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Taking the next step in an academic careers: Peter Kindgren (left) and Peter Marhavý (right) have delivered their docent lecture at the Swedish University of Agricultural Sciences (photo: Anne Honsel).
The decision has not yet been made, but the final requirement has been fulfilled: the two UPSC group leaders, Peter Kindgren and Peter Marhavý, have delivered their docent lectures this week. The appointment as a docent is the next step in an academic career following the PhD. It shows that the candidates have significantly developed their academic expertise, demonstrated their scientific independence, and proved that they are capable of acting as principal supervisors.
Peter Kindgren and Peter Marhavý both began establishing their independent research group at the Umeå Plant Science Centre and the Swedish University of Agricultural Sciences at the beginning of 2020. Since then, their groups have grown to include several group members, their research is producing results and they are also regularly teaching students. As they now approach the next milestone in their academic career, we asked them in the following interview about their motivation to continue in academia, their research focus and what they enjoy about their work.
- The docent lecture marks the next step of your academic career. What inspired you to take this path and pursue a career in academia?
Peter Kindgren: I always thought that an academic career was a perfect fit for me, I am curious and love to do research in a team. It gives you a tremendous freedom to pursue what you think is interesting, but also research topics that will lead to a better and sustainable future for society. As a teacher, it is also great to convey this message to undergraduate and graduate students.
Peter Marhavý: Throughout my career, I have been fascinated by the underlying logic of biological systems - particularly how plants coordinate repair processes at the cellular level. Academia offers a unique environment where such intellectual curiosity is not only encouraged but forms the foundation of meaningful progress. For me, the docent lecture represents more than a personal milestone; it reflects a continued commitment to the cumulative and collaborative pursuit of knowledge, with the goal of contributing to scientific advancement and societal benefit.
- Can you shortly describe the focus of your current research and its potential impact?
Peter Marhavý: My research centers on two main areas: first, we investigate the early responses of plants to localized wounds caused by factors such as plant-parasitic nematodes; second, we explore how undamaged neighbouring plants perceive and respond to signals emitted by their injured neighbouring plants. Together, our research aims to reveal how plants detect and communicate stress, which could lead to innovative strategies for improving plant health.
Peter Kindgren: In my research group, we are interested in transcription, the process of RNA synthesis by reading the DNA template. We are both interested in the coding regions of the DNA sequence, the genes, but also the non-coding regions. Especially non-coding DNA is an emerging topic in life sciences, and we see that much of it is actually transcribed into RNA. However, the RNA is not used for protein synthesis, it is mainly used to regulate the coding RNA output in the organism. Plants use non-coding transcription differently than other higher organisms, and it seems like it is very important for how plants respond to stress. If we can fully understand how a plant uses its DNA sequence, we can make plants that tolerate stress better and grow faster and with increased biomass.
- What challenges have you faced in your research journey, and how have you overcome them?
Peter Marhavý: There are many challenges in research and academia: setbacks, failed experiments, rejected grants and papers are all part of it. But one of the key lessons I have learned is that persistence is essential. You simply cannot give up after a failure; each obstacle is an opportunity to learn, adapt, and refine your approach.
Peter Kindgren: Research is always a roller coaster ride, there are ups and downs that you need to be able to cope with. An important aspect of an academic career nowadays is to be mobile and seek new and interesting ideas throughout the world. I have been fortunate to work in great scientific teams in Sweden, Australia and Denmark in my career. It is also important to be productive in your work, and foremost publications counts high. I was lucky to get my publications at the right time and in good journals to apply for new grants to continue my work. A big challenge is the transition from postdoc to independent group leader. With my experience, I was able to have a solid foundation with ideas and preliminary results when I started my group. That helped a lot for me to establish myself in the field.
- What do you enjoy most about your work, and what keeps you motivated?
Peter Kindgren: My curiosity has always been driving me as a researcher. It is amazing to work in a group where you discuss new results and try to come up with a model of how things work in biology. The anticipation of new results keeps me motivated and it is also what I enjoy most with my work. Another side of my work is the supervision and teaching, and it is equally remarkable to see students develop into full grown researchers.
Peter Marhavý: What I enjoy most about my work is the intellectual freedom it provides; the opportunity to think creatively and pursue interdisciplinary approaches to address the questions I have. This openness makes the work constantly engaging and rewarding. What motivates me is the satisfaction of overcoming research challenges and the ongoing sense of discovery that comes with advancing our understanding step by step.
- What advice would you give to young scientists who wish to pursue a similar career path?
Peter Kindgren: Work towards independence early and have multiple projects ongoing at the same time. Be mobile and find good research groups where you can learn new things. Be helpful to your colleagues and humble, it will pay back multiple times in the future.
Peter Marhavý: I am not sure I am the best person to give advice, but what I can say is: stay curious, be patient, and do not be discouraged by failure – it is a natural part of the scientific process. Most importantly, pursue questions that truly excite you. That passion will carry you through the inevitable challenges and keep your work meaningful.
