fungus

Hope for amphibians

May 6, 2024 By EarthWise Leave a Comment

There are more than 7,000 known species of amphibians, the group of animals that includes frogs, toads, and salamanders. Over the past 25 years, more than 90 species are believed to have gone extinct and at least 500 more have declining populations.

There are many factors contributing to the decline of amphibian populations but the most alarming is a fungus called Batrachochytrium dendrobatidis – or Bd – that ravages the skin of frogs and toads and eventually causes heart failure. The fungus has been devastating amphibians on nearly every continent.

In a recent paper in the journal Current Biology, scientists at the University of California Riverside documented the discovery of a virus that infects Bd and could be engineered to control the fungal disease.

The researchers were studying the population genetics of the Bd fungus with DNA sequencing technology and uncovered the virus inside the fungal genome. Some strains of the fungus are infected with the virus and others are not. They are now looking for insights into the ways that the virus operates to see how it gets into the fungal cells. The goal is to engineer the virus to infect more strains of the fungus and potentially end the global amphibian pandemic.

Frogs and toads control bad insects, crop pests, and mosquitos. If their populations around the world collapse, it could be devastating. They are already having difficulty coping with warmer temperatures, stronger UV light, and worsening water quality in many places.

Some amphibian species are already acquiring resistance to Bd. The UCR researchers are hoping to assist nature in taking its course.

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Discovery could end global amphibian pandemic

Photo, posted August 25, 2010, courtesy of Kev Chapman via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Fungus And Carbon Storage | Earth Wise

July 26, 2023 By EarthWise Leave a Comment

It is well-known that plants and trees store enormous amounts of carbon. What has not been common knowledge is that the vast underground network of fungi across the world’s lands stores billions of tons carbon, roughly equivalent to 36% of yearly global fossil fuel emissions.

These mycorrhizal fungi form symbiotic relationships with almost all land plants. The fungi transport carbon, converted by sugars and fats by plants, into soil. They have been supporting life on land for at least 450 million years and form sprawling underground networks everywhere – even beneath roads, gardens, and houses – on every continent on earth.

An international team of scientists analyzed hundreds of studies looking at plant-soil processes to understand how much carbon is being stored by fungi on a global scale. The findings, published in the journal Current Biology, revealed that over 13 billion tons of CO2 is transferred from plants to fungi each year, more than China emits annually. This process transforms the soil beneath our feet to a massive carbon pool and constitutes the most effective carbon storage activity in the world.

Given that fungi have such a crucial role in mitigating carbon emissions, the researchers are recommending that fungi should be considered in biodiversity and conservation policies. More needs to be done in protecting the underground networks of mycorrhizal fungi. The UN has warned that human activities are degrading soils and that 90% of the world’s soils could be degraded by 2050. Not only would this obviously be very bad for the productivity of crops and plants, but we now know this could be catastrophic for curbing climate change and rising temperatures.

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Fungi stores a third of carbon from fossil fuel emissions and could be essential to reaching net zero

Photo, posted May 28, 2023, courtesy of Geoff McKay via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Plastic Eating Fungus | Earth Wise

May 26, 2023 By EarthWise Leave a Comment

More than five billion tons of plastic have accumulated on land and sea including the most remote regions of the planet as well as in the bodies of animals and humans. There is a compelling need to recycle as much plastic as possible but doing so is a major challenge. Plastic comes in many varieties and breaking it down for reuse requires different methods for each.

Polypropylene is one of the biggest challenges for recycling. It is a very common plastic used for all sorts of products including food containers, coat hangers, plastic wrap, toys, and much more. It accounts for roughly 28% of the world’s plastic waste, but only 1% of it is recycled.

Polypropylene is seldom recycled because it generally has a short life as a packaging material, and it often becomes contaminated by other materials and plastics. Thus, it generally ends up in landfills.

Researchers at the University of Sydney in Australia have discovered that two common strains of fungi were able to successfully biodegrade polypropylene. The fungi species – with unavoidable Latin names of Aspergillus terreus and Engyodontium album – are typically found in soil and plants.

The researchers found that the fungi were able to break down polypropylene after it had been pre-treated with either UV light or heat, by 21% over 30 days, and by 25-27% over 90 days. This seems rather slow but compared with the nearly endless life of polypropylene in landfills, it is a major improvement.

The hope is that methods like this could ultimately reduce the amount of plastic polluting the environment by encouraging plastic to biodegrade naturally under the appropriate conditions.

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Fungi makes meal of hard to recycle plastic

Photo, posted March 5, 2010, courtesy of Kevin Krejci via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

A Growing Threat To Wheat | Earth Wise

January 27, 2023 By EarthWise Leave a Comment

Wheat is one of the most widely-grown crops in the world and plays a major role in human nutrition. In fact, wheat contributes approximately 20% of the protein and 20% of the calories consumed by humans globally. It is grown on every continent except Antarctica.

But wheat is under growing attacks from harmful toxins. According to a new study by researchers from the University of Bath and the University of Exeter in the U.K., almost half of wheat crops across Europe are impacted by the fungal infection that gives rise to mycotoxins.

Mycotoxins are naturally occurring toxins produced by the fungus that causes Fusarium Head Blight. Fusarium Head Blight is a disease that affects wheat and other grains growing in the field. Eating products contaminated with mycotoxins can cause sickness in humans and livestock, including vomiting and other gastrointestinal problems.

In the study, the research team examined 10 years of government and agribusiness data, which tracked Fusarium mycotoxins in wheat entering the food and animal supply chains across Europe and the U.K. Half of the wheat intended for human food in Europe contained the Fusarium mycotoxin. In the UK, 70% of wheat was contaminated.

