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Several of the female scientists that are currently working at UPSC
[2021-02-11] Today is the International Day for Women and Girls in Science. We have asked three female professors at UPSC who are at different states in their career about their way to science, their career and their ideas to inspire the next generation of women in science.
The purpose of the International Day for Women and Girls in Science is to empower women and girls in science to achieve equality. It was established in 2005 by the United Nations General Assembly and implemented by UNESCO and UN-Women. According to UN-Women, 30 percent of researchers world-wide are women and they are still disadvantaged in their career.
Why did you choose to become a scientist?
Anita Sellstedt: It is my basic curiosity for natural science that has been and is still my driving force. That has led me into basic science. In addition, I have always been interested in research that could be of benefit for developing countries. This research has now turned out to also be sustainable, such as nitrogen fixation and hydrogen production by the aid of bacteria.
Åsa Strand: I was always very curious and creative, and I also wanted to do my own thing. A scientific career suited my personality.
Stéphanie Robert: To be a scientist was just obvious for me. I was also very curious and was fascinated by what science can do in our everyday life.
Do you remember a key moment that influenced your decision to go into science?
Åsa Strand: Yes, when I was in high school a relative introduced me to the work of Barbara McClintock. I can still remember how fascinated I was by the “jumping genes”. When I got to see the actual corn cobs of Barbara McClintock when I was invited to Cold Spring Harbor for a seminar - it was a special moment.
Stéphanie Robert: In my childhood, my grandmother had a very cutting-edge heart operation, and I remember being on the hospital parking lot and thinking that I wanted to participate in the scientific progress that led the surgeons to perform such an operation. I am not working in the medical field today, but we are doing basic research and you never know to which applications your results might lead in the future.
Anita Sellstedt: The key moment for me came when I had taken my last course in plant physiology and I was able to do a project on nitrogen fixation. Then I felt that “This is my research field”. The interaction between plants and bacteria, a combination of plant physiology and microbiology, was fascinating me throughout my career.
What were the biggest obstacles you had to overcome during your career?
Stéphanie Robert: At the beginning of my work as a group leader, I struggled because I was trained as a scientist by being in the lab as a PhD and post-doc fellow but not to lead and mentor other people. The science was not a problem, but many other things were such as hiring people, understanding how to make a budget, how to write successful grant applications, how to learn to not say “yes to everything”, or dealing with conflicts within the group. I am still learning every day.
Anita Sellstedt: I think that the uncertainty with fundings was the main obstacle for me. When I was a PhD student, I was funded several years by stipends and to be able to continue as a research after my PhD, I had also to apply for funding. Perhaps the new system with Assistant Professor positions that come with some fundings is better. You are evaluated after a couple of years and hopefully get the option to continue your research.
Åsa Strand: Early in my career it was to fight against the ingrained notion that women are not as career driven as men and that we do not have the same wish to excel and are rather happy to be in the background. Now that I am in leadership position this is something that I am very conscious of.
What do you think can we do to inspire the next generation of women in science?
Åsa Strand: If anything good has come out of this horrible pandemic it is that it has become clear how important science is to our society. Being part of that process is rewarding and should appeal to and inspire also the next generation of both men and women.
Anita Sellstedt: I think the best way to inspire the next generation of women in science is to have basic fundings. Next it is of importance to have a mentor system with female scientists that can meet with the newly recruited scientist and discuss both science and other things around work. Perhaps, it also would be good if the female mentor is within a similar field as the newly recruited scientist. I also think that the structure of the Departments at Umeå University of today with representatives of equal opportunities gives a basic structure that will benefit for the underrepresented group, for example women in science.
Stéphanie Robert: Seeing women from many backgrounds doing science their own way is inspiring, I think. The diversity of women in science should be the same than in the real world. The important thing is to find your own way to do science.
What skills do you think should young (female) researchers have or develop when starting their career in science nowadays?
Anita Sellstedt: The skills of most importance are to have real interest in the specific field of science, stubbornness, as well as both moral and financial support, and other female scientists to discuss with.
Åsa Strand: It is important to be smart and build your scientific profile, develop a research profile that is both unique and desirable. Define your own research question that is relevant to your specific field and that can be elevated into a more general context. Express clearly what you want and what your goals are. Accept tasks that you initially feel that you are not quite ready for, take on the challenge and make yourself ready and you will be rewarded by valuable experiences that will get you ahead.
Stéphanie Robert: Self-assessment. The most important to me is to be able to identify what are your strong and weak points. You can build on your strong points and request help on the weakest ones. Nobody knows it all, but it is good to be able to listen to constructive comments and integrate them in your way of doing things. This is valid for any gender.
The three interviewed professors from UPSC: Stéphanie Robert (left), Anita Sellstedt (middle) and Åsa Strand (right)
Stéphanie Robert was recently, in the end of 2020, appointed as professor at the Department of Forest Genetics and Plant Physiology at the Swedish University of Agricultural Sciences recently. She studies how plant cells require their shape and received the Sven and Ebba-Christina Hagberg Prize for her research achievements in 2019.
