What does Professor Bergianus do?

Hanna Johannesson with her dog. Photo: private.

The position of Professor Bergianus is unique. It was established as early as 1791 and the intention was that the holder, in addition to conducting research, would be the director of the Bergian Garden. This was the case until 2014, when Hanna's predecessor, Birgitta Bremer, retired. 

By then, it had become clear that it was an almost impossible task to both conduct good research and manage the garden's entire operations. Now a special director position has been created and Professor Bergianus has become an adjunct professor at Stockholm University and can devote themself wholeheartedly to their research, without responsibility for the garden. Neither administration nor teaching is included in the position, and the income from the Bergianus Foundation provides good basic funding. “It's really luxurious,” says Hanna, who in 2022 took up the position of Professor Bergianus number ten.

The meeting with the fungi

But that Hanna would become a biologist was certainly not a given. At school, she was mostly interested in math, physics and music. A future as a church musician, architect or writer was what attracted her most. But in the end she decided to study biology at Uppsala University, because biology is creative and as a biologist you can write and count as much as you want. 

When she eventually came to a course on fungi, she immediately felt that this was something for her. Fungi are so interesting and important and yet so little studied. And imagine how many different kinds of life cycles there are in fungi!

At the time Hanna finished her master's degree, there were very limited opportunities to immerse herself in the world of fungi at Uppsala University, so she 
graduate studies at SLU instead. At the Department of Forest Mycology and Pathology she studied the life cycle of a fire-breeding fungus and its relationships with fire-breeding insects. Hanna was conducting basic research, but the project also had an exciting applied conservation perspective. 

From Uppsala to California and back

After her PhD in 2000, she went to Berkeley in California for a postdoc with her husband and two young children. It was an instructive time in many ways. Among other things, it became even clearer that in the future she wanted to focus more on basic research than applications and to integrate mycology with evolutionary biology.

And so it was. Hanna returned to Uppsala University and a research assistant position at the Evolutionary Biology Center (EBC). She liked it there because, although she was the only one working on fungi, the whole department had a strong evolutionary biology profile with many common questions. Over time, she became both a lecturer and a professor at the EBC.

A fresh start at DEEP

At the same time, she moved into the administrative field. She became section dean and later deputy vice-rector of the Faculty of Science and Technology. Administration turned out to be more fun than she thought, because it was a lot about leadership and opportunities to influence and shape the research environment. But in the long run, it became too burdensome to devote herself to both research and administration, and Hanna felt she had to decide what to focus on. The choice was not obvious.

Then - what luck! - the position of Professor Bergianus was advertised in Stockholm. It was so incredibly attractive, says Hanna. She applied for the position, got it and moved to DEEP, and it was a real new start for her to focus on research.

The focus of her research

Since returning to Sweden, Hanna's research has focused on fungal reproduction and evolution and the question of how variation is created and inherited in natural populations.

As a model organism, she first chose the spore fungus Neurospora crassa, an old acquaintance for anyone who has studied genetics. But recently, she has also been focusing on basidiomycetes. The current favorite is the carnation fungus, a fungus that can form large fairy rings. It is not possible to make it complete its life cycle in the lab, so we have to rely entirely on studying natural populations. 

Genetic analysis of individual fruiting bodies in a single fairy ring is used to understand where and when mutations occur and why some cells become spores while other cells build the fruiting body. The main methods used are comparative genomics, population genetics and bioinformatics.

Fairy ring at Berthåga church yard outside Uppsala. Photo: Hanna Johannesson.

BIG's first mushroom course

BIG has never had a specific course on fungi. But this fall, the Biology of Fungi, a new 7.5-credit orientation course with Hanna as course leader, will start. The course will provide an introduction to modern mycology, covering the form and function of fungi and their various roles as parasites, decomposers and symbionts. 

Hanna is expecting a lot of applications - fungi have become all the rage. She emphasizes that it is important that we reach out with our knowledge to schools and to the public. She has therefore also thought about writing a book about fungi or perhaps creating a website that could inspire biology teachers. We'll see what happens with that. Can we even hope for a more advanced mushroom course in the future? “I'd love to,” says Hanna, ”but first we'd have to get more people in the department working with fungi.

In the forest in her spare time

What does a mushroom researcher do in his spare time? Picking mushrooms? Well, although Hanna appreciates well-known edible mushrooms, she has great respect for mushrooms' ability to form deadly toxins. Nevertheless, she is often out in the forest. She has inherited a forest that was previously managed in the traditional way. 

Now she wants to transform it into a different kind of forest with a high diversity of tree species and ages. It's become a project that involves the whole family; old oaks are being removed, the planted spruces are being thinned out and new trees are being planted - it may end up as an arboretum. And when the forest is not within reach, Hanna likes to relax with a moment at the piano. Music is still important in her life.