Figure illustrating the different stages of the annual growth cycle of a juvenile aspen tree
Figure illustrating the annual growth cycle in a juvenile aspen treeFrom bud burst to bud set: The different stages of the annual growth cycle in a juvenile aspen tree (Illustration: Domenique André).

Why are flowering genes important for non-flowering young aspen trees? PhD student Domenique André started to work in Ove Nilsson’s group because she was interested in flowering, but the research led her to studying the annual growth cycle. She showed that key genes that regulate flowering in other plants are crucial for proper bud set and burst in young aspen trees and they control growth during summer. Domenique André will defend her PhD thesis at SLU on Friday this week, 27th of August.

You came to UPSC as Bachelor student about ten years ago and did your master thesis at UPSC. How does it feel to finish your PhD now after all this time?

It is a weird feeling, like “the end of an era”. I have been here now for nine and a half years. UPSC is the place where I grew up academically and scientifically and it feels like my home in a way. And because of that, I also tried to give back as much as possible. For example, I was PhD representative of my department and attended the UPSC Board meetings. I also helped organising events and participated in various outreach activities like Soapbox Science and Fascination of Plants Day. I will miss UPSC for sure.

In your thesis, you studied the annual growth cycle in aspen trees concentrating on the molecular regulation. What interested you about this project?

I started in Ove Nilsson’s group during my master. At that time, I was mainly interested in flowering, and he was the only person working on it at UPSC. But then, Ove’s group started to shift focus from flowering towards the annual growth cycle because it turned out that the genes we were focussing on played a different role in aspen. So, I kind of slipped into this topic together with the group and the flowering topic moved more to the side. To be honest, it took me some time to understand how the annual growth cycle works because I had no previous experience with trees. Aspen trees look very different after they have gone through the first growth cycle and there were big changes between the start and the end of our experiments. That can be confusing. I tried to illustrate this in my thesis: why the growth cycle exists, what stages the tree goes through and how all this is regulated. I really enjoyed the time during my master thesis in Ove’s group and we both agreed that it would be cool if I could continue the project during my PhD and in the end, there is even a little bit about flowering included in my PhD thesis.

You focussed in your research on FLOWERING LOCUS T genes which are most known for their role in regulating flowering, but you studied their role in non-flowering juvenile aspen trees. What are your key findings?

The key findings are that the FLOWERING LOCUS T or FT genes have mainly functions unrelated to flowering but rather control the annual growth cycle in juvenile aspen trees. There are in total three FT genes in aspen. The first one, FT1, is important during winter and makes sure that the tree can wake up from its dormancy during spring. The other two, we call them FT2a and FT2b, are important during summer making sure that the tree grows. Whether they are involved in flowering at all in nature is currently not clear.

What makes it so difficult to prove that the FT genes are important to regulate flowering in aspen?

When we enhanced the gene activity of either of the three FT genes by mutation, the trees started to flower very early. Those flowers did not look normal and were sterile. This is the one flowering part in my thesis. But just because we could induce flowering with more FT, it does not mean that FT is important for flowering in nature. To prove that FT is indeed required, we would have to block FT activity and show that flowering is delayed or doesn’t occur at all. And we have indeed removed FT activity with the CRISPR-Cas9 technology, but the problem is that flowering takes too much time. A normal tree will flower only after 5 years (if you’re lucky), so how long would we have to wait to see it in our mutants? And given how important FT is for the annual growth cycle, it is unlikely that the mutated trees would survive for so long anyway.

Which of your results was most surprising for you?

We did not know that there were two FT2 genes when I started. When we wanted to block the FT2 gene activity using the CRISPR technology, it worked perfectly. We had no FT2 gene activity, but the trees looked absolutely normal. That was really surprising because we knew from mutant lines with reduced gene activity that even if you have only twenty percent of the expression left, you get a very significant effect and in our CRISPR lines there was nothing. It turned out then that there was a second copy of the FT2 gene and when we blocked the activity of both genes at the same time, we got a really, really strong effect. The trees were just around five centimetres tall and almost do not grow. They are alive and they can be propagated in tissue culture, but they grow very slow. This shows that the genes are very important for the trees.