Read more about Stéphanie Robert’s research
Anita Sellstedt, since 2002 professor at the Department of Plant Physiology, Umeå University, is studying energy production by microorganism. She has received two prizes for the environmental impact of her research and has been for several years’ equal opportunity representative at the department. Anita Sellstedt will retire in 2021.
Read more about Anita Sellstedt’s research
Åsa Strand became professor at the Department of Plant Physiology in 2013. Her research focus is on the regulation of cellular energy metabolism. Åsa Strand received in 2019 the Physiologia Plantarum Prize from the Scandinavian Plant Physiology Society (SPPS), she is currently member of the Scientific Council for Natural and Engineering Sciences that is appointed by the Swedish Research Council and she coordinates two large SSF (Swedish Foundation for Strategic Research) project grants.
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Norway Spruce seedlings growing in the greenhouse (photo: Sonali Ranade)
[2021-02-01] Sweden is a country with big differences in light conditions between the South and the North. Norway spruce tolerates low light or shade generally well but Sonali Ranade and Rosario García-Gil from UPSC showed now that there are latitudinal differences. Seedlings from Northern Sweden are better adapted to low light conditions than seedlings from Southern Sweden. This genetic adaptation seems to come along with a higher resistance to diseases. The results were published last week in the journal Planta.
The researchers from UPSC compared the growth of Norway spruce seedlings that derive from different latitudes in Sweden and showed that the seedlings from the north were better adapted to shady conditions than the ones from the south. When analysing the genetic set-up of the different trees, they found, among other, differences in genes involved in lignin and cell wall synthesis, in stress responses and immunity. The two researchers concluded that the northern Norway spruce populations have not only adapted to low light conditions but might be also more resistant to diseases.
“Shade causes stress to most plants. They try to grow towards light so that they can use the full light energy for their photosynthesis,” says Sonali Ranade, postdoctoral researcher in Rosario García-Gil’s research group. “In a previous study, we saw that Norway spruce seedlings are more shade tolerant than for example Scots pine seedlings. Now, we realized that this is not so simple. The seedlings from the north developed longer stems than the seedlings in the south when growing under shady conditions. This shows that Norway spruce is able to adapt to local light conditions and we think that this goes along with modifications of the lignin metabolism.”
The lignin content often decreases when plants are exposed to low light conditions and this weakens the stem. Lignin is one of the main components in cell walls and helps to make the walls stronger allowing the plant to grow upright. In the cell walls, lignin also provides a barrier for pathogens to enter the cells. By scaling up lignin and cell wall biosynthesis and in parallel activating defence related genes, the northern Norway spruce populations might be able to adapt to shady conditions and in parallel improve their resistance to diseases.
“Studying the genetic diversity of trees from the same species help us to understand how plants adapt to local climatic conditions”, explains Rosario García-Gil, group leader at the Department of Forest Genetics and Plant Physiology at the Swedish University of Agricultural Sciences that is part of UPSC. “In Northern Sweden, the trees experience extended periods of shade-like conditions during their growing season. Climate change might lead to higher temperatures, but the light conditions will not change. To know the genetic factors that allow trees to adapt to the local conditions is crucial for forest breeding.”
Norway spruce is one of the most important tree species for forest industry in Sweden. To find the best adapted trees for a certain location is one forest management strategy to deal with climate change. Genetic markers like the genes identified in this study are used as tools to characterize different tree variants. The long-term goal is to identify as many marker genes as possible for a wide range of environmental conditions, including for example light, temperature and resistance to diseases. This will allow to design forest management strategies specifically adjusted to the local conditions.
About the article:
Ranade, S.S., García-Gil, M.R. Molecular signatures of local adaptation to light in Norway spruce. Planta 253, 53 (2021). https://doi.org/10.1007/s00425-020-03517-9
The previous study:
Ranade, S.S., Delhomme, N. & García-Gil, M.R. Transcriptome analysis of shade avoidance and shade tolerance in conifers. Planta 250, 299–318 (2019). https://doi.org/10.1007/s00425-019-03160-z
For more information, please contact:
Sonali Ranade
Umeå Plant Science Centre
Department of Forest Genetics and Plant Physiology
Swedish University of Agricultural Sciences
Email:
María Rosario García-Gil
Umeå Plant Science Centre
Department of Forest Genetics and Plant Physiology
Swedish University of Agricultural Sciences
Email:
https://www.upsc.se/rosario_garcia
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Jenny Lundströmer on campus in Umeå in front of Norway spruce trees (photo: Sonali Ranade)
[2020-01-25] How will Norway spruce behave in a changing climate? Jenny Lundströmer, industrial PhD student in Rosario García Gil’s group at UPSC and at former Bergvik Skog, investigated how warmer temperatures, more frequent spring frosts and drought affect Norway spruce from different origins. She recommends breeding not only for better growth but also for drought tolerance and other characteristics that help to adapt to a changing climate. In case of seed shortage from Swedish seed orchards, she advices Norway spruce provenances from Eastern Europe as valuable alternative. Jenny Lundströmer will defend her PhD thesis at SLU on Friday this week, 29th of January.
