1U5A0746 2 1920x1080Mateusz Majda. Photo: Stéphanie Robert

The cells in the outmost layer of leaves have irregular shapes, which help them to interlock with each other like jigsaw puzzle-pieces to form a sturdy layer. How this growth pattern is achieved has been debated, but now a team led by SLU researchers has proposed a possible mechanism.

The study aims to understand how plant cells get shaped. The form of the plant cell can be very specific, like the jigsaw puzzle-shaped pavement cells in the outer epidermal layer of plants. It was previously thought that these cell types are formed by locally different expansion rates, i.e. that the cell wall around the cell grows differently fast and that this causes the local bending of the cell wall inwards or outwards.

In this study, Mateusz Majda together with colleagues from SLU and seven other universities have used a computational modelling approach that shows that a differently growing cell wall cannot alone explain the specific form of the jigsaw puzzle-shaped cells. The cell wall surrounding the cell also needs to have varying mechano-chemical properties – a cell wall is easier to bend where it is "softer" than where it is more rigid. The researchers could prove this by using advanced microscopy techniques in combination with genetic studies with different cell wall mutants.

"The cell wall is composed of different sugars and some proteins. We have shown that cell growth and shape acquisition is controlled by very local changes in the distribution of sugars", says Mateusz Majda at Umeå Plant Science Centre. He is a doctoral student at SLU and first author of the article.

By analyzing mutants with a wide range of defects related to major cell wall components, the team first showed that even minor alterations in the cell wall composition lead to severe defects in the geometry of the leaf pavement cells. A computational modeling approach then suggested that mechanical heterogeneity in the cell wall is needed to initiate the interdigitated shape of pavement cells in an epidermis that is under tension. Such heterogeneities were detected by atomic force microscopy (AFM) in straight cell walls prior to and at a very early stage of lobe formation. In addition, the direction of bending from the mechanically stronger toward the mechanically weaker cell wall domain, as predicted by the model, was confirmed by AFM in cell walls at the very early stage of wall lobing.

"Cell walls are the main component of wood and represent the majority of the industrial terrestrial biomass. In the long-term perspective, this research in understanding cell wall biosynthesis in unprecedented detail will permit us to engineer or develop new approaches to modulate the biomass", says Stéphanie Robert, senior lecturer at SLU's Department of forest genetics and plant physiology in Umeå, and lead author of the article.

The article was published on November 6th in Developmental Cell by researchers from the Swedish University of Agricultural Sciences and colleagues from Uppsala University, Université de Lyon, Lund University, University of Wroclaw, Umeå University, University of Potsdam and University of Cambridge.

Fig Majda 1920x1080llustration of jigsaw puzzle shaped epidermal cells of a leaf. The coffee bean shaped structures are the stomata. Illustration: Mateusz Majda


Link to the Swedish press release on the SLU homepage


The article

Mateusz Majda, Peter Grones, Ida-Maria Sintorn, Thomas Vain, Pascale Milani, Pawel Krupinski, Beata Zagorska-Marek, Corrado Viotti, Henrik Jönsson, Ewa J. Mellerowicz, Olivier Hamant & Stéphanie Robert. Mechanochemical polarization of contiguous cell walls shapes plant pavement cells. Developmental Cell 43, 290–304, November 6, 2017.
https://doi.org/10.1016/j.devcel.2017.10.017

More information

Contact persons
Mateusz Majda, PhD student
Umeå Plant Science Centre
Department of Forest Genetics and Plant Physiology
Swedish University of Agricultural Sciences
+46 (0)90-786 55 16, This email address is being protected from spambots. You need JavaScript enabled to view it.

Stéphanie Robert, Senior Lecturer
Umeå Plant Science Centre
Department of Forest Genetics and Plant Physiology
Swedish University of Agricultural Sciences
+46 (0)76-767 45 95, This email address is being protected from spambots. You need JavaScript enabled to view it.
https://www.upsc.se/stephanie_robert

Text: Mateusz Majda, Stéphanie Robert, David Stephansson
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Vetenskapsrådet granted three research projects associated with UPSC. The projects from Catherine Bellini, Ewa Mellerowicz and Xiao-Ru Wang will address adventitious root initiation, signalling from secondary cell walls and the processes of hybrid speciation and adaptation to extreme habitats.