Studying aspen can be demanding because it can be very time-consuming. Was this the biggest challenge you faced during your PhD?

Yes, indeed. People studying wood for example grow their trees in the greenhouse for about two to three months. For us, it takes ten months to do one growth cycle experiment. We simulate the seasons in a growth chamber by adjusting daylength and temperature so that we can see the different seasonal stages on the trees like bud set and bud burst. The most limiting factor during my PhD was the lack of space in growth chambers because I could only do one of these long-lasting experiments at once. I had no problem keeping myself busy with other things while waiting for the experiment to be done but it took very long to get results and move on with my research questions. It was also challenging to decide which experiment to focus on and to plan them very detailed to get as much out as possible, but I learned a lot and became more independent. Overall, I liked my time as a PhD student. I felt it was a nice and relaxed time and I got the freedom to do what I wanted.

What are your plans now? Would you like to stay longer at UPSC?

I will stay at UPSC until the end of the year to hopefully get our manuscripts out. After that I will see. I would like to stay in Umeå, and I like to work in the university environment. I am very interested in teaching and took basically all teaching courses that I was allowed to take as a PhD student. I would love to be a lecturer or head of a lab. I would like to learn new things and develop, but also do something I’m already good at. I’m sure I will find something fun.

About the public defence:

Domenique André will defend her thesis on Friday, 27th of August 2021 in P-O Bäckströms sal at SLU Umeå. Faculty opponent will be Professor Soraya Pelaz from the Centre for Research in Agricultural Genomics in Barcelona, Spain. Supervisor is Ove Nilsson. The dissertation will be live broadcasted via Zoom.

Title of the thesis: Molecular Regulation of the Annual Growth Cycle in Populus Trees

Link to the thesis: https://pub.epsilon.slu.se/24748/

For more information, please contact:

Portraitphoto of Domenique AndréPhoto: Rory Shelton

Domenique André

Department of Forest Genetics and Plant Physiology

Umeå Plant Science Centre

Swedish University of Agricultural Sciences

Email: This email address is being protected from spambots. You need JavaScript enabled to view it.

Twitter: @FloweringLocusT

High-resolution image of photosystem II in the plant thale cress
High-resolution image of photosystem II in the plant thale cress.Using cryoelectron microscopy, Umeå researchers have succeeded in producing a high-resolution image of photosystem II in the plant thale cress. Image: Wolfgang Schröder, © 2020 andre

For the first time, Umeå researchers have, with the help of cryogenic electron microscopy, succeeded in producing a high-resolution image of photosystem II - the central complex of photosynthesis - of the model plant Arabidopsis. The enormous complex is responsible for the vital oxygen production in photosynthesis that once made life possible on our planet. The study is published in Scientific Reports.

"The structure gives us detailed information about the various cofactors such as chlorophyll and the lipid molecules in photosystem II. We have also managed to show exactly where and how detergents bind and affect the stability of the complex," says Wolfgang Schröder, professor at the Department of Chemistry at Umeå University Sweden and associated researcher at UPSC, who led the study.

The plant researchers' "experimental rat" has for the past 25 years been the plant thale cress/mouse-ear cress Arabidopsis thaliana. The reason for this is that this "weed" grows rapidly even at our northern latitudes in Sweden and in 2000, researchers succeeded in sequencing all its genes.

At the heart of the photosynthetic process is the Photosystem II complex. It contains almost 30 different proteins and a number of cofactors such as different pigments and metals and it is without any doubt one of the largest complexes in plant chloroplasts. The now published structure from this study has the same high-resolution as the two previous structures obtained from spinach and pea, which for the first time enables a comparison of plants' photosystem II complex with the same level of detail.

"I have worked with this complex since I became a PhD student in plant protein chemistry at Lund University in 1983,” says Wolfgang Schröder. “I remember that as a doctoral student I joked at the coffee break “think if you could dive into photosystem II and look around”. Today, with new technology and my extremely talented doctoral student André Graça and my two fantastic research colleagues Michael Hall and Karina Persson, we have now been able to do this."

