The sight of trees swaying in the wind has captivated the imagination of artists and nature enthusiasts. However, for the trees themselves, this continuous mechanical stimulation can be a source of stress. A research team led by Ewa Mellerowicz from UPSC and SLU set out to study the effect of such repetitive flexing on aspen trees and found that the trees grew faster.
The study was published yesterday in the journal New Phytologist. Researchers from Umeå Plant Science Centre, a collaboration between Swedish University of Agricultural Sciences and Umeå University, were leading the study and were supported by researchers from RISE (Research Institutes of Sweden), Umeå University and from the Laboratory of Growth Regulators, a joint facility between the Faculty of Science, Palacký University, and the Institute of Experimental Botany, Czech Academy of Sciences.
It is long known that plants exposed to continuous mechanical stimulation, such as wind, adjust their growth and development. Trees that are repeatedly bent by the wind tend to grow shorter and sturdier as a defense against mechanical stress. However, the research team around Ewa Mellerowicz, group leader at UPSC and professor at the Swedish University of Agricultural Sciences, observed somewhat different results when they exposed aspen trees to recurrent flexing.
“We used an automated conveyor belt system carrying young aspen trees and applied flexing stress by moving the belt. Especially when the belt started to accelerate and when it stopped, the trees experienced low-intensity multidirectional stem flexures”, explains János Urbancsok, first author of the paper and former postdoc in Ewa Mellerowicz’s group. His colleague Evgeniy Donev, postdoc in the same group and shared first author of the paper, adds:
“Compared to control trees that were growing on a non-moving belt besides them, the flexed trees grew faster with increased stem diameter and root growth. Similar effects have been observed before in bent or touched plants, but we were astonished to also see an increased shoot elongation and leaf size. This was not reported previously.”
The researchers speculated that stem elongation and leaf expansion might have been stimulated by vibrations associated with the shaking which was applied to the plants when the conveyor belt was abruptly accelerated or brought to a halt. They knew from other studies that vibrations coming for example from sound can stimulate growth in general. This led them to delve deeper and investigate if they could find more parallels or differences in response to vibration or other mechanical stimulation such as bending or touching.
To start, they analysed the properties of the “flexure wood” - the wood that is formed under mechanical stress such as stem flexing. They discovered that this wood contained more cellulose and formed gelatinous fibres, similar to the wood fibres formed on the upper side of a bent tree. These fibres were much easier to convert into sugars which makes “flexure wood” interesting for biofuel production.
In a next step, the researchers examined differences in gene activities and concentrations of plant hormones. Plant hormones are low-concentrated growth-regulating compounds known to be involved in stress responses, especially regulating gravity-induced changes that occur for example under bending. Most of the changes in gene activity and plant hormone concentrations were in line with prior findings but the researchers also discovered something new: changes in the metabolism of polyamines.
“We are not sure yet how to interpret these results”, says Ewa Mellerowicz. “Polyamines play important roles in regulating plant growth and development but also in stress responses. It might be that polyamines were just not analysed in previous studies, or they are only induced by vibration and not by bending or other forms of gravistimulation. These questions need to be addressed in future studies, but we believe that our study gives novel and important insights into the mechanobiology of higher plants which could result in practical application like for example for plant cultivation practices.”
The article
Urbancsok, J., Donev, E.N., Sivan, P., van Zalen, E., Barbut, F.R., Derba-Maceluch, M., Šimura, J., Yassin, Z., Gandla, M.L., Karady, M., Ljung, K., Winestrand, S., Jönsson, L.J., Scheepers, G., Delhomme, N., Street, N.R. and Mellerowicz, E.J. (2023), Flexure wood formation via growth reprogramming in hybrid aspen involves jasmonates and polyamines and transcriptional changes resembling tension wood development. New Phytol. https://doi.org/10.1111/nph.19307
For questions, please contact:
Professor Ewa Mellerowicz
Umeå Plant Science Centre
Department of Forest Genetics and Plant Physiology
Swedish University of Agricultural Sciences
Phone +46 (0)90 786 8367
Email:
https://www.upsc.se/ewa_mellerowicz
Karin Ljung, group leader at UPSC and professor at SLU, has been awarded the Arvid Lindman medal for her “outstanding contribution to research, teaching and supervision in the fields of forest biotechnology and experimental plant biology”. The Arvid Lindman medal is an award that SLU has dedicated to excellence within forest research. It was officially awarded to Karin Ljung at SLU’s doctoral award ceremony last Saturday.