More information about the docent lectures
For questions, please contact:
Peter Kindgren
Umeå Plant Science Centre
Department of Forest Genetics and Plant Physiology
Swedish University of Agricultural Sciences
Email:
https://www.upsc.se/peter_kindgren
Peter Marhavý
Umeå Plant Science Centre
Department of Forest Genetics and Plant Physiology
Swedish University of Agricultural Sciences
Email:
https://www.upsc.se/peter_marhavy
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Jun Yu (left), Maria E. Eriksson (middle) and Bertold Mariën (right) are discussing their collaboration project in IceLab (photo: Gabrielle Beans, IceLab).
A new study from Umeå University has revealed that the trees’ circadian clock guides their growth and the timing of seasonal events like the appearance of leaves in spring. The researchers investigated the growth of genetically modified poplars in greenhouse and field conditions, combining statistical learning and plant biology methods. Their findings suggest that adjusting clock-associated genes could help trees better synchronize with changing climates, offering new opportunities for forestry.
A Large-Scale Approach to Understanding a Tree’s Clock
Trees, like humans, have a circadian clock that regulates their daily and seasonal rhythms. Research has suggested that this clock is important to regulate growth and the timing of important seasonal events, like for example bud formation in autumn and bud opening in spring. However, most of this research has been done in controlled greenhouse conditions and not outside in the field where plants are exposed to natural environmental conditions. In the field, as in the real world, temperature fluctuations, insect predation and other factors affect plant growth.
To address this, the researchers conducted an extensive study based on 68 genetically modified poplar or aspen lines with different, modified properties. Among the genes that were modified were many associated with the circadian clock. These trees’ growth was studied in multiple greenhouse and field experiments over several years. The results clearly showed that the circadian clock has a strong role in regulating tree growth and the timing of seasonal events in the life of a tree, like the budding of leaves.
“Our study is the first to combine datasets from greenhouse and field studies to show that multiple aspects of the circadian clock system influence tree growth and the timing of life-cycle events,” says Bertold Mariën, lead author of the study. “By applying statistical modelling to these datasets, we were able to pinpoint which circadian clock-associated genes impact tree growth or, for example, the time when leaves appear or change colour.”
Jun Yu (left), Maria E. Eriksson (middle) and Bertold Mariën (right) are inspecting young trees at UPSC (photo: Gabrielle Beans, IceLab).
Insights for Forestry and Climate Adaptation
The study provides a new perspective on how trees use their circadian clock to coordinate their growth with the environment. For example, certain genetic modifications in key clock regulators changed the trees’ sensing of the day length and allowed trees to continue growing later into the season.
“This study is a proof-of-concept that trees conditioned to a particular length of day at a certain latitude can be adapted to a new latitude, effectively extending their growing season. This is especially useful at higher latitudes like in Northern Sweden where short growing seasons limit timber production,” explains Maria E. Eriksson, last author of the study.
Additionally, some gene modifications improved the trees’ resilience under environmental fluctuations. By focusing on these specific genes, it would be possible to breed tree varieties that are better adapted to rapid changes in the local climate, and to new growing locations, for example in other latitudes.
"In the future, forestry management could be improved by integrating trees’ circadian clocks and their natural growth cycles with traditional practices”, says Eriksson. “In this way, tree growth and resilience could be optimized in a changing world.”
Beyond the implications for forestry, the study also has relevance for global vegetation models that predict forest growth and carbon storage. The importance of the clock in shaping trees’ sensitivity to environmental conditions is often underestimated in these models, according to Mariën. He concludes, “By properly incorporating our findings on the circadian clock into global vegetation models, we can improve predictions of how forests will respond to climate change.”
About the study
Mariën, B., Robinson, K.M., Jurca, M. , Michelson, I.H., Takata, N., Kozarewa, I., Pin, P.A., Ingvarsson, P.K., Moritz, T., Ibáñez, C., Nilsson, O., Jansson, S., Penfield, S., Yu, J. & Eriksson, M.E.. Nature’s Master of Ceremony: The Populus Circadian Clock as Orchestrator of Tree Growth and Phenology. npj Biol Timing Sleep 2, 16 (2025). https://doi.org/10.1038/s44323-025-00034-4
Contact
For more information, please contact:
Maria E. Eriksson, Associate professor, Umeå Plant Science Centre, Department of Plant Physiology, Umeå University
Email:
Bertold Mariën, Postdoctoral researcher, Department of Mathematics and Mathematical Statistics, Umeå University
Email:
Related information
Swedish version of the news on the homepage of Umeå University
More information about the Integrated Science Lab (IceLab) at Umeå University
More information about the Department of Mathematics and Mathematical Statistics
Text: Gabrielle Beans & Anne Honsel
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Several group leaders from UPSC shared their experiences with the participants of the symposium at a panel discussion highlighting different academic journeys (photo: Anne Honsel).
End of March, the UPSC Early Career Plant Scientists Symposium took place. Six talented young researchers from around the globe were visiting UPSC, presented their research and got to know the research environment. Feedback from the participants highlighted the welcoming atmosphere and the stimulating interactions with group leaders and postdoctoral researchers.