Karina Persson, André Graça, Wolgfang Schröder and Michael Hall standing infront of the electron microscope at Umeå UniversityKarina Persson, André Graça, Wolfgang Schröder and Michael Hall (from left to right) constitute the successful research group at Umeå University. Photo: André Graça

The technology that the researchers have used is called cryogenic electron microscopy (Nobel Prize in Chemistry 2017) and it briefly means that biological samples are shot down into liquid ethane (-190 degrees Celsius). Nearly 100,000 two-dimensional EM particle images from random orientations are selected. Using several computational resources, the collection of 2D images can then be used to reconstruct a three-dimensional structure.

"Additionally, it was extremely exciting to see if our previous biochemical analyses of the complex were correct. Usually, the privilege of publishing structures with this size and resolution is only possible to larger research teams from different laboratories, as it requires a lot of data, time, and effort. In our case we are four Umeå researchers within the network Integrated Structural Biology, ISB, who created this structure, so it is "locally" produced research," says Wolfgang Schröder with a smile.

See moving image on the photosynthesis complex

The research is mainly funded by the Carl Tryggers Foundation. Data were collected at Umeå Core Facility for Electron Microscopy, UCEM, which is part of the National Microscopy Infrastructure, NMI.

About the scientific study:

Graça, A.T., Hall, M., Persson, K. and Schröder W.P.: High-resolution model of Arabidopsis Photosystem II reveals the structural consequences of digitonin extraction. Sci Rep 11, 15534 (2021).
https://doi.org/10.1038/s41598-021-94914-x

More reading:

About Umeå Core Facility for Electron Microscopy
The network Integrated Structural Biology, ISB
About cryo-Electron microscopy and the Nobel prize 2017

For more information, please contact:

Wolfgang Schröder
Department of Chemistry
Umeå University
Email: This email address is being protected from spambots. You need JavaScript enabled to view it.
Phone: +46 90 786 69 74
https://www.umu.se/en/staff/wolfgang-schroder/
https://www.upsc.se/wolfgang_schroder

André Graça
Department of Chemistry
Umeå University
Email: This email address is being protected from spambots. You need JavaScript enabled to view it.
Phone: +46 90 786 66 87
https://www.umu.se/en/staff/andre-graca/

Text: Ingrid Söderbergh

Raghuram Badmi in an in vitro growth room for poplar at UPSC
Raghuram Badmi in an in vitro growth room for poplar at UPSCPhoto: Kanchan Vishwakarma

Raghuram Badmi, postdoc in Judith Lundberg-Felten’s group at UPSC, was granted a Career-Fit PLUS fellowship from Enterprise Ireland, an Irish governmental organisation that leads the national support network for Horizon Europe. The fellowship will be for three years and is oriented on experienced researchers to work on applied research projects. Raghuram Badmi will study how Botrytis cinerea, a fungus, causes fruit rot in strawberries. He will start his new position in autumn this year in Cork, Ireland.

What was motivating you to apply for this competitive fellowship and how did you choose your project?

Raghuram Badmi: One of the main attractive features of this Career-Fit Plus fellowship is that it is designed for researchers who want to transition into industry as a ‘Marie Skłodowska-Curie Fellow’ as well as a ‘Career-FIT PLUS Fellow’. I realized that my skill set could be valuable in developing solutions to agricultural problems and this fellowship provided me with the right platform to act as a bridge between the academic university and the company partners. My previous work on strawberry-Botrytis interactions left me with quite a few exciting questions to pursue. I chose the most exciting and most pressing problems that the agricultural sector is currently facing and proposed to solve them by employing advanced techniques such as non-transgenic (footprint-free/DNA-free) genome editing.

With whom will you work in your future project and what do you plan to do?