Governments set legal limits on mycotoxin contamination levels in wheat that is to be consumed by humans. But with the ubiquitous nature of these mycotoxins, the effect of constant, low-level exposure in the diet over the course of a lifetime is not known.

With climate change and the war in Ukraine already impacting both wheat yield and price, preventing toxin contamination is critical to help maintain a stable crop price and to protect global good security.

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Harmful fungal toxins in wheat: a growing threat across Europe

Photo, posted July 11, 2011, courtesy of Maria Keays via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Fighting Disease in Cavendish Bananas | Earth Wise

January 31, 2022 By EarthWise Leave a Comment

Cavendish bananas account for about half of global banana production and the vast majority of bananas entering international trade. The plant is unable to reproduce sexually and instead is propagated via identical clones. So, the genetic diversity of the Cavendish banana is exceedingly low.

In 2008, Cavendish cultivars in Sumatra and Malaysia started to be attacked by Panama disease, a wilting disease caused by a fungus. In 2019, Panama disease was discovered on banana farms in the coastal Caribbean region, its first occurrence in the Americas. In the 1950s, Panama disease wiped out the Gros Michel banana, the commercial predecessor of the Cavendish.

Scientists at the University of Cambridge have found a novel way to combine two species of grass-like plants – which include bananas, rice, and wheat – using embryonic tissue from their seeds. The technique allows beneficial characteristics, such as disease resistance, to be added to the plants.

Joining the shoot of one plant to the root of another to grow as one plant is known as grafting. It was thought to be impossible to do with grass-like plants – called monocotyledonous grasses – because they lack a certain tissue type in their stems. But the new research, published in the journal Nature, showed it can be done with the plants in their earliest embryonic stages.

Cavendish bananas are sterile, so disease resistance can’t be bred into future generations. But the grafting technique may provide a way to produce Cavendish banana plants that are resistant to Panama disease. It may be possible to save an important food crop before it is too late.

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New grafting technique could combat the disease threatening Cavendish bananas

Photo, posted July 1, 2015, courtesy of Augustus Binu via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Bananas In Danger

October 8, 2019 By EarthWise Leave a Comment

For a few years we have been talking about the precarious position of the global banana crop, which is almost entirely based upon a single cloned cultivar known as the Cavendish banana. The banana you buy in Rome is identical to the one in Rochester. And therein lies the danger: if a fungal blight can kill one banana shrub, it can kill them all.

For decades, a fungal disease known as Panama Disease Tropical Race 4 has been wreaking havoc on banana plantations in the Eastern Hemisphere. Even though it was first identified in Taiwanese soil samples in the early 1990s, the destructive fungus remained confined to Southeast Asia and Australia until it was confirmed in both the Middle East and Africa in 2013. Experts continued to fear its eventual appearance in Latin America, which is the epicenter of the global banana export industry.

In August, Colombian agricultural authorities announced that laboratory tests have positively identified the presence of Tropical Race 4 in the Caribbean coastal region and declared a national state of emergency.

The infection of the banana plant does not produce bananas that are unsafe for humans. What happens is that the infected plants eventually stop bearing fruit.

Cavendish bananas are a prime example of the dangers of growing crops with limited genetic diversity – known as monoculture. It leaves food systems dangerously vulnerable to disease epidemics.

This has happened to the global banana crop before when the predecessor to the Cavendish banana – the Gros Michel – was mostly eradicated by another fungal outbreak. At the moment, there is no ready replacement banana to bail out the industry, but scientists are desperately trying to breed one. In the meantime, the world’s supply of bananas is in real danger.

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The banana is one step closer to disappearing

Photo, posted July 9, 2009, courtesy of Dabin Lambert via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Frogs Are In Big Trouble

May 22, 2019 By EarthWise Leave a Comment

Scientists first noticed in the 1970s that some frog populations were declining rapidly. By the 1980s, some species appeared to be extinct. The loss of frog species was mysterious because many were actually living in pristine habitats that did not face pollution or deforestation.

By the late 1990s, researchers had identified that frogs in widely different places around the world were infected with a deadly fungus called Batrachochytrium dendrobatidis – or Bd for short. The fungus originated on the Korean peninsula, but the pathogen spread throughout the world, probably via the international trade in pet amphibians. By 2007, researchers speculated that Bd might be responsible for all known declines of frogs that had no other apparent cause – about 200 species.

Recently, a group of 41 scientists published the first worldwide analysis of the fungal outbreak and the devastation turns out to be far worse than anyone had previously realized. Populations of more than 500 species of amphibians have declined significantly because of the outbreak, including at least 90 species presumed to have gone extinct. These figures are more than twice as large as earlier estimates.

According to biologists, Bd is now considered to be the deadliest pathogen known to science. But the decimation of frogs peaked in the 1980s. Today, although 39% of the species that suffered population declines in the past are still declining, 12% are showing signs of recovery, possibly because natural selection is favoring resistant animals.

There is cautious optimism for the surviving amphibian species, but scientists worry that another strain of Bd or some different species of fungus altogether may prove even deadlier. The best we can do is not participate in moving pathogens around the world.

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The Plague Killing Frogs Everywhere Is Far Worse Than Scientists Thought

Photo, posted June 19, 2010, courtesy of Chris Luczkow via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Coffee And Climate Change

November 16, 2015 By WAMC WEB

Climate change is threatening crops all around the world, but maybe none more so than coffee. According to the Union of Concerned Scientists, “higher temperatures, long droughts punctuated by intense rainfall, more resilient pests and plant diseases—all of which are associated with climate change—have reduced coffee supplies dramatically in recent years.”