The two-day event, held on 26-27 March, was filled with scientific and networking activities. The first day commenced with a scientific session where invited early career scientists presented their research, and several UPSC group leaders provided a brief overview of their work. This was followed by a matchmaking event with individual discussions between UPSC group leaders and the invited researchers, aimed at exploring potential collaborations.
“Our goal is to build connections with promising young scientists selected based on their application and their qualification to apply for one of the competitive European postdoctoral fellowships,” said Stephan Wenkel, one of the organisers of the symposium. “UPSC is a unique and encouraging place to work. It is a very supportive and collaborative research environment, and Umeå offers a fantastic quality of life, something that people often do not expect so far north.”
Building connections with young scientists and showcasing UPSC
On the second day, participants joined a workshop on European Union funding opportunities, organised by Umeå University's Research Support and Collaborations Office. This workshop provided information about available European research grants and insights into grant writing, which was highly appreciated by the young researchers. After lunch with postdocs from UPSC, the programme continued with a guided tour of the UPSC facilities.
“UPSC is well equipped with cutting-edge research facilities, providing an excellent environment for conducting plant and especially tree research,” explained Laura Bacete, another organiser of the symposium. “We wanted to showcase UPSC but also give constructive feedback to the participants on their research, helping them refine their ideas and approaches and support them in their careers.”
Annika Johansson is presenting the Swedish Metabolomics Centre to the participants of the UPSC Early Career Plant Scientists Symposium (photo: Anne Honsel).
After a panel discussion highlighting different academic journeys, the event concluded with a Pizza and Ping-Pong evening in the UPSC lunchroom, where the symposium participants could mingle informally with the UPSC staff. In response to a survey after these two intense days, feedback from all six participants was very positive.
When asked if the symposium fulfil their expectations, all six participants agreed. One participant responded: “Yes, everyone was very welcoming and the interactions with PIs and other post docs were very stimulating. The workshop was very helpful and detailed.” Another participant commented: “Yes, I found a suitable researcher to talk about my research plan and obtained helpful information on the application for the Marie Curie Postdoctoral Fellowship.”
Engagement with Group Leaders was greatly appreciated
Overall, the opportunity to engage with group leaders was greatly appreciated by the participants. When asked which part of the programme was the most useful, one participant wrote: “I would say the one-to-one discussions with the PI. In general, their availability and their disponibility to discuss and share their personal experiences.” Another participant emphasized that “being able to have open conversations about careers with different people throughout the symposium was very useful.”
Most of the participants are considering applying together with one of the UPSC group leaders for a European fellowship, although some pointed out that they need more time. When asked if they had any additional comments or suggestions for the organisers of the symposium, one participant commented:
“I was truly touched by the warm welcome! However, one thing that felt a bit disappointing was how short the time was to learn about the PIs' work. A two-minute pitch felt too brief - but I understand that time was limited. Regardless, I’m really grateful for this opportunity!”
“This is the third time in a row that this symposium has been organised, and it is great to see that it was so well-received by the participants,” said Kelly Swarts, the third organiser. “We will now go through the feedback from the participants and discuss with the UPSC group leaders how to proceed next year and and what improvements can be made.”
The symposium finalised with a pizza & ping-pong event in the UPSC lunchroom (photo: Anne Honsel).
More information about the UPSC Symposium for Early Career Plant Scientists
For questions regarding the symposium, please contact:
Laura Bacete
Umeå Plant Science Centre
Department of Plant Physiology
Umeå University
Email:
https://www.upsc.se/laura_bacete
Kelly Swarts
Umeå Plant Science Centre
Department of Forest Genetics and Plant Physiology
Swedish University of Agricultural Sciences
Email:
https://www.upsc.se/kelly_swarts
Stephan Wenkel
Umeå Plant Science Centre
Department of Plant Physiology
Umeå University
Email:
https://www.upsc.se/stephan_wenkel
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Chile is like Sweden a country with extreme climate zones. Photo: Maria E Eriksson.
In January 2026, researchers from Sweden and Chile will meet in Concepción, Chile, for the ACCESS Forum 2026. The aim is to foster networking and exchange between researchers from both countries, with focus on the UN’s Sustainable Development goals. One of the participating scientists is Maria E. Eriksson from UPSC and Umeå University. Together with Luisa Bascuñán from Universidad de Concepción, she will lead the research theme “Resilient plants for the future: Lessons learned from challenging environments” and organise a workshop.
Maria E. Eriksson, who studies how the circadian clock regulates plant growth also under adverse environmental conditions, has a long-standing collaboration with Chilean researchers. In 2015, she started even a Research Links project supported by the Swedish Research Council, that allowed her and her Chilean partner to intensify their collaboration. The focus of the research theme workshop that she will co-host with Luisa Bascuñán at the ACCESS Forum 2026 will be on current plant improvement and health approaches and discuss what is needed to tackle increasingly challenging environmental conditions.