Raghuram Badmi: The project involves three partners, an academic university partner, the University College Cork, a company partner, Plantedit, and a Technology Center, Shannon ABC, all based in Ireland. The main goal of this project is to develop non-transgenic genome edited strawberry plants that have higher resistance against grey mould disease caused by Botrytis cinerea fungus. The project involves interdisciplinary computational approaches to better understand the strawberry-Botrytis interactions and I also plan to employ some beneficial microbial interactions to improve disease resistance, strawberry growth and yield.

Do you think your experiences from your current research project in Judith Lundberg-Felten’s group will benefit your future project?

Raghuram Badmi: Yes of course, I plan to use my experience in working with mycorrhizal fungus to develop bioinoculant based solutions to improve strawberry growth and disease resistance. In this respect, I wish to continue my association with UPSC by collaborating with my supervisor Judith Lundberg-Felten, whose support and recommendation was crucial in obtaining this fellowship.

Which were the biggest challenges writing your proposal?

Raghuram Badmi: This proposal is the result of at least four years of continuous grant applications and the rejections that followed. I got to learn a lot on how to develop a project that perfectly fits my expertise, develop compelling arguments, and present myself as the perfect fit for the project. I would like to thank my previous supervisors at the Norwegian Institute of Bioeconomy Research, whose guidance on proposal writing was invaluable in developing this proposal.

Do you have some tips for other postdocs or PhD students applying for similar fellowships that are funded by the European Union?

Raghuram Badmi: My suggestions to my younger self would be to identify a specific niche area and develop oneself around it. Writing is hard, and the earlier you start the better. Proposal/grant writing training programs such as for Marie Curie Individual Fellowships, Young Research Talent grants, ERC grants have benefitted me a lot and this could be helpful to many others wanting to apply for fellowships.

Career-FIT PLUS programme is launched by Enterprise Ireland and is aimed for experienced researchers from all over the world to work on research projects that are of interest for Irish enterprises. The fellows will work three years in Ireland hosted by a Third Level Institution, like e.g., a university, that is associated with a Technology Centre/Gateway. During this time, they will have the opportunity to spend a six to twelve months long secondment in a partner company.

The Career-FIT PLUS fellowship programme has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 847402.
EU flag yellow low


Read more about the Career-FIT PLUS programme

For more information, please contact:

Raghuram Badmi
Umeå Plant Science Centre
Department of Forest Genetics and Plant Physiology
Swedish University of Agricultural Sciences
Sweden
Email: This email address is being protected from spambots. You need JavaScript enabled to view it.; This email address is being protected from spambots. You need JavaScript enabled to view it.
Twitter: @raghubadmi

Text: Raghuram Badmi and Anne Honsel

Swedish pine forest
Swedish forest                    Photo: Sonali Ranade

UPSC is offering together with SciLifeLab a tenure track position as Associate Senior Lecturer (Assistant Professor) in genomics with focus on data driven research on evolution, adaptation and biodiversity in trees. The position is part of the SciLifeLab and Wallenberg National Program for Data-Driven Life Science (DDLS). This is a 12-year initiative funded by the Knut and Alice Wallenberg Foundation that aims to train the data-driven next generation of life scientists. Each DDLS Fellow will receive a comprehensive recruitment package and be part of the SciLifeLab and DDLS network.

Read the full job description on the homepage of the Swedish University of Agricultural Sciences

More information about the DDLS Fellow recruitment on the SciLifeLab homepage

All currently available jobs at UPSC

Portrait photo of Sanaria Abbas Jaafer Alallaq
Portrait photo of Sanaria Alallaq taken during the poster presentation on the KBC Days 2018Sanaria Alallaq at the poster presentation on the KBC Days 2018 (photo: Eva-Maria Diehl)

Many plants can easily be regenerated and multiplied using cuttings. Crucial is that the cutting can initiate the formation of roots, a process called adventitious rooting. Sanaria Abbas Jaafer Alallaq showed in her PhD thesis that some of the molecular regulators that control the initiation of adventitious roots in plants are similar in non-woody and woody plants like Norway spruce and poplar. She will defend her PhD thesis at Umeå University on Thursday, 3rd of June 2021.

