Understanding plant signaling systems for more resilient crops

Agricultural yields will have to double by 2050 to meet increasing food demands. The world's population is growing, and climate change is reshaping where crops can be grown. Hence, more resilient and efficient crops are essential to meet the demand for staples like corn, rice, wheat and soybeans. So, what are the solutions?

A part of the answer lies in a humid, illuminated greenhouse on the roof of the KBC building at Umeå University. Here we find Åsa Strand, a resolute professor of molecular biology. For nearly 25 years, she has been exploring how plant cell nuclei communicate with the cell's powerhouses: the mitochondria and chloroplasts. She has also tried to find out how the signaling system respond to stressors like cold, heat or drought.

“The activity of the mitochondria and chloroplasts is highly sensitive to stress; it halts. I am interested in how to get the activity going again without significant loss of plant productivity,” says Åsa Strand.

Knocking out genes randomly

Together with her research team, she has used genetic screening – a method where a reporter gene, such as luciferase from fireflies, is added to the plant in order to find out which signals control specific functions. By randomly knocking out the genes in thousands of unique individuals, the researchers can pinpoint when regulation in a particular line fails, indicated by the plant not emitting light. 'It's like building a giant puzzle, piece by piece.

“I have always been interested in plant breeding and I like challenges. I'm very independent and quite competitive, so I like to run my own projects. At first, I was going to study horticulture, but it seemed too narrow. Instead, I decided to study molecular biology. I chose Umeå because it was the university with the closest connection to research activity,” says Åsa Strand.

If I had to choose a place to conduct plant research in Sweden, Umeå was the obvious choice and still is.

In the early 2000s, she completed her post-doc at the Salk Institute in San Diego, where new experimental methods to study organelle and nucleus communication were being developed. During her post-doc, Åsa Strand identified the first signal used by organelles to communicate with the cell nucleus. At the same time, Umeå University and Swedish University of Agricultural Sciences was establishing the Umeå Plant Science Centre, UPSC.

“I was eager to be part of that. If I had to choose a place to conduct plant research in Sweden, Umeå was the obvious choice and still is. It is by far the strongest centre for experimental plant biology in Sweden, and one of the strongest in Europe and globally.”

Customised crops can feed humanity

Åsa Strand's research primarily focuses on basic biology, offering vital insights into cellular function, not only in plants but also in animals and humans. Recently, she has also launched several projects addressing one of the biggest societal challenges of our time: food security.

One way to feed humanity in the future is to customise crops through genetic modification. However, the GMO debate is contentious, and Europe enforces strict regulations on genetically modified plants. Currently, such plants are only grown in Sweden for research purposes. In the greenhouse at Umeå University, protective clothing and airlocks are used to prevent the risk of contamination.

Regions like Spain and southern France will face extreme heat and severe drought, drastically altering the agricultural lanscape

“I think it has been a mistake to obstruct this technology for so long. It has been devastating for agriculture. Especially now, with climate change, the North is becoming more suitable for farming and we need to prepare for that by developing crop varieties adapted to our climate. Regions like Spain and southern France will face extreme heat and severe drought, drastically altering the agricultural lanscape,” says Åsa Strand.

Gene-editing technology may be a solution

Yet, there may be a hopeful prospect, she says. The EU is currently discussing easing the regulation of using CRISPR-cas9 gene-editing technology. Compared to other gene modification, CRISPR-cas9 requires more knowledge and preparation, but there is great potential.

One of Åsa Strand's research projects, funded by the Swedish Foundation for Strategic Research, aims to improve the efficiency of photosynthesis by removing inhibitory elements within plant cells using gene-editing technology. This would make plants more productive under optimal growing conditions. In her project, she is studying cyanobacteria, a simple single-celled organism with similar photosynthetic function to a chloroplast in a plant cell, but without the complex regulatory mechanisms seen under harsh conditions. The objective is to take specific knowledge from the cyanobacteria and transfer it to the plants to “reclaim the photosynthesis”.

“Then we can apply the knowledge we have accumulated over 20 years to plant breeding. We'll assess the necessary components of the signaling system and identify whether anything can be removed. It's quite exciting engineering,” says Åsa Strand.

Priority research area

A key factor in Umeå University's success in plant biology is the collaboration between different research groups. At the Umeå Plant Science Centre, researchers from the Department of Plant Physiology at Umeå University and the Department of Forest Genetics and Plant Physiology at the Swedish University of Agricultural Sciences work side by side. They share lunch rooms, lab environments and advanced technical equipment.

One of Umeå University's three priority research areas is plant research.

“We collaborate with the Faculty of Social Sciences to explore agriculture and nutrition, and we are interested in more collaborations. Through the priority research areas, we have established a forum for these collaborations. It is still in its early stages, but I believe it has great potential,” says Åsa Strand.