It's like a little magnetic "nom, nom."
- Venus flytrap leaves shut in response to physical touch, salt water, or thermal stimuli.
- A team of scientists from Berlin have captured the magnetic charge that accompanies the closing of the plant's trap.
- Incredibly sensitive, non-invasive atomic magnetometers picked up the elusive signal.
For many children, the revelation that there's such a thing as a Venus Flytrap, Dionaea muscipula, is an amazing moment. The choppers of the sneaky plant predators are like something out of a fairy tale gone wrong. Adults can't help but be fascinated by them too, and now scientists at Johannes Gutenberg University Mainz (JSU) and the Helmholtz Institute Mainz in Germany have discovered something new that's surprising about these little demons: Every time they entrap prey, they give off a measurable magnetic charge.
"We have been able to demonstrate that action potentials in a multicellular plant system produce measurable magnetic fields, something that had never been confirmed before," says lead author Anne Fabricant.
Guilt as magnetically charged
The plants' bivalved snap trap (left), side view of a destained trap lobe (right)
Credit: Fabricant, et al./Scientific Reports
According to Fabricant, the finding isn't that much of a shock: "Wherever there is electrical activity, there should also be magnetic activity," she tells Live Science. And it is electrical activity in the form of action potentials that trigger its maw—really a pair of leaf lobes—to close when a hapless bug lands inside them, attracted by the nectar with which the plants bait their trap.
Along the inner surfaces of the lobes are trichomes, hair-like projections that cause the trap to close when they're disturbed by prey. One touch of a trichome is unlikely to cause the trap to shut — perhaps a mechanism that helps the plant avoid wasting energy on false alarms. A couple of touches, though, and it's chow time. The lobes come together as the bristles at their edges intertwine to help contain the prey. As the traps compress the trapped insect, its own secretions such as uric acid cause the trap to shut even more tightly, and then digestion begins.
In any event, just because the JSU researchers had reason to suspect the plant would give off a magnetic charge, catching it doing so was not a simple task.
Reading the Venus flytrap's magnetic output
Average action potential and corresponding magnetic signals
Credit: Fabricant, et al./Scientific Reports
"The problem," says Fabricant, "is that the magnetic signals in plants are very weak, which explains why it was extremely difficult to measure them with the help of older technologies." Still, where there's a will: "You could say the investigation is a little like performing an MRI scan in humans."
It's not just trichome flicks that trigger the trap — it will also close if triggered by salt-water, or with an application of either hot or cold thermal energy. The researchers applied heat via a purpose-built Peltier device that wouldn't introduce any background magnetic noise to mask or overwhelm the faint magnetic signal they were seeking. For the same reason, the experiments were conducted in a magnetically shielded room at Physikalisch-Technische Bundesanstalt (PTB) in Berlin.
The researchers used atomic magnetometers to measure the planets magnetic charges. The atomic magnetometer is a glass cell containing a vapor of rubidium atoms. When the traps were triggered, the magnetic charges released changed the spins of the atoms' electrons.
The researchers picked up magnetic signals at an amplitude of up to 0.5 picoteslas. "The signal magnitude recorded is similar to what is observed during surface measurements of nerve impulses in animals," says Fabricant. It's over a million times weaker than the Earth's own magnetic field.
Other researchers have detected magnetic charges coming the firing of animal nerves — including within our own brain. The phenomenon is referred to as "biomagnetism." Since other plants have action potentials, they may also generate biomagnetism, though less research has been done on them.
It's to other plants that the attention of the JSU team now turns, as they go looking for even smaller magnetic charges from other species. In addition to providing new understanding of nature's use of electricity, non-invasive detection technologies such as the one employed by the group could one day be utilized for more insightful monitoring of crops as they respond to thermal, pest, and chemical influences.
Researchers document the first example of evolutionary changes in a plant in response to humans.
- A plant coveted in China for its medicinal properties has developed camouflage that makes it less likely to be spotted and pulled up from the ground.