Several economically and ecologically valuable tree species are difficult to multiply via cuttings because their cuttings do not form roots. Sanaria Abbas Jaafer Alallaq, who did her PhD in Catherine Bellini’s group at the Umeå Plant Science Centre, used the knowledge that her group and other researchers acquired with the non-woody plant thale cress and studied how it translates to the woody species Norway spruce and poplar. She demonstrated that, the initiation of adventitious roots is regulated in Norway spruce seedlings and poplar cuttings in a similar manner like in thale cress. Key regulatory factors are light and small signalling molecules, the plant hormones, auxin, cytokinin and jasmonate.

“Adventitious root initiation is a complex developmental program governed by a plethora of external and internal factors including plant hormones and light. The exact molecular mechanisms underlying this process are still largely elusive especially with respect to trees,” says Sanaria Abbas Jaafer Alallaq. “The recent availability of the reference genomes of some tree species such as Norway spruce or poplar make it possible to tackle adventitious root initiation from an evolutionary developmental perspective which we believed was a timely step.”

For her experiments, Sanaria Abbas Jaafer Alallaq grew Norway spruce seedlings from seeds and removed the roots when they were three weeks old to see under which conditions, they regenerate adventitious roots. When kept under normal white light conditions, the de-rooted seedlings did not regenerate easily adventitious roots but under red light conditions, hundred percent of the seedlings rapidly developed adventitious roots. Sanaria Abba Jaafer Alallaq and her colleagues analysed the concentration of plant hormones in the cutting base of the de-rooted Norway spruce seedlings and found higher levels of the plant hormones cytokinin and jasmonate in the seedlings grown under white light conditions.

“These two plant hormones hinder the formation of adventitious roots also in thale cress while auxin is known to stimulate adventitious rooting,” explains Sanaria Abbas Jaafer Alallaq. “We wanted to understand more how similar the regulation is on the molecular and genetic level. Norway spruce still has its limitations to do these studies even though its genome has been sequenced. That is why we included poplar in our studies which offers currently many more possibilities to study for example gene expression.”

Sanaria Abbas Jaafer Alallaq compared hybrid poplar and hybrid aspen, two closely related poplar species with different ability to form adventitious roots. She took cuttings from three-month-old trees grown in the greenhouse and placed them in nutrient solution. The cuttings of hybrid poplar easily formed adventitious roots, while the hybrid aspen cuttings did not root under these conditions. Sanaria Abbas Jaafer Alallaq analysed the gene expression in the base of the cuttings and saw that many more genes were activated in hybrid poplar than in hybrid aspen.

“We identified many key genes that are involved in the regulation of auxin in hybrid poplar while genes involved in the biosynthesis of jasmonate were activated in hybrid aspen,” describes Sanaria Abbas Jaafer Alallaq. “This confirmed that also in poplar cuttings auxin and jasmonate have opposite effects on the initiation of adventitious roots and that at least some of the underlying regulatory mechanisms were conserved during evolution. These results from our basic research are small steps that hopefully help in future to improve adventitious rooting of horticultural and forest species.”

About the public defence:

Sanaria Abbas Jaafar Alallaq, Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, will defend her PhD thesis with the title “Characterization of adventitious root formation in Populus species and Norway spruce” on Thursday, 3rd of June 2021. Faculty opponent will be Professor María Carmen Díaz-Sala Galeano, Department of Life Sciences, University of Alcalá, Madrid, Spain. The thesis was supervised by Catherine Bellini. The dissertation will be live broadcasted via Zoom.

Link to Sanaria Abbas Jaafar Alallaq's thesis


For more information, please contact:

Sanaria Abbas Jaafar Alallaq
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.


Text: Sanaria Abbas Jaafar Alallaq & Anne Honsel

Portrait photo of Kristoffer Jonsson
Portrait photo of Kristoffer JonssonKristoffer Jonsson at the Poplar Transgenics Facility at UPSC

The Scandinavian Plant Physiology Society (SPPS) announced this week that Kristoffer Jonsson from Rishikesh Bhalerao’s group at UPSC is one of the two awardees that receive the SPPS Best PhD Thesis Prize. The other awardee is Bin Sun, who did his PhD at the Department of Plant and Environmental Sciences at the University of Copenhagen. Both awardees will present their work at the SPPS congress in Svalbard in August this year.

