2018 Summer Fungal News Update

Fungi appear in the news with surprising frequency. However, many of those stories do not provide any new information. Below is a summary of news stories that have taught me something about fungi from mid-May through Early September 2018. Read each summary to learn about: zombie ants, mushroom poisonings, White Nose Syndrome, Bananas, and more.

With the growing concern over untrustworthy news sources and the media’s tendency to inaccurately report scientific studies, can these sources be trusted? Yes they can, with a bit of caution. I have checked to make sure all the articles based on scientific papers draw from peer-reviewed journals and that they accurately reflect the content of the papers. For articles not linked to scientific papers, I try to stick to sources with a good track record in reporting on science or to local sources for region-specific information. However, I encourage you to do your own research and decide for yourself whether these sources are trustworthy.

Mushrooms Sicken 800 Iranians, Killing 11

Iran had a great year for mushrooms – plenty of rain led to a mushroom boom.  This seemed good for the mushroom-eating populace, until hundreds of people became ill.  Most of the poisonous mushrooms were sold in roadside stands and people in 10 provinces in the western part of the country became sick in separate incidents.  In all, over 800 people were poisoned, 11 died, and at least two received kidney transplants.  Many of these poisonings were probably due to amatoxin-containing mushrooms (see FFF#091), such as the Death Cap (FFF#051). Read more at: https://www.bbc.com/news/world-middle-east-44194078, https://www.theguardian.com/world/2018/may/21/toxic-mushrooms-iran-poison

Zombie Ant Fungus Evolution Driven by Climate Change

Ophiocordyceps spp. are fungi that infect ants, take control of their bodies, and force them to climb up plants before killing them and fruiting out of their heads (see FFF#006 for more).  In the final stage of infection, the fungus directs the ants to climb up a plant and either bite into a leaf or grab a stem.  Today, zombie ants in tropical regions bite leaves while in temperate areas they hug twigs.  Based on 47-million-year-old fossils of leaves from Germany, all zombie ants used to bite leaves.  When the earth’s climate cooled, the fungus was presented with a problem: leaves no longer stayed on trees year-round.  Some of the zombie ant fungi adapted to this by forcing their hosts to bite onto and hug twigs.  Temperate fungi also evolved to grow more slowly, waiting to fruit until after winter.  Read more at: https://www.wired.com/story/climate-change-made-zombie-ants-even-more-cunning/

Bat-Killing Fungus Reaches South Dakota and Wyoming

Early summer came with some bad news for North American bats.  The fungus Pseudogymnoascus destructans, which causes the deadly bat disease White Nose Syndrome (WNS, see FFF#026), was discovered in South Dakota and Wyoming.  Although no bats have been found with symptoms of WNS, this continues the fungus’s seemingly unstoppable spread westward.  Additionally, researchers in Kansas found the fungus causing disease in a new bat species: the Cave Myotis Bat, Myotis velifer.  Read more at: https://blogs.scientificamerican.com/extinction-countdown/bat-killing-fungus-spreads-to-2-new-species-and-2-new-states/

Pollution Killing Europe’s Mycorrhizas

Mycorrhizal fungi are critical for the health of trees (see FFF#073), but because of their elusive nature they are difficult to study in the environment.  In a ten-year study headed by Imperial College London and Kew Gardens, researchers studied forest health and correlated that to the soil community.  This research indicated that pollution in the soil was changing the mycorrhizal makeup of forests, allowing fungi that take more than they give to dominate mycorrhizas.  The study authors suggested that Europe could alleviate this problem by reducing current levels of pollution – perhaps by as much as half.  Read more at: https://phys.org/news/2018-06-pollution-fungi-nourish-european-trees.html

Cordyceps spp. Help Asian Cicadas Survive

It’s hard being a cicada.  As larvae, the insects feed on plant sap that is low in nutrients.  Cicadas cannot get all their required nutrients from their diet, so they supplement it with chemicals produced by bacteria living inside their bodies.  Most cicadas need species of both Sulcia and Hodgkinia in order to survive.  However, some Japanese cicadas were discovered that lacked Hodgkinia.  That surprising result led to an even more astounding discovery: in these cicadas, Hodgkinia had been replaced by a species of Ophiocordyceps!  Ophiocordyceps is a notorious fungal insect pathogen, most famous for turning ants into zombies (see FFF#006).  Somehow, these cicadas had taken one of their worst enemies and turned it into a life support system.  Apparently, this unusual scenario evolved in response to a breakdown in the cicada’s relationship with Hodgkinia.  Hodgkinia doesn’t reproduce very well, and sometimes the daughter cells won’t receive all necessary DNA.  This can be fatal to the cicadas if the wrong piece of DNA is lost.  In this case, the cicadas made up for the loss by domesticating Ophiocordyceps.  Read more at: https://www.theatlantic.com/science/archive/2018/06/how-to-tame-a-zombie-fungus/562544/

