According to research to be published in the journal eLife, the Great Famine was caused by a previously unidentified strain of the fungus-like pathogen Phytophthora infestans. Scientists have long known that this pathogen caused the famine, but the events in Ireland had previously been linked to a strain of the pathogen called US-1.
A research team led by Sainsbury Laboratory in the U.K. wanted to know if that was true. They extracted DNA from several museum samples collected in the 1840s — potato plant leaves that contained traces of the blight — and compared them to modern-day strains of the pathogen. They found that it was not US-1 and was, in fact, something new. "This strain was different from all the modern strains that we analyzed — most likely it is new to science," Sainsbury Laboratory's Sophien Kamoun told BBC News. They have dubbed the strain HERB-1.
Kamoun said the research revealed something else: the HERB-1 blight may no longer exist. "We can't be sure, but most likely it's gone extinct," he said.
The researchers say HERB-1 likely originated in Mexico, which supports long-held suppositions. Their genetic tests found that it was similar to US-1, which is still found around the world. As they wrote in the abstract to their paper, "HERB-1 is distinct from all examined modern strains, but it is a close relative of US-1, which replaced it outside of Mexico in the 20th century."
HERB-1 may have only existed on Earth for a few decades, and possibly only a few years before it began its deadly impact. The US-1 and HERB-1 strains "seem to have separated from each other only years before the first major outbreak in Europe," co-author Hernán Burbano from the Max Planck Institute for Developmental Biology said in a news release about the discovery.
Source: mnn
No comments:
Post a Comment