Plants have the same variation in body clocks as that found in humans, according to new research that explores the genes governing circadian rhythms in plants.
The research shows a single letter change in their DNA code can potentially decide whether a plant is a lark or a night owl. The findings may help farmers and crop breeders to select plants with clocks that are best suited to their location, helping to boost yield and even the ability to withstand climate change.
To investigate the genetic basis of these local differences, the team examined varying circadian rhythms in Swedish Arabidopsis plants to identify and validate genes linked to the changing tick of the clock.
Dr. Hannah Rees, a postdoctoral researcher at the Earlham Institute and author of the paper, said: “A plant’s overall health is heavily influenced by how closely its circadian clock is synchronised to the length of each day and the passing of seasons. An accurate body clock can give it an edge over competitors, predators and pathogens.
The team studied the genes in 191 different varieties of Arabidopsis obtained from across the whole of Sweden. They were looking for tiny differences in genes between these plants which might explain the differences in circadian function.
Their analysis revealed that a single DNA base-pair change in a specific gene—COR28—was more likely to be found in plants that flowered late and had a longer period length. COR28 is a known coordinator of flowering time, freezing tolerance and the circadian clock; all of which may influence local adaptation in Sweden.
“It’s amazing that just one base-pair change within the sequence of a single gene can influence how quickly the clock ticks,” explained Dr. Rees.
The scientists also used a pioneering delayed fluorescence imaging method to screen plants with differently-tuned circadian clocks. They showed there was over 10 hours difference between the clocks of the earliest risers and latest phased plants—akin to the plants working opposite shift patterns. Both geography and the genetic ancestry of the plant appeared to have an influence.