“Chile and Sweden have in common that they are two countries with many growing zones and extreme climates. Chile is located near the southern polar circle and Sweden near the northern one,” says Maria E. Eriksson. “I hope this collaboration will help us build more bridges and deepen our understanding of future needs and challenges, drawing on the expertise of plant scientists from both countries. The ecosystem services that plants provide, such as being the basis for many medicines, clean water and providing us with food and oxygen, are the foundation of our entire existence.”
Researchers from all fields and different career stages are invited to the ACCESS Forum in Concepción to stimulate multidisciplinary networking and provide the participants with new perspectives and methods focussing on the Sustainable Development Goals defined by the United Nations. Priority is given to researchers that are employed at one of the member universities of ACCESS (Academic Collaboration Chile Sweden), a collaboration of eight Swedish and seven Chilean universities, but researchers from other universities are also welcome. The overall goal of ACCESS is to encourage and increase research collaborations between Sweden and Chile.
More information:
The ACCESS Forum 2026 in Concepción, Chile, will take place on January 12-16. The deadline for signing up is April 21, 2025. The Sustainable Development Goals (SDG) selected for the 2026 Forum are SDG #3 - Good Health and Well-being, SDG #11 - Sustainable Cities and Communities, SDG #13 - Climate Action, SDG #14 - Life Below Water and SDG #15 - Life on Land.
More information about ACCESS and the ACCESS Forum 2026 in Chile
Contact:
Photo: Happy Wilder.
For more information about the research theme “Resilient plants for the future: Lessons learned from challenging environments”, please contact:
Maria E. Eriksson, Associate Professor, Umeå Plant Science Centre, Department of Plant Physiology, Umeå University,
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PhD student Alice Marcon has studied flowering and seasonal growth in trees.
Spring is on its way and trees will soon flush their buds. Deciduous trees have to adjust their growth and development to the respective season, but how is this regulated? PhD student Alice Marcon set out to investigate this and characterised the function of two flowering genes that regulate not only flowering but also seasonal growth in poplar. She also created a seasonal roadmap of gene activities and identified key genes regulating bud dormancy, bud flush and flowering providing valuable information for tree breeding programmes.
- 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?
Alice Marcon: 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?
Alice Marcon: 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?
Alice Marcon: 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?
Alice Marcon: 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?
Alice Marcon: 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?
Alice Marcon: 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?
Alice Marcon: 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.
About the public defence:
Alice Marcon, Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, will defend her PhD thesis on Friday, 4th of April 2025. Faculty opponent will be Timo Hytönen, Department of Agricultural Sciences, Viikki Plant Science Centre (ViPS), University of Helsinki, Helsinki, Finland. The thesis is supervised by Ove Nilsson.
Title of the thesis: Regulation of flowering time and phenology in Populus trees
Link to Alice Marcon’s PhD thesis: https://res.slu.se/id/publ/132951
For more information, please contact:
Alice Marcon
Umeå Plant Science Centre
Department of Forest Genetics and Plant Physiology
Swedish University of Agricultural Sciences
Email:
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Thale cress seedlings with defective RG-II pectin dimerization (right seedling) cannot establish a full apical hook like non-modified seedlings (right seedling). The apical hook is formed when seedlings emerged from the soil to protect their sensitive leaves on top (collage: Anne Honsel).
Plant cell walls give stability to the plant, but they are not just rigid structures. The wall components dynamically interact with each other to influence growth and development. An international research team led by Rishikesh Bhalerao from SLU uncovered a new regulatory link between the plant cell wall and plant hormones. Their results were recently published in Science Advances.
When hearing about walls, one thinks of rigid structures like medieval town walls that served as protection against intruders. Plant cell walls fulfil similar defence functions, but they are not as inert and rigid as town walls. On the contrary, they are much more flexible and dynamic and play a crucial role during plant growth and development.
“The cell wall is a highly complex network of proteins and several long-chain carbohydrate molecules like cellulose, hemicellulose and pectin”, explains Rishikesh Bhalerao, professor at the Swedish University of Agricultural Sciences and group leader at Umeå Plant Science Centre. “These key components have been known for a long time, but how they interact with each other and how these interactions functionally contribute to the control of plant growth and development is still poorly understood.”
A defective RG-II pectin dimerization causes weaker cell walls
Rishikesh Bhalerao and his colleagues from United Kingdom, Belgium, Switzerland, China and Canada focused on the cell wall component RG-II pectin. This is a highly modified pectin whose role in the cell wall has remained obscure. RG-II pectin is usually present as a dimer, meaning that two RG-II pectin molecules are bound together. To understand its role in plant development, the researchers used a thale cress mutant in which this dimerization did not work, resulting in weaker cell walls.
“We discovered nearly ten years ago that deficiency of RG-II pectin causes a particular defect in development of the apical hook, a structure that is formed by germinating seedlings that bend down when emerging from the soil”, continues Rishikesh Bhalerao. “We had already established the link between certain other pectin modifications, and mechano-chemical control of the distribution of the plant hormone auxin in apical hook development. Now, we could show that there is also a link between RG-II pectin and auxin and another hormone called brassinosteroid.”