Karin Ljung has been a research group leader at UPSC since 2005 and was promoted to professor at SLU in 2015. Her research at UPSC has mainly revolved around investigating the roles of plant growth regulators or hormones in root development and the integrative coordination of above and below ground growth. Apart from her “outstanding contribution to research, teaching and supervision”, her “exceptional contribution to the high international ranking of both UPSC and SLU within plant science research” was also highlighted in the motivation for the award.
Karin Ljung has also developed advanced methods both for hormone profiling in plant tissues and the analysis of hormone distribution and metabolism at cellular and sub-cellular resolution. Her successful research has resulted in multiple publications in high-ranking journals and she has been included since 2014 on the Clarivate Analytics list of the world’s highest-cited researchers. Besides her significant scientific contributions, Karin Ljung has taken over several commitment of trusts within UPSC, at SLU’s Faculty of Forest Science and on national and international levels, for example as a member of the Scientific Advisory Board for the European Forest Institute.
Karin Ljung could not join the doctoral award ceremony last Saturday in Uppsala and was presented the Arvid Lindman medal in absentia. At this ceremony, new doctors who have defended their theses since the last ceremony as well as honorary and jubilee doctors are officially conferred and medals and awards given by SLU are presented. Even though Karin Ljung could not be present at SLU’s doctoral award ceremony in Uppsala last Saturday, UPSC was well-represented.
Two new doctors from the Department of Forest Genetics and Plant Physiology who defended their PhD thesis before August 31st 2023 received their insignia, as well as honorary doctor Malcolm Bennett, professor at the University of Nottingham. He was nominated by the Faculty of Forest Science due to his important long-standing collaborations with researchers at UPSC. Furthermore, Stéphanie Robert, also group leader at UPSC and professor at SLU, was given the honour of holding the inspirational lecture to the new doctors at the ceremony and she presented her research on the regulation of plant cell shape.
More information about the Arvid Lindman medal
Arvid Lindman was a former Swedish prime minister who in 1915 was the first chairman of the board of the Forestry College, which is now SLU’s Faculty of Forest Science. The SLU Board chooses the medal awardee based on the suggestion of the Faculty of Forest Sciences. The medal will be awarded whenever the Faculty Board thinks it is appropriate. It is a reward for particularly meritorious scientific achievements and is awarded in connection with the annual doctoral award ceremony in October.
More information about SLU’s Doctoral Award Ceremony:
https://www.slu.se/en/about-slu/academic-ceremonies/doctoral-award-ceremony-2023/
You can also find the live broadcast of the doctoral award ceremony 2023 and of the honorary doctor’s lectures there.
Additional information
An interview with Karin Ljung for the International Day for Women and Girls in Science
More information about Malcolm Bennett’s appointment as honorary doctor
Stéphanie Robert received last year a large project grant from the Wallenberg Foundation to study plant cell identity. Read more the project “Decoding cell fate with positional information” here.
Text: Siamsa Doyle & Anne Honsel
Which career possibilities exist for (plant) scientists outside of academia? Laura Tünnermann and Tinkara Bizjak, both PhD students at Umeå Plant Science Centre, thought that it is not talked enough about this at the university and started to organise the seminar series “Outside of Academia”. Read more about their motivation and how they choose topics and speakers in this interview with them.
You started beginning of this year to organise the seminar series “Outside of Academia”. What motivated you to start this seminar series up at UPSC?
Laura Tünnermann: At the UPSC PhD and Postdoc retreat 2022, it was mentioned that a similar seminar called “Careers outside academia” was organized by former UPSC scientists. We thought that this was a great way to show different career options.
Tinkara Bizjak: Exactly, when you start a PhD it is assumed that you stay in academia, so you are not presented with other career options. That is why we wanted to revive this seminar series.
What is the purpose of this seminar series and how does the format look like?
