HalehHayatgheibi 1920x1080Haleh Hayatgheibi and her PhD supervisor Harry Wu (Photo: Anne Honsel)

On Friday, 18th of May, HalehHayatgheibi successfully defended her PhD thesis. She has worked on lodgepole pine (Pinus contorta), a fast-growing tree that was largely introduced into Sweden in the mid-1960s. One major problem of lodgepole pine trees is that their stems are often bending or even break and this lowers the economic value of the wood. Haleh Hayatgheibi designed breeding strategies to optimize both wood quantity and quality of lodgepole pine to reduce stem bending and breakage. 

Haleh Hayatgheibi estimated genetic parameters which determine wood quality and quantity of lodgepole pine. She measured for example the diameter of the stem as parameter for wood quantity and the stiffness of the stem. A higher stiffness might prevent the breakage of the stem when it bends and decrease the economic loss. This feature is especially interesting for Northern Sweden. 

Lodgepole pine trees from different origin in Canada were planted in different climatic regions in Northern Sweden, e.g. close to the coast or more inland. Haleh Hayatgheibi compared those trees with each other to see which are best suited for which region in Northern Sweden. Based on her results, she can now recommend tree breeders which lodgepole pine trees have the best prerequisites for which climatic region. 

Title of the thesis: “Quantitative genetics of lodgepole pine (Pinus contorta) wood quality traits in Sweden

Link to the doctoral thesis: http://urn.kb.se/resolve?urn=urn:nbn:se:slu:epsilon-e-4836

The public defence took place in Björken at SLU Umeå on Friday, 18thof May 2018. Faculty opponent was Yousry A. El-Kassaby from the Forest Sciences Centre, University of British Columbia, Canada. The supervisor was Harry Xiaming Wu. 

Six collaborative projects were selected by external reviewers and are now open for application. The postdoctoral fellows will be recruited at the Umeå Plant Science Centre in Sweden but will spend some time at the collaborating partner institute either in France or in Spain. The goal is to intensify the exchange between the three partners of the INUPRAG cooperation

The INUPRAG cooperation exists since 2015 and is a collaboration between the Umeå Plant Science Centre(UPSC, Sweden), the National Institute for Agricultural Research(INRA, France) and the Centre for Research in Agricultural Genomics(CRAG, Spain). The goals are to foster joint research projects in plant science between the different partners and to train young scientists through regular exchanges between the partner laboratories. 

The six granted postdoctoral projects cover different topics within plant science. All group leaders from UPSC could apply with collaborative projects for the postdoctoral fellowships. Three (?) external referees evaluated all submitted projects and selected the six best, three from Umeå University (Department of Plant Physiology) and three from SLU (Department of Forest Genetics and Plant Physiology). 

Are you interested in applying for one of the fellowships? Have a look on the job announcement here

More information about the INUPRAG cooperation 

The granted projects are: 

Project 1: Interactions between Plastid and Light Signalling Pathways

Project leaders: Åsa Strand (UPSC) & Elena Monte (CRAG)

Read more about project 1

Project 2: Regulation of the Master Floral Regulator LEAFY by Ubiquitination through the E3 Ligases UFO and BOP2 

Project leaders: Markus Schmid (UPSC), Ove Nilsson (UPSC) & François Parcy (INRA, Grenoble)

Read more about project 2

Project 3: An evo-devo approach to elucidate the role of PIRIN proteins during non-cell autonomous lignification

Project leaders: Hannele Tuominen (UPSC) and Richard Sibout (INRA, Nantes)

Read more about project 3

Postdoctoral project 4: Unravelling cluster root emergence in white lupin

Project leaders: Stéphanie Robert (UPSC) & Benjamin Péret (INRA, Montpellier)

Read more about project 4

Project 5: Cell wall mediated control of differential cell elongation in Arabidopsis hook Development

Project leaders: Rishikesh Bhalerao (UPSC) and Olivier Hamant (ENS, INRA, Lyon)