You investigated how Norway spruce can adapt to a changing climate. What aroused your interest into this PhD topic?
I am from a small village just below the arctic circle and grew up with the forest just besides me and have always been interested in how we can use the forest in a sustainable way and still enjoy it. The PhD topic was focussing on where to plant which provenances of Norway spruce to see which ones we should choose today that can survive the next 60 years. The project was part of the industrial graduate school in forest genetics, biotechnology and breeding and was in collaboration with Bergvik Skog that is now part of Stora Enso. For me, that sounded like a great opportunity to work more applied - which I was not doing during my masters - and combine it with my interest in forestry.
How was it to be part of the industrial graduate school that is a collaboration between the UPSC Centre for Forest Biotechnology and its industrial partners?
It was really great because we had regular meetings where we presented our projects and discussed them. I really appreciated this extra training but also the opportunity to follow the projects of the others over the years, see how they develop, discuss problems and exchange tips. Harry Wu also arranged great lectures with top professors in their field and courses that were specifically adjusted to our needs, as well as a trip to the US and Brazil where we saw some breeding institutes and plant nurseries. We also visited each other’s companies and met people there. My industrial partner was Bergvik Skog, where I did a project with seed orchards at their nursery, but I also had collaboration projects with Skogforsk and could get a deeper look into their work. I am really happy that I was part of the graduate school because I learned a lot, got additional experiences and valuable insights into industry and I found new friends through the graduate school.
What are the major threats for Norway spruce due to climate change in Sweden?
One of the biggest problems will be warmer temperatures. You could think that warmer temperatures are good because the trees can grow more as they have a longer vegetation time, but the winters will still be cold with freezing temperatures. This means that the trees have to stop their growth during autumn. There will also be more temperature backlashes in spring increasing the risk for frost damage - especially if bud burst starts earlier due to higher temperatures. In summer, higher temperatures increase the risk for drought. That is why we need trees that set their buds in time despite warmer autumns, that are able to bud burst at the right time in spring to prevent frost damage and that are drought tolerant. Both drought and spring frosts are mostly local problems. The crux will be to choose the right tree for the right place like for example trees with later bud burst on frost prone sites.
Do you think Norway spruce is able to tolerate future climate changes?
It has been growing good here for a long period and I think Norway spruce will survive the near and far future. To predict climate changes in the far future is difficult but the seedlings are the ones that are most sensitive to frost and drought, which make the prediction for the near future more valuable. One of my projects was to test how seeds from Eastern Europe with later bud burst and bud set perform when planted in the South of Sweden. It turned out that the trees are growing good there even though they start the vegetation period later than the Swedish ones. The growth rates are not as good as for trees from Swedish seed orchards but specifically on frost prone sites, the Eastern European provenances with later bud burst are a good alternative. This indicate that in a future with more spring frost events transfer of Norway spruce has to be performed for it to survive.
Which of your results is the most fascinating for you?
We analysed not only the first generation of Eastern European Norway spruce in Sweden but also second-generation material. These are trees that derive from Eastern European stands planted in Sweden that were open pollinated with Swedish populations around and which seeds were then planted out. Normally, we would assume that these trees have about 50% genetic material from the Eastern European material and 50% from the surrounding Swedish ones and that they bud burst after the Swedish material but before the Eastern European material. Astonishingly, we saw that they were closer to the Swedish population in terms of bud burst. Some other studies showed that the climate on the site where you plant a tree is affecting its seeds and we think that this might happen also here. I find it really fascinating to see that Norway spruce has the capacity to adapt this fast to the climate on its local site.
What challenges did you face during your PhD?
Everything took longer than planned but especially the last year was really challenging for me - not only because I wanted to finish my thesis but also because of Corona and all changes connected to this. I used to work from home a lot also before, but I found it strange to not be able to communicate with others in the usual way. The discussions are different if everything is online.
Do you have any recommendations for breeders, forest companies and/or forest owners?
I think that it is important to breed not only for better growth characteristics but also for trees that are able to adapt to a changing climate like for example that are more drought and frost tolerant. By comparing different clones, we saw that there are some that can deal better with drought than others. So, there is the potential. Provenances with later bud burst are better to use on frost prone sites because they are more likely to survive. I can just enhance the recommendation to use also seeds from Eastern Europe, especially as there is a shortage of seeds from Swedish seed orchards due to unregular flowering, insects and pests. Even the second generation of Eastern European trees are a good alternative, but it will be good to think about where to plant them to make sure they are suitable for the respective site.