Tinkara Bizjak: The purpose of this seminar is very simple - we want to show different career options that are waiting for scientists outside of academia.
Laura Tünnermann: About the format, we are trying to organize a seminar once a month. The speakers have about 30 – 40 min to introduce themselves, their background, and their current position. It is very important for us that the speakers explain why and how they left academia. After the presentation, we plan time for a question-and-answer session.
Tinkara Bizjak: The seminar is also always followed by a lunch with the speaker to enable further networking. And we can only encourage everybody to sign up and join the lunch!
How do you choose topics and search and engage speakers?
Laura Tünnermann: We try to find career options that people might not be aware of but are relevant to our participants, for instance, a patent attorney. When we select our speakers, we are looking for someone with a plant science background who did a PhD or even a postdoc.
Tinkara Bizjak: We try to focus some of the seminars on the industry in and around Umeå. We noticed a great interest of our participants in job opportunities in Umeå. Also, anyone who has an idea or a wish can contact us and we try to address it with a seminar.
Laura Tünnermann: After we decide on a topic, we try to find suitable speakers and companies and contact them by email.
What was most challenging and what most inspiring for you so far?
Tinkara Bizjak: The most challenging is to get the contacts. Sometimes it is hard to find their email or get an answer.
Laura Tünnermann: I agree, that is very frustrating, but I think the good feedback from our participants is worth it.
You have so far organised 3 different seminars inviting former researchers that are now working with patents, or in different local companies. Which topics are you planning to cover next?
Tinkara Bizjak: In October we are inviting two speakers who have spent 20 years in academia before switching to the industry. This will be followed by a seminar in November about being a scientific illustrator.
Laura Tünnermann: For next year, we are planning seminars about how to start your own company with the help of the Umeå Biotech Incubator. We are also trying to contact potential speakers from bigger companies like Eurofins or Qiagen.
Did you decide already which direction you would like to go after your PhD – inside or outside of academia?
Tinkara Bizjak: I am not sure yet, but I am leaning towards leaving academia at some point.
Laura Tünnermann: I have not decided yet either, but I hope organizing these seminars will help me with the decision.
More about the "Outside of Academia" Seminar series
Laura Tünnermann and Tinkara Bizjak plan to organise about five to six seminars per year in the frame of the "Outside of Academia" seminar series. The topics they covered so far were "Science & Law" and "Industry in Umeå" with contributions from Nordic Biomarker and Arevo. The next and fourth seminar with the topic "Postdoc in plant science – and then? Two career options" will take place on Friday next week, 13th of October. The speakers will be Rumen Ivanov, regulatory affairs manager at KWS in Germany, and Tzvetina Brumbarova, project manager at the Clinical Trials Centre Cologne, Germany. Both worked first as postdoc and senior researcher in academia before switching profession.
More information about the upcoming seminar on October 13 and the link to the registration form here
Contact:
For questions or suggestions please contact Laura Tünnermann (
Today, the photo exhibition “An Eye for Science” was opened at SLU in Umeå. Every photo is accompanied by a longer article describing the story behind the photo. The SSF funded project “Landscape breeding”, which is led by Rosario García Gil from UPSC, is one of eleven research projects that are highlighted in the exhibition.
The Swedish University of Agricultural Sciences (SLU) wants to show with the photo exhibition “some concrete examples on how SLU takes on fundamental issues that affect all of us”. Since May, the exhibition has toured around all main SLU campuses in Sweden starting in Uppsala, followed by Alnarp and Skara. Finally, it has now arrived in Umeå where it will be displayed until the end of October.
The selected eleven photographs cover a wide range of different research fields from biodiversity research, sustainable ecosystem management to research on antibiotic resistance, food security and safe drinking water. Rosario García Gil’s project “Landscape breeding” aims on providing new tools for sustainable forest management by developing a novel tree breeding strategy.
The research team includes experts in tree breeding and genetics, forest pathology and remote sensing technologies coming from SLU, Skogforsk (Forestry Research Institute of Sweden) and RISE (Sweden’s research institute and innovation partner). Together they want to develop tools that allow fast and accurate predictions on the performance of specific Norway spruce trees in a certain environment. The project is funded by the Swedish Foundation for Strategic Research (SSF).
