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  • [♪ INTRO]

  • There's more to mushrooms than the cute button varieties you find at your local grocery store.

  • The wordfungusdescribes a whole kingdom of organisms that are neither plant nor animal.

  • It includes chanterelles and shiitakes, but also molds and yeasts.

  • Mushrooms are the part of the fungus that spreads its spores in order to reproduce.

  • And there are some really strange examples of fungi and their fruiting bodies out there.

  • They're not just interesting looking, either.

  • Some have the power to trick animals into caring for them, or even clean up radiation.

  • So here are six weird mushrooms and other fungi,

  • and what sets them apart from regular garden fare.

  • The first fungus on our list has a pretty clever survival technique.

  • The genus Fibularhizoctonia, also known as the cuckoo fungus,

  • hides itself in piles of termite eggs by mimicking their size and color.

  • Its little round balls aren't technically mushrooms.

  • They're actually the fungus's sclerotia form.

  • That's a resting state that will eventually sprout a new colony when conditions are right.

  • By making itself look like termite eggs, the fungus ensures it's safe until it's time to sprout.

  • See, termites will pile all their eggs together in one place and groom and lick them

  • to protect them from dryness and infection.

  • By hiding in the heap, the fungal termite balls get the same protection.

  • But it's not just a matter of looking like a termite egg.

  • The cuckoo fungus smells like them too.

  • To blend in, the fungi make an enzyme called beta-glucosidase.

  • This same enzyme is made by termite eggs to help adults recognize them.

  • And in an experiment from 2000,

  • termites didn't care for glass beads resembling termite eggs

  • unless they were coated in egg-recognition chemicals.

  • Researchers have found that multiple species of fungus

  • can all hide away in the same termite mound;

  • all it takes is looking and smelling similar enough.

  • There's just one catch to all this protection:

  • the fungal balls can't sprout with worker termites around.

  • Researchers think that maybe the termite's saliva keeps them from growing somehow.

  • When the termites run out of food and relocate to a new colony,

  • they carry their own eggs,and the fungus, with them.

  • And then the fungus can sprout.

  • It's a handy way for the fungus to hitch a ride

  • and set up camp in a brand new location before its competitors get there.

  • This next fungus on the list sounds and looks positively frightening.

  • But it turns out, all its weirdness is just a mushroom living its life.

  • The bleeding tooth fungus gets its name in part

  • from the teeth-shaped structures on its underside.

  • In fact, all members of the hydnoid family of fungi have these structures,

  • not just the bleeding tooth.

  • Most mushrooms use gills or pores to release their spores.

  • You can easily spot the gills if you flip over a portobello.

  • But hydnoids use teeth instead. And the bleeding part?

  • That dark red liquid oozing from the mushroom's top

  • is actually because of the fungus's internal transportation system.

  • See, fungi transport nutrients and water up from the soil through root-like structures called hyphae.

  • Under the right conditions, pressure can build up in the hyphae

  • and push fluid up and out of the pores on the mushroom's surface.

  • Although there haven't been any studies to figure out exactly why the fluid is red,

  • one fungi expert we asked thinks the mushroom might add red pigments

  • to attract insects that help spread its spores;

  • the same insects that are also attracted to red flowers.

  • Not creepy and bleeding at all!

  • One of the other cool things about these fungi

  • is how they get their nutrients in the first place.

  • Bleeding tooth fungi are mycorrhizal,

  • meaning they form symbiotic relationships with trees like pine or spruce.

  • The fungi get carbohydrates from the trees and, in return,

  • they give the tree nitrogen and phosphorus.

  • And you could say it's quite an intimate relationship.

  • The fungus's hyphae grow as a layer on the outside of the tree's root tips,

  • actually growing in between the tree's cells,

  • so they can easily hand nutrients back and forth with one another.

  • I'm not sure I'd be comfortable with having a gruesome-looking fungus latched on to me.

  • But it seems to work out just fine for the trees!

  • When you think of a wild mushroom, chances are you picture something like the Fly Agaric.

  • And I know we're supposed to be talking about weird mushrooms, but stick with me.

  • This iconic mushroom is depicted in everything from

  • Germanic Christmas decorations to Super Mario.

  • But its recognizability has as much to do with its chemistry as it does aesthetics.

  • See, the Fly Agaric's name may not actually refer to insects.

  • Instead, it may be related to an older usage of the word 'fly',

  • which could refer to madness or possession.

  • That's because the world's prettiest, most stereotypical mushroom has hallucinogenic properties.

  • But they're also kind of toxic, so just in case we have to say it, don't.

  • There are accounts dating back to at least the 18th century, and perhaps much earlier,

  • of European and Asian peoples using the mushrooms in religious rituals.

  • If ingested, the mushrooms cause confusion, dizziness, space distortion,

  • unawareness of time and hallucinations, followed by drowsiness and fatigue.

  • The two main compounds responsible are muscimol and ibotenic acid.

  • They have a chemical structure that's really similar to the neurotransmitter GABA.

  • And they act in kind of the same way

  • to make neurons in the spinal cord and brain less likely to fire.

  • Which has kind of a calming effect.

  • But they also explain the mushroom's psychedelic effects.

  • Muscimol and ibotenic acid trigger the release of additional neurotransmitters

  • dopamine and serotonin, which give those happy feelings.

  • At least that's what the mice studies have shown.

  • The funny thing is, these mushrooms are actually trying not to be eaten.

  • Their distinctive red and white color is a warning to animals that, hey, I'm toxic!

  • Seems one creature's warning system is another's video game powerup.

  • This next group of fungi have earned the nickname 'Hulk bugs'.

