Hannele Tuominen (left) and Stéphane Verger (right) have each received a four-year project grant from the Swedish Research Council. Photos: Fredrik Larsson, Johan Gunséus
How does nitrogen influence wood formation in trees? And what keeps neighbouring plant cells firmly attached? Two researchers from Umeå Plant Science Centre have received project grants from the Swedish Research Council to investigate these questions.
The grants were awarded to Hannele Tuominen and Stéphane Verger as part of the Swedish Research Council's 2026 funding decisions for natural and engineering sciences. Both projects will receive funding for four years, starting in 2027.
Nitrogen's role in wood formation
Nitrogen is essential for tree growth, but its role in wood formation is more complex than simply providing nutrients. Previous research from Hannele Tuominen's group at UPSC has shown that nitrogen can influence not only tree growth but also how wood cells develop.
In her new project, Tuominen, professor at the Swedish University of Agricultural Sciences (SLU), will investigate how nitrogen is transported, taken up and used in the tissues where new wood forms in aspen trees.
The researchers will combine molecular analyses with studies of natural genetic variation in aspen to develop a mathematical model aimed at predicting how nitrogen metabolism influences growth and wood formation. They will then test the model's predictions through genetic modifications.
“We hope to understand how nitrogen transport and metabolism in wood-forming tissues regulate tree growth and wood formation, ultimately identifying mechanisms that could improve nitrogen use efficiency and forest productivity,” says Hannele Tuominen.
How plant cells stay attached as they grow
As plants grow, their tissues are subjected to forces that pull and stretch them. Yet neighbouring cells must remain firmly attached to prevent the tissues from coming apart.
Stéphane Verger, associate professor at Umeå University and group leader at UPSC, and his team have previously found that plant cells rely on more complex mechanisms to stay attached than scientists had long assumed. Their research points to structurally reinforced regions of the cell wall at the outer edges of neighbouring epidermal cells, rather than adhesion depending solely on a glue-like substance between the cells.
In his new project, Stéphane Verger will investigate how these reinforced regions are built when new cells form and what happens to them as tissues grow. Using advanced microscopy and the model plant Arabidopsis, his team will also examine how cells sense mechanical forces and whether they respond by strengthening the regions that keep them attached.
“How plant cells stay attached sounds like such a basic question that you might expect us to already know the answer. But we are now realizing that our previous picture was too simple. This project gives us the chance to understand what is actually happening and how plants manage to keep their tissues together as they grow,” says Stéphane Verger.
Projects funded by the Swedish Research Council
• Mechanistic framework linking nitrogen homeostasis in vascular tissues with growth dynamics of aspen trees
Hannele Tuominen
Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences
https://www.upsc.se/hannele_tuominen
• StickyEdges - A new paradigm for plant cell adhesion: Structure, formation and maintenance of adhesion at cellular edges
Stéphane Verger
Umeå Plant Science Centre, Department of Plant Physiology, Umeå University
https://www.upsc.se/stephane_verger
Swedish Research Council: Funding decisions in natural and engineering sciences 2026