The plant hormone auxin promotes cell growth and elongation in plants. During apical hook formation auxin accumulates on one side of the seedling. This promotes a faster cell growth on this side compared to the opposite side, which ultimately leads to the bending of the seedling. The researchers showed that RG-II pectin dimerization also affects the regulation of auxin distribution, but it acts more centrally by affecting the activity of several genes of the auxin transport machinery.
Cell wall components and hormones interact in a dynamic manner
Unexpectedly, the researchers also found a connection between RG-II pectin dimerization and brassinosteroids – another group of plant hormones involved in regulating cell division, elongation and differentiation. The defective RG-II pectin dimerization suppressed the biosynthesis of brassinosteroids which in turn impacted RG-II pectin, thus demonstrating a hormonal feedback on RG-II pectin dimerization.
“Cell wall components and hormones interact with each other in a dynamic manner and thus regulate growth and development”, says Rishikesh Bhalerao. “It has taken a long time and considerable effort especially from my former postdoc Pawan Kumar Jewaria, who is now a group leader at the National Institute of Plant Genome Research in India, to reach this point.”
Rishikesh Bhalerao and his colleagues are convinced that the new regulatory mechanisms they discovered are not only relevant for apical hook formation but also for other processes that involve differential growth such as the directed growth towards light. They hope that other researchers in the field of cell wall mechanics and development can use these results now and build further on them to understand how cell wall mechanics and its interplay with plant hormones can regulate plant architecture.
About the scientific publication
Title: Reduced RG-II pectin dimerization disrupts differential growth by attenuating hormonal regulation
Authors: Pawan Kumar Jewaria, Bibek Aryal, Rifat Ara Begum, Yaowei Wang, Gloria Sancho-Andrés, Abu Imran Baba, Meng Yu, Xiaojuan Li, Jinxing Lin, Stephen C. Fry, Stephane Verger, Eugenia Russinova, Kristoffer Jonsson, Rishikesh P. Bhalerao
Published in Science Advances 11, eads0760(2025). DOI:10.1126/sciadv.ads0760
https://www.science.org/doi/10.1126/sciadv.ads0760
For more information, please contact:
Rishikesh Bhalerao, Professor, Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences
Email:
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Åsa Strand, Professor at the Department of Plant Physiology at Umeå University, is appointed as the first substitute for the three teacher representatives at the University Board of Umeå University (photo: Mattias Pettersson, Umeå University).
With the start of the new term of office on January 1, Åsa Strand has been appointed as a member to the University Board of Umeå University, the highest decision-making body at the university. She will serve as the first substitute for the three teacher representatives until the end of 2027.
Åsa Strand has already previously accepted various commissions of trust at Umeå University and Umeå Plant Science Centre, as well as external roles, such as with the Swedish Research Council. As teacher representatives at the University Board, her role is to ensure that the perspectives and interests of the academic staff are considered in the decision-making process.
The University Board is responsible for making key decisions regarding the allocation of resources, setting important organizational matters, and lodging annual reports and budget documents to the Swedish government. It also sets admission regulations for undergraduate and graduate education and oversees appointment procedures.
More information about the board of Umeå University (in Swedish)
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PhD student Sanchali Nanda (front) and her supervisor Stefan Jansson (back) at the ChloroSpec instrument at Umeå Plant Science Centre (photo: Anne Honsel).
Light drives photosynthesis, but excessive light can be harmful. Plants protect themselves by converting surplus energy in their chloroplasts into heat for dissipation. PhD student Sanchali Nanda helped validate a novel instrument that monitors the stress levels of plants and used it to gain new insights on their energy dissipation mechanisms.
- You did your PhD in Stefan Jansson’s research group at Umeå Plant Science Centre. Coming from India, how was it for you to work and live in Northern Sweden?
Sanchali Nanda: I enjoy challenges, and this was a fun challenge. On my first night in Umeå, seeing the greenhouse lights glowing was an enlightening moment - I was thrilled from the start. I arrived in August when it was still bright and sunny, but everything was new: the environment, the people and the culture. I experienced my first snowfall, skied for the first time, and even learned to cycle through winter. Coming from a rather pampered background as an Indian student, I had to become more self-reliant, managing things independently and taking responsibility not just professionally but also personally. I think these are the core lessons that I carry from my five and a half years of experience in Umeå.
- You studied how plants protect themselves from too much light. Why is this important?
Sanchali Nanda: Photosynthesis is the most important process on Earth, driving oxygen evolution, food production and sustaining life - yet it remains not fully understood. While its core fundamentals are known, much more is at play. Light powers photosynthesis, but plants cannot use all of it. Once saturated, excess energy can lead to radical formation, oxidative stress and damage to the photosynthetic machinery. Such damage is costly, so plants have evolved mechanisms to dissipate surplus energy and prevent such inadvertent effects.
- What kind of mechanisms have plants developed to protect themselves?