Catherine Bellini, Professor at Umeå University and group leader at UPSC, works on adventitious root initiation. Adventitious roots play an important role for plant vegetative propagation. Many factors are involved in the initiation of adventitious roots and Catherine Bellini’s group has identified several of them. The aim of the approved project is to understand better how those different factors act together and cross-talk with each other.

Ewa Mellerowicz, Professor at the Swedish University of Agricultural Sciences and group leader at UPSC, focuses in her research on wood formation. Wood is produced by the activity of the vascular cambium, which consists of actively dividing cells. Ewa Mellerowicz's group and others have recently observed that certain modifications of the secondary cell wall composition of wood cells lead to increased cambial growth. With the new funding from VR, they want to identify the key players that are involved in this novel signalling pathway.

One research focus of Xiao-Ru Wang, Professor at Umeå University and associated group leader at UPSC, is to understand which role hybridization between species plays for the evolution of new species. Hybridization is a very dynamic process that can generate genetic diversity for novel adaptation. With the new project, Xiao-Ru Wang and her group want to understand the process how new hybrids develop, and how they evolve to colonize new ecological niches.

Titles of the approved projects:
Catherine Bellini: Control of adventitious root initiation in Arabidopsis thaliana: deciphering the increasing complexity of molecular cross-talks
Ewa Mellerowicz: Novel signalling pathways from secondary walls
Xiao-Ru Wang: Dynamics of hybrid speciation and adaptation to extreme habitats

More information:
Catherine Bellini
Umeå Plant Science Centre
Department of Plant Physiology
Umeå University
Phone: +46 (0)90 786 9624
Email: This email address is being protected from spambots. You need JavaScript enabled to view it. 
https://www.upsc.se/catherine_bellini

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: This email address is being protected from spambots. You need JavaScript enabled to view it.
https://www.upsc.se/ewa_mellerowicz

Xiao-Ru Wang
Department of Ecology and Environmental Sciences
Umeå University
Phone: +46 90 786 99 55
Email: This email address is being protected from spambots. You need JavaScript enabled to view it.
https://www.upsc.se/xiao-ru_wang
http://www.emg.umu.se/english/about-the-department/staff/wang-xiao-ru/

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The one week lasting intensive PhD course provided a brief overview of wood organization, chemistry and structure in conifers and hardwoods, from the molecular level to the tissue organization level, followed by an update on molecular, genetic and physiological aspects of wood cell differentiation and cell wall formation. Current tools for studying wood structure and chemical composition, as well as the bioinformatics tools available for wood biology were introduced with practical demonstrations. Lectures and seminars were given by experts in the field.

Read more here
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The new Master’s programme called “Plant Biology for Sustainable Production” is intended for national as well as international students. It is taught entirely in English. The teaching on this programme is strongly geared towards preparing students for research, and all four specialisations on the programme have links to strong research environments.

The program utilises competence on three campuses of the Swedish University of Agricultural Sciences located in Alnarp, Ultuna and Umeå. During the first year, all lectures are streamed live allowing to follow the courses from any of the three campuses.

During the second year, the students can specialise in either plant breeding and protection, abiotic and biotic interactions of plants or forest biotechnology. In fourth study track, students can decide to focus directly from the beginning on genetic and molecular plant biology.

Read more about SLU's new Master's programme here: 
https://www.slu.se/en/education/programmes-courses/masters-programmes/plant-biology-for-sustainable-production/

IMG 1481 crop 1920x1080 2Videoplatform with aphids (Photo: Karen Kloth)

Researchers at Umeå University and Wageningen University have discovered how plants can defend themselves against aphids. They recorded aphid behavior on video, and identified a plant protein that keeps aphids from feeding. The study is published in the journal The Plant Cell.

During her PhD, Karen Kloth studied aphid feeding behavior on different varieties of the model plant Arabidopsis thaliana, collected from 350 different locations on the northern hemisphere. Together with other Dutch researchers she built a video-tracking platform to measure how often aphids penetrated the plants and were feeding. On resistant plants, the aphids were feeding less from the sugar-rich sap than on susceptible plants. This behavior was associated with one specific plant gene, coding for a protein with unknown function.