The photo exhibition "An eye for science" will be displayed in Lyckan (floor 2) at SLU in Umeå until the 31st of October.
Read more about SLU’s photo exhibition “An eye for science"
Direct link to the photo story about the “Landscape breeding” project
About one year ago, UPSC organised the UPSC Days in Saxnäs. After two years of restrictions due to the COVID-19 pandemic, the goal was to bring people together, strengthen the community at UPSC and identify possibilities to improve UPSC’s research environment. What has happened since then? Many good suggestions were brought up during the meeting - some were easy to implement, others are still in the progress to be realised. We take a look back on the last year.
More than 80 people working at UPSC spent three days in the beautiful environment of Saxnäs in South Lapland and discussed in different constellations UPSC’s strengths and weaknesses as well as opportunities and threats for UPSC. The engagement of the participants was great and the feedback collected during these discussions enormous.
“It took us quite some time to go through and structure everything that came up during the meeting and we still have not manage to address everything,” says Totte Niittylä, Head of Department of Forest Genetics and Plant Physiology, SLU. “We started with things that were easy to solve. For example, we have now once per month in our joint UPSC-all meeting a presentation from one of our scientific facilities to help increasing their visibility. This was an easy fix but other more structural improvements need longer time to be implemented.”
It is not always easy to understand the structure of UPSC which is part of two universities with different rules and regulations. The administration including HR and economy is separated between the two departments and also the PhD education differs somewhat between the two universities. The facilities and equipment on the other hand are shared by all research groups and seminars and events are jointly organised for all of UPSC.
“The close collaboration of the two departments under the umbrella of UPSC is the main strength of UPSC but it can be confusing to understand that a colleague working besides me is from a different university and may have different guidelines and rules to follow,” explains Johannes Hanson, who is Head of the Department of Plant Physiology at Umeå University since beginning of this year. “The discussions in Saxnäs and afterwards made it apparent that we can improve our internal communication and that is what we are working on now.”
Since the beginning of the year, newcomers at UPSC are invited for a UPSC Welcome Meeting where UPSC’s structure and facilities are presented. Once a year in November a lecture is given on the Swedish academia and the career paths it offers. The postdocs and PhD students started a Buddy initiative to help new arriving postdocs and PhD students finding their way at UPSC and help them integrating in the community. Twice per year a lecture with talks from UPSC group leaders is organised and this week the first joint seminar day for half-time PhD students took place.
“We cannot fully harmonize the PhD education at the two departments nor the administration since the systems at SLU and UmU differ, but we do it as often as possible,” says Ove Nilsson, director of UPSC. “We also know we can improve our internal communication and we are very glad about the strong commitment of our staff that is helping us to constantly improve on this front. Excellent research output is very much dependent on a good work environment, and we need to all work together to shape a competitive UPSC.”
Formas, the Swedish governmental research council for sustainable development, awarded Thomas Wieloch, postdoc at Umeå Plant Science Centre and SLU, a mobility grant for early-career researchers. He will investigate which processes hinder carbon assimilation in wheat and try to identify possible ways to improve productivity. His project will be in collaboration with his current supervisor Totte Niittylä and with Alex Sessions from the California Institute of Technology.
Congratulations to your mobility grant! Are you excited to start your project?
Thank you! Absolutely! This is the next step in my academic career. In addition to developing my own research, which I am already familiar with, I will now also have to manage project funds. A great responsibility I have not had before. I am very grateful to Formas for their trust and support.
You plan to identify processes that inhibit photosynthesis and carbon assimilation in C3 plants focusing on wheat. Why did you choose to work with wheat?
I would like to work with wheat because wheat is an extremely important crop both nationally and globally. It is actually one of the so-called ‘big three’ cereal crops feeding the world which means that it contributes substantially to the diet of several billions of people. In my opinion, these are very good reasons to try and better understand how this plant works at the metabolic level and to improve it.
Why is it important to identify processes that inhibit photosynthesis?