Read more about project 5

Project 6: Enabling scale-up of somatic embryogenesis (SE) plant production by physiological analysis of embryos processed in bioreactors and the R&D SE System for harvest

Project leaders: Ulrika Egertsdotter (UPSC) and Marie-Anne Lelu-Walter (INRA, Orleans)

Read more about project 6

IMG 4506 1920x1080Christoffer Johnsson and his supervisor Urs Fischer; photo: Anne Honsel

On Friday, 20th of April, Christoffer Johnsson successfully defended his thesis titled “Elucidating the phytohormonal control of xylem development”. He could show in his thesis that the plant hormones auxin and gibberellin are important signals for normal wood development in poplar trees. The public defence took place in P-O Backströms sal at SLU Umeå. Faculty opponent was Andrea Polle from the Buesgen Institut, Georg-August University Göttingen, Germany. His academic supervisor was Urs Fischer.

Link to the doctoral thesis: http://urn.kb.se/resolve?urn=urn:nbn:se:slu:epsilon-e-4828 

You can find more background information about Christoffer Johnsson’s work here (in Swedish):

J4A1095 1920x1080 TNasholm photoJohan MarklundTorgny Näsholm is awarded the 2018 Marcus Wallenberg Prize. Photo: Johan Marklund

Torgny Näsholm discovered that amino acids play an important role as nitrogen source for plants. He receives now the Marcus Wallenberg Prize 2018 for his ground-breaking research. 

Please have a look on the Marcus Wallenberg Foundation homepage for more information:

NatStreet teaching 1920x1080Photo: Kathryn Robinson

The plant geneticist and lecturer at the Department of Plant Physiology, Nathaniel Street, is awarded the pedagogical prize from the Faculty of Science and Technology. The prize jury motivated its decision due to his outstanding ambition, good organization and strong interest in developing new ways of teaching. Nathaniel Street will receive the prize during the Spring graduation ceremony of Umeå University on the 19th of May.

“I was on the Ski lift and checked my emails when I found out that I was awarded for the prize”, tells Nathaniel Street. “I was so surprised that I had to read the message twice to be sure that it was true. It is fantastic to know that the efforts made for teaching are acknowledged and appreciated. I really did not expect this, especially because there are so many other excellent teachers in our institute.”

Nathaniel Street came as a postdoc to Umeå University in 2007. In 2011, he became Assistant Professor and is since January 2016 Associate Professor at the Department of Plant Physiology.

During his time at Umeå University, he has fast developed his teaching skills further. He became the course leader of the department’s genomics courses in 2011 and has refined the course since then. Nathaniel Street is also teaching on the courses Bioinformatics and Genome Analysis and Microbiology and Basic Molecular Biology at Umeå University as well as the course Plant Biology for Future Forestry at the Swedish University of Agricultural Sciences (SLU).

The prize motivation emphasizes Nathaniel Street’s extremely careful preparation of his teaching. He gives well prepared and clear lectures that are greatly appreciated by the students and he is continuously improving his teaching methods. Among others, he has introduced interactive and student-led discussions, new practical classes in the lab and discussions on ethics. Several of these initiatives have subsequently been taken over by other teachers at the institution.

“He involves both his own research group and the bioinformatics platform at the Umeå Plant Science Centre in his work and successfully creates extremely smooth ways of teaching, that not only allow the students to get in contact with actual research, but are also very interesting for the research itself”, is stated in the prize motivation. “His high competence in both plant biology and genetics as well as in advanced computing has made this possible.”

Nathanial Street focuses his research on finding the genes that control natural variation and he is analysing microbial communities that are living close together with forest trees. His ambition is to combine his research interest with his educational ambition and strong willingness to develop his teaching methods further.

“My hope is to convey my own fascination and interest in my research area. It can be a challenging area to teach because it is changing very fast, but I try to keep the courses up to date. I do not want the students to just sit and listen to me. It is fun to think of new ways to motivate the students to learn together and from each other and to help them develop skills to learn independently in the future. The courses I have attended at the University Education and Teacher Support (UPL) have been a great inspiration for this.”