In Benedicte Albrectsen’s lab at the Umeå Plant Science Centre, the researchers studied where in the plant the protein was located. They transformed plants with a fluorescent version of the protein, and found that the protein coats the inside of the vessels where sugar-rich sap is transported. In addition, it associated around mitochondria in the vessels.

Further experiments showed that aphids had a slower sap ingestion and produced fewer offspring on resistant plants. The researchers think that the protein might occlude the narrow food canal of the aphid. At high temperature, plants produced more of the protein and were more resistant to aphids. In addition, plants with the protein had another advantage: they were able to produce more seeds during heat stress.

Karen Kloth, today Postdoc in Benedicte Albrectsen's lab, has been working for almost six years on this study: “In the beginning, we did not know if the video platform would work. We kept the aphids in a very artificial environment, and it is debatable whether this represents whole plants in natural conditions. When the first results confirmed that we had indeed found a new resistance gene, I was really excited.”

Natural plant resistance to aphids and better tolerance to heat stress are of interest for plant breeding companies. Breeding crops with effective resistance proteins can help to reduce insecticide application and yield losses due to hot conditions. In the long term, this research might help to produce more sustainable fruits and vegetables.

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You can find the full publication and videos recorded at the video-tracking platform under these links:
http://www.plantcell.org/content/early/2017/09/27/tpc.16.00424 (publication)
Video 1 Plant (open access)
Video 2 Plant (open access)

For more information please contact:
Karen Kloth, Department of Plant Physiology, Umeå University
This email address is being protected from spambots. You need JavaScript enabled to view it.



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The Department of Plant Physiology started its work at Umeå University in 1967. It is now part of the Umeå Plant Science Centre (UPSC), a world leading plant research institute. UPSC celebrates the 50 years anniversary with a three-day lasting symposium about the past, the present and the future of Plant Science in Umeå (and the world). The Symposium will take place on August 21-23 at the UPSC in Umeå.

The research at UPSC today is fundamentally different from the science of 1967. UPSC comprises not only the Department of Plant Physiology but also the Department of Forest Genetics and Plant Physiology from the Swedish University of Agricultural Sciences (SLU), founded in the late 1970s. These two Departments joined their forces in 1999 and created the Umeå Plant Science Centre (UPSC), first “virtually”, and in 2001 also physically.

Today, over 200 persons from about 45 different nationalities work at the UPSC - in contrast to the handful of people that started in August 1967. How has this tremendous development been possible, where is plant science today and what is its importance for the society and the citizens of Sweden? These are questions that will be discussed during the anniversary symposium.

The first day of the symposium will focus on the history of plant science in Umeå. On the second day, current group leaders from the UPSC will present their research and the third day concentrates on future perspectives of Plant Science. The invited speakers are famous plant scientist from all over the world, who influenced the development of Plant Science in Umeå. They are all honorary doctors either at Umeå University or at SLU.

The history of Plant Science in Umeå is now also summarized in a booklet (in English) that will be printed for the Symposium. This booklet is based on a more detailed book with the title “Från King Alfred till grangenomet: 50 år av växtforskning i Umeå” (in Swedish) that will be published presumably in autumn 2017.

More about the symposium:

Event: Plant Science 50years in Umeå Symposium
Date: 21-23 of August
Place: Umeå Plant Science Centre, Umeå University Campus, Umeå
 

Program for the 50 years Plant Science in Umeå Symposium 2017

    Preliminary program
    Location:  Stora hörsalen, KBC, Umeå

    Day 1: Monday, 21 August 2017
    Plant Science in Umeå (and the world) in the past

