Zymoseptoria pseudotritici, a pathogenic fungus that damages wheat crops, is a good example. This recent hybrid resulted directly from the coupling of two genetically distinct, nonpathogenic fungi that had been brought into contact through human trade and agricultural practices. The offspring, unlike its parents, is a killer.
"If there is some new environmental condition in which they can't thrive, some fungi change their reproductive strategy and they reproduce sexually. Fungal sex is far more common than we ever thought. In terms of sheer numbers, they're among the most successful organisms on the planet," Fisher says.
One of the most sinister weapons in fungi's survival arsenal is its ability to hide in any life-form that is being shipped from one country to another—and then to wait out poor conditions. For instance, Phytophthora ramorum, the funguslike oomycete that has caused the die-off of native oak trees in California and Oregon in the past decade, probably hitched a ride on a non-susceptible host in Asia, mostly likely a rhododendron, through the ornamental plant trade. "There were no warning bells for this disease," says Matteo Garbelotto, extension specialist at the Department of Environmental Science, Policy and Management at the University of California, Berkeley. Once the fungus arrived on the California coast, the warm weather and intermittent rainfall enabled it to move easily among hosts. "What we think happened was the pathogen moved from the rhododendron to the California bay laurel, where it can lay dormant for years. There is no direct oak-to-oak transmission," Garbelotto says.
When environmental conditions aren't perfect, phytopthora bides its time. "In dry years, they don't propagate," Garbelotto says. "Phytophthora is a zoospore, which means it goes through a swimming phase during its life cycle. If it's dry or the temperature is low, there is no outbreak. But when the conditions are right, an epidemic can go from nonexistent to affecting innumerable trees within a few weeks."
Not all fungi are bad—far from it. Without fungi we wouldn't have Penicillium which ages blue cheese, rots oranges and from which the antibiotic drug penicillin was extracted. "Without fungi, life on Earth would look very different," Fisher adds. "Forests themselves depend on fungi for their survival." Mycorrhizal, or symbiont fungi, have evolved mutualistically with plant-root vascular systems. They transfer nitrogen and phosphorus from the soil to the plant roots through these associations.
Fungi are among evolution's most successful organisms. Yet it took only a few generations for some of nature's most awe-inspiring assets to become some of its most fearsome liabilities for other species on the planet.
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Add CommentThe article deserves more distribution and longer length.
Reply | Report Abuse | Link to thisAmong the phytophthera species are others unmentioned:
cinnamomi, which was introduced to North American avocado trees, and kills about 100% when the roots are inundated in soils which do not dry. In those which do dry, the killing is slowed.
P lateralis was first noticed far north of Port Orford Cedar country, in Seattle. It was spread, a Cal State Humboldt group, discovered by the mud adhering to boots and equipment of loggers, and wastefully, by the spread of offroad vehicles, in National Forests. The method of discovery of human broadcast is interesting, in that developing disease was shown to begin high in a watershed wherever an access road was available, and spread down from there. Since Port Orford Cedar was overexploited, largely for cosmetic and superstitious use (another story), it was already in danger of extinction. With ORV use that extinction is becoming more likely. For this species, some good news: considerable USDA Forest Service surveying has found some individuals with strong resistance, and hopes to interbreed.
BTW, animals are more closely related to fungi than we are to plants; and mycorrhizae have been found to be even more pervasive and important to the life of vascular plants, and thus to all living things, than the short article above implies.
I believe the use of fungicide in agriculture contributes to fungi evolution as well. I live next door to a flower farmer who blows fungicide on his myrtle plants several times per week. It seems to me that fungus would have the ability to evolve resistance to fungicide just as bacteria evolve resistant to antibiotics. Who knows what other characteristics this fungus evolution caused by humans will bring.
Reply | Report Abuse | Link to thisTo what extent these problems arise from the fact that urban areas may be are growing too much? In other words: Are habitats of these species shrinking to the point that they can not longer survive? I do not think so. But if that is the case steps should be taken to provide them with enough quality breathing space. I have the sense that if they begin to die, we also begin to die. But frankly I do not think they are dying out. Probably it is just normal that snakes, and other species, get sick from time to time. But it is very valuable the studies that are been carried out.
Reply | Report Abuse | Link to thisHello,
Reply | Report Abuse | Link to thisGood article and some interesting claims like funghi evolution explosion as result of wars and globaltization in logistics. Could be the solution to raise attendance of blue-green algae in our daily life?
Like building enormous pools on the level of urban cities - dispersed on several places of the city, towns, states? Than in daily life of each individual?
Than for example along the logistic paths like railways to have long and narrow pools with blue gree algaes ...
What economic model should we provide on level of the town or landscapes to sense added value in daily life and this way more blue-green is our daily life.
Who should invest? Mostly those who had benefit in previous years on environment as it was and this way also agreed with the funghinization of the world. Raise of funghi populations s probably response of the nature to our consiousness. So if we do the step probably I can turn to another path. Funghi would still be needed for decay processes but it seems we are now in need for blue-green and photosintetic process to be motivated. How to make this as good investment accessible to all? How to raise consiousness of people with money in big accounts and politicians that only them have first step in the pocket for de-funghization of the towns and rural desserted areas with blue-gree.
What if the fungus ISN'T pathogenic, but is just responding to issues within the ecological system? In nature, fungus deals with death and decay. It breaks down matter into reusable substances. That in itself is not pathogenic, but responsive.
Reply | Report Abuse | Link to thisWhat if the fungus is reacting to decay within the system due to other factors such as toxins within the environment - the air, the water, the soil, the depletion of nutritional elements within the food, or substances that are altering the nutritional elements and preventing absorption and support?
Thinking outside the box, what if the germ 'theory' is wrong? Doesn't that throw everything that we currently believe to be true out of the window? If all germs and microbes are reactive rather than pathogenic, doesn't that open up a whole new ball-game?
I was riddled with fungus - a veritable walking 'fungus-factory', but having reshaped my diet to remove anything that isn't nutritionally complete, and added supplements to make up any shortfall, the fungus is history.
We live in a nutritionally devoid world. We live in world where our food - and the food of many other species too - has been meddled with and maladjusted to the point of no return. We are sick and slowly and insidiously decaying from the inside out because our bodies lack the nutritional support needed to cope with the onslaught of modern living.
Toxic chemicals, drugs, food additives, denatured foods, air and water pollution, etc., are all undermining our health, and the health of the system around us. Natural beings were made to consume natural foods and substances. Remove or change even one element and it is no longer complete.
We as humans may have the knowledge and understanding to be able to combat the problem to a certain extent, but animals do not have that capacity and are then at the mercy of the toxic environment. Whole forests of trees are dying. Why? Because something in the air or water or soil is damaging them.
It's no good 'fighting' the fungus. Prevention is always far better than 'cure'. The only way to deal with the fungus is to STOP the rot. And the only way to stop the rot is to peel back the layers to the root cause - the toxic environment we all live in.