- You studied flowering and seasonal growth in poplar working in Ove Nilsson’s group. What sparked your interest in this topic and how did you end up joining Ove’s group?
I believe that understanding how plants, especially trees, adapt to their environment is crucial, particularly in the face of climate change. As perennial plants, trees have to endure seasonal shifts year after year, making their ability to regulate growth and dormancy essential for survival.
SLU is one of the world’s leading universities for forestry studies, and I was particularly drawn to its cutting-edge research in tree biology. I was searching for a PhD project focused on tree development and seasonal adaptation. Since Ove Nilsson’s group is well established and renowned for producing high-quality research in plant development, especially in understanding flowering and seasonal growth regulation in trees, it seemed like the perfect fit.
- You focused on a flowering regulating gene network that is present in annual and perennial plants. What are the main differences in this regulation between annual perennial plants?
The main difference in flowering regulation between annual and perennial plants lies in how they balance flowering with long-term survival. Annual plants complete their life cycle in a single growing season, so they flower quickly and invest all their resources into reproduction. Perennial plants, on the other hand, must maintain vegetative growth for multiple years while also timing flowering appropriately. The flowering gene network in annuals is typically activated strongly and irreversibly once the right environmental conditions (such as day length and temperature) are met. Key regulators like the FLOWERING LOCUS T protein promote a rapid transition to flowering. In aspen, the genes involved in the regulation of flowering have duplicated and diverged to take different functions related to the control of seasonal growth as well. For example, perennials have mechanisms to enter seasonal dormancy, halting growth and flowering during unfavourable conditions, which in aspen is also controlled by flowering genes.
- What do you consider as the major outcome of your thesis?
During my PhD I investigated the molecular mechanisms regulating flowering time and the annual growth cycle in aspen. With my work I provided a better understanding of the function of the two poplar flowering genes FLOWERING LOCUS T (FT)-like and TERMINAL FLOWER 1 (TFL1)-like, that are similar to the genes described in the annual plant Arabidopsis thaliana, and the interplay between them in controlling seasonal growth and flowering time. Moreover, I generated a transcriptional roadmap that describes the different gene activities during the annual growth cycle of aspen and identified key genes governing dormancy, bud flush, and flowering time.
- Were there any results that were unexpected or astonishing?
The genes I focused on during my PhD are crucial for plant development, and their functions and molecular mechanisms are well-known in other model species such as Arabidopsis thaliana. While the roles of the two flowering genes FLOWERING LOCUS T (FT)-like and TERMINAL FLOWER 1 (TFL1)-like in poplar are similar to the ones in other model species, the poplar genes have acquired additional functions in controlling seasonal growth. Therefore, the results were not entirely unexpected. However, the extreme phenotypes observed in mutants lacking one of the different poplar flowering genes were astonishing. When analysing the gene activity in one of the flowering mutants, we saw that the activity of thousands of genes was altered. Realizing that the mutation of just a single gene can have such a striking impact on plant development highlights the importance of these genes in controlling growth and flowering.
- What is the relevance of your results e.g. for forest management and tree breeding?
My work provides valuable genetic insights that can be applied in breeding programmes to develop trees with optimized growth patterns, improved adaptation to climate change, and enhanced productivity in forestry. By understanding and manipulating these genetic pathways, forest management strategies can be refined to ensure sustainable and resilient tree populations.
- Did you face any challenges that you had to overcome during your PhD and that would you like to share with us?
While I thoroughly enjoyed working at UPSC and take great pride in the outcomes of my PhD, the long-term nature of the project presented significant challenges. One of the greatest difficulties was maintaining focus and perspective throughout the years.
Research is rarely a linear process—unexpected results and the constant need to refine hypotheses can make it easy to lose sight of the bigger picture. For me, one of the hardest aspects was synthesizing years of work into a coherent and compelling story. Writing my thesis and publications forced me to take a step back, reassess my findings, and structure them in a way that effectively communicates their significance.
- Nearing now the end of your PhD thesis, what are your next plans?
My plan is to continue working in academia, and I will be moving to Germany to work as a postdoc at the Max Planck Institute for Plant Breeding in Cologne, in George Coupland’s group. I will continue investigating flowering, but this time in Arabidopsis thaliana. Working with another model species will provide me with deeper insights into the molecular mechanisms involved and offer the opportunity to learn new techniques to further strengthen my skills.