The Madagascan Banana and the Race to Save the Cavendish

Bananas are threatened by a variety of diseases, perhaps most significantly by Panama Disease (FFF#107).  One of the most promising ways to protect bananas from disease is by increasing the genetic diversity in the grocery store banana, known as the Cavendish banana.  To do this, researchers are trying to identify useful genes in wild bananas and their relatives.  One of those bananas – the Madagascan banana, Ensete perrieri – seems promising because it is not known to contract Panama Disease.  Unfortunately, there are only five mature trees left in the wild.  Researchers are concerned that if this and other species go extinct in the wild, they will lose valuable genes that could be used in the fight against Panama Disease.  Read more at: https://www.bbc.com/news/science-environment-44712034

Cicada Fungus Alters Insect Behavior Using Psychotropic Drugs

Periodical cicadas, which live as larvae for 13 or 17 years before emerging all at once, have one specialized pathogen: the fungus Massospora cicadina (FFF#221).  The fungus attacks adult periodical cicadas and replaces their abdomens with masses of spores.  The cicadas then fly around and spread their spores through the air and through mating attempts.  M. cicadina subtly alters the behavior of its victims to promote mating attempts – even though the insects are missing their abdomens.  One way the fungus does this is by giving the cicada a dose of psychedelic drugs, including psilocybin (the hallucinogenic compound in “magic mushrooms,” see FFF#098) and cathinone (an amphetamine).   Read more at: https://www.theatlantic.com/science/archive/2018/07/massospora-parasite-drugs-its-hosts/566324/

‘Ōhi’a Trees Likely to Survive Fungus

The ‘ōhi’a tree is one of the most iconic trees in Hawaii.  Recently, the ‘ōhi’a has come under attack from Rapid ‘Ōhi’a Death, a diseased caused by two fungi.  However, researchers are hopeful that even without intervention ‘ōhi’a will survive the fungal onslaught.  One reason is that not all trees are equally susceptible to the fungus.  Certain trees survive infection, suggesting that there is inherent genetic variation that will allow ‘ōhi’a to adapt to the new disease.  The disease’s progression has also slowed recently, although the reasons for this are not clear.  Researchers understand a little better how the fungus spreads.  ‘Ōhi’a trees behind fences seem to be less susceptible, possibly because they are less exposed to animals.  Animals cause damage to the trees, which helps spread infection.  Another reason for hope is the Kilauea volcano.  ‘Ōhi’a is the first tree to colonize lava fields, and Kilauea is creating lots of new lava fields.  In older forests, ‘ōhi’a would have a difficult time re-establishing itself because of faster-growing tree species.  On lava fields, however, ‘ōhi’a has no competition; this will ensure the trees have the opportunity to dominate new forests and will make its recovery easier.  Additionally, a $70,000 prize was established as The Ohia Challenge to encourage teams of people to come up with a practical solution to Rapid ‘Ōhi’a Death.  Read more at: http://www.sciencemag.org/news/2018/08/fears-lessen-invasive-fungi-will-completely-wipe-out-hawaiis-iconic-native-tree and http://www.hawaiitribune-herald.com/2018/08/16/hawaii-news/challenge-offers-70k-prize-for-finding-solutions-to-save-the-ohia/

Key Fungal Cell Development Gene Discovered

The cellular components of certain fungi are well-studied.  Baker’s Yeast (Saccharomyces cerevisiae), for example, was used as a model organism to work out the processes involved in the cell cycle.  Recently, researchers from Ruhr-Universität Bochum and Georg-August-Universität Göttingen described the role of the gene KIN3 in coordinating certain developmental pathways.  In the fungus Sordaria macrospora (and likely others), KIN3 controls multiple pathways involved in cell development.  Without a functioning KIN3 gene, cells develop incorrectly and cannot form cross-walls.  Additionally, cells without a KIN3 gene could not develop into sexual cells.  These impacts appear to be the result of improper distribution of proteins in the cells, suggesting that KIN3 plays an important role in regulating protein distribution.  KIN3 or similar genes are found in all organisms with a nucleus, including humans.  The human version of KIN3 probably plays a similar role, so understanding how this fungal gene works could lead to new treatments for a variety of diseases, including certain cancers.  Read more at: https://www.sciencedaily.com/releases/2018/09/180904114647.htm

Other News Stories

Some recent news stories have not provided any new information, but are still good summaries of ongoing fungus-related issues.

This story from the Washington Post describes how researchers are trying to gather more information about how White Nose Syndrome affects different species of bats: https://www.washingtonpost.com/local/a-mysterious-disease-is-killing-millions-of-bats-these-scientists-are-trying-to-save-them/2018/07/12/bc76a2fa-8524-11e8-9b24-29df1293d810_story.html

Psilocybin and other hallucinogens have been popping up in news stories regularly because of ongoing but slow research on treating mental diseases.  A recent one from the BBC broadly summarized how researchers are considering hallucinogens as solutions to a variety of mental health issues: https://www.bbc.com/news/health-44575139