Plants cannot run away! Instead, over millions of years of evolution, they have developed smart strategies to quickly respond and adapt to sudden changes in their environment. Such changes are experienced as stress, which can be biotic- (e.g. pathogens, herbivores) or abiotic stress (e.g. cold, heat, salinity, drought). Our main focus is to understand the role of phospholipid-based signal transduction pathways in temperature- (cold, heat) and water stress (drought, salinity and hypoosmotic stress), and during plant-pathogen interactions (see below).
Research in the lab of Plant Cell Biology is focussed on the role of phospholipids in Plant Cell Signalling and Development. Especially, phosphatidic acid (PA), DGPP and polyphosphoinositides, like PIP and PIP2, have our interest. These molecules are present at very low concentrations in cellular membranes and are rountinely missed by HPLC and MS analyses, simply because structural lipids, such as PC, PE, PI and PG, that make up the mass of all membranes, are too abundant. Nonetheless, these minor signalling lipids can easily be picked up by 32Pi-labelling (see TECHNIQUES), because their turnover is much faster than structural phospholipids and because they are synthesised via lipid kinases which use ATP that is one of the first compounds to be labelled. The key players involved in their metabolism are depicted in the scheme above. Routinely, this involves PLC-and PLD signalling cascades and a variety of lipid and inositolphosphate kinases. PA can be generated through both PLC- and PLD pathways, likely at different locations and in response to different stimuli resulting in different outputs.
Phospholipids are routinely analysed using in vivo 32P-orthophosphate (32Pi)-labelling. In general, cells-, seedlings- or tissues like leaf discs are used, and labelling times vary from min to hrs or even O/N, depending on the type of experiment (e.g. turnover vs mass levels). To monitor PLD activity in vivo, transphosphatidylation assays are conducted, which uses primary alcohols as substrate (see 'All Publications' ref 9, 18). Shown is an example of the green alga Chlamydomonas. Cells were prelabelled for 4 hrs and then stimulated for 5 min in the presence and absence of a low concentration of a primary alcohol that cells don't mind. Lipids were then extracted and chromatographed using an Ethylacetate TLC system that separates phosphatidylalcohols from other phospholipids (panel a). PLD catalyses the transphosphatidylation so the production of 32P-labelled phosphatidylalcohols is a relative measure for in vivo PLD activity. Autoradiography visualises their positions while PhosphoImaging is used for their quantification. As such, we have shown that PLD is activated in response to various environmental stresses, including, heat, drought, salt, and in response to pathogens. Arabidopsis contains 12 PLDs, rice 17. We are still investigating which PLD does what.
Using time-course experiments, the timing and duration of PLD activation can be established. Similarly, the activation of PLC, and PI-, PIP-, DAG- and PA kinase can be analysed. For this, lipids are chromatographed by an Alkaline TLC system that separates each of the phospholipids (panel b). Note the hydrolysis of PIP2 (PtdInsP2) within 15 sec to produce DAG that is converted to PA by DAG kinase. PI- and PIP-kinase activities also increase to maintain PIP2 levels. Since PLC is down regulated before these lipid kinases are, PIP and PIP2 are transiently over-produced. In the same time frame, the PA signal is attenuated by PA kinase producing DGPP. Figure is adapted from Ref. 27. Note that 'land plants' contain 30- 100- fold lower levels of PIP2 that Chlamydomonas or animal cells. This discrepancy has majoy consequences for the interpretatiuon of lipid signalling in plants and what PLC takes as substrate in vivo (see ref. 70).
Chlamydomonas cells were metabolically prelabelled with 32P-orthophosphate for the times indicated and subsequently treated for 1 min with either buffer (control; panel A, B) or 1 µM mastoparan (stimulated; panel C, D), both in the presence of 0.1 % n-butanol. Lipids were then extracted, split into half, and either seperated on EtAc TLC (A, C), to separate the PLD-catalyzed phosphatidylbutanol (PBut), or Alkaline TLC (B, D), to visualize the rest of the phospholipids, including PA and its phosphorylated product, diacylglycerolpyrophosphate (DGPP). The point is that all cells are treated for the same time period (1 min) but that the PBut will only be radioactive when its substrate (i.e. PE) becomes labelled (>40min). The same holds of course for the PA that would be coming through the PLD pathway. In contrast, when PA is generated via DGK, then the label comes from ATP and since this is labelled within seconds, a massive radioactive PA response can be witnessed if a DGK was involved. Since PA kinase also uses ATP, a similar response in DGPP can be picked up(panel D). Since the specific radioactivity of 32P-ATP decreases in time, the 1-min response decreases concomitantly. The combined assay is a relative measure and evidence for PA coming through a DGK and/or PLD pathway. See details in Arisz et al. , 2009 (Ref 68, 84) and in response to cold stress (ref 80).
