Crop Biotech Update

First Harmful Algal Bloom Species Genome Sequenced

February 25, 2011

Researchers at Stony Brook University's School of Marine and Atmospheric and Woods Hole Oceanographic Institution (WHOI) in USA have revealed why the microscopic phytoplankton Aureococcus anophagefferens dominates other phytoplankton in the oceans by causing brown tides. Through the new advances in genomics, they were able to identify the phytoplankton's unique gene complement that enables it to outcompete others and bloom in human-modified ecosystems. Though the plankton does not produce toxins that poison humans, the long-term bloom poisons bivalves and destroys sea grass beds and shellfisheries leading to billion dollar worth of losses.

"When we looked at the coastal ecosystems where we find Aureococcus blooms, we found they were enriched in organic matter, were very turbid and enriched in trace metals," said research leader Christopher Gobler. "And when we looked at the genome of Aureococcus, it ended up being enriched in genes to take advantage of these conditions. The surprise was the concordance between the genome and the ecosystem where it's blooming…We now know this organism is genetically predisposed to exploit certain characteristics of coastal ecosystems. We also know the characteristics are there because of activities of man," Gobler said. "If we continue to increase, for example, organic matter in coastal waters, then it's going to continue to favor brown tides since it is genetically predisposed to thrive in these conditions."

Results of their study is published in the February 21 edition of the Proceedings of the National Academy of Sciences. The research team is now investigating the RNA of Aurecoccus to know how genes are expressed during the lifetime of the bloom.

For more information, visit http://www.whoi.edu/page.do?pid=7545&tid=282&cid=90450&ct=162.