Seaweed Surprise: Marine Plant Uses Chemical Warfare to Fight Microbes

The finding helps explain why some seaweeds, sponges and corals appear to avoid most infections by fungi and bacteria, according to a study published May 19 in the Proceedings of the National Academy of Sciences.

"Seaweeds live in constant contact with potentially dangerous microbes, and they have apparently evolved a chemical defense to help resist disease," said lead author Julia Kubanek, an assistant professor of biology and chemistry at the Georgia Institute of Technology in Atlanta. "These plants have a really effective way of defending themselves."

Few studies have addressed disease resistance in seaweeds, and seaweed diseases are little understood, except for species that are commercially important - for example, the seaweed used for sushi. This study's report of isolating a potent antifungal compound contained in the common seaweed species Lobophora variegata reveals an unusual chemical structure not seen before in plants.

And the study lends insight into the ecological interactions between this seaweed species and other marine organisms, Kubanek said. Also, it presents the possibility of biomedical applications for the newly discovered antifungal compound, she added.

The research - funded in part by the National Science Foundation - was conducted in collaboration with colleagues Paul Jensen and William Fenical at the Scripps Institution of Oceanography in San Diego, Calif., Paul Keifer of Varian Inc. in Palo Alto, Calif., and researchers M. Cameron Sullards and Dwight Collins of Georgia Tech.