Kristoffer Jonsson defended his PhD thesis in June 2019. Several articles resulted from his thesis. Currently, he is finishing up his projects as postdoc in Rishikesh Bhalerao’s group. In December last year, he received an international postdoc grant from the Swedish Research Council to start his own postdoc project jointly at UPSC and in the group of Anne-Lise Routier-Kierzkowska from the Plant Biology Research Institute at the Université de Montréal in Canada.

“When I learned that I was awarded this prize, I was of course thrilled and honoured. My immediate thought was that this award is equally a recognition of all the people that I have worked with, especially Rishi Bhalerao. Without his guidance and the environment, he created for me, we wouldn’t have done as well as we did”, says Kristoffer Jonsson. “While I’m honoured, I’m also surprised to be selected among all the other excellent PhD colleagues, who I know also worked hard towards their goals, and who I feel are equally deserving this prize. In any case, this should also be seen as a recognition of UPSC, which is a fantastic research environment that really nurtures young researchers.”

In his PhD thesis, Kristoffer Jonsson showed that the correct transport of components to the cell surface as well as the chemical composition of the cell wall are important for differential growth during the development of the apical hook. This hook is formed by seedlings that grow towards the soil surface after germination to protect their sensitive first leaves from damage. First when the seedling reaches the surface, the hook unfolds and the seedling opens its leaves towards the sun.

An uneven distribution of the plant hormone auxin is one crucial factor for differential growth. Auxin accumulates on the inner side of the hook and inhibits there the elongation of cells. Cells on the outer side of the hook, where the auxin concentration is low, expand at a high rate and this ensures that the bending is maintained. Auxin transporting proteins are controlling how much auxin is transported in and out of a cell and thus create the auxin gradient in the hook.

Kristoffer Jonsson studied how newly synthesized auxin transporters are packed in the distribution centre of the cell, the trans-Golgi network, and transported from there to the cell surface. He showed that the packaging and the transport of different transport proteins follows very distinct routes. If components of either the packing or the transport chain are mutated and not fully functional anymore, the transport proteins are not reaching the right place and the apical hook is not developing properly.

“The auxin gradient across the hook affects the composition and mechanical properties of the cell wall and vice versa. We demonstrated that the cell walls on the inner side of the hook became more rigid in response to auxin than on the outer side of the hook”, explains Kristoffer Jonsson. “We could show that this is not a one-way regulation. Signals from the cell wall affected the auxin machinery, enhancing the auxin response on the inner side, essentially forming a feedback required for proper growth asymmetry. These findings opened up many new questions that I will address in my new postdoc project.”

The SPPS Best PhD Thesis Prize is a monetary prize that is awarded every second year together with other awards given out by the Scandinavian Plant Physiology Society. The awardee must be a scientist that defended her/his PhD thesis in a Nordic country within the last two years. All SPPS awardees are expected to give a scientific talk during the biannual SPPS Congress that will take place this year on August 24-27 in Svalbard, Norway.

More information

Title of Kristoffer Jonsson’s PhD thesis: Understanding the Molecular Basis of Differential Growth during Apical Hook Development
Link to the PhD thesis

Read more about Kristoffer Jonsson’s international postdoc grant 


For questions, please contact:

Kristoffer Jonsson
Umeå Plant Science Centre
Department of Forest Genetics and Plant Physiology
Swedish University of Agricultural Sciences
Email: This email address is being protected from spambots. You need JavaScript enabled to view it.