What are your plans for the future?
First, I would like to take time for myself and my family. Then, I want to finish my papers and do some further analyses that I could not finish before. In parallel, I will look for a job. I would like to work in the forest industry. It does not have to be breeding but should be related to forestry or forest work and it would be nice to do something practical and not only computer work. In one of my projects, I joined the final assessment of the trees at the field sites. The weather was horrible, but I enjoyed doing practical work and see how the trees grow.
About the public defence:
The public defence will take place on Friday, 29th of January 2021 at SLU Umeå. Faculty opponent will be Darius Danusevičius from Vytautas Magnus University, Lithuania. Jenny Lundströmer was first supervised by Bengt Andersson Gull and later by María Rosario García Gil and co-supervised by Anna Maria Jönsson from Lund University. She was member of the industrial graduate school in forest genetics, biotechnology and breeding and worked with Bergvik Skog that is now part of Stora Enso, with Oskar Skogström as co-supervisor. At Skogforsk with which she had collaboration projects, she was co-supervised by Johan Westin and Mats Berlin. The dissertation will be live broadcasted via Zoom.
Title of the thesis: Adaption of Norway spruce (Picea abies (L.) Karst.) to current and future climatic conditions
Link to the thesis: https://pub.epsilon.slu.se/21159/
For more information, please contact:
Jenny Lundströmer
Department of Forest Genetics and Plant Physiology
Umeå Plant Science Centre
Swedish University of Agricultural Sciences
Email:
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Yan Ji (left) and her supervisor Åsa Strand (right) after Yan Ji's defence (photo: Anne Honsel)
What are the first developmental steps when a cell turns green? This question was addressed by Yan Ji, PhD student in Åsa Strand’s group, who studied the development of chloroplasts, the sites in the cell where photosynthesis takes place. Chloroplast development is a very complex process involving a series of regulatory steps and Yan Ji could show that certain regulatory steps happen already earlier than previously assumed. She successfully defended her PhD thesis at Umeå University on Tuesday, 15th of December.
The greening process starts as soon as the cell receives light for example when a germinated seedling reaches the soil surface. The chloroplast originates from a cyanobacterium that was taken up by a eukaryotic cell. During evolution, some of the genetic information from the cyanobacterium has been transferred to the gene material of the host cell that is stored in the nucleus. Chloroplast development therefore requires a coordinated communication between the chloroplast and the nucleus. Yan Ji studied the early stages of chloroplast development in the plant Arabidopsis thaliana.
You studied chloroplast development during the greening process. What aroused your interest in this topic?
To understand photosynthesis is of course very important for plant research but I did not had very much background about the whole process of chloroplast development when I was applying for this position. However, when I started to work on this project and got to know more about it, I got more and more intrigued. And when I was then for the first time inducing the greening process in our cell culture system, I thought this is really cool.
What is the advantage of using a cell culture system to study chloroplast development?
Our project was focussing on early stages of chloroplast development. The cell culture system allowed us to better resolve these early stages temporally. When dark grown seedlings receive light, it takes about 12 to 24 hours until the chloroplasts are green and fully mature. In our cell culture system, it takes five days until the cells start to turn green after they receive light and the cells develop more synchronised. resembles the chloroplast development in true leaves, which are the leaves that develop after the seedling has reached the soil surface. The cell culture system is of course more artificial because the cells are isolated from their tissue context which plays also an important role for development. That is why we always complemented our cell culture experiments with experiments with seedlings to verify our results.
What was the most fascinating for you during your PhD? Have you experienced any unexpected surprises during your studies?
I focussed in my studies on the role of the plastid-encoded plastid RNA polymerase, called PEP. This is a multi-subunit protein complex in the chloroplast that is responsible for the activation of most of the genes needed for photosynthesis. It was thought that the fully assembled complex associated with additional proteins is only available in the light when the chloroplast is developing and becoming mature, while in the dark, PEP was thought to be mainly present in its core form consisting of just four core subunits. We wanted to study when the different subunits are recruited to the protein complex during chloroplast development and focussed on the time when the cells just started to become green. However, we realized that the fully assembled complex was already available both in our dark grown cells and in the dark grown seedlings. We could also indirectly show that the complex was already active at this stage. The difference to the more mature chloroplast was that the abundance of complexes available was much lower. There were some hints in this direction before from experiments with other plants, but we did not expect to find the fully assembled complex so early during chloroplast development in true leaves.
What was the biggest challenge you faced during your PhD?
The discovery that the full assembled PEP complex is already available much earlier than we thought was of course very fascinating but also quite challenging for me because I had to rethink and redesign my hypotheses and experiments as a whole. Some of the planned follow-up experiments did not make sense or were not feasible anymore. That was very challenging. I also faced some technical challenges when I wanted to isolate chloroplasts from the cell culture. This is a standard method for plants, but the established protocol did not work for cells from the cell culture because their cell walls seem to be stronger. We had big problems to break the cell walls which is needed to isolate the chloroplasts. We tried many different ways to get it done and this took very long time which was quite frustrating.
