Plants can be hazelnuts or night owls just like us

Plants have the same variation in body clocks as found in humans, according to new research exploring the genes that govern circadian rhythms in plants.

Research shows that a one-letter change in the DNA code can decide whether a plant is a mole or a night owl. The findings can help farmers and crop growers select plants with clocks that are best suited to their location, helping to increase yield and even the ability to withstand climate change.

The circadian clock is the molecular metronome that guides organisms during the day and night – cockadoodledooing the arrival of the morning and drawing the closed curtains at night. In plants, it regulates a wide range of processes, from photosynthesis of priming at dawn to the regulation of flowering time.

These rhythmic patterns can vary depending on geography, latitude, climate and seasons – plant clocks need to adapt to best meet local conditions.

Researchers at the Earlham Institute and the John Innes Center in Norwich wanted to better understand how much circadian variation exists naturally, with the ultimate goal of reproducing crops that are more resistant to local environmental change – a pressing threat to climate change.

To investigate the genetic basis of these local differences, the team examined various circadian rhythms in Swedish Arabidopsis plants to identify and validate genes related to clock-changing ticking.

Dr. Hannah Rees, a postdoctoral researcher at the Earlham Institute and author of the paper, said: “The overall health of a plant is strongly influenced by how closely its circadian clock is synchronized with the length of each day and the passing of the seasons. the body clock can give it an advantage over competitors, predators and pathogens.

“We were interested to see how circadian plant clocks in Sweden would be affected; a country that faces extreme variations during the day and in the climate. Understanding the genetics behind the variation and adaptation of the body clock could help us grow more climate-resistant crops in other regions. “

The team studied the genes in 191 different varieties of Arabidopsis obtained from all over Sweden. They were looking for tiny gene differences between these plants that could explain the differences in circadian function.

Their analysis revealed that a single change in the base DNA pair in a specific gene – COR28 – was more likely to be found in plants that flowered late and had a longer shelf life. COR28 is a well-known coordinator of flowering time, frost tolerance and circadian clock; all of which can influence local adaptation in Sweden.

“It’s amazing that just a change in the base pair in a single gene sequence can influence how fast the clock ticks,” Dr. Rees explained.

Scientists have also used a pioneering method of delayed fluorescence to examine plants with differently adjusted circadian clocks. They showed that there is a difference of over 10 hours between the clocks of the oldest ascendants and the latest plants with stages – similar to plants that work with opposite patterns of change. Both the geography and the genetic ancestors of the plant seemed to have an influence.

“Arabidopsis thaliana is a model plant system,” said Dr. Rees. “It was the first plant to sequence its genome and has been studied extensively in circadian biology, but this is the first time someone has done this type of association study to find the genes responsible for different types of clocks.

“Our findings highlight some interesting genes that could be targets for crop breeders and provide a platform for future research. Our delayed fluorescence imaging system can be used on any green photosynthetic material, making it applicable to a wide range of plants. The next step will be to apply these findings to key crops, including brassicas and wheat. “

The results of the study were published in the journal Plant, cell and environment.