    Chair: Stefan Jansson
    13.00 - 13:10 Opening of the Symposium
    Hans Adolfsson, Vice chancellor, Umeå University and Mikael Elofsson, Dean of the faculty of science and technology
    13.10 - 13.30 Introduction - Plant Science in Umeå 50 years
    Stefan Jansson, Prefect at the Department of Plant Physiology, Umeå University
    13.30 - 14.00 My 50 years in Plant Physiology
    Gunnar Öquist, Professor emeritus, Umeå University
    14.00 - 14.15 How did it go? Some reflections 50 years later
    Lars Ericson, Professor emeritus, Umeå University
    14.15 - 14.45 Genphys 1978-1999
    Jan-Erik Hällgren, Professor emeritus, SLU
    14.45 - 15.30 Coffee break
    15.30 - 16.00 The early era of transgenic plants in Umeå: hairy, shooty, shiny, bonsai and with a touch of fish
    Olof Olsson, Lund University
    16.00 - 16.30 Biochemists invading Plantphys under the polar night
    Bertil Andersson, Nanyang Technological University, Singapore, Honorary doctor at Umeå University
    16.30 - 17.00 UPSC 1999-2017
    Ove Nilsson, Director of UPSC, SLU
    17.00 Guided tour through UPSC
    19.00 Dinner/Barbecue (KBC cafeteria)
      "Botanist pub" and music (UPSC coffee room)
       

    Day 2: Tuesday, 22 August 2017
    Plant Science in Umeå (and the world) today

    Session 1: Plant Growth and Development 
    Chair: Thomas Moritz
    9.00 - 9.25 The roots of vegetative propagation
    Catherine Bellini, Umeå University 
    9.25 - 9.50 Integration of flowering time signals in Arabidopsis thaliana
    Markus Schmid, Umeå University
    9.50 - 10.15 The transcriptome of wood formation
    Torgeir Hvidsten, Umeå University/Norwegian University of Life Sciences Ås
    10.15 - 10.45 Coffee break
    10.45 - 11.10 Populus FT-like genes - from flowering to tree phenology
    Ove Nilsson, SLU
    11.10 - 11.35 Root invasion by ectomycorrhizal fungi during symbiosis formation – cell wall remodelling under the influence of auxin?
    Judith Felten, SLU
    11.35 - 12.00 Carbon for wood cell walls
    Totte Niittylä, SLU
    12.00 - 13.30 Lunch
     
    Session 2: Plant Responses to Environmental Changes
    Chair: Per Gardeström
    13.30 - 13.55 Studies of biological stress at UPSC
    Benedicte Albrectsen, Umeå University
    13.55 - 14.20 Deciphering the metabolic regulations associated with leaf senescence
    Olivier Keech, Umeå University
    14.20 - 14.45 Light response, a tale of two genomes
    Åsa Strand, Umeå University
    14.45 - 15.15 Coffee break
    15.15 - 15.40 Genetic architecture of gene expression variation in Swedish aspen
    Nathanial Street, Umeå University
    15.40 - 16.05 Local adaptation in conifers
    Rosario Garcia Gil, SLU
    16.05 - 16.30 Translational dynamics in Arabidopsis
    Johannes Hanson, Umeå University
    19.00 Dinner and 50th anniversary party (Universum)
       

    Day 3: Wednesday, 23 August 2017
    Plant Science in Umeå (and the world) in the future

    Chair: Karin Ljung
    9.00 - 9.30 Plant Science - The next 50 years?
    Ottoline Leyser, Director of the Sainsbury Laboratory, University of Cambridge, Honorary doctor at SLU
    9.30 - 10.00 Challenges for photosynthesis research
    Eva-Mari Aro, Turku University, Honorary doctor at Umeå University
    10.00 - 10.30 Coffee break
    10.30 - 11.00 Budgeting for a fluctuating future - Learning from the predictable and living with the unpredictable.
    Mark Stitt, Max Planck Institute of Molecular Plant Physiology, Golm-Potsdam, Honorary doctor at Umeå University
     11.00 - 11.30 Ex-temporary research
    Birger Lindberg Møller, Copenhagen University, Honorary doctor at Umeå University
    11.30 - 12.00 The future for basic science in Sweden and Umeå
    Göran Sandberg, Executive director, KAW
     12.00 - 12.30 Concluding words and closing of the symposium
    Peter Högberg, Vice chancellor SLU, Göran Ståhl, Dean of the Faculty of Forestry
     12.30 - 14.00  Lunch

    Practical information

      Symposium Venue

      The conference will take place in the Large Lecture Room ("Stora hörsalen", KB.E3.03) at the Chemical Biological Centre (KBC) on the Campus of Umeå University.