Sanchali Nanda: Various mechanisms regulate light energy. My PhD research focused on non-photochemical quenching processes, which are photoprotective mechanisms whose molecular characterization began in the 1990s. One highly debated mechanism in the field is direct energy transfer between the two photosystems in the thylakoid membrane inside the chloroplast, commonly referred to as spillover. First described in the literature in 1976, this phenomenon is now supported by evidence from our experiments.
During photosynthesis, light is absorbed by the light-harvesting complex, which consists of proteins, chlorophylls and other pigments within the chloroplasts of plant cells. This energy is then transferred via several steps to fuel carbon fixation and sugar synthesis. When this pathway becomes saturated, excess energy can be released either as light of different wavelengths or as heat through non-photochemical quenching. There are different processes, some slower and some faster ones, involving different molecular players. The aim of my thesis was to propose a more holistic approach to describing non-photochemical quenching by integrating data from fluorescence spectra obtained from in vivo samples at physiological temperature for the first time.
- When summarising your thesis, what do you consider as the major outcome?
Sanchali Nanda: I used a novel chlorophyll fluorescence measuring technique with an instrument called ChloroSpec, which is currently exclusively available in Umeå. This instrument measures the fluorescence emitted by chlorophyll as a proxy for estimating the intensity of non-photochemical quenching processes. Since fluorescence and non-photochemical quenching are competitive processes, greater energy dissipation as heat results in reduced fluorescence emission. However, non-photochemical quenching not only affects the overall fluorescence intensity but also alters the spectral properties of the emitted light, depending on the quenching process involved.
The ChloroSpec instrument combines two functions in one: it measures fluorescence at key wavelengths with high temporal resolution while simultaneously detecting the full light spectrum. Its greatest advantage is the ability to perform these measurements on living plants, in real time and at physiological temperatures. To validate the instrument, we compared our measurements with fluorescence parameters described in the literature. I was heavily involved in troubleshooting, testing the software and contributing to its further development. This required significant effort but progressed surprisingly well. Now, we can characterise multiple fluorescence parameters with a single measurement in living plants, enabling a more holistic assessment of plant stress. We hope that many other researchers will benefit from this advancement.
Using ChloroSpec, we re-examined the roles of two key molecules, in non-photochemical quenching: PsbS, a protein that is part of photosystem II, and zeaxanthin, a yellow pigment that is part of the light-harvesting complex. Our findings revealed that PsbS facilitates quenching in the light-harvesting complex, while zeaxanthin regulates energy transfer between the two photosystems, working together to protect plants from light damage. Electron microscopy also showed how non-photochemical quenching causes structural changes in plant cells, providing a clearer understanding of how plants adapt to light stress. We expanded our model by testing hybrid aspen mutants, validating our results. Overall, our work offers new insights into the dynamic, time-dependent nature of non-photochemical quenching, extending beyond previous research focused on steady-state conditions.
- Were there any results that you did not expect or that were astonishing you?
Sanchali Nanda: What surprised me the most were the results we obtained when comparing naturally occurring aspen varieties from different latitudes in Sweden. While we theoretically expected variation, seeing up to two-fold differences in non-photochemical quenching and plant height was truly astonishing. This finding raised exciting questions about the genetic basis of this variation, and we are now exploring whether these differences are linked to specific genetic variations, though we don't have those results yet.
- Doing a PhD is often very challenging. Would you like to share some of the challenges that you had to overcome?
Sanchali Nanda: Ultimately, everything turned out positively, but I’d be remiss not to acknowledge the challenges that came along the way, both personally and professionally. I had to switch supervisors, a difficult decision, but the department was incredibly supportive, for which I am deeply grateful. I am fortunate to have found mentors who believed in me and understood my journey at a crucial time. Of course, there were also the inevitable challenges of failed experiments, modifying plans and adjusting projects. Flexibility and continuous evaluation of my work were key. Throughout this process, I discovered more about myself - my strengths and limitations - and learned how to cope with setbacks, how to talk about them openly, and how to take responsibility. It feels like a mental metamorphosis, like transitioning from unquenched fluorescence to regulated non-photochemical quenching - learning to channel energy efficiently under pressure. Now, as I near the end of my PhD, I am exhausted but content with the progress I’ve made, and I have no regrets.
- What are your plans now?
Sanchali Nanda: I am currently seeking my next challenge - a postdoc abroad. I am actively applying and have connected with researchers interested in my profile. I have identified a couple of labs that I would like to work with and am exploring ways to make this possible. In the coming months, I will remain at UPSC to wrap up some unfinished work. Two of my papers are still in progress: one has already been submitted, while the other awaits further analysis of data. I plan to take a break after my defence before diving back in to finish my final chapter in Umeå.
About the public defence:
Sanchali Nanda, Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, had defended her PhD thesis on Thursday, 6th of March 2025. Faculty opponent was Matt Johnson, Professor at the University of Sheffield, United Kingdom. The thesis was supervised by Stefan Jansson.