Link to the Swedish press release

For more information, please contact:

Nathaniel Street
Associate Professor
Umeå Plant Science Centre
Department of Plant Physiology
Umeå University
Phone: 090-786 54 73
E-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

Bud from the model organism hybrid aspen (Populus tremula x Populus tremuloides); Photo taken by Pal MiskolcziBud from the model organism hybrid aspen (Populus tremula x Populus tremuloides); Photo: Pal Miskolczi

For trees in boreal and temperate climates, it is important that buds do not burst precociously, but only when it's spring for real. Therefore, the buds are put in dormancy in the autumn, which means they have to go through a long cold period before they slowly become susceptible to the signals of spring. The mechanism behind this is revealed in a new study led by Rishi Bhalerao from UPSC, recently published in the journal Science.

Trees are amongst the longest-living organisms on Earth, and some species can live for thousands of years. One of the key mechanisms that enable such a long life is their synchronization of growth with change in seasons. For example, in temperate and boreal ecosystems, trees stop their growth and establish dormancy prior to the advent of winter. Growth cessation and dormancy establishment is a key adaptive mechanism for winter survival, since failure to cease growth and establish dormancy can result in fatality from extreme low temperatures in the winter.

How trees know when to stop their growth and establish dormancy is a question that has been of interest to researchers since a long time. That growth stops in response to the decrease in daylight during autumn has been well understood. The establishment of dormancy, which means that buds cannot burst before they have experienced a long cold period, and are not awakened by short warm periods during winter, has been more of a mystery. The recent article in Science, however, provides an important insight into how winter dormancy is regulated in perennial trees.

What the researchers could show is that the so-called plasmodesmata, channels that connect different cells with each other, are closed by the deposition of callose, a polysaccharide, in response to the shortening of day length in the autumn. The blockage of the plasmodesmata prevents cells from receiving growth promotive signals, thereby maintaining growth arrest and establishing dormancy in the buds.

The researchers also show that short-day induced dormancy is regulated by the plant hormone abscisic acid which activates (among others) the production of the callose that is used to block the plasmodesmata. Once blocked, a long exposure to low temperatures is needed to slowly re-open the plasmodesmata again, so that the growth-inducing signals can reach the buds and stimulate the growth in the buds in the spring.

"Interestingly, some of the facets of the dormancy regulation mechanism described in our paper have been observed in winter wheat as well as characean algae, suggesting that this mechanism is probably ancient and evolutionarily conserved", says Rishikesh Bhalerao.

The study was conducted using hybrid aspen, which is a model plant in tree research.

The study has been conducted by a research team led by Rishi Bhalerao from SLU's Department of Forest Genetics and Plant Physiology and the Umeå Plant Science Center. The colleagues come from SLU in Alnarp, Uppsala University, University of Helsinki, Cambridge University, Monash University and the University of Environmental and Life Sciences in Norway.

Link to the Swedish press release on the SLU homepage

More information

Contact person
Rishikesh P. Bhalerao, Professor
Umeå Plant Science Centre
Department of Forest Genetics and Plant Physiology
Swedish University of Agricultural Sciences, Umeå
+46 (0)90-786 84 88, +46 (0)70-678 37 32, This email address is being protected from spambots. You need JavaScript enabled to view it.


