Endosymbiont aids pathogenic fungi

Laila Partida-Martinez and Christian Hertweck of the Leibniz Institute for Natural Products Research and Infection Biology, Jena, Germany, demonstrated that rhizoxin, a plant-rotting toxin believed to come from pathogenic fungi in the genus Rhizopus is in fact synthesized by an endosymbiotic bacterium.1 They posit that the relationship confers a metabolic benefit to both to bacteria and its fungal host, giving each access to nutrients released by decaying plant material after infection.

Microbiologist June Kwon-Chung of the National Institute of Allergy and Infectious Diseases says that this is the first example in fungi of a toxin-producing bacterial symbiont.

?We know that virus existing within fungi can sometimes act to help the fungus become more or less virulent, but bacterial toxins helping fungi to invade the host is very rare and new. So it opened my eyes. What if deadly diseases in humans caused by Zygomycetes, the fungal phylum that includes...