Plants have the same variation in body clocks as humans. This is emerging from new research examining the genes that control the circadian rhythm in plants.
Research shows that changing the DNA code by a single letter can potentially determine whether a plant is a lark or a night owl. The results can help farmers and plant breeders choose plants with clocks that best suit their location, increasing yield and even the ability to withstand climate change.
The circadian clock is the molecular metronome that guides organisms through day and night – cockadoodledooing the arrival of the morning and the closing of the curtains at night. In plants it regulates a variety of processes, from photosynthesis at dawn to regulating the flowering period.
These rhythmic patterns can vary depending on geography, latitude, climate, and seasons. Plant clocks need to adapt to best suit local conditions.
Researchers at the Earlham Institute and the John Innes Center in Norwich wanted to better understand how many circadian variations exist naturally, with the goal of growing plants that are more resilient to local environmental change – an urgent threat from climate change.
To examine the genetic basis of these local differences, the team examined various circadian rhythms in Swedish Arabidopsis plants to identify and validate genes associated with the changing tick of the clock.
Dr. Hannah Rees, postdoctoral fellow at the Earlham Institute and author of the paper, said, “A plant’s overall health is greatly affected by how closely its circadian clock is synchronized with the length of each day and the course of the seasons. An accurate body clock can give an advantage over competitors, predators and pathogens.
“We were interested to see how circadian plant clocks would work in Sweden. There are extreme variations in daylight hours and the climate in this country. Understanding the genetics behind the variation and adaptation of the body clock could help us identify climate-resistant plants in other regions breed. “”
The team examined the genes of 191 different Arabidopsis varieties from across Sweden. They looked for tiny differences in genes between these plants that might explain the differences in circadian function.
Their analysis found that a single change in the DNA base pair in a particular gene – COR28 – was more likely to be found in plants that bloomed late and had a longer period. COR28 is a well-known coordinator for flowering time, freezing tolerance and the circadian clock. All of this can affect local adjustment in Sweden.
“It’s amazing that just one base pair change within the sequence of a single gene can affect how fast the clock ticks,” said Dr. Rees.
Scientists also used a breakthrough fluorescence delayed imaging technique to screen plants with differently tuned circadian clocks. They showed that there was a difference of more than 10 hours between the clocks of the earliest risers and the latest phased plants – similar to the plants that work opposite layering patterns. Both the geography and the genetic origins of the plant appeared to have an influence.
“Arabidopsis thaliana is a model plant system,” said Dr. Rees. “It was the first plant to have its genome sequenced and it has been studied extensively in circadian biology. However, this is the first time anyone has done this type of association study to find the genes responsible for different types of clocks .
“Our results highlight some interesting genes that are targets for plant breeders and could 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 variety of plants. The next step on these findings should be transferred to important agricultural crops like cabbage and wheat. ”
The results of the study were published in the journal Plant, cell and environment.
Notes to Editors For media inquiries, please contact Greg Jones at the Earlham Institute: Tel +44 (0) 7792 154497 or [email protected]
Rees, H. et al., Naturally Occurring Circadian Rhythm Variation Associated with Clock Gene Loci in Swedish Arabidopsis Accessions. Plant, cell and environment, 2020. DOI: 10.1111 / pce.13941
About the Earlham Institute
The Earlham Institute (EI) is a leading global research institute engaged in the development of genomics and computational biology. Based in Norwich Research Park, EI is one of eight institutions to receive strategic funding from the Biotechnology and Biological Science Research Council (BBSRC) – £ 5.43m in 2017/18 – as well as support from other research funders. EI operates a national capability to advance the application of genomics and bioinformatics to advance research and innovation in the life sciences.
EI offers a state-of-the-art DNA sequencing facility that is unique in that it operates several complementary data generation technologies. The institute is a UK hub for innovative bioinformatics through research, analysis and interpretation of multiple complex data sets. It houses one of the largest computer hardware facilities for life science research in Europe. It is also actively involved in the development of novel platforms to provide multiple academic and industrial users with access to computing tools and processing capabilities, and to promote computer life science applications. In addition, the institute offers a training program with courses and workshops as well as a contact program aimed at important interest groups and a broader audience through dialogue and science communication activities.
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