- In areas where the plant isn't often picked, it's bright green. In harvested areas, it's now a gray that blends into its rocky surroundings.
- Herbalists in China have been picking the Fritillaria dealvayi plant for 2,000 years.
Fritillaria dealvayi<p>The plant is <em> </em><a href="http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=200027633" target="_blank"><em>Fritillaria dealvayi</em></a><em>,</em> and its bulbs are harvested by Chinese herbalists, who grind it into a powder that treats coughs. The cough powder sells for the equivalent of $480 per kilogram, with a kilogram requiring the grinding up of about 3,500 bulbs. The plant is found in the loose rock fields lining the slopes of the Himalayan and Hengduan mountains in southwestern China.</p><p>As a perennial that produces just a single flower each year after its fifth season, it seems <em>Fritillaria</em> used to be easier to find. In some places its presence is betrayed by bright green leaves that stand out against the rocks among which which it grows. In other places, however, its leaves and stems are gray and blend in with the rocks. What's fascinating is that the bright green leaves are visible in areas in which Fritillaria is relatively undisturbed by humans while the gray leaves are (just barely) visible in heavily harvested areas. Same plant, two different appearances.</p><div id="19cbf" class="rm-shortcode" data-rm-shortcode-id="c68d3086f5411ffd951edaad1cb811b9"><blockquote class="twitter-tweet twitter-custom-tweet" data-twitter-tweet-id="1329832938985435138" data-partner="rebelmouse"><div style="margin:1em 0">2/2: The picture on the left shows a Fritillaria delavayi in populations with high harvest pressure, and the one on… https://t.co/oriBNZGcsV</div> — University of Exeter News (@University of Exeter News)<a href="https://twitter.com/UniofExeterNews/statuses/1329832938985435138">1605891854.0</a></blockquote></div>
How we know we're the cause<p>There are other camouflaging plants, but the manner in which <em>Fritillaria</em> has developed this trait strongly suggests that it's a defensive response to being picked. "Many plants seem to use camouflage to hide from herbivores that may eat them — but here we see camouflage evolving in response to human collectors."</p><p>"Like other camouflaged plants we have studied," Niu says, " we thought the evolution of camouflage of this fritillary had been driven by herbivores, but we didn't find such animals." His close examination of Fritillaria leaves revealed no bite marks or other signs of non-human predation. "Then we realized humans could be the reason."</p><p>In any event, says Professor Hang Sun the Kunming Institute, "Commercial harvesting is a much stronger selection pressure than many pressures in nature."</p><img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDgyNzM0My9vcmlnaW4ucG5nIiwiZXhwaXJlc19hdCI6MTYzMDc3NDQwMn0.lXwsG0ShcnMcVLl06APdEeEOY5_WOs4UfN8oVCKsgtc/img.png?width=980" id="ccc8e" class="rm-shortcode" data-rm-shortcode-id="907e152dd5ad0429aa6350c53f5a85aa" data-rm-shortcode-name="rebelmouse-image" alt="herb shop" data-width="2448" data-height="1377" />
Credit: maron/Adobe Stock
The study<p>Since herbalists have been plucking <em>Fritillaria</em> from the rocks for 2,000 years, one might hope a record would exist that could allow researchers to identify areas in which the plant has been most thoroughly picked. There is no such documentation, but Liu and Stevens were able to acquire this type of information for five years (2014–2019), tracking the harvests at seven <em>Fritillaria</em> study sites. This allowed them to identify those areas in which the plant was most heavily harvested. These also turned out to be the locations with the gray-leaf variant of <em>Fritillaria</em>.</p><p>Further supporting the scientists' conclusion that gray <em>Fritillaria</em> was more likely to evade human hands and live long enough to reproduce was that participants in virtual plant-identification tests confirmed the species was hard to spot in the wild.</p><p>"It's possible that humans have driven evolution of defensive strategies in other plant species, but surprisingly little research has examined this," Stevens notes.</p><p>Hang Sun says such studies make clear that humans have become drivers of evolution on our planet: "The current biodiversity status on the earth is shaped by both nature and by ourselves."</p>
Medicago is growing a SARS-CoV-2 vaccine candidate in a relative of the tobacco plant right now.