The article
S. Tylewicz, A. Petterle, S. Marttila, P. Miskolczi, A. Azeez, R. K. Singh, J. Immanen, N. Mähler, T. R. Hvidsten, D. M. Eklund, J. L. Bowman, Y. Helariutta, R. P. Bhalerao. 2018. Photoperiodic control of seasonal growth is mediated by ABA acting on cell-cell communication. Science 10.1126/science.aan8576 (2018). 
DOI: 10.1126/science.aan8576

Direct link to the article in Science

Text: David Stephansson (SLU)

Mateusz IMG 7837 Edited 1920x1080Mateusz Majda and his opponent Malcolm Bennett from the University of Nottingham. Photo: Stéphanie Robert
On Monday, 12th of February, Mateusz Majda has defended his PhD thesis with the title "Role of the cell wall in cell shape acquisition". In his thesis, he has analysed how the cell wall influences the shape of a cell. He focused on so called pavement cells that are forming the outmost cell layer of leaves and have a very specific jigsaw puzzle-shape. The public defence took place at 9:30h in Björken at SLU Umeå. Faculty opponent was Malcolm Bennett from the University of Nottingham, UK, supervisor Stéphanie Robert.

If you are interested in reading more about Mateusz Majda's findings, have a look here: https://www.upsc.se/about-upsc/news/5235-the-growth-of-puzzle-piece-shaped-leaf-cells-gets-an-explanation.html

Link to the doctoral thesis: https://pub.epsilon.slu.se/15263/

IMG 4096 1920x1080Three of the scientists (from left to right): Åsa Strand, Tamara Hernández-Verdeja, Tim Crawford (photo: Anne Honsel)
[2018-01-03] It has long been assumed that light activates chloroplastic gene expression via so-called thiol-mediated redox regulation. However, the mechanism giving rise to this regulation has remained elusive until now. Åsa Strand and her group at the Umeå Plant Science Centre have now identified the components involved in this redox regulatory mechanism. Their results are published in the journal Nature Communications.

The chloroplast is the place in the cell where photosynthesis occurs. When a seedling comes out of the soil, it gradually turns green, and during this greening process the photosynthetic machinery in the chloroplasts develops and becomes fully functional. The establishment of photosynthesis is a complicated process that involves the activation of gene expression in the chloroplast in response to light. Åsa Strand and her group identified a component that connects the light signal to the activation of gene expression in the chloroplast.

It was demonstrated that certain proteins, called thioredoxins, transfer electrons, primarily derived from light, to the protein PRIN2 (PLASTID REDOX INSENSITIVE2). PRIN2 becomes reduced and changes its structure from a dimer (i.e. two PRIN2 proteins are bound together) to a monomer (single proteins). The PRIN2 monomers then activate photosynthetic gene expression in the chloroplast. This type of regulation is called thiol-mediated redox-regulation because the functional chemical group mediating the transfer of electrons is the sulphur containing thiol group.

“We identified PRIN2 several years ago. We knew that it was sensitive to redox changes and that it was required for normal gene expression in the chloroplast”, explains Åsa Strand. “We have now shown that PRIN2 is regulated by light via thioredoxins and that it then activates a protein complex called PEP. This protein complex is responsible for expression of the photosynthesis related genes in the chloroplast.”

The protein complex PEP (plastid-encoded RNA polymerase) reads the information stored in the DNA of the chloroplast genome and copies it into RNA (ribonucleic acid). RNA serves then as template to translate the information stored in the DNA into proteins. PEP is a large protein complex that needs several associated proteins to gain its full function. One of these associated proteins is PRIN2.

The proteins required for a fully functional photosynthetic machinery are partly encoded in the nucleus and partly in the chloroplast genome of a cell. Thus, some form of communication between the two cellular compartments is required to ensure that all components are available at the right time during seedling development. PRIN2 plays an essential role in the communication between the two compartments because the status of the PEP complex links the functional state of the chloroplast to the nucleus, enabling the plant to synchronize expression of photosynthetic genes from the nuclear and chloroplast genomes during seedling development.

FinalVersion 1920x1020
Schematic overview about the molecular mechanism linking light and chloroplast development
(created by Daria Chrobok): When light is received for the first time by the cell, etioplasts (top left side) develop into chloroplasts (top right side). The photosystem II (PSII) starts to use the light energy to split water. The released electrons are transferred over the electron transport chain consisting of plastoquinone (PG), cytochrome b (Cyt b6f) and plastocyanine (PC) to the photosystem I (PSI). From PSI the electrons are transferred over several steps to thioredoxin which becomes reduced and then transfers the electrons further to PRIN2. PRIN2 can now activate PEP and PEP activates the expression of the photosynthesis related genes.

