 spectrum, Earth-like land fractions can be confidently detected with 0.3-1.1 um spectral coverage (resolution R~140 in the visible, R~7 in the UV, with Earth-like atmosphere and clouds). We emphasize the need for UV spectroscopy down to at least 0.3 um to break an O₃-land degeneracy.

We find that the SNR and resolution requirements in the visible/UV imply that a larger aperture (~8 m) will be necessary to ensure the observing times required for land detection are feasible for most HWO terrestrial habitable zone targets. These results strongly inform the HWO minimum requirements to corroborate possible oxygen biosignatures.

Anna Grace Ulses, Joshua Krissansen-Totton, Tyler D. Robinson, Victoria Meadows, David C. Catling, Jonathan J. Fortney

Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:2506.21790 [astro-ph.EP] (or arXiv:2506.21790v1 [astro-ph.EP] for this version)
https://doi.org/10.48550/arXiv.2506.21790
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Submission history
From: Anna Grace Ulses
[v1] Thu, 26 Jun 2025 22:12:38 UTC (1,517 KB)
https://arxiv.org/abs/2506.21790
Astrobiology,

Scientists analysing the cascading impacts of record low levels of Antarctic sea ice fear a loss of critical US government satellite data will make it harder to track the rapid changes taking place at both poles.

Researchers around the globe were told last week the US Department of Defence will stop processing and providing the data, used in studies on the state of Arctic and Antarctic sea ice, at the end of this month.

Tracking the state of sea ice is crucial for scientists to understand how global heating is affecting the planet.

Sea ice reflects the sun’s energy back out to space but, as long-term losses have been recorded, more of the planet’s ocean is exposed to the sun’s energy, causing more heating.

The National Snow and Ice Data Center, based at the University of Colorado, maintains a Sea Ice Index used around the world to track in near real-time the extent of sea ice around the globe.

In two updates in the past week, the centre said the US government’s Department of Defence, which owns the satellites that contain onboard instruments used to track sea ice, would stop “processing and delivering” the data on 31 July.

Climate scientists have been warning that Trump administration cuts have targeted climate functions across government, and there has been fears the sea ice data could be targeted.

The news comes as new research, some of which relied on the data, found that record low amounts of sea ice around Antarctica in recent years had seen more icebergs splintering off the continent’s ice shelves in a process scientists warned could push up global sea levels faster than current modelling has predicted.

Dr Alex Fraser, a co-author of the research at the Australian Antarctic Program Partnership (AAPP), said NSIDC’s sea ice data was “our number one heart rate monitor” for the state of the planet’s ice.

“It’s our early warning system and tells us if the patient is about to flatline. We need this data and now [the scientific community] will be forced to put together a record from a different instrument. We won’t have that continued context that we have had previously.”

NSIDC has said it is working with alternative and higher-resolution instruments from a different satellite, but has warned that data may not be directly comparable with the current instruments.

Fraser said: “We are seeing records now year on year in Antarctica, so from that perspective this could not have come at a worse time.”

The research, published in the journal PNAS Nexus, found a link between increasing numbers of icebergs calving from floating ice shelves and the loss of sea ice.

While the loss of sea ice does not directly raise sea levels, the research said it exposed more ice shelves to wave action, causing them to break apart and release icebergs faster.

Glaciologist Dr Sue Cook, also from AAPP, said “like a cork in a bottle” those shelves help to slow down the advance of land-based ice that does raise sea levels if it breaks off into the ocean.

She said the higher rates of iceberg calving seen in Antarctica were not accounted for in calculations of how quickly the ice sheet might break apart and contribute global sea levels.

“If we shift to this state where summer sea ice is very low but we continue using models based on previous periods, then we will definitely underestimate how quickly Antarctica will contribute to sea level rise,” she said.

The study also outlined other knock-on effects from the record low sea ice levels in the Antarctic, including the loss of more seals and penguins if trends continued.

As many as 7,000 emperor penguin chicks died in late 2022 after the early break-up of the stable ice they used for shelter while they grow their waterproof plumage.

Guardian Australia has requested comment from NSIDC and the US Department of Defence.