Researchers from Vanderbilt University have discovered that cyanobacteria can predict and prepare for seasonal changes based on the amount of light they are exposed to. Experiments showed that bacteria exposed to short daylight hours had a two to three times greater chance of survival in cold conditions.
An interesting discovery was made about cyanobacteria, one of the simplest life forms on Earth. According to the results of an experiment conducted on bacteria, they can predict and prepare for the change of seasons based on the amount of light they are exposed to.
It has been known for more than a century that complex organisms can use the length of the day as a clue to future environmental conditions (e.g. shorter days before it gets colder). Events such as migration, flowering, hibernation and seasonal reproduction are all driven by such responses in plants and animals, known as photoperiodism.
Until now, however, this has never been observed in simple life forms such as bacteria.
SOME BACTERIA HAVE SURVIVED THE COLD
Luísa Jabbur of Vanderbilt University and colleagues artificially exposed Synechococcus elongatus cyanobacteria to different day lengths and found that bacteria with simulated short days had two to three times better survival rates in icy cold temperatures. This suggests that the bacteria are preparing for winter-like conditions.
By testing shorter and longer durations, the researchers determined that this response takes four to six days to develop. These organisms form a new generation within a few hours, which means that the cells pass on information about day length to their descendants. However, the researchers do not yet understand how this information is transmitted.
Cyanobacteria, which capture energy from sunlight through photosynthesis, have been around for more than 2 billion years and are found almost everywhere in the world.
‘The fact that an organism as old and simple as cyanobacteria can have photoperiodic responses suggests that this is a phenomenon that evolved much earlier than we can imagine,’ said Jabbur, who is now working at the John Innes Centre in the UK.