What are your plans for the future?
I definitely want to do a postdoc either back in China or somewhere here. During my PhD, I learned many lessons and I am really looking forward to starting a new project and applying my experiences from this time. Hopefully, I find a nice project in photobiology or photosynthesis research to be able to continue in this field. I would be very interested to study these topics in other species to see which processes and components are conserved among species.
About the public defence:
The public defence took place on Tuesday, 15th of December at Umeå University. Faculty opponent was Eevi Rintamäki, Department of Biochemistry at the University of Turku in Finland. Yan Ji's supervisor was Åsa Strand. The dissertation was live broadcasted via Zoom.
Title of the thesis: Regulation of chloroplast development during the greening process
Link to the thesis: urn:nbn:se:umu:diva-176773
For more information, please contact:
Yan Ji
Department of Plant Physiology
Umeå Plant Science Centre
Umeå University
Email:
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Kristoffer Jonsson (left) and Abdellah Lakehal (right)[2020-12-16] Last Friday, the Swedish Research Council announced their decision regarding the autumn call for the international postdoc grant. The projects from Kristoffer Jonsson and Abdellah Lakehal were among the approved projects. Both finished their PhD at UPSC in 2019 and are currently working as postdoc there. The grant offers them secure employment conditions for the next three years and allows them to work on their research projects abroad to acquire new competences and expand their international networks.
You are the first two postdocs bringing this research grant in this form to UPSC. How does it feel to receive this grant?
Abdellah Lakehal: I didn’t know that we were the first ones, it’s definitely an honour to bring such a prestigious grant to the institute that forged my career. I am very happy and excited at the same time.
Kristoffer Jonsson: It is a nice validation that my proposed project is of general interest, which makes me even more motivated to get started addressing my questions. Also, I’m happy that Abdellah also received this grant, since we started our PhD roughly at the same time, and followed each other throughout the years.
What are you planning to do in your project?
Kristoffer Jonsson: Within the framework of the grant, I want to examine the basis of self-organization in morphogenesis, and how endogenous mechanical cues instruct cellular growth decisions. The project is planned to involve three overall layers of methodology: cellular resolution growth tracking, mechanical measurements and 3D computational modelling.
Abdellah Lakehal: I’m interested in de novo lateral root organogenesis in plants. Lateral roots are the main determinant of root system architecture and they play crucial roles in plant productivity by ensuring an efficient uptake of water and nutrients. My project aims at uncovering the evolutionary history of the molecular networks that guide stem cell specification during lateral root organogenesis using an early divergent plant species as a model system. To achieve this goal, I will take advantage of the state-of-the-art technologies such as single-cell analysis and genome editing.
Where do you plan to go?
Abdellah Lakehal: I plan to perform my research in the lab of Prof. Tom Beeckman at VIB-UGent, Ghent, Belgium.
Kristoffer Jonsson: The plan is to join the lab of Anne-Lise Routier-Kierzkowska at the Plant Biology Research Institute (IRBV) at Montreal University, Montreal, Canada.
Why did you choose your host institution?
Kristoffer Jonsson: I mainly wanted the chance to work with Anne-Lise Routier-Kierzkowska, who is doing very exciting work in the field of plant biomechanics and computational modeling. Anne-Lise is a biophysicist, and perhaps therefore has a very different approach to biological questions from what I am used to, which I find very stimulating. Beyond my host lab, IRBV is a multidisciplinary institute, and Montreal is the home of two renowned plant research centers (IRBV and the Plant Science Dept at McGill University). Several international plant research meetings are regularly held in Montreal. Thus, I’m hoping to meet a dynamic environment.
Abdellah Lakehal: I chose VIB because it is one of the strongest and most influential research centres in the world. In one hand, VIB will provide me with easy access to all the facilities and services needed for the accomplishment of the project. On the other hand, I will have ample opportunities to develop new skills. I will be working under the guidance of Prof. Tom Beeckman, who is an internationally recognized expert in lateral root development and stem cell regulations. His lab made incredible contributions to this field. I will certainly learn a lot there. During my stay at VIB, I will also have the opportunity to establish collaborations with world-top experts in evolutionary biology.
How much time do you plan to spend at your host institution?
Abdellah Lakehal: At the moment, I plan to spend 3 years at VIB.
Kristoffer Jonsson: We haven’t decided the exact timeline yet. Besides the work situation, I also have my family to consider. I’m just starting to put this puzzle together now.
What are your next steps now?
Kristoffer Jonsson: I’m still involved in ongoing projects with the Bhalerao lab which I hope we can conclude shortly, so I will continue at UPSC/SLU at least until the summer 2021.