      Travel and Arrival

      Umeå is easily accessible via plane, railway, bus, car, and even by ferry.

      By Plane
      It takes around one hour to fly from Stockholm to Umeå. Scandinavian Airlines (SAS) and Norwegian Air Shuttle operate several daily flights to and from Stockholm Arlanda International Airport. BRA also offers frequent flight service via Stockholm Bromma Airport.
      SAS may offer limited direct connections from Gothenburg and Helsinki, and Nordic Airways from Luleå, Kiruna and Östersund.
      From Umeå Airport it is only a 10-minute drive to the city centre. Taxis are available for quick access to your desired destination in Umeå and can be pre-booked with no extra charge. The price to take a taxi to the city centre is about 280 SEK.
      The Airport Shuttle (No. 80, "Flygbuss" in Swedish), offers regular bus service from Umeå Airport to the city centre and passes by the university campus as well. A one-way ticket costs 65 SEK.

      Please Note: cash is no longer accepted on any of the local buses, including the Airport Shuttle! Major credit and debit cards are accepted onboard, except for online cards, such as Maestro or Visa Electron.

      By Train
      SJ and Norrtåg offer train services to Umeå. There are overnight trains and day trains, some of them connected to bus lines, from Stockholm, and from Gothenburg via Örebro. Both lines continue to Luleå in the county of Norrbotten and Kiruna and Alvik further north are accessible via Luleå.
      Umeå East (Umeå Östra) railway station is located near the University Hospital of Umeå, and is directly adjacent to Campus Umeå.

      By Bus
      Buses arrive from all over Sweden to the central bus terminal near the town centre. Nearly all major cities and towns can be reached via several bus carriers. Länstrafiken operates regional buses, which connect to other bus carriers. Ybuss offers affordable service to and from Stockholm, for those on a tight budget.

      By Car
      Take Highway E4 to Umeå (or E12 from western Västerbotten and Norway) and follow the signs to the hospital (Norrlands Universitetssjukhus) until you see specific signs for the University (Universitet). Parking areas can be found in front and around the KBC building.
      Parking on campus must be paid for in advance at the ticket machines located in the parking area, which accept all major credit cards (but can be slow especially when handling foreign cards).

      Accommodation

      Umeå is a busy tourist and academic town, especially in the summer. Consequently, hotel rooms can be scarce and a booking in advance is recommended. You can find several options on this page or https://www.visitumea.se/en/ or via accommodation services such as AirBnB and Booking.com or directly contacting hotels.



      Useful Links

      Timetables of local buses (The bus stops closest to the venue are "Umeå växthuset" and "Umeå Universum")

      Time table for buses to and from Umeå Airport

      Swedish Rail Road (SJ) - Train information

      Umeå Airport - Information site, including flight information and car rental

      Tourist information about Umeå


      Programme for download: pdfProgramme_Anniversary_Symposium.pdf

      For questions please contact:
      Anne Honsel, UPSC Communication officer
      phone: +46 (0)90 786 8139
      mobile: +46 (0)70 285 6657
      Email: This email address is being protected from spambots. You need JavaScript enabled to view it.
       
      Vetenskapslunch2017 SJansson 1920x1080Vetenskapslunch February 2017 (Umeå University)
      [2017-06-20] Ten new members from different fields were inaugurated to the Royal Swedish Academy of Engineering Sciences during the second Assembly of the Academy. Stefan Jansson, professor at UPSC and Umeå university, was elected into the Division for Biotechnology.

      The Royal Swedish Academy of Engineering Sciences (IVA) is an independent engineering academy that fosters knowledge transfer activities and projects, and has the intention to have an impact on societal development and policy making.

      “It’s an extreme honour to be inducted into IVA. Hopefully my experience in plant biotechnology will be of some help in the Academy’s projects and activities,” says Stefan Jansson.


      SSF June2017 1920x1080From left to right: Stefan Björklund, Åsa Strand, Martin Rosvall (Photo: Anne Honsel)
      [2017-06-16] Åsa Strand, Stefan Björklund and Martin Rosvall, all researchers at Umeå University, have been awarded 35 million SEK from the Swedish Foundation for Strategic Research for a five-year research program on systems biology. The interdisciplinary project aims to map how plants react to abiotic stresses such as drought or extreme temperatures.