- Canadian biotech company Medicago is growing a vaccine candidate in Nicotiana benthamiana.
- An Australian relative to tobacco, plant-based vaccines could be cheaper and more reliable than current methods.
- Medicago just completed phase 3 clinical trials of an influenza vaccine, which could be a game-changer for vaccine production.
Credit: alphaspirit / Adobe Stock<p>Clark <a href="https://www.medicago.com/en/newsroom/medicago-begins-phase-i-clinical-trials-for-its-covid-19-vaccine-candidate/" target="_blank">says</a> it's important to attack the novel coronavirus from all sides.</p><p style="margin-left: 20px;">"Creating a sufficient supply of COVID-19 vaccines within the next year is a challenge which will require multiple approaches, with different technologies. Our proven plant-based technology is capable of contributing to the collective solution to this public health emergency."</p><p>Unlike many common vaccines, VLP vaccines contain no genetic material. You won't get infected by it, which is always a risk in live vaccines. </p><p>This SARS-CoV-2 vaccine is not the only project on Medicago's hands. The company <a href="https://clinicaltrials.gov/ct2/show/NCT03301051" target="_blank">just completed</a> phase 3 clinical trials on an influenza. While no plant-based vaccine has been approved for use, the company hopes to replace the more cumbersome and expensive egg-based model, or at least offset some of the costs of that model. The plant model could help researchers adapt more quickly to the ever-changing influenza strains each season. </p><p>Plants offer a wonderful alternative to the current vaccination model. Besides price, VLP vaccines scale much easier and faster. If the SARS-CoV-2 vaccine works, Medicago <a href="https://www.medicago.com/en/newsroom/medicago-begins-phase-i-clinical-trials-for-its-covid-19-vaccine-candidate/" target="_blank" rel="noopener noreferrer">believes</a> they can produce a billion doses a year, by far the most ambitious yield to date. At a time when speed, cost, and reliability are all essential factors in vaccine development, we should put tobacco to better use: healing instead of harming. </p><p>--</p><p><em>Stay in touch with Derek on <a href="http://www.twitter.com/derekberes" target="_blank">Twitter</a> and <a href="https://www.facebook.com/DerekBeresdotcom" target="_blank" rel="noopener noreferrer">Facebook</a>. His new book is</em> "<em><a href="https://www.amazon.com/gp/product/B08KRVMP2M?pf_rd_r=MDJW43337675SZ0X00FH&pf_rd_p=edaba0ee-c2fe-4124-9f5d-b31d6b1bfbee" target="_blank" rel="noopener noreferrer">Hero's Dose: The Case For Psychedelics in Ritual and Therapy</a>."</em></p>
Modern crops have been optimized for a lot of things, but not for climate change.
- Growers are struggling to protect their crops from failure as conditions change due to global warming.
- Modern crops lack the fortifying genetic diversity of their ancestors.
- Scientists publish a new guide for strengthening crops through the reintroduction of wild-variety traits based on the latest science.