The article
Manuel Guinea Díaz, Tamara Hernández-Verdeja, Dmitry Kremnev, Tim Crawford, Carole Dubreuil & Åsa Strand. Redox regulation of PEP activity during seedling establishment in Arabidopsis thaliana. Nature Communications, (2018) 9:50, DOI:10.1038/s41467-017-02468-2

For more information please contact:
Åsa Strand
Umeå Plant Science Centre
Department of Plant Physiology
Umeå University
Email: This email address is being protected from spambots. You need JavaScript enabled to view it.
Phone: +46907869314
IMG 4122 1920x1080From left to right: Linn Fransson (Agrisera), Anna Gustavsson, Joanna Porankiewicz-Asplund (Agrisera), Catherine Bellini (Chair of the UPSC board); photo: Anne Honsel
[2017-12-12] The winner of the UPSC Agrisera Prize 2017 was announced today during the UPSC Christmas lunch. The prize is awarded to Anna Gustavsson for her contribution to promote cell biology research at UPSC.

Anna Gustavsson is honoured for her effort in developing and improving the UPSC confocal laser scanning microscopy/macroscopy platform and the platform services. Her useful advices helped to improve the work environment at UPSC and she contributed significantly to several cutting-edge research publications. Anna Gustavsson’s achievement benefitted a lot from Agrisera products emphasizing that she is a very good candidate for the prize even though this was no required criteria this year.

The UPSC Agrisera Prize was presented by Linn Fransson and Joanna Porankiewicz-Asplund from Agrisera and by the chair of the UPSC board, Catherine Bellini. The prize is awarded every year to a PhD student, Postdoc or technician at UPSC for excellent scientific achievement and positive contributions to improve the UPSC working environment. It is a personal cash prize in form of a check and can be used for travel costs.

20170808 155930 ASchneider 1920x1080Unfertilized control plot of Scots pine at the field site "Rosinedal", Sweden; photo: Andreas Schneider
Last week, SciLifeLab announced that they will support 14 sequencing projects with 33 million SEK. The project from Nathanial Street and his co-applicants Vaughan Hurry, Torgny Näsholm and Sandra Jämtgård is one of them. They will use metagenomics and metatranscriptomics to analyse the effect of various types of nitrogen fertilisation on the diversity of the belowground metacommunity.

The belowground metacommunity describes the community of all microbes, e.g. fungi and bacteria, that are living in the soil and possibly interact with each other and with plant roots. Metagenomics studies help to resolve the composition of a metacommunity while metatranscriptomics gives insight in the activity and function of the microbes in a metacommunity. Nathanial Street and his co-applicants will use these tools to understand how nitrogen fertilisation influences the diversity of the metacommunity and the processes within the community.

The researchers will compare the metacommunity diversity in Scots pine forest stands that have been fertilised for a short period with inorganic or organic nitrogen. They will also analyse the effect of a long-term fertilisation with inorganic nitrogen as well as the development of the metacommunity many decades after the last nitrogen fertilisation was applied.

SciLifeLab, the Swedish national centre for molecular biosciences, has started the national sequencing project initiative to provide sequencing support for large-scale genomic research in Sweden. This initiative comprises two programs: the Swedish Genomes Program and the Swedish Biodiversity Program. The project from Nathanial Street and his colleagues is part of the Swedish Biodiversity Program that is directed to projects studying genomic variability in nature. The awarded funding is assigned to subsidize sequencing costs.

Link to the press release from SciLifeLab:

Title of the project:
Diversity impacts on the belowground metacommunity associated with contrasting nitrogen fertilization sources

For more information, please contact:
Nathanial Street
Department of Plant Physiology
Umeå University
Phone: +46 (0)90 786 5473
Email: This email address is being protected from spambots. You need JavaScript enabled to view it.