Abdellah Lakehal: It is hard to predict the future as goals are dynamic and change over time, however, my ultimate goal is to come back to Sweden and establish my independent research group. I plan to decode the secrets behind “stem cellness” in plants by adopting an evolutionary perspective. In other words, how and what was needed for the early divergent plant species to evolve this unique capacity allowing them to conquer land and adapt to the ever-changing environmental conditions. Acquiring such fundamental knowledge will certainly allow us to shed light on key aspects of lateral root organogenesis in the extant seed plants.
The Swedish Research Council approved 41 out of 169 project applications. The applicants must have received their PhD no more than 2 years before the call closes. The grant will be administered by a Swedish University or public organisation meaning that the applicants will be employed in Sweden while working abroad.
For questions, please contact:
Kristoffer Jonsson
Department of Forest Genetics and Plant Physiology
Umeå Plant Science Centre
Swedish University of Agricultural Sciences
Email:
Project title: Sensing yourself: Mechanical feedback between organ curvature and cell-based decisions
Host institution: Department of Plant Physiology, Umeå University
Visiting institution: Plant Biology Research Institute (Institut de Recherche en Biologie Végétale IRBV), Université de Montréal, Canada
Abdellah Lakehal
Department of Forest Genetics and Plant Physiology
Umeå Plant Science Centre
Swedish University of Agricultural Sciences
Email:
Project title: Decoding the molecular basis of lateral root stem cell specification in plants
Host institution: Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences
Visiting institution: Center for Plant Systems Biology, VIB-UGent, Belgium
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Pine tree in winter (Photo: Stefan Jansson & Pushan Bag)
[2020-12-15] How can conifers that are used for example as Christmas trees keep their green needles over the boreal winter when most trees shed their leaves? Science has not provided a good answer to this question but now an international team of scientists, including researchers from Umeå University, has deciphered that a short-cut in the photosynthetic machinery allows the needles of pine trees to stay green. The study was published today in the journal Nature Communications.
In winter, light energy is absorbed by the green chlorophyll molecules but cannot be utilized by the downstream reactions in the photosynthetic machinery as freezing temperatures stop most biochemical reactions. This is especially a problem in the early spring when temperatures can still be very low, but sunlight is already strong, and the excess light energy can damage the proteins of the photosynthetic machinery. The researchers showed that the photosynthetic apparatus is wired in a special way which allows pine needles to stay green all year long.
Under normal conditions, the two photosystems, the two functional units where light energy is absorbed and converted into chemical energy, are kept apart from each other to prevent a short-cut and allow efficient photosynthesis. In winter, the structure of the thylakoid membrane, where the two photosystems are located, is reorganized which brings the two photosystems in physical contact. The researchers showed that photosystem II donates energy directly to photosystem I and this short-cut mode protects the green chlorophyll and the needles when conditions become harsh.
“We have followed several pine trees growing in Umeå in northern Sweden over three seasons”, says Pushan Bag, PhD student at Umeå university, who has collected samples all around the year and made many of the analyses. “It was essential that we could work on needles “straight from outdoors” to prevent that they adjusted to the higher temperatures in the lab environment before we analysed them for example with electron microscopy which we used to visualize the structure of the thylakoid membrane.”
All plants have safety valves to deal with the excess light energy which is either dissipated as heat or as fluorescence light. However, only conifers seem to have such powerful valves that they can keep the photosynthetic apparatus intact over the extreme boreal winter. The research team combined biochemistry and ultrafast fluorescence analysis, a very sophisticated method that can resolve chlorophyll fluorescence light at a picosecond time scale. Like this, they could demonstrate how the pine needles deal with excess light energy to protect their sensitive photosynthetic apparatus from damage.
“We needed to adjust the equipment to study pine needles in cold temperatures in order to trap the unique mechanism”, explains Volha Chukhutsina from Vrije Universiteit Amsterdam, who has performed much of the ultrafast fluorescence analysis. “We also tried spruce needles but they were hard to fit in a good way into the equipment”. Alfred Holzwarth, who has developed the time-resolved fluorescence measurements adds: “The pine needles gave us the opportunity to study this shortcut mechanism - also called spill-over - as they really show an extreme adaptation.”
The study was done with pine trees, but the researchers believe that the mechanism is probably similar for other conifer species – like the typical Christmas trees spruces and firs - because their photosynthetic apparatus is similar. “This remarkable adaptation not only enjoys us during Christmas but is in fact extremely important for mankind”, says Stefan Jansson from Umeå university. “Hadn´t conifers been able to survive in extreme harsh winter climates vast areas in the northern hemisphere may not have been colonized as conifers provided firewood, housing and other necessities. Still today they form the basis of the economy in most of the circumpolar taiga region”.