Mustard aphid (Lipaphis). To monitor aphid feeding behaviour in great detail, a golden thread connected to recording devices was glued to its back with silver glue.  Photographer: Hans Smid, Wageningen University & Research.
Mustard aphid (Lipaphis). To monitor aphid feeding behaviour in great detail, a golden thread connected to recording devices was glued to its back with silver glue. The photo is taken by Hans Smid from Wageningen University & Research. Mustard aphid (Lipaphis). To monitor aphid feeding behaviour in great detail, a golden thread connected to recording devices was glued to its back with silver glue. (Photo: Hans Smid, Wageningen University & Research)


Researchers at Wageningen University & Research, Umeå University and Keygene have discovered that a resistance gene in thale cress (Arabidopsis thaliana) against the green peach aphid, also affects other aphids and whiteflies. However, not every aphid or whitefly species is put off. The tobacco whitefly and mustard aphid are unaffected and still feast on the plant, but for the latter this does involve an unusual spitting ritual.

Identifying the genetic code for disease resistance in plants is normally a tricky thing. A single gene can usually only offer protection against a specific disease or parasite. But this time it’s different. The research from Karen Kloth from Wageningen University & Research and her colleagues sheds new light on how plants defend themselves from insect pests – and vice versa.

Aphids are widespread on plants and agricultural crops. They feed on plant sap, but also spread viruses. Efforts to reduce the use of insecticides in agriculture therefore include a lot of research into natural defence mechanisms in plants.

Karen Kloth, a researcher in the Entomology laboratory of WUR and former postdoc in Benedicte Albrectsen’s group at Umeå Plant Science Centre, Umeå University, specialises in this area. In 2017 she discovered a gene that makes one plant species – thale cress – more resistant to the green peach aphid. In a new experiment, published in Plant, Cell & Environment, she and her fellow researchers demonstrate that this gene is only active in the so-called phloem – the cells which transport the sugar-rich sap through the plant. They also discovered that the gene works against other species of aphid and whitefly which, like the green peach aphid, feed on phloem sap.

Plant gene reduces insect reproduction and appetite

“It turns out that the tobacco aphid, cabbage aphid and cabbage whitefly don't fare so well on plants that contain this gene”, says. Karen Kloth. “They produced fewer offspring or eggs during the experiment. Detailed behavioural tests also revealed that when plants contained the resistance gene, the aphids spent more time salivating before they could start to eat, and also spent less time feasting on the phloem sap.”

Mustard aphid spits up to 20 times before it starts to eat

However, the gene doesn’t work against the mustard aphid or the tobacco whitefly. The mustard aphid displayed unusual behaviour that might disable the resistance. Karen Kloth explains: “These aphids would repeatedly inject their needle-like mouth parts into the phloem and then spit, doing so up to 20 times before they actually began to eat. This suggests that repeatedly injecting spit with special proteins helps the Mustard aphid bypass resistance."

Increasing the natural resilience of crops

The research, carried out in collaboration with Umeå University and KeyGene, was partially funded by a Veni grant awarded to Karen Kloth in 2018 by the Dutch Research Council (NWO) to carry out research into natural defence mechanisms in plants against insect pests and viruses that could help reduce the use of insecticides. “Many crops are affected by infestations of aphids and whiteflies. They are difficult to deal with, leading to the spread of plant viruses and jeopardising yields,” says Karen Kloth. “It’s therefore quite remarkable to discover that a single gene in thale cress offers protection against different species of aphid and whitefly. It’s hoped that further research will reveal the underlying mechanism at work and how this gene can be used to increase the natural resilience of crops.”

The research article:

Kloth, KJ, Shah, P, Broekgaarden, C, Ström, C, Albrectsen, BR, Dicke, M. SLI1 confers broad-spectrum resistance to phloem-feeding insects. Plant Cell Environ. 2021; 1– 12. https://doi.org/10.1111/pce.14064

For more information, please contact:

Karen J. Kloth
Laboratory of Entomology
Wageningen University & Research
This email address is being protected from spambots. You need JavaScript enabled to view it.
+31 6 1867 1349

Benedicte R. Albrectsen
Umeå Plant Science Centre
Department of Plant Physiology
Umeå University
This email address is being protected from spambots. You need JavaScript enabled to view it.
More about Benedicte Albrectsen's research

Text: Wageningen University & Research

Phenotyping platform at Umeå Plant Science Centre

We normally would have celebrated the International Fascination of Plants Day this week with a public event. Due to the current ongoing pandemic, we have postponed our event to 2022. Still, we would like to use this opportunity to give you some insights on what we are doing at UPSC. Have a look on the below videos and follow Noemi inside our greenhouses!