Title of the thesis: New light on photoprotection: Spectral resolution of non-photochemical quenching
Link to Sanchali Nanda’s PhD thesis
For more information, please contact:
Sanchali Nanda
Umeå Plant Science Centre
Department of Plant Physiology
Umeå University
Email:
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PhD student Varvara Dikaya has studied how plants adjust to cold by focussing on the protein PORCUPINE (photo: Nabila El Arbi).
Plants have developed versatile processes to react to cold temperatures. Varvara Dikaya studied PORCUPINE, a protein that is part of a hub regulating responses to environmental cues like cold. In her PhD thesis, she showed that there is not just a single link between PORCUPINE and cold signalling, but multiple intertwined passes that act simultaneously.
To acquire cold resistance, plants developed complicated temperature sensing and adaptation mechanisms. Much of the research done so far to study such temperature responses focuses on changes in gene expression and on molecules that ensure cold resistance, for example amino acids, sugars and other molecules that prevent freezing. Components of the splicing machinery like the PORCUPINE protein were not part of this picture for a long time.
“Splicing acts as a central hub controlling the information flow from DNA to RNA defining which proteins are synthesised from a certain gene,” explains Varvara Dikaya who is working in Markus Schmid’s group at the Department of Plant Physiology, Umeå University, which is part of Umeå Plant Science Centre.
“Only recently attention shifted towards splicing proteins that play a role in cold signalling. One of these proteins is PORCUPINE which is named after the spiky look of the shoot tip of its mutant. It was discovered because Arabidopsis plants with mutated porcupine gene are cold sensitive.”
A single gene can give rise to multiple proteins
Many processes affect how many RNA copies are synthesised from a certain gene and which protein information these copies contain. During splicing, some parts of the initial RNA copy are cut out, changing the resulting sequence and information of the mature RNA that is used as template for the protein synthesis. This way a single gene can give rise to multiple mature RNAs and consequently different proteins.
“Splicing is a ubiquitous process common for animals, plants and fungi,” says Varvara Dikaya. “For plants, splicing is especially important when responding to environmental cues like for example cold. Depending on the growth conditions, the mature RNA copies synthesised from one gene can drastically differ and cause a redirection in the developmental programs.”
Hundreds of proteins are involved in splicing. Together with a special RNA type, they form a biological machine, the spliceosome. The spliceosome contains a core unit of several proteins which are evolutionary conserved. PORCUPINE is one of these core proteins, but, unlike many of the other core proteins, its loss makes plants particularly sensitive to cold.
“It is quite common to see growth and development alterations or even lethal effects when one of the core splicing proteins is mutated,” continues Varvara Dikaya. “The PORCUPINE mutant appears normal under ambient temperature conditions but cannot develop properly in case of even a mild temperature drop. Already at 16 degrees, the mutant grows shorter roots with increased root hair density and much smaller rosettes than normal. This is very special.”
PORCUPINE protein is involved in multiple intertwined signalling pathways
Varvara Dikaya and her colleagues were wondering in which way the PORCUPINE protein regulates responses to cold and why its loss causes cold sensitivity. However, the answer was not easy. They found that the PORCUPINE protein is involved in multiple intertwined signalling pathways.
On the one hand, temperature directly regulated the amount of the PORCUPINE RNA copies in the cell. The colder it is, the more RNA copies of the PORCUPINE gene were produced, assuming that also more PORCUPINE protein was available for the spliceosome. On the other hand, the spliceosome is tightly connected to the machinery that synthesises RNA from DNA - timewise and also with respect to its location in the cell. When one of the processes is adjusted to dropping temperatures, the other is likely to be affected as well. PORCUPINE might just be one of the multiple core splicing proteins that are affected by a general adjustment at the spliceosome making it very difficult to identify PORCUPINE-specific responses.
The researchers also investigate which genes’ splicing is directly controlled by PORCUPINE in a temperature-dependent manner. They identified several genes and some of them were key genes regulating the temperature response in plants. Varvara Dikaya and her colleagues think that the misregulation of these genes at least partially caused the specific look of the porcupine mutant.
“If all mentioned processes are coordinated properly in time and space, plants successfully adapt to the temperature drop,” concludes Varvara Dikaya. “Our current findings show the complexity of the cold response in plants. It is important to understand all aspects and identify fundamental mechanisms that could be applied later on in a practical manner. Such knowledge will be essential to create more resilient plants capable of withstanding environmental challenges in the future, but it is still a long way to go.”
Depending on the current needs of the cell, the reassembling of the different exons and introns during the splicing process can be adjusted resulting in different mature RNA variants and consequently various proteins with different functions. This so-called alternative splicing adds an additional level of complexity but allows more flexibility to adjust to changing conditions. In plants, it is especially important in response to environmental cues like temperature changes.