Ultimately, my project is all about releasing the brakes on photosynthesis. Biochemical mathematical models suggest that plants in general do not usually achieve their full photosynthetic potential. I believe that identifying inhibitory processes will provide the scientific basis for efforts aimed at optimising photosynthesis genetically, and this has enormous potential for improving agricultural productivity and food security.
You plan to work with stable isotopes which are naturally occurring, non-radioactive forms of a chemical element that are often used as tracers in biological systems. How can isotope technologies help to understand photosynthesis and carbon assimilation in plants, especially in C3 plants?
Stable isotopes can tell us how plants utilise their resources. Using isotope technologies, we may obtain information on where, within a metabolic network, resources get lost or where they are not used in the best possible way. This is not especially true for C3 plants, but for plants in general.
You are currently working as postdoc in Totte Niittylä’s group at UPSC and plan to continue there during the first two years of the project. Why did you choose to join UPSC and Totte Niittylä’s group in the first place and how will the group’s expertise contribute to your research project?
UPSC is one of the strongest research environments in experimental plant biology in Europe. It is home to excellent research groups covering a broad range of topics and very well equipped with basically everything I need to conduct my experiments. While I am quite proficient in modelling biochemical processes based on isotope data, Totte Niittylä’s group has longstanding experience in conducting isotope tracer experiments and biochemical analyses which means that our skillsets are complementing each other in very good ways. Besides, Totte is very supportive, and this is making a real difference especially for an early-career researcher. He is going out of his way to help me advance my career, and I am extremely grateful for that.
The third and fourth year of your project you plan to spend with Alex Sessions at the California Institute of Technology in Pasadena. What do you hope to learn in his group and how will this benefit your project?
Alex Sessions’ group is working on solving highly challenging problems within the stable isotope field that many other groups seemingly tend to stay away from. Recently, his group developed software for modelling isotope changes in complex networks. I believe this software constitutes an important breakthrough since it allows estimations of carbon fluxes based on natural-abundance isotope data in a convenient way. Sooner or later, everyone in the stable isotope field will want to implement these software capabilities in their research to obtain the best results possible, and I would like to be at the forefront of this development. I have great respect for this group’s dedication to pushing current boundaries.
Why did you choose to apply at Formas for the mobility grant for early-career researchers?
Formas provides a great mobility grant package. This package enables young scientists to independently develop their own line of research and visit research environments outside of Sweden where they may learn new methods, expand their research network, and get inspired by what others do. The package not only includes the awardee’s salary, but also covers additional living costs for the time spent at research institutes outside of Sweden, project-related costs, pension benefits and so on. To sum it up, Formas offers early-career researchers an entirely fair framework in which to advance their careers.
Do you have some tips for other early-career researchers applying for similar grants?
I am not feeling entirely comfortable about giving advice on what to do to get a research grant because my experience in this area is still quite limited. I think what helped me though was a longer list of published first- and corresponding-author papers which show that I have successfully and independently completed research projects before. I have also tried to make sure that my proposed project clearly addresses societal needs and asked Totte, Alex, and our Grants Office for advice as I developed my application which I believe made it a lot more competitive.
Project title: Releasing the brakes on photosynthesis – Identifying processes impeding photosynthesis in wheat leaves by cutting-edge isotope techniques
More information about Formas’ mobility grants for early-career researchers
For questions, please contact:
Thomas Wieloch
Umeå Plant Science Centre
Department of Forest Genetics and Plant Physiology
Swedish University of Agricultural Sciences
Sweden
Email:
Twitter: @WielochThomas
The European Molecular Biology Organization (EMBO) announced today the election of 69 new EMBO Members and Associate Members. One of them is Rishikesh Bhalerao, professor at the Department of Forest Genetics and Plant Physiology at SLU, who is honoured with the membership for his “outstanding contributions to life sciences”.
Every year, the EMBO Council elects new members who have made outstanding contributions to the field of life sciences. This year, 60 new EMBO members from 17 different European countries and nine Associated Members based outside of Europe will join the membership organisation. They will contribute with their expertise to the execution of EMBO’s activities and help shaping the future direction the organisation will take to strengthen research communities across Europe and beyond. The EMBO Membership is a lifelong honour.