      The three researchers from Umeå University bring different expertise to this interdisciplinary project. Åsa Strand’s research is focussed on cellular signalling events, how a change in the environment is perceived and transduced to the nucleus. Stefan Björklund is an expert in the regulation of gene expression in the nucleus and Martin Rosvall develops mathematical models and algorithms to map complex networks. Together, they want to decode how plants acclimate to stressful growth environments.

      “We plan to use several different large-scale methods in our project to study how plants can defend themselves against different kinds of stress, e.g. heat, cold or salinity”, explains Åsa Strand, Professor in cell and molecular biology and main applicant of the project. “Extreme heat or cold as well as limited water availability are stress situations that lead to reduced plant productivity and yield.”

      Organisms respond to stress primarily by changing their gene expression. Stress signals are received by receptors either on the surface of a cell or by cellular organelles. These stress signals are then transmitted further to the nucleus in the cell where genes are activated to later be translated into proteins that are needed to adapt the organism to the stress situation. A large protein complex in the nucleus, the Mediator complex is conserved in all eukaryotic organisms and plays an essential role in the activation of genes.

      “Our research focuses on the role of the Mediator complex in plant acclimation to stress”, says Stefan Björklund, Professor in Medical Biochemistry. “The Mediator complex is a central point that coordinates different signals and controls how much of certain proteins is synthesised so that cells can adapt in the best way to a changing environment. Our hypothesis is that reactions to stress lead to effects in the cell nucleus in a complex and coherent manner.”

      Many recent methods for biological research generate massive amounts of data. The challenge is to interpret and analyze these data to infer causal mechanisms. Only by combining large-scale analyses with computational modelling is it possible to better understand interactions between different components in stress response. In this project, Martin Rosvall, Associate Professor in physics, will lead this component of the programme.

      “The wide expertise available at the Chemical Biological Centre (KBC) at Umeå University has been crucial for the cooperation that is the basis of our application”, underlines Martin Rosvall. “We are glad to be part of this interdisciplinary research environment.”

      Systems biology is a growing research area that aims to understand complex relationships within biological systems. The Swedish Foundation for Strategic Research (SSF) has approved nine projects in the frame of the call for proposals in the field of Systems biology and will support those projects in total with 300 million SEK.


      Link to the Swedish Press Release from Umeå University
      Link to the press release from SSF (in Swedish only)

      Read more about Åsa Strand’s research
      Read more about Stefan Björklund’s research
      Read more about Martin Rosvall’s research

      For more information, please contact:
      Åsa Strand, Professor, Umeå Plant Science Centre, Department of Plant Physiology, Umeå University
      Phone: 090-786 93 14, 070-309 62 97
      email: This email address is being protected from spambots. You need JavaScript enabled to view it.

      Stefan Björklund, Department of Medical Biochemistry and Biophysics, Umeå University
      Phone: 070-216 28 90
      email: This email address is being protected from spambots. You need JavaScript enabled to view it.

      Martin Rosvall, Associate Professor, Department of Physics, Umeå University
      Phone: 070-239 19 73
      email: This email address is being protected from spambots. You need JavaScript enabled to view it.


      On the 20th of May 2017, the Fascination of Plants Day 2017 was organised at Sliperiet in Umeå. Many people visited Sliperiet for the Fascination of Plants Day 2017 in Umeå although it was the first nice spring weekend in Umeå. The visitors could try to take an aphid on the leash, taste CRISPR-ig chips made from gene-modified cabbage, isolate DNA from strawberries and participate in many other activities, all related to plants. Have a look on the short movie to get an impression about the Fascination of Plants Day 2017 in Umeå.

      The event in Umeå was organised by scientists from the Umeå Plant Science Centre and from other Departments from Umeå University and from the Swedish University of Agricultural Science, as well as by Arboretum Norr, the urban gardeners Umeå together with Studiefrämjandet, the horticulture class from Forslunda Gymnasiet, the Swedish Bonsai society (Bonsaisällskapet) and The Swedish Society for Nature Conservation (Naturskyddsföreningen).