The splicing process: when a gene is activated, the DNA is transcribed into RNA via the protein complex RNA polymerase. The resulting RNA copy or RNA transcript is then processed by the spliceosome that cuts out introns (regions that are not important for the protein synthesis) and joints the remaining exons (regions that contain protein information). Depending on the needs of the cell, different variants of the mature RNA are assembled by the spliceosome (illustration: Varvara Dikaya).About the public defence:
Varvara Dikaya, Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, will defend her PhD thesis on Friday, 28th of February 2025. Faculty opponent will be Richard Immink from Wageningen University and Research Centre, the Netherlands. The thesis was supervised by Markus Schmid.
Title of the thesis: Broken Sm-ring: A quest to the source of the cold sensitivity of the A.thaliana SmE1 splicing mutant
Link to Varvara Dikaya’s PhD thesis
For more information, please contact:
Varvara Dikaya
Umeå Plant Science Centre
Department of Plant Physiology
Umeå University
Email:
Text: Varvara Dikaya & Anne Honsel
- Details
The researchers Olivier Keech and Clément Boussardon are studying pollen grains from Arabidopsis plants. Photo: Rebecca Forsberg
Scientists at Umeå University have found a way to break open the protective walls of pollen grains – one of the hardest biomaterials in the world – without damaging the inside cell and its components. This achievement opened the possibility to isolate and study mitochondria – parts of the cell essential for energy production. To their surprise, several proteins that are key for maintaining the energy production of the mitochondria, were nowhere to be found.
“Flowering plants are dependent on pollen to reproduce, and the pollen grains are very special in many ways,” says Olivier Keech, Associate Professor at the Department of Plant Physiology, Umeå University and group leader at Umeå Plant Science Centre, UPSC. He explains that each pollen grain contains a tiny capsule, a cell that carries the male genetic material necessary for the next generation of plants.
Pollen Grains: Nature's Resilient Capsules
When a pollen grain encounters a female plant of the same species, fertilization may happen and can give rise to a new generation. But immediate contact is not always a given. To survive harsh environments, pollen grain has developed a specific outer structure that protects the cell, allowing it to travel long distances with the wind or pollinators, such as insects, birds or reptiles.
“This tough outer wall is largely made of one of the most resistant biomaterials known on this planet. This makes the pollen grain wall highly resistant to environmental damage and some pollen grains can remain preserved in sedimentary rocks for millions of years,” says Olivier Keech.
Olivier Keech, Associate Professor at the Department of Plant Physiology at Umeå University is studying how mitochondria respond to stress. Photo: Johan Gunséus
That a pollen grain can survive for such long time span is thanks to an in-house energy production – the mitochondria. “It’s a tiny compartment of the cell that is essential for its survival,” says Olivier Keech.
The mitochondria have its own genetic material, essential for its biological activity, and notably for producing the energy that keeps the cell alive. But to study the pollen mitochondria, they had to break open the protective wall.
A Surprising Discovery and a Collaborative Success
The idea to study pollen mitochondria germinated at a conference in 2019. Olivier Keech and his colleague at UPSC, Clément Boussardon, presented a new technique developed in Umeå, that enables trapping and isolation of mitochondria. This innovative technique intrigued collaborators who studied pollen cells.
However, from the birth of the idea, it took a few years to reveal the secrets of pollen, quite literally. “Breaking up pollen grains and isolating intact mitochondria was truly challenging. These are biological structures, a million times smaller than a meter, encapsulated in a tiny safe – dynamite was not an option!” says Clement Boussardon, Senior Research Engineer in Keech’s group and first author of the study published in Current Biology.
Staff scientist Clément Boussardon is studying mitochondria from Arabidopsis pollen grains. Photo: Rebecca Forsberg
Clément Boussardon, together with their collaborator Matthieu Simon from INRAE in France, spent over four years perfecting their method to open the pollen grains while preserving the cell. What they discovered, was not what they expected.
“What we found was quite surprising,” says Olivier Keech. “We discovered that the proteins that are associated with maintenance and the expression of the genetic material in mitochondria, essential for keeping it alive, were nowhere to be found.”
“This is a bit like mitochondria were ready to produce energy but were not equipped for any repairs if needed. This discovery may explain why a pollen grain in the end has a limited lifetime, and why it is fine tuned to survive for the duration of its unique mission - fertilization,” says Olivier Keech.
Olivier Keech and Clément Boussardon credit their success to the multidisciplinary nature of the study, which brought together researchers from Germany, France, New Zealand, and of course Umeå. “Combining the expertise of our diverse research teams has been a great pleasure and was key to this success,” concludes Clement Boussardon.
About the scientific publication
Title: The atypical proteome of mitochondria from mature pollen grains
Clément Boussardon, Matthieu Simon, Chris Carrie, Matthew Fuszard, Etienne H. Meyer, Françoise Budar, Olivier Keech
Published in Current Biology, Doi.org/10.1016/j.cub.2024.12.037
Link to the article in Current Biology
For more information, please contact:
Olivier Keech, Associate Professor at the Department of Plant Physiology,
Umeå Plant Science Centre, Umeå University
Email:
Clément Boussardon, Senior research engineer at the Department of Plant Physiology, Umeå Plant Science Centre, Umeå University (English speaking)
Email:
Text: Rebecca Forsberg