Using GFP fusions of various lipid-binding domains and expressing them stably in tobacco BY-2 cells and Arabidopsis seedlings, we have been able to topographically visualize where certain lipids are localised, and where they are generated. Currently, we have biosensors for PI3P (ref 28), PI4P (ref 62), PI(4,5)P2 (ref 55), PI(3,5)P2 (ref 107) and DAG (ref 106). We are still working on PA sensors. The one published for Spo20 does not work in our hands (ref 106). Biosensor lines are shared with whoever wants them.
Using T-DNA insertion mutants, evidence for the participation of individual PLC, PLD and DGK in stress signalling- and development is investigated. Arabidopsis contains 9 PLC-, 12 PLD- and 7 DGK genes. In addition, there are 11 PIP5K, 12 PI4K, 1 PI3K and multiple PA- and PPI phosphatase genes too. For most of them we have mutants, which we are happy to share with other labs.
Below, an example of reduced salt tolerance in Arabidopsis pld mutants is shown. Seeds from wild-type (Col-0, black circles), pldα1 (open squares), pldδ (open triangles) or pldα1/pldδ double (open diamonds) knock-out mutant lines were sown on agar plates and grown vertically in a growth chamber. After 3 days seedlings were transferred to fresh plates supplemented with 0, 75 or 150 mM NaCl. Plates were scanned after 8 days (a) and primary root growth was followed and averaged ± SE during 4 days after transfer (b; n=12-16; a representative experiment is presented). (ref 63)
Polyphosphoinositides play distinct roles in membrane trafficking. This is examplified during cell divison, where PI3P, PI4P and PI(4,5)P2 exhibit distinct roles in generating a new membrane and cell wall for the seperating mother cell into two daughter cells, were the respective lipids were followed via genetically-encoded biosensors (green YFP or red mRFP for PI4P). The lipophylic dye, FM4-64 was used to stain membranes in general (red). While PI3P accumulates vesicles (late endosomes) surrounding the cell plate and is never part of the new plasma membrane (panel C), PI4P and DAG are always on the plasma membrane, right from the start when it is build (panel B, D), whereas PI(4,5)P2 is only present at the leading edges of the forming cell plate (A).
Heat stress induces an array of physiological adjustments that facilitate continued homeostasis and survival during periods of elevated temperatures. Recently, we found that within minutes of a sudden temperature increase, plants deploy specific phospholipid-based signalling pathways to specific intracellular locations: a PLD and a phosphatidylinositolphosphate kinase (PIPK) are activated, and PA and PIP2 rapidly accumulate. Using our PIP2-specific lipid biosensor, we could show that the heat-induced PIP2 is localized to the plasma membrane, the nuclear envelope, nucleolus and punctate cytoplasmic structures ( see pict below). Increases in the steady-state levels of PA and PIP2 occured within several min of temperature increases from ambient levels of 20-25°C to 35°C and above. Similar patterns were observed in heat stressed Arabidopsis seedlings and rice leaves. The PA which accumulates in response to heat stress results in large part from the activation of PLD rather than the sequential action of PLC and DGK. 32P-Pulse-labelling analysis reveals that the PIP2 response is due to the activation of a PIPK rather than the inhibition of a lipase or PIP2 phosphatase (see ref 64, 69).
Osmotic stressresponses involve not only salinity, or drought but also hypotonic stress . Using 32Pi-labelling, specific PA and PPI responses have been uncovered (18, 21, 26, 29, 30, 40, 55). For the PPIs, different isomers are involved, which can be analyzed by HPLC using a strong anion-exchanger after deacylation, generating so-called GroPIns' (see HPLC profile below).
At the moment, we are using lipid biosensor lines to find out where these lipid signals are generated, (55) and T-DNA insertion mutants to pinpoint which isoenzymes and genes involved (63; Zarza et al., In prep).
PLC and PLD signalling cascades can individually generate PA, an important eukaryotic lipid second messenger. PLC generates it indirectly via the hydrolysis of PI(4,5)P2 and the subsequent phosphorylation of diacylglycerol (DAG) into PA via DAG kinase (DGK). PLD generates PA directly by hydrolyzing structural pospholipids, such as phosphatidylcholine (PC). Earlier, we have provided evidence for the role of PA in plant defence using elicitor-challenged cell suspensions of tomato, parsley and alfalfa. Currently, we are adressing PA's role genetically using the model system, Arabidopsis thaliana .
