An international team of researchers has finally decoded the science behind a plant responsible for no small degree of human misery: poison ivy.
For the first time, we now know why poison ivy leaves – the bane of campers, hikers, and overly curious kids alike – make us itch, and the answer lies in a key molecule called CD1a, which scientists have long known about but didn’t fully understand until now.
“For over 35 years we have known CD1a is abundant in the skin,” says researcher Jerome Le Nours from Monash University in Australia. “Its role in inflammatory skin disorders has been difficult to investigate and until now has been really unclear.”
One of the reasons for that lack of clarity has been that many experiments on skin disorders involve animal testing – specifically lab mice. And mice don’t produce CD1a, effectively creating a kind of ‘blind spot’ in the studies up to this point.
To get around this and examine whether CD1a might play a part in how human skin reacts when we brush up against poison ivy (Toxicodendron radicans) and similar rash-inducing plants, the researchers genetically engineered mice that did produce the molecule.
In doing so, the team found that CD1a – a protein that plays an important role in our immune systems – triggers a skin-based allergic reaction when we come into contact with urushiol, the allergen that functions as the active ingredient in plants like poison ivy, poison oak, and poison sumac.
When urushiol interacts with skin cells called Langerhans cells, the CD1a proteins (which are expressed by Langerhans cells) activate the immune system’s T cells. In turn, the T cells produce two proteins – interleukin 17 and interleukin 22 – which cause inflammation and itchiness.
Discovering #PlantsOnPink with Painter Stella Maria Baer
To see more colorful botanical posts on Instagram, browse the #PlantsOnPink hashtag.
Every week, we’re showcasing some of the most creative community hashtags on Instagram. Today we’re highlighting #PlantsOnPink. “I like the hashtag because it is a meditation on color,” explains painter Stella Maria Baer (@stellamariabaer). “I spend a lot of time thinking about the colors of the desert in the Southwest where I grew up. Adobe walls often show up in the #PlantsOnPink photographs, some from my hometown of Santa Fe, New Mexico.” The cactus gardens of Arizona and California are the perfect place to snap a photo and contribute to the hashtag, but for those who can’t travel so far, Stella assures us: any pink wall will do.
Finding the Perfect Plant with Botanical Artist Charles Loh
To see more of Charles’ art, follow @mossingarden on Instagram.
For botanical artist Charles Loh (@mossingarden), every plant has its own character and preferences. “Plants are strange creatures,” he says. “I always look out for foliage, textures, color and how wild they could be — I love plants with roots and stems all over.” He spends hours at nurseries to find the perfect plants for his projects. But of all those he works with, his favorite is moss. “I’m telling the story of how even common plants, which are always around us, can be beautiful enough to be appreciated,” Charles, who lives in Singapore, says. “I would like to encourage people to slow down and take a second look at what is around us.”
Charles also collaborates with fashion houses such as @gucci, for which he designed this scene (pictured).“It’s been a blessing to be able to see and meet artists around the world connecting with one another through this project.”
Going viral is a good thing. Viral infections can help some plants attract more pollinators and produce more seeds, essentially boosting – rather than hurting – their evolutionary fitness, a new study has found.
Now, a team of researchers lead by John Carr from the University of Cambridge has shown in greenhouse experiments that a cucumber mosaic virus can change the types and amounts of chemicals emitted by an infected tomato plant, so that it attracts more bumblebees to pollinate it. As a result, the plants in their experiments produced more seeds.
Without pollination, the virus affected the plants negatively, decreasing their seed production, compared with non-infected plants. But when bumblebees were present, it had the opposite effect.
When the researchers then modelled what would happen under natural conditions, they found that such viruses could indeed enhance plant attractiveness to pollinators enough to make up for loss of fitness due to infection.
This means that the benefits of the virus could outweigh the drawbacks, allowing genes for susceptibility to persist in plant populations.
“To my knowledge, this is the first evidence that virus infection can make plants more attractive to pollinators,” says Carr.