The problem with domestication<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDQ3NjU0Ny9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYxNzA2MDc2NX0.T41B0nuT0RnVyd_oFrmcCQMf6ZT6FpG2Gmrx9TCZ-mI/img.jpg?width=980" id="e86ad" class="rm-shortcode" data-rm-shortcode-id="19f58b1f2f0ba8c2295c824ff73514a5" data-rm-shortcode-name="rebelmouse-image" alt="plants" data-width="1440" data-height="960" />
Credit: Markus Spiske/Unsplash<p>"When plants were domesticated," <a href="https://www.port.ac.uk/news-events-and-blogs/news/scientists-help-reboot-50-years-of-plant-advice" target="_blank">says</a> Dr. Perez-Barrales, one of the study's authors, "they were artificially selected for a specific desirable trait. Artificial selection and farming have led to quality improvements in foods such as meat, milk, and fruit. However, over hundreds of years, there has been a negative impact to this process — a reduction in plant genetic diversity."</p><p>This lack of diversity could spell doom for crops as the conditions in which they grow are impacted by climate change. Scientists believe that a plant's natural genetic makeup, which evolved in response to its surrounding conditions, makes it more likely to be able to continue to adapt. Domesticated crops may lack such flexibility.</p><p>According to Dr. Perez-Barrales, "Climate change is altering the way crops behave." Unfortunately, she adds, "Crops have lost so much genetic diversity they are less able to adapt and respond to climate change. Scientists are now looking at wild crop relatives to see what traits can be improved to make crops better adapted to the current environmental challenges."</p><p>This revisiting of crops' ancestors is very much on the mind of the new study's authors.</p>
A break from past practices<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDQ3NjU2NS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY3MzI5MzEyOX0.xrTnfeksMY3mvVNr7Ebvu2RRgjszpVHvJI8zc4SZkEM/img.jpg?width=980" id="5451b" class="rm-shortcode" data-rm-shortcode-id="70f3d0885d71401c00ba9329a6b480c5" data-rm-shortcode-name="rebelmouse-image" alt="farmer spraying fields" data-width="1440" data-height="1027" />
Credit: ittipon/Shutterstock/Big Think<p>The researchers began with a re-visiting of <a href="https://www.jstor.org/stable/1218252?seq=1" target="_blank">guidelines</a> published in 1971 to see how they might be modified. Says Perez-Barrales, "The classification developed in the early 1970s needed to be updated, and in effect rebooted, to integrate this modern information."</p><p>The study's lead author <a href="https://www.kew.org/science/our-science/people/juan-viruel" target="_blank">Juan Viruel</a> of Kew Garden explains, "With this information we can better select the wild species to improve our crops. It is an invaluable checklist for plant breeders and will help production of crops in a more sustainable way."</p><p>Those earlier guidelines also endorse the use of pesticides, now understood to harm fauna and leave fields toxic. The new study suggests a more benign, forward-looking way to deal with pests, says Perez-Barrales: "An alternative for plant breeders is to use wild crop relatives and use the natural genetic variation in those species that protects them against the natural enemies."</p>
An example: linseed<p>To explain the type of guidance offered in the new study, Perez-Barrales offers linseed as a case in point:</p><p>"Some crops have just a few closely related species, whilst others might have a hundred or so," she says. "For example, linseed has more than 150 related species, and the challenge is how do we select the relevant traits and from what wild relatives? In answering this question, we realized that we needed to learn more from the biology of the species, which can only be done by using modern classification developed using the latest science."</p><p>Perez-Barrales continues:</p><p>"There may be a demand to grow linseed, for example, in countries at different latitudes. Linseed (<em>Linum usitatissimum</em>) was domesticated in the Middle East 10,000 years ago, and we can grow it in England because it naturally captured genes from pale blue flax, <em>Linum bienne</em>, allowing the crop to grow in northern and colder environments. My research looks at the natural variation in flowering of wild <em>Linum</em> species to see if we can use it to improve linseed. That way the right genes can be selected and introduced into the crop, something that plant breeders do regularly. These new guidelines will help plant breeders become more sustainable and efficient. We believe it is the future of farming."</p>
Declining bee populations could lead to increased food insecurity and economic losses in the billions.
From bee to farm to table<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMzUyOTUzOC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY1NzM3MDkwNH0.coXBXgDBoRvXaZYIgKaH9fH_jhlUKp3O22-h2rY8jMQ/img.jpg?width=980" id="a317b" class="rm-shortcode" data-rm-shortcode-id="bd61c660c9d52353ba975145fab59625" data-rm-shortcode-name="rebelmouse-image" data-width="1569" data-height="628" />
A bar graph showing the percentage of pollination limitation for the seven crops studied.