      The International Fascination of Plants Day falls always on the 18th of May and is launched under the umbrella of the European Plant Science Organisation (EPSO). It is a biannual event, first organised in 2012 on a European level, but now activities are organised all over the world. The aim is to fascinated people for plants and to generate awareness for the importance of plant science.

      You can find more information about the event in Umeå here:
      http://www.fascinerandevaxtersdag.se/aktiviteter/106-fascinerande-vaexters-dag-i-umea-2017.html
      Stefano Papazian 1141x1080
      [2017-05-30] All living organisms harbour complex chemical networks inside their cells. The sum of all these chemical reactions is the driving force of life and is called metabolism. Stefano Papazian, PhD student at the Department of Plant Physiology, Umeå University, has studied how plants adapt their metabolic networks to respond to different environmental stresses. He will defend his thesis on Friday, 2nd of June 2017.

      In the environment, constant exposure to both living and non-living factors make plants vulnerable to a variety of threats. As plants cannot escape, they rely on their inner chemistry to confront all sorts of challenging scenarios.

      “Plants are masters of metabolism, which they can re-shape and adjust according to their different needs,” says Stefano Papazian. “We can see plants as very sophisticated chemical factories. They are able to produce thousands of different compounds, each one presenting unique biological properties.”

      Most of these chemical compounds – called phytochemicals, play an important role inside the plant, for instance in the defence against insects that feed on leaves. In his research, Stefano Papazian aimed to understand how the plant chemistry helps plants to defend against insect pests, such as butterfly caterpillars and aphids.

      Different insects cause different damage to the plant. While some butterfly caterpillars chew on the leaves, aphids feed by piercing through the plant surface and sucking its sap. “The plant metabolic response is very specific, and it adapts its defence strategy according to the different enemies the plant encounters,” says Stefano Papazian.

      Plants produce many toxic compounds that can impair and slow down the growth of their enemies, but in order to do so, they have to balance other central metabolic activities, such as photosynthesis. Stefano Papazian’s findings show that, in addition to producing substances to defend against caterpillar and aphid attacks, plants also reconfigure their sugar composition.

      In his research, Stefano Papazian also studied how air pollution by ozone affects the plant-insect interaction. “At an altitude of 50 kilometres in the atmosphere the ozone layer protects us from UV solar radiation, but at ground-level ozone is a toxic air pollutant, which affects both human health and plants”, explains Stefano Papazian. He showed in his thesis how exposure to ozone affects the growth of insects and also results in changes in the plant metabolism with negative effects on photosynthesis and the ability to defend themselves.

      “If we combine ecology with the study of plant chemistry and metabolism we can improve our understanding of plant-insect interactions in nature and agriculture. This comprehensive approach can help us to predict the effects of climate change and human impact on these delicate ecosystems,” says Stefano Papazian.

      Stefano Papazian was born and raised in Milano, Italy. He has a Bachelor's degree in Environmental Biotechnology from the University of Milano (Italy) and a Master´s degree in Experimental Plant Biology from Stockholm University. He performed his graduate studies at the Plant Physiology Department of Umeå University within the Umeå Plant Science Centre and in collaboration with the Swedish Metabolomics Centre.

      About the public defence of the dissertation:
      Friday, 2nd of June, Stefano Papazian from the Department of Plant Physiology, Umeå University will defend his thesis entitled Black Mustard and the Butterfly Effect. Metabolomics of Plant-Insect Interactions under Multiple Stress Conditions. The public defence will take place at 10.00 in ”Lilla Hörsalen” (KB.E3.01), in the KBC building at Umeå University. Faculty opponent is Professor Edward (Ted) Farmer, University of Lausanne, Switzerland.

      Link to the full dissertation: urn:nbn:se:umu:diva-134653
      Link to the Swedish press release on the homepage of Umeå University: http://www.teknat.umu.se/nyhet//.cid282856

      For more information, please contact:
      Stefano Papazian
      Umeå Plant Science Centre
      Department of Plant Physiology
      Umeå University

      Phone: +4672 3160 854
      Email: This email address is being protected from spambots. You need JavaScript enabled to view it.

      Text: Stefano Papazian, Anna-Lena Lindskog
      Photo: Karen Kloth