About the article:
Bag P., Chukhutsina V., Zhang Z., Paul S., Ivanov A.G., Shutova T., Croce R., Holzwarth A.R., Jansson S. (2020) Direct energy transfer from photosystem II to photosystem I confers winter sustainability in Scots Pine. DOI: 10.1038/s41467-020-20137-9
https://www.nature.com/articles/s41467-020-20137-9
For more information, please contact:
Professor Stefan Jansson
Umeå Plant Science Centre
Department of Plant Physiology
Umeå University
Email:
Phone +46-70-6772331
Text: Stefan Jansson & Pushan Bag
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Ioanna Antoniadi (left), winner of the UPSC Agrisera Prize 2020, and her group leader Karin Ljung (right) who is congratulating to the prize at the end of the UPSC Christmas Celebration on Zoom[2020-12-14] Ioanna Antoniadi is awarded with the UPSC Agrisera Prize 2020 to acknowledge her scientific achievements and her engagement to improve the work environment at UPSC. The UPSC Agrisera Prize is awarded every year to a person working at UPSC and was announced today during the virtual UPSC Christmas Celebration.
Ioanna Antoniadi works as a postdoc in Karin Ljung’s group at the Department of Forest Genetics and Plant Physiology at SLU. Since she started at UPSC, she contributed to several scientific publications, among others to a publication in Nature Communications in 2020. She is the expert for fluorescent-activated cell sorting (FACS) at UPSC - an advanced technique that allows to separate cells according to certain physical characteristics like for example different cell size – and was co-applicant for a successful grant application that allowed to purchase a new FACS instrument recently.
Besides her scientific contribution and her responsibility for supervising and training new users to the FACS instrument, Ioanna Antoniadi is part of the Departmental Common Laboratory Resources group that manages the laboratories at the Department of Forest Genetics and Plant Physiology. The nomination letter pointed out that “she is very engaged in improving the lab environment to make it work at its best” and that she spontaneously took over additional tasks besides her daily responsibilities to improve the work environment at UPSC.
The UPSC Agrisera Prize is awarded every year to a PhD student, a postdoc or a technician for excellent scientific achievement and great commitment to improve the UPSC work environment. It is sponsored by Agrisera but the members of the UPSC board select the winner of the prize. Everyone working at UPSC can nominate a colleague for the UPSC Agrisera Prize. This year, the UPSC Board received nine nominations, the highest number of nominations since 2014.
“The prize gives us the possibility to acknowledge great achievements and commitments and it is every year very difficult to choose one candidate out of many good suggestions”, says Catherine Bellini, chairmen of the UPSC Board who announced the winner of the prize today together with Joanna Porankiewicz-Asplund from Agrisera. “We were delight that we received this high number of nominations this year. It shows that people care about their workplace.”
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Bernadette Sztojka (right) and her supervisor Hannele Tuominen (left) chatting after Bernadette's defence
[2020-12-11] Lignin is the compound that makes plant cell walls waterproof and rigid. This allows plants to stand upright and transport water within their stem. Bernadette Sztojka, PhD student in Hannele Tuominen’s group, studied how lignin is synthesised and deposited in the cell walls, a process called lignification. She showed that cooperation between neighbouring cells is important for lignification of water-transporting vessel elements and identified three new regulators involved in this process. Bernadette Sztojka successfully defended her PhD thesis at Umeå University yesterday.
You did already your master thesis at UPSC but on a different topic. Why did you choose to switch topic and study lignification during your PhD thesis?
The projects I worked on before in the group of Rishikesh Bhalerao were more cell biology-oriented, related to vesicular trafficking. That was already quite a shift because my original background is horticulture. For my PhD, I wanted to further explore new territories this is why I applied for this PhD position, focusing on cell wall and wood formation.
You identified and characterised three new regulators involved in lignification. What do these regulators have in common and why are they peculiar?
The first regulator that we chose to work on was PIRIN2. A gene which is closely related to PIRIN2 was identified earlier in a cell culture system and shown to play a potential role in lignification. That is why we decided to characterise this gene in Arabidopsis. To better understand the molecular function of PIRIN2, we looked for proteins that interact with PIRIN2. That is how we came across the other two molecular players we studied, and this allowed us to expand the known molecular network. One of these two proteins has the opposite effect on lignin biosynthesis than PIRIN2. While PIRIN2 is suppressing the synthesis of certain types of monolignols, which are the basic modules of lignin, this protein is promoting it. The other protein we identified has no direct effect on lignin content or composition but connects lignin biosynthesis to diurnal timing.
Why does lignin biosynthesis need diurnal timing?
There have been a few previous studies that suggested that lignin-biosynthetic genes are activated in a diurnal pattern but there was never any upstream regulator found that controls these genes. Lignin is a very big carbon sink that means that a lot of carbon is required for its biosynthesis. That is why lignin biosynthesis has to be coordinated with resource availability and that brings in the diurnal regulation to connect lignin biosynthesis with carbon fixation during photosynthesis.
Which of your results is the most fascinating for you?