With the election of Rishikesh Bhalerao, the SLU Department of Forest Genetics and Plant Physiology, that is part of UPSC, has two scientists who are members of EMBO. The other is Ove Nilsson who was elected in 2016. Rishikesh Bhalerao and Ove Nilsson are the only EMBO Members in Sweden actively engaged in plant research.
“I am honoured and humbled by being elected as EMBO member and pleased to join this exclusive group of international researchers", says Rishikesh Bhalerao. “This election signifies the recognition of our work not just nationally but at international level. The credit naturally goes to all my group members and to the UPSC research environment that have made this possible.”
In his research, Rishikesh Bhalerao and his group investigate how plants adapt their growth to the environment focusing on how this is controlled on the molecular level. They follow two main lines of research. Using the perennial plant hybrid aspen as an experimental model, they study how daylength and temperature control seasonal growth cycles in trees. In the second line of research, Rishikesh Bhalerao’s group studies mechano-chemical control of bending of tissues in plants using apical hook development in thale cress - among scientists better known as Arabidopsis thaliana.
Rishikesh Bhalerao’s findings have been published in high-ranking journals like Science, PNAS, Nature Communications and Plant Cell. After his PhD at Umeå University, he went for a postdoc at the Max Planck Institute for Plant Breeding in Cologne, Germany. In 1997, he came back to Umeå and joined SLU where he was appointed as professor in 2005. He has been part of UPSC since its foundation in 1999 and as vice-chair of the UPSC board he is actively involved developing the research centre further.
As EMBO Member Rishikesh Bhalerao will join a network of 1900 life scientists and can actively participate in EMBO’s activities. Members participate for example in the evaluation of funding applications. They are serving on EMBO’s Council, committees and editorial boards of EMBO Press journals and also act as mentors for young scientists. All new members will be formally welcomed at the annual EMBO Members’ Meeting on October 25-27 in Heidelberg in Germany.
Link to the official press release from EMBO
More information about EMBO on the website of the organisation
For questions, please contact:
Rishikesh Bhalerao
Umeå Plant Science Centre
Department of Forest Genetics and Plant Physiology
Swedish University of Agricultural Sciences
Email:
https://www.upsc.se/rishikesh_bhalerao
Why can Norway spruce from Northern Sweden tolerate shade better than Norway spruce from Southern Sweden? Sonali Ranade and María Rosario García-Gil from UPSC compared the DNA sequence of Norway spruce trees from different latitudes across Sweden and found variations in the genes of light-sensing photoreceptors. These variations could be aligned with the light conditions at the different latitudes. Their results were published recently in the journal Plant, Cell and Environment.
Sonali Ranade and María Rosario García-Gil have shown earlier that Norway spruce populations in Sweden are differently adjusted to the different local light conditions in Sweden. Norway spruce from the North tolerates shade much better than Norway spruce populations from Southern Sweden and this comes along with a better resistance to diseases. Now, the researchers have identified one underlying factor for this adaptation to the latitudinal different light conditions – variations in the genes for photoreceptors.
“Photoreceptors are light sensitive proteins. Plants use them to understand light quality and to sense daylength. Based on the perceived information, plants regulate processes and signalling pathways to adjust their development to their environment”, explains Sonali Ranade, first author of both studies. “We could show now that the genes for two photoreceptors - phytochromes and cryptochromes - genetically vary in Swedish Norway spruce populations and that this variation follows a gradient from North to South.”
The variation is located in functional parts of the photoreceptor
The researchers were comparing the DNA sequence of 1654 different Norway spruce trees that derived from different latitudes across Sweden. They divided the group into six smaller populations according to different latitudes and were looking for small variations in the DNA sequence of the different trees. To focus first on photoreceptors, especially on phytochromes, was obvious for them as they are central regulators of the light pathways in plants.
Phytochromes perceive red and far-red light which is at the extreme end of the visible light spectrum. Under shade conditions, the red to far-red light ratio is low because there is much more far-red light available than red light. Cryptochromes sense blue light and play an important role for adjusting the plant’s growth and development to the day-night cycle. The variations that the researchers identified in the DNA sequences of the phytochrome and cryptochrome genes of Norway spruce were all located in regions that contain information for functional parts of the photoreceptor.
