Fungus spores use superglue.

Fungus spores use superglue 

Biologists working to understand a devastating and costly fungal infection in ripe plants, called rice blast disease, have happened upon a natural adhesive that sticks to smooth surfaces like Teflon, even underwater.

Researchers from E.I. du Pont de Nemours and Co. in Wilmington, Del., were studying how the rice blast fungus Magnaporthe grisea adhered to a rice leaf surface, which is extremely smooth and water repellent. Scientists have traditionally thought that when a fungus spore alights on a leaf, it spends several hours manufacturing a tube that pierces the leaf like a harpoon and finally anchors the spore.

But the du Pont biologists discovered that M. grisea spores have a built-in superglue that allows them to hold onto surfaces within minutes of landing. This sticky fibrous matrix, called spore tip mucilage, is originally packaged in unhydrated form within the tip of the spore, but bursts through the cell wall of the spore in the presence of water. Within 20 minutes of being deposited on a Teflon film, which mimics the surface of a rice leaf, 90 percent of the spores had attached themselves. Hours after sticking to the surface, these spores began to develop the infection structures that scientists had originally believed held the spores to the leaf.

According to the researchers, whose report appears in the Jan. 15 SCIENCE, this discovery shows that M. grisea is more complex than previous theories had predicted. Without expending any metabolic energy, the spores are able to attach themselves to a leaf, an event that is the first stage in the infection process. The discovery may help in controlling the spread of rice blast disease. And if researchers are able to learn enough about the substance and how to reproduce it, the adhesive eventually may prove useful in medicine and other areas.