The Fascination of Plants Day is organised under the umberella of EPSO, the European Plant Science Organisation. Every second year, it is celebrated internationally with events taking place all over the world. The goal is to fascinate people for the world of plants. Due to Covid-19, EPSO postponed the 6th International Fascination of Plants Day to 2022 but individual events took place.  You can check them out on the official homepage of the Fascination of Plants Day: https://plantday18may.org

The videos were produced for ForskarFredag 2020 at Curiosum, the new science center in Umeå.

Swedish pine forest (photo taken by Sonali Ranade)
Swedish pine forest (Photo taken by Sonali Ranade)Swedish pine forest (Photo: Sonali Ranade)

Can trees be tailored to absorb more carbon dioxide and thus help alleviate global warming? In the latest episode of the podcast “Om Vetenskap” the UPSC group leader Ove Nilsson and Skogforsk Tree Breeding Program Manager Thomas Kraft talk about how the carbon dioxide uptake in forest trees may be improved with modern technology. “Om Vetenskap” is produced by the Swedish Foundation for Strategic Research - SSF. The episode was released April 25.

The podcast episode “Hur skapas det perfekta trädet för koldioxidupptag?” (eng. How to create the perfect tree for carbon dioxide uptake?) was recorded in Swedish and is available at various podcast apps.

Background of the podcast episode (in Swedish)
https://strategiska.se/nytt-poddavsnitt-hur-skapas-det-perfekta-tradet-for-koldioxidupptag/

Links to the podcast (in Swedish)

Acast
https://play.acast.com/s/om-vetenskap/hur-skapas-det-perfekta-tradet-for-koldioxidupptag

Spotify
https://open.spotify.com/embed-podcast/episode/4dQivEZu5BmyJJWPpv28jE

Göran Sandberg at the official farewell as rector of Umeå University at Sävargården in Umeå (photo taken 2010 by Elin Berge, MOMENT)
Göran Sandberg at the official farewell as rector of Umeå University at Sävargården in Umeå (photo taken 2010 by Elin Berge, MOMENT)Göran Sandberg at the official farewell as rector of Umeå University at Sävargården in Umeå (photo taken 2010 by Elin Berge / MOMENT

On its meeting in April, the Royal Swedish Academy of Sciences decided to award Göran Sandberg, executive director at the Knut and Alice Wallenberg Foundation, with the “Äldre Linnémedaljen i guld”. The academy motivates its decision with his outstanding efforts that have promoted Swedish research and increased its international competitiveness. Göran Sandberg is professor at the Department of Plant Physiology, Umeå University, and took an active part in establishing Umeå Plant Science Centre.

Göran Sandberg defended his thesis at the Department of Forest Genetics and Plant Physiology, SLU. After post-doc periods in the USA and in the UK, he came back to the Department of Forest Genetics and Plant Physiology and became professor in plant physiology 1989. Between 2005 and 2010 he was vice chancellor at Umeå University, before joining the Knut and Alice Wallenberg Foundation as executive director.

”Göran Sandberg’s research as well as his visions and commitment on the management level were extremely important to make UPSC to what it is now – an internationally competitive plant science centre”, says Ove Nilsson, director of UPSC. “We would like to congratulate him to this award and thank him for all his great efforts that consistently encourage us to develop our research centre further.”

The “Äldre Linnémedaljen i guld” is awarded as reward for merits for the Royal Swedish Academy of Sciences or the Academy’s institutes. The Academy gives out different “Linnémedaljer” and several other prizes besides the Nobel Prizes in physics and chemistry. Together with Göran Sandberg, seven other scientists were awarded with different prizes for their efforts to promote Swedish research.

Read more on the homepage of the Royal Swedish Academy of Sciences (in Swedish only):
https://www.kva.se/sv/nyheter/priser-och-medalj-delas-ut-av-akademien