Arabidopsis contains 9 PLCs, 7 DGKs and 12 PLDs. To identify the genes involved in plant defence and characterise their individual functions, T-DNA insertion lines of most genes have been collected. Plants were then analysed for their disease resistance and sensitivity using virulent and avirulent strains of the bacterial pathogen, Pseudomonas syringae and its natural pathogen Hyaloperonospora parasitica , the causal agent of downy mildew. A DGK gene was found to be required for full resistance against virulentPseudomonas and H. parasitica, while two PLD genes were found to be involved in resistance against avirulent Pseudomonas.
Work from Dr. Laura Zonia has been focussing on one of the fastest growing cells on this planet, pollen tubes. The goal of this research is to identify key information cascades that control pollen tube growth and to understand how these networks link to the biomechanics that drive cell elongation. Severalkey cascades were identified, including actin cytoskeleton, ion fluxes and various phospholipid signals. Other workers have identified other cascades important for pollen tube growth, including GTPases, protein kinases, and processes involved in cell wall synthesis. When we searched for common themes across these information cascades, osmoregulation and cell volume status emerged as a key component. Further work indicates that indeed many of these networks converge with processes involved in cellular osmoregulation. Our most recent work shows that transcellular hydrodynamic flux drives pollen tube growth and modulates rates of exocytosis and endocytosis
Time-lapse images of tobacco pollen tubes double-labelled with FM 1-43 (green) and FM 4-64 (red) to identify sites of endocytosis and exocytosis and visualize membrane trafficking patterns. The first 3 images are from a pollen tube undergoing normal growth. The next 3 images are from a pollen tube undergoing hypertonic stress, which stimulates endocytic membrane retrieval at the apex and inhibits exocytosis. The last 2 images are from a pollen tube undergoing hypotonic stress, which stimulates exocytosis and growth, and attenuates endocytosis. Together with previous work (Zonia and Munnik, 2007), these data reveal that transcellular hydrodynamic flux is a key integrator of pollen tube growth, providing a motive force for cell elongation and regulating the rates of membrane insertion( exocytosis ) and retrieval (endocytosis). see refs 40, 49, 51, 53,57,60, 66)
Accumulating evidence suggests that PA plays a pivotal role in the plant's response to environmental signals. Besides PLD activity, PA can also be generated by DGK. To establish which metabolic route is activated, a differential 32P-radiolabelling protocol can be used ( see above). Based on this, and more recently on reverse-genetic approaches, DGK has taken center stage, next to PLD, as a generator of PA in biotic and abiotic stress responses. The DAG substrate is generally thought to be derived from PI-PLC activity. The model plant system Arabidopsis thaliana has 7 DGK isozymes, two of which, AtDGK1 and AtDGK2, resemble mammalian DGKε, containing a conserved kinase domain, a transmembrane domain and two C1 domains. The other DGKs have a much simpler structure, lacking the C1 domains, not matched in animals. Several protein targets have now been discovered that bind PA (Testerink and Munnik, 2011). Whether the PA molecules engaged in these interactions come from PLD or DGK remains to be elucidated. Cold stress rapidly triggers PA formation via DGK within minutes (ref 107).
In comparison to mammals (which possess only two PLD genes) or yeast (one), plants possess a multitudinous and varied family of PLD genes. The genome of Arabidopsis thaliana contains twelve PLD family members and this diversity has been found in assorted higher plant species. PLD enzymes in eukaryotes are characterized by two highly conserved carboxy-terminal (C-terminal) catalytic domains and an amino-terminal (N-terminal) lipid-binding region (Figure). The two catalytic HxKxxxxD (HKD) motifs interact and are essential for the lipase activity of rat PLD1.
The plant PLD family can be divided into two sub-families, based on their N-terminal lipid-binding domains (see below). In Arabidopsis, two of the 12 PLDs contain a Phox homology- (PX) a pleckstrin homology (PH) domain, whereas the remaining 10 PLDs contain a C2 domain. PX and PH domains have been shown to mediate protein-membrane targeting and are closely linked to PPI signaling. C2 domains also mediate the localization of soluble proteins to membranes by binding lipids in a Ca2+-dependent manner. Importantly, PX, PH and C2 domains have also been implicated in protein-protein interactions. The plant-PLD family can be subdivided further into six classes, on the basis of sequence homology and in vitro enzymatic activity. The Arabidopsis genome contains three α-, two β-, three γ-, one δ-, one ε- and two ζ-class PLD isoforms; the latter class contains the PX and PH domains and shares more homology with yeast and mammalian PLDs than with other plant PLD classes.