Follow @looseleaf__ on Instagram to learn more about Charlie and Wona’s work.
Looking back, it feels as if Charlie Lawler and Wona Bae were destined to open Loose Leaf (@looseleaf__), a plant nursery and floral studio in Melbourne, Australia. “We were both born into the plant world,” says Charlie. “Wona grew up on a flower farm in South Korea, and my grandparents had a plant nursery in Tasmania, where I spent my youth helping out.” Wona’s experience as a florist and sculptor, combined with Charlie’s as a designer and artist, laid the perfect foundation for collaboration. The duo faced challenges getting Loose Leaf off the ground — “Wona calls it ‘jeon-hwa-wi-bok,’ meaning ‘blessing in disguise’ or ‘from bad good things come’” – but these days their business is as thriving as the plants that fill it, offering floral classes and workshops to local customers. Charlie urges other small business owners to celebrate their differences. “We’ve been inspired to share new and original concepts, which isn’t about creating content – it’s about creating work that you are passionate and proud of.”
Calgary scientists have made a breakthrough that could help celiac patients digest gluten with the help of an enzyme from bug-eating pitcher plants.
Pitcher plants are like “disposable stomachs” that are filled with an enzyme-rich liquid that helps them digest insect prey, explained lead researcher David Schriemer.
The professor at the University of Calgary says preliminary research shows the enzymes in these so-called monkey cups are “enormously potent” in breaking down gluten, and could work in a human stomach.
Scientists have shown how sunlight and a cheap catalyst can unlock significant amounts of hydrogen from fescue grass.
The method, now demonstrated for the first time, could potentially lead to a sustainable way of producing hydrogen, which has enormous potential in the renewable energy industry due to its high energy content and the fact that it does not release toxic or greenhouse gases when it is burned.
“This really is a green source of energy,” says coauthor Michael Bowker, a professor at the Cardiff Catalysis Institute. “Hydrogen is seen as an important future energy carrier as the world moves from fossil fuels to renewable feedstocks, and our research has shown that even garden grass could be a good way of getting hold of it.”
Coconuts are renowned for their hard shells, which are vital to ensure their seeds successfully germinate. But the specialised structure of coconut walls could help to design buildings that can withstand earthquakes and other natural disasters.
Coconut palms can grow 30 m high, meaning that when the ripe fruits fall to the ground their walls have to withstand the impact to stop them from splitting open. To protect the internal seed, the coconut has a complex structure of three layers: the outer brown, leathery exocarp, a fibrous mesocarp and a tough inner endocarp surrounding the pulp which contains the developing seedling. As part of a larger project on “Biological Design and Integrative Structures”, researchers at the Plant Biomechanics Group of the University of Freiburg have been working with civil engineers and material scientists to investigate how this specialised structure could be applied in architecture.
The researchers used compression machines and an impact pendulum to investigate how coconuts disperse energy. “By analysing the fracture behaviour of the samples and combining this with knowledge about the shell’s anatomy gained from microscopy and computed tomography, we aimed to identify mechanically relevant structures for energy absorption” says plant biomechanist Stefanie Schmier.
Their investigations found that within the endocarp layer – which consists mainly of highly lignified stone cells- the vessels that make up the vascular system have a distinct, ladder-like design, which is thought to help withstand bending forces. Each cell is surrounded by several lignified rings, joined together by parallel bridges. “The endocarp seems to dissipate energy via crack deflection” says Stefanie. “This means that any newly developed cracks created by the impact don’t run directly through the hard shell”. It is thought that the angle of the vascular bundles helps to “divert” the trajectory of the cracks. The longer a crack has to travel within the endocarp, the more likely it is that it will stop before it reaches the other side.
The distinct angle of the vascular bundles in the endocarp could be applied to the arrangement of textile fibres within functionally graded concrete, to enable crack deflection. “This combination of lightweight structuring with high energy dissipation capacity is of increasing interest to protect buildings against earthquakes, rock fall and other natural or manmade hazards” says Stefanie.