Photo: Jan Petersen.

From Copenhagen to Stockholm

"This is not what I had in mind," says Gitte Petersen, when she notes that she became a lecturer in plant systematics at DEEP in spring 2018. What she could not have foreseen was that higher education in Denmark would be subjected to such severe cuts as she had just experienced. 

Education at the University of Copenhagen, where Gitte had been working since 1990, had been suffering 2% cuts per year for several years, and there is a limit to how far you can streamline. It was inevitable that many people would lose their jobs, and Gitte was one of them, so the announcement of the lectureship in Stockholm was very timely! And when she says that her career didn't turn out as she had planned, she actually looks quite happy.

Early interest in plants

That Gitte would devote herself to plant systematics was no surprise. Even as a child, she was interested in botany and grew her own plants in a corner of her parents' garden. She has also always liked to classify things, so systematics was a natural choice. 

Her studies at the Royal Veterinary and Agricultural University led to a thesis, completed in 1990, on hybridization between different cereals. 

After her PhD, Gitte remained at the University of Copenhagen, except for a short post-doc period at the University of Minnesota. Until 2005, she was employed at the then Department of Botany, but then she applied to the Natural History Museum of Denmark, the Danish equivalent of the National Museum of Natural History in Sweden. It was not a long step, because unlike the Swedish National Museum, the Danish museum is an integral part of the university, and Gitte stayed there until she came to SU.

Unraveling tangled plant genomes

Once Gitte started researching plant systematics, she also had reason to say "this is not what I had in mind". A whole new world opened up when she 
started using molecular data. At first she was reluctant to spend her working hours in the lab and in front of the computer instead of in gardens and greenhouses, but soon she became fascinated by all that DNA molecules can reveal. 

Plant cells have three genomes: nuclear, chloroplast and mitochondrial. Of these three, the mitochondrial genome has proved to be particularly interesting and highly dynamic, with an astonishing variety of shape and structure. In addition, DNA from other genomes (even from other species) can be incorporated into mitochondrial DNA. 

Although Gitte has always been a neat and tidy person - you can see it in her tidy desk - she finds research most exciting when everything seems to be a mess. Finding biological explanations for why things don't fit with previous phylogenetic hypotheses is like detective work!  

Mistelns mysterier

Mistletoe on Campus. Photo: Margareta Ohné.

Efter att en tid ha studerat gräs och andra enhjärtbladiga växter kom hon så småningom in på parasitiska växter och det är fortfarande hennes huvudintresse. Favoritorganismen är mistel, en parasitisk växt som i Sverige kan hittas på grenar av lind och lönn och vars bär sprids av dubbeltrastar och andra fåglar. 

Fördelen med att studera just mistel är att den är så stor att det går hyfsat lätt att isolera ren mistelvävnad och undersöka cellerna. Vad man då har upptäckt är bland annat att mistel saknar vissa gener, som man trodde var essentiella, i sitt mitokondrie-DNA. Gitte överlåter åt biokemister och fysiologer att reda ut hur misteln klarar sin cellrespiration utan dessa gener och deras produkter; det hon vill förstå är vilka evolutionära mekanismer som lett till dessa genförluster. 

Förutom mistel och dess nära släktingar har Gitte också studerat både parasitiska och icke-parasitiska växter som tallört, blomvass och olika liljeväxter.

Teaching about plant diversity

Gitte was no novice in teaching when she joined DEEP; both at the museum and at the Department of Botany in Copenhagen, there was a lot of teaching at all levels, including distance learning. She has also developed several courses in phylogeny and molecular plant systematics and has been a driving force behind the Nordic Master's Program in Biodiversity and Systematics (NABiS). 

At DEEP, Gitte has from occasional lectures on Organismal Diversity and Evolution now taken over the course management. She is constantly working to develop and adapt the course to requirements that meet both scientific knowledge and students' prior knowledge. She is also the course leader of a master's course on land plant diversity and this is where her broad interest in plants really comes into its own. She can also talk about parasitic plants. But you can't be an expert in everything, which is why Gitte invites lecturers from the Swedish Museum of Natural History to both courses.

Appreciated songbirds

Despite the misery at the University of Copenhagen, it can offer something that SU lacks, namely vacation cottages that employees can rent. Some of them are in Sweden, and Gitte has spent many summers near Anderstorp in Småland. It's also close to the Store Mosse National Park, a lovely area for those who, like Gitte, have a keen interest in birds. 

When she moved to Stockholm, she explored the city's surroundings by subway and fell in love with Bagarmossen. It was primarily the proximity to Nackareservatet that attracted her, where she enjoys walks and birdsong. But at the same time, it is close enough to another appreciated place for beautiful singing, namely the Royal Swedish Opera.