PI-PLCs have been classified into six different subfamilies, i.e. β, γ, δ, ε, η and ζ, based on their domain structure and organization, (Figure; Munnik & Testerink, 2009). Mammalian cells contain all six isoforms (13 in total), whereas plants only exhibit one, i.e PLCζ, the class that lacks the Pleckstrin Homology (PH) domain present in all other PI-PLCs. In mammalian cells, PLCζ is specifically expressed in sperm.
PLCζ represents the most simple PI-PLC isoform, only consisting of the catalytic X- and Y-domain, an EF-hand domain and a C2 lipid-binding domain. Other subfamilies contain, besides the beforementioned domains, conserved sequences that allow them to be regulated by e.g. heterotrimeric G-proteins (PLCβ), tyrosine kinases (PLCγ), or Ras (PLCε). How PLCδ, -η and -ζ isoforms are regulated is not clear but may involve Ca2+.
Domain structure and organization of PI-PLC isozymes. Plant PLCs belong to the most simple group, the PLCζ. PLCη undergoes alternative splicing, generating variable C termini with a PDZ-binding motif being only present in the longer forms.
Abbreviations: EF, EF-hand domain; PH, Pleckstrin homology domain; RA, Ras-binding domain; RasGEF, guanine-nucleotide-exchange factor for Ras; SH, Src homology domain; X and Y, catalytic domain.
Lipid Signaling in Plants . Series: Plant Cell Monographs,
Vol. 16 , Munnik, T. (Ed.) 2010, 330 p. 49 illus., 7 in
color., Hardcover. ISBN: 978-3-642-03872-3. Springer Verlag, Heidelberg,
Plant Lipid Signaling Protocols. Munnik T . and Heilmann I. ( Eds.) 2013. Series: Methods in Molecular Biology 1009, Humana Press, NJ, USA. 305 p.
1. De Nobel JG, Munnik T, Priem J, van den Ende H, Klis FM. (1990) Conditions for increased cell wall porosity in Yeast. Proceedings 3rdNetherlands Biotechnology Congress, Amsterdam, April 3-4, 1990. H Breteler, RF Beudeker and KChAM Luyben (Eds), pp. 300-304.
2. De Vrije T. & Munnik T. (1998) Signal Transduction pathways and senescence. In: The Post-Harvest Treatment of Fruit and Vegetables - Current Status and Future prospects. Eds. Woltering EJ, Gorris LG, Jongen WMF, McKenna B, Höhn E, Bertolini P, Woolfe ML, de Jager A, Ahvenainen R, Artes Calero F, Luxembourg, European Communities, pp 329-338 (ISBN 92-828-2003-3).
3. Testerink C. & Munnik T. (2004) Plant response to stress: phosphatidic acid as a second messenger. In Encyclopedia of Plant & Crop Science(RM Goodman, ed.), Marcel Dekker Inc, New York, 995-998.
4. De Wit PJGM, Brandwagt BF, van den Burg HA, Gabriëls SHEJ, van der Hoorn RAL, de Jong CF, van ‘t Klooster JW,de Kock MJD, Kruijt M, Luderer, R, Munnik T, Stulemeijer IJE, Thomma BPHJ, Vervoort JJM, Westerink N, Joosten MHAJ. (2004) Molecular basis of plant response to microbial invasion.In: Biology of Plant-Microbe Interactions, Vol. 4, Tikhonovich I, Lugtenberg B, Provorov N (Eds.), International Society for Molecular Plant-Microbe Interactions, St. Paul, Minnesota, USA, pp. 203-207.
5. Zonia L. & Munnik T. (2006) Cracking the green paradigm: Functional coding of phosphoinositide signals in plant stressresponses. In: Subcellular Biochemistry, Vol. 39:Biology of Inositols and Phosphoinositides (Majunder AL and Biswas BB, eds.), Kluwer/Plenum Publishers, London, UK, pp207-237.
6. Lee Y, Munnik T, Lee Y (2010) Plant Phosphatidylinositol 3-kinase. In Lipid Signaling in Plants. Series: Plant Cell Monographs, Vol. 16, Munnik, T. (Ed.), Springer-Verlag, Heidelberg, Germany, pp95-106.
7. Arisz SA and Munnik T. (2010) Diacylglycerol kinase. InLipid Signaling in Plants. Series: Plant Cell Monographs, Vol. 16, Munnik, T. (Ed.), Springer-Verlag, Heidelberg, Germany, pp107-114.
8. Vermeer JEM and Munnik T. (2010) Imaging lipids in living plants. In: Lipid