  • That's because they seem to have the ability to absorb radiation.

  • These superhero fungi have been found in areas with some seriously high levels of radiation,

  • like inside the damaged nuclear reactor at Chernobyl

  • and even hanging out on the outsides of spacecraft.

  • Some fungi on the outskirts of Chernobyl even grow towards the source of radiation.

  • Hence their name, radiotropic fungi;

  • tropism being a term for when an organism turns towards a particular stimulus.

  • But radiation is nasty stuff for most living things, given its ability to shred DNA.

  • So how can these fungi tolerate it?

  • Some fungi, like black yeast, can protect themselves by using the radiation

  • to activate particular genes related to DNA repair and defense.

  • These fungi seem to have a sensor for detecting UV light, which can also cause DNA damage.

  • And that sensor may be picking up radiation and turning on DNA repair.

  • And they don't just absorb it and cope.

  • The radiation actually helps some fungi grow stronger.

  • For example, when black yeast was exposed to low doses of radiation

  • over 24 hours in the lab, it grew 30 percent more cells,

  • and those cells were larger than the ones that hadn't been exposed to radiation.

  • And the single-celled fungus Cryptococcus neoformans grew faster

  • when exposed to high levels of gamma radiation in the lab.

  • Scientists think this might have to do with melanin in the fungi's cell walls.

  • Yes, the same pigment that gives our skin its color.

  • They think melanin might be acting in a similar way to other biological pigments

  • like chlorophyll to turn radiation into usable energy.

  • When researchers exposed fungi containing melanin to gamma rays,

  • they found an increase in cellular energy production.

  • But not all fungi found in radioactive areas have melanin,

  • so there may be something else going on that we don't understand yet.

  • And it would be a good thing to investigate,

  • since some radiotropic fungi may have the ability to

  • decompose and decontaminate radioactive material,

  • meaning they could be used for environmental cleanups.

  • Two fungi are doing just that with the debris at Chernobyl.

  • But scientists don't yet whether the fungi retain the radioactive particles

  • or spit them back out into the environment somehow,

  • which is to say, more research is needed to see if they can truly decontaminate radiation.

  • Still, maybe we should rename them Captain Planet bugs?

  • Speaking of names, you can learn a lot about the fungi in this next group

  • from both their scientific and common names.

  • Their family name, Phallaceae, alludes to these fungus's distinctive shape.

  • But that's not the whole story.

  • These mushrooms actually come in a wide variety of forms,

  • from geometric, to alien looking, to something quite beautiful.

  • Scientists aren't exactly sure why these fungi take so many different shapes,

  • but some have speculated that it might increase the mushrooms' surface area

  • to help spread their spores.

  • That's where this family's other name comes in: Stinkhorn fungi.

  • They secrete a foul-smelling slime that reeks of rotting flesh

  • thanks to a chemical called dimethyl trisulfide.

  • The same chemical is given off by necrotic wounds.

  • This attracts flies that gobble up the slime, as well as a bunch of spores.

  • The flies then spread those spores to another location when they poop,

  • helping the mushrooms reproduce.

  • And it's not just flies that are interested in this mushroom as a snack.

  • Despite its horrid odor, pickled stinkhorn eggs are a delicacy in China and Europe.

  • One species, the bridal veil stinkhorn, is dried and eaten on special occasions in China.

  • Once dried they apparently smell more earthy, musty or almondy than putrid,

  • and when cooked have a nice umami flavor.

  • So, don't judge a mushroom by its smell I guess?

  • Lion's Mane sounds like something you might add to a potion. And it kind of is.

  • This fluffy, white mushroom is edible;

  • it's said to have a fleshy texture and seafood-like taste.

  • It's been used in Chinese medicine for centuries as an antimicrobial,

  • antioxidant and anti-aging supplement.

  • Claims abound in support of the beneficial properties of the various chemicals

  • found within lion's mane mushrooms.

  • And there seems to be some evidence to support these claims.

  • One group of compounds, the hericerins, slows the growth of cancer cells.

  • Another, belonging to a class of chemicals called polysaccharides,

  • stimulates immune responses by activating the body's defensive cells.

  • And in a double blind study from 2008,

  • elderly people who took tablets containing the dry mushroom powder scored better

  • on a test of cognitive function after 16 weeks than those who received a placebo.

  • But before you start stockpiling Lion's Mane, you should know there are a few snags.

  • For one, a lot of these studies were done in vitro,

  • that is, with a culture dish of cells rather than an actual person.

  • And others were done on rodents.

  • There's a big difference between rodents and people,

  • and between cells and full-blown human bodies,

  • so the effects probably aren't as staggering as some people might have you believe.

  • Still, if there's a silver lining, it's that this mushroom still tastes pretty good.

  • These magnificent mushrooms and fancy fungi all stand out for different reasons,

  • but it goes to show that there's a lot more going on than what's in your backyard.

  • Unless there's stinkhorns in your backyard.

  • Those things smell terrible. I'm so sorry.

  • Thanks for watching this episode of SciShow.

  • If this list piqued your interest,

  • there's a whole episode of our spin-off podcast SciShow Tangents about the fungus among us.

  • And that's just one of the lightly competitive, science poem-filled topics on offer.

  • It's brought to you by the same super smart people who make SciShow,

  • as well as Complexly and WNYC Studios.

  • Check it out wherever you find podcasts.

  • [♪ OUTRO]

[♪ INTRO]

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6つの変なキノコ(その他の菌類も (6 Weird Mushrooms (And Other Fungi))

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    林宜悉 に公開 2021 年 01 月 14 日
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