Ecological and edible incentives<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMzUyOTUzMS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYyNTM4NzQwMX0.vclSktT0d_Mvns_QTZ7ZkFT_pWgIIpyb6ZNP1Tla2Qs/img.jpg?width=1245&coordinates=0%2C215%2C0%2C216&height=700" id="93d5d" class="rm-shortcode" data-rm-shortcode-id="b1e5b70e616daf5fcc0a63a041675e7a" data-rm-shortcode-name="rebelmouse-image" alt="hand holding dead bees" data-width="1245" data-height="700" />
A protester shows a handful of bees that died by pesticides. The protest was held during the Bayer AG shareholder meeting in 2019.
(PhooMaja Hitiji/Getty Images)<p>The concern extends beyond these seven. Crops such as coffee, avocados, lemons, limes, and oranges are also highly dependent on pollinators and may prove pollination limited. If declining bee populations are tied to such yields, it could mean barer supermarket shelves and increased prices. While that may only be an annoyance to some, to poor and vulnerable communities who already struggle to secure <a href="https://www.ers.usda.gov/amber-waves/2011/december/data-feature-mapping-food-deserts-in-the-us/" target="_blank">salubrious, affordable food</a>, such a deficit would present another barrier to the vital micronutrients necessary for a healthy life and diet.</p><p>Unfortunately, <a href="http://sro.sussex.ac.uk/id/eprint/54228/1/Science_1255957_Goulson_RV_revised_CA_edited.pdf" target="_blank">the threats to bees are numerous</a>. Parasites, agrochemicals, monoculture farming, and habitat degradation all play a role, and neither stressor works in isolation. Sublethal exposure to neonicotinoids, an insecticide, can cause <a href="https://bigthink.com/surprising-science/baby-bees-and-pesticides" target="_self">impairments in bees</a>, while monoculture farming serves up a monotonous and unhealthy floral buffet. Both impede bees' immune systems, rendering them vulnerable to parasites such as <a href="http://entnemdept.ufl.edu/creatures/misc/bees/varroa_mite.htm" target="_blank"><em>Varroa destructor</em></a>, a mite that can transmit debilitating viruses as it feeds on bees' fat bodies. And all of these stressors will likely be inflamed by climate change in the years to come. </p><p>Some have proffered mechanical solutions, such as Japan's National Institute of Advanced Industrial Science and Technology where technicians are developing <a href="https://www.newscientist.com/article/2120832-robotic-bee-could-help-pollinate-crops-as-real-bees-decline/" target="_blank">robotic bees</a>. These micro-drones are covered in gelled horsehair and have successfully cross-pollinated Japanese lilies. Other experiments include <a href="https://www.capitalpress.com/ag_sectors/orchards_nuts_vines/pollen-spray-could-replace-honeybees/article_f9a1c102-d5b3-519d-9dab-b0c44cfb99c5.html" target="_blank">pollen sprays</a>. However, the large-scale viability of tech-centric solutions seems questionable. After all, wild bees currently perform their ecological services pro bono and are as effective as managed honeybees. Any technological solution implemented in their absence would add to the agricultural costs and likely increase prices anyway.</p><p>Ecological amelioration will be necessary. To combat habitat fragmentation and strengthen biodiversity, many cities are implementing green-way strategies. For example, the Dutch city of Utrecht has decked its bus stop roofs with plants and grasses to <a href="https://bigthink.com/technology-innovation/urban-bees?rebelltitem=1#rebelltitem1" target="_self">create bee and butterfly shelters</a>, while other cities are looking to foster <a href="https://www.csmonitor.com/Environment/2020/0731/Can-roadsides-offer-a-beeline-for-pollinators" target="_blank">bee-friend roadsides</a>. And <a href="https://www.fsa.usda.gov/Assets/USDA-FSA-Public/usdafiles/FactSheets/2015/CRPProgramsandInitiatives/Honey_Bee_Habitat_Initiative.pdf" target="_blank">government initiatives</a> incentivize farmers and landowners to adopt bee-friendly management practices. These solutions aren't only a matter of ecological conservation but also food security and public health.</p>