Different populations have adapted to local light conditions
“We do not know how and if the function of the photoreceptors in the different Norway spruce populations is changed but we think that these modifications were probably important to adapt the tree’s growth and development to the latitudinally different light conditions in Sweden,” says Sonali Ranade. “The growing period in Northern Sweden is much shorter than in the South. The trees would not have survived if they would burst their buds when it is still freezing in spring or have not set their buds yet when the first snow arrives in autumn.”
Genetically, all populations of Norway spruce in Sweden derive from two different origins reflected in two main populations - a southern and central population and a northern population. The researchers were expecting that the genetic variation would reflect mainly these two main populations. Instead, they found that the gradient changed continuously from South to North, clearly following the changing light quality through the different latitudes across Sweden, meaning that different populations have adapted to local light conditions.
“Detecting the genetic basis of local adaptation to environmental conditions in coniferous tree species is difficult”, says María Rosario García-Gil, group leader at Umeå Plant Science Centre. “Often many genes of small effect contribute to a certain characteristic leading to a complex genetic architecture. These species also have a huge genome size compared to herbaceous plants like for example thale cress and their genome is still much less understood.”
The findings from the current study are interesting from an evolutionary perspective illustrating how populations adapt to the local environment but the researchers think that this is not all. Norway spruce is an economically important conifer species for the Swedish forest industry. Understanding how trees to adapt to local conditions - like in this case local light conditions - and knowing which genes are influencing a certain tree characteristic might be also useful to design novel strategies for breeding programmes for Norway spruce.
About the article:
Ranade, S.S., García-Gil, M.R. (2023) Clinal variation in PHY (PAS domain) and CRY (CCT domain) - Signs of local adaptation to light quality in Norway spruce. Plant, Cell & Environment, 1– 10. https://doi.org/10.1111/pce.14638
The previous study:
Ranade, S.S., García-Gil, M.R. (2021) Molecular signatures of local adaptation to light in Norway spruce. Planta 253, 53. https://doi.org/10.1007/s00425-020-03517-9
Link to a news about the previous study of Sonali Ranade and María Rosario García-Gil
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
Plants give us oxygen through photosynthesis - this is commonly taught in school. An international research team have now shown that particularly in early spring when low temperatures coincide with high light, conifer needles consume – not produce – oxygen by using an ancient mechanism. The results were published in Nature Communications.
Plant photosynthesis, that occurs in the thylakoid membranes inside the chloroplasts of the leaves, release oxygen to our atmosphere and produce carbohydrates. Animals and fungi perform the opposite reaction and consume oxygen during respiration. Plants also respire, for example during the night and in the roots but during the day leaves and needles are true “oxygen factories”.
"I thought there was something wrong with the instrument"
Tatyana Shutova, senior research engineer at Umeå University, was very surprised while testing a new instrument to measure the oxygen released by these needles. She found that green thylakoid membrane samples from pine and spruce needles in the winter behaved opposite to summer needles. They consumed oxygen in the light.
“I thought there was something wrong with the instrument and repeated the measurements,” said Tatyana Shutova, who works in Stefan Jansson’s group at Umeå Plant Science Centre. “The results were consistent over several winters and for both Scots pine and Norway spruce”.
The samples Tatyana Shutova analysed were collected by Pushan Bag who studied in his PhD project at Umeå University how conifers could stay green during the long and cold boreal winters.
"We took an elimination approach to opt out other pathways."
Puzzled by the results, the researchers set out to investigate the phenomena using a combination of sophisticated techniques. Together with Dmitry Shevela from Umeå University and Johannes Messinger, professor at Uppsala University, they used a specialised instrument that allowed them to distinguish between oxygen produced and consumed.
“To pinpoint where exactly the oxygen was taken up, we took an elimination approach to opt out other pathways that could potentially consume oxygen and were finally left with only one option: the oxygen consumption occurred around photosystem I - one of the two main photosynthesis complexes - and involved a special type of protein called Flavodiiron proteins” explained Pushan Bag, now Human Frontiers long term fellow at University of Oxford. The team also included Sanchali Nanda and Jenna Lihavainen from Umeå university and Alexander Ivanov from University of Western Ontario, London, Canada.
