Arabidopsis is a small, inconspicuous plant. It grows naturally in many parts of the world, and in Sweden it can be found along roadsides, trails and in fields. Notwithstanding its modest appearance, it is widely used as a model plant by researchers in both plant biology and genetics.

The reason is that it grows quickly and has a relatively small genome that is easy to modify. We now have a wealth of genetic information about Arabidopsis. Another advantage is that it does not require much space to grow, as Schmid points out. He is based at the Swedish University of Agricultural Sciences (SLU).

He opens the door to one of several rooms in which the flowering Arabidopsis plants are growing in tightly packed rows on shelves. The room is currently bathed in light, but the researchers can control the climate precisely as they wish. When one of Schmid’s doctoral students exposed the plants to a slightly lower temperature than usual, she made a surprising discovery.

“Normally, we grow the plant at our standard temperature of 23 degrees Celsius. But when we lowered it to 16 degrees, one of the plants became very small, grew poorly, and didn’t seem to be in good health. It’s very unusual for such a small drop in temperature to have that kind of impact.”

Disrupted genetic process

The explanation was that the plant bore an unusual mutation. When the researchers examined the genome of the plant, they found a change in one of the genes involved in the splicing of RNA molecules, which serve as a blueprint for protein synthesis. In the mutated plant, this process was disrupted, making it particularly sensitive to temperature changes.

“We performed extensive genetic and genomic analyses and realized there is a connection between how plants react to stress and this process.”

The splicing process is complex and requires the coordinated activity of several hundred different genes and proteins.

“It’s an incredibly complex process. Many of the genes involved have not yet been studied in any great depth.”

New method

A new method was needed to study the process in more detail, and to investigate how different proteins interact with each other. One of Schmid’s postdocs took on the challenge, resulting in a new way to map complex protein interaction networks.

“If we imagine there are 400 proteins in Arabidopsis linked to splicing, that means myriad possible interactions. The standard techniques currently used are not very good at analyzing all these at once.”

Developing the new method took nearly three years, and now the researchers are on the verge of patenting it.

“It would never have been possible without funding under the Wallenberg Scholar scheme. The grant gives us the opportunity to address unexpected research ideas. It has also given me with a way to allow my colleagues greater freedom,” says Schmid.

Applied research is important, but if it dominates, we risk losing fundamental breakthroughs that lead to unexpected insights. We must find a balance in how research is funded.

The next step is to use the method to map the entire splicing machinery and ascertain how it relates to the transcription of DNA to RNA. A greater understanding could make it possible to help other plants cope with stress and changing temperatures. One possible approach is to strengthen plant resistance using natural or synthetic proteins – a kind of vaccine against temperature changes.

“If we find small proteins that can modify splicing, we could give plants greater resilience in coping with different forms of stress. We have no idea whether it will work, but it’s definitely worth trying.”

Schmid points out that new technologies such as CRISPR-Cas9 facilitate genome engineering at unprecedented ease and specificity. Perhaps such an approach could open up new ways to provide cultivated plants with better resistance to climate change.

“I wouldn’t recommend anyone to build their career on this idea, given that the risk of failure is high. But as a team leader, it’s important that l provide my colleagues with security as well as topics that are fun and exciting to explore.”

Driven by curiosity

Schmid discovered the new mutant while at the Max Planck Institute in Tübingen, Germany. Since then, he has worked at Umeå University and now leads a research team at SLU in Uppsala.

“My work has always been based on my curiosity: I simply want to understand how things work – like how plants respond to temperature and how they adapt their growth and development to temperature changes.”

Although he describes himself as a lazy student with mediocre grades, he was drawn to the natural sciences and a career in academic research early on.

“It’s worth remembering that this is a very uncertain career path, where much can go wrong. Success requires contacts and a lot of luck. Researchers at the start of their career need to build a good network that they can rely on for support and advice,” says Schmid.

Text Magnus Trogen Pahlén
Translation Maxwell Arding
Photo Magnus Bergström