For me the first project, characterizing PIRIN2 and the non-cellautonomous lignification, was the most fascinating. PIRIN2 is a negative regulator of lignification but in a cell-type specific way. It is affecting the lignin composition of the cell walls of its neighbouring cells where it is not expressed. It is located in cells next to xylem vessels which form the water transporting “pipes”. We believe that the vessels need a specific lignin composition to allow for efficient water transport and PIRIN2 makes sure that they acquire the correct composition by suppressing the biosynthesis of certain monolignols which may not be optimal for water transport. I find these types of cooperative processes between cells really fascinating.
What was the biggest challenge you faced during your PhD?
It was hard sometimes to give up on ideas. We might have had a hypothesis and not necessarily showed that the hypothesis was proven right or wrong, but we realized that we did not had the means or time to follow up on this hypothesis. My original project that made me interested in the PhD topic became a bit squeezed in time because some other projects which I was supposed to finish quickly took over like for example the PIRIN2 project. It worked out fine for me in the end, but sometimes it was challenging to accept that I had to let a part of my project go unfinished.
Do you think your results might lead to practical applications in future?
I think especially PIRIN2 could be interesting for the forest industry. By manipulating PIRIN2 it might be possible to generate woody biomass with different lignin composition. Plants often get really sick when the lignin content is modified genetically but this is not the case when PIRIN2 is mutated. The effect on the chemical composition is not very strong in PIRIN2 mutants but those changes can still be beneficial for industrial use and they do not compromise the plant’s fitness.
What are your plans for the future? Do you want to continue with research?
I would like to transition towards more applied research, combining my background in horticulture with my PhD experience in plant molecular biology. This could be either in academia or industry. I am still curious to explore new territories and would like to change a bit the subject again.
About the public defence:
The public defence took place on Thursday, 10th of December at Umeå University. Faculty opponent was Simon Hawkins from the Department of Biology, University of Lille, France. Bernadette Sztojka's supervisor was Hannele Tuominen. The dissertation was live broadcasted via Zoom.
Title of the thesis: New regulators of xylem lignification in Arabidopsis
Link to the thesis: http://umu.diva-portal.org/smash/record.jsf?pid=diva2%3A1500629
For more information, please contact:
Bernadette Sztojka
Department of Plant Physiology
Umeå Plant Science Centre
Umeå University
Email:
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Tree phenotyping platform at UPSC (photo: Anne Honsel)
[2020-12-08] Stefan Jansson and Ove Nilsson were interviewed by the Swedish TV about CRISPR/CAS9, the technique for which discovery Emmanuelle Charpentier and Jennifer A. Doudna received the Nobel Prize in Chemistry this year. Several reports are broadcasted this week by the Swedish TV to highlight this year’s Nobel Prizes which are officially celebrated on Thursday, the 10th of December. The interviews with the two researchers from UPSC were broadcasted yesterday in “Vetenskapens värld” on Swedish Television (SVT) and in the news on TV4.
CRISPR/CAS9 is already now broadly used in plant research and also at UPSC several plants have been already genetically modified using this technique. This is presented in the reports done by the Swedish TV channels. In “Vetenskapens värld”, a popular science programme on SVT, Stefan Jansson explains how he uses CRISPR/CAS9 in his research and in TV4 News, Ove Nilsson presents the phenotyping platform at UPSC and describes the advantages of CRISPR/CAS9 for plant research. The two reports are online available and contain also a lot of footage from the plant material at UPSC.
Links to the video clips (both in Swedish):
“Vetenskapens värld” on SVT
Footage from UPSC is shown between minute 05:12 and 06:37 and between 10:02 and 10:24
https://www.svtplay.se/video/29350256/vetenskapens-varld/vetenskapens-varld-sasong-33-nobelpristagarna-2020?position=1765&id=e4zWnox
TV4 News from the 7th of December at 22:00 o’clock
Footage from UPSC is shown between minute 18:46 and 21:21
https://www.tv4play.se/program/nyheterna/13308076
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Ondřej Novák (left) and Karin Ljung (right) at the Swedish Metabolomics Facility in Umeå (photo: Carolin Rebernig)
On Wednesday last week, Clarivate published its annual list of Highly Cited Researchers 2020. Karin Ljung and Ondřej Novák are again under the top one percent of the world’s most highly cited researchers in the field of “Plant & Animal Science”. This is the third time that Ondřej Novák is on Clarivate’s list and the seventh time for Karin Ljung.
The methodology behind Clarivate’s list is based on citation analyses that determines the top one percent of Highly Cited Researchers using the Web of Science database. More than 6,000 researchers, in 21 fields of the sciences and social sciences, and cross field categories were selected based on the number of highly cited papers they produced over an 11-year period from January 2009 to December 2019.
More information and the full list of Highly Cited Researchers can be found here:
https://recognition.webofscience.com/awards/highly-cited/2020/