14 DAY TRIAL // Early fungi were aquatic organisms that branched off from animals, renounced the swimming flagella and evolved to spread their spores in a terrestrial ambient.
"What's particularly interesting is that species retained their flagella for different lengths of time and developed different mechanisms of spore dispersal," said David McLaughlin, professor of plant biology at the University of Minnesota in the College of Biological Sciences.
In an international effort to decode the origins of species, a complex team of 70 researchers from 35 institutions is analyzing information from six key genetic loci from 200 contemporary species to rebuild the origins of fungi and their relations with other organisms.
This ample research sheds a light into the evolution of life on Earth but will also help to understand how to encounter uses for fungi's unique properties in medicine, agriculture, conservation and industry.
Fungi play extremely important roles in nature.
Over 90% of plant species have some kind of mycorrhizal (root-fungi) relationship and are dependent upon this relationship for survival, because the fungi provide water and nutrients.
Along with bacteria, fungi are the main decomposers of dead organisms in most terrestrial ecosystems. There are about 1.5 million species of fungi estimated on the Earth, but only about 10 % are known.
People have only identified uses for very few, like yeasts to make bread, beer, wine, cheese; molders to produce antibiotics or mushrooms farming and gathering.
"Understanding the relationships among fungi provides tools to identify unknown species that may lead to new products for medicine and industry. It also helps us to manage natural areas, such as Minnesota's oak savannahs, where the fungi play important roles but are often hidden from view."
"Fungi are also intriguing because their cells are surprisingly similar to human cells," McLaughlin said.
In 1998, a genetic analysis showed that fungi split from animals about 1.538 billion years ago, whereas plants split from animals about 1.547 billion years ago.
In this case, fungi are actually more closely related to animals than to plants.
The fact that primitive fungi preserve in some stages of their life motile cells propelled by flagella (photo) is an anatomical support to their kin relation with the animals.
More, fungi are heterotrophs, like the animals (they eat organic matter already made, unlike the plants that realize photosynthesis, making organic matter from water, carbon dioxide and minerals).
But, unlike animals (we mean here primitive animal cells), fungi absorb food (animals ingest it).
And they have wall cells, like plants, even if of different chemical structure. (animal cells don't have cell walls at all). Some fungi can be harmful.
A small percent can provoke human and animal diseases, like candidiasis.
Usually, in humans, fungi provoke dermatitis but these can develop deadly in case of AIDS or cancer chemotherapy or transplantations.
A fungus, Batrachochytrium, is responsible for wiping out entire populations of amphibians around the world.
But fungi deadly to insects can be used against pest insects.
Treating fungi provoked diseases can be risky because human and fungal cells are similar and medicines that kill the fungus can harm the sick person.
Understanding more about fungi could help us find new and better ways to treat serious fungal infections in humans. Parasite fungi (like rusts and smuts) are along with the insects the most important cultural pests, so developing more efficient and environmentally friendly fungicides is a very important task.