Flavodiiron proteins are used by algae and cyanobacteria to protect their photosynthetic apparatus from damage by excess light. Flowering plants have lost them during their evolution but conifers not, and this study suggest that they contribute to photoprotection also in conifers.
"Conifers seem to have adopted a “better safe than sorry”- strategy."
In a previous study that the researchers published three years ago in the same journal they identified another mechanism – a kind of shortcut between photosystem II and I that is used by conifers to protect their photosynthetic apparatus.
“There are interesting parallels between these two studies,” says Stefan Jansson, professor for plant cell- and molecular biology at Umeå University who led the project. “In both cases, conifers have retained a process that is present in lower plants but that flowering plants have lost or do not utilize to the same extent. Conifers seem to have adopted a “better safe than sorry”-strategy which may be less efficient under optimal conditions but makes them more competitive in a harsh climate.”
The article
Bag, P., Shutova, T., Shevela, D., Lihavainen J., Nanda, S., Ivanov, A. G., Messinger J. & Jansson S.; Flavodiiron-mediated O2 photoreduction at photosystem I acceptor-side provides photoprotection to conifer thylakoids in early spring. Nature Communications 14, 3210 (2023). https://doi.org/10.1038/s41467-023-38938-z
Link to the news about the previous article published three years ago in Nature Communications
The previous article:
Bag, P., Chukhutsina, V., Zhang, Z. et al. Direct energy transfer from photosystem II to photosystem I confers winter sustainability in Scots Pine. Nature Communications 11, 6388 (2020). https://doi.org/10.1038/s41467-020-20137-9
For questions, please contact:
Professor Stefan Jansson
UPSC, Department of plant physiology
Umeå university
901 87 Umeå
Phone 070-677 23 31
Email
Text: Pushan Bag & Stefan Jansson
Last week, SLU announced the names of honorary doctors for 2023. Malcolm Bennett, Professor of Plant Science at University of Nottingham, is one of them. He has close collaborations with several research groups at UPSC and his support has been crucial for the development of UPSC as a world leading centre for experimental plant biology. He was appointed by the Faculty of Forest Sciences to which one of the two UPSC departments belong.
Malcolm Bennett’s research focusses on how plant roots grow and adapt in their soil environment. His group originally identified the first gene that controlled root angle and encodes the first transport protein described for the plant hormone auxin. Malcolm and colleagues later developed cutting edge non-invasive visualisation techniques for monitoring root growth in natural soil environments using X-ray microtomography and AI-based image analysis techniques.
His most recent work discovered how roots sense soil stresses such as compaction or water availability. This was done in collaboration with UPSC researchers and published in Science in 2021 and 2022. Malcolm Bennett has published over 200 articles in leading journals and is the recipient of several research awards including election as a Fellow of the Royal Society and a member of the European Molecular Biology Organisation (EMBO).
“I am thrilled to be awarded the honorary doctorate from SLU", says Malcolm Bennett. “I have worked closely with collaborators at UPSC throughout my career, publishing over 20 joint research papers since 2000. The world leading plant biology researchers and hormone profiling expertise at UPSC has played a key part in sustaining and deepening this collaboration over the past decades.”
Six new Honorary Doctors are appointed this year: two for the Faculty of Landscape Architecture, Horticulture and Crop Production Sciences, one for the Faculty of Natural Resources and Agricultural Sciences, two for the Faculty of Forest Sciences and one for the Faculty of Veterinary Medicine and Animal Science. The new Honorary Doctors will be officially appointed during SLU’s Doctoral Award Ceremony on the 7th of October 2023 in Uppsala. The day before, on the 6th of October, they will give a public lecture about their research field.
More information about the six honorary doctors on SLU’s homepage (only in Swedish)
More information about Malcolm Bennett's research
The articles in Science to which researchers from UPSC contributed:
Poonam Mehra et al., Hydraulic flux–responsive hormone redistribution determines root branching. Science 378,762-768(2022). DOI:10.1126/science.add3771
Bipin K. Pandey et al., Plant roots sense soil compaction through restricted ethylene diffusion. Science 371,276-280(2021). DOI:10.1126/science.abf3013