jtotheizzoe:
Grandaddy of the Plants
Meet Cyanophora paradoxa.
This single-celled freshwater alga has recently shone some sunlight on the origin of plants on Earth. About 2.5 billion years ago, oxygen began to accumulate in our atmosphere, and since nothing had coped to use it, it led to perhaps the most extreme extinction event in the planet’s history. The source of much of that oxygen were tiny prokaryotic photosynthesizers called cyanobacteria.
But how did these single-celled prokaryotes become the redwoods, seaweeds and multitudes of other eukaryotic plants we see on Earth today? It all started with endosymbiosis. A team at Rutgers sequenced the genome of Cyanophora paradoxa, and discovered that it shares a lot of characteristics with the creature that first swallowed a cyanobacteria in order to become a photosynthesizer.
Using genome sequencing, they deduced that an amoeba-like predator likely absorbed the cyanobacteria, and, instead of digesting it, began to farm its energy. But that’s not all … it likely took a second endosymbiosis ingestion of an unrelated bacterium to give Cyanophora all the tools it needed to become the ancestor of the plants we know today.
(image via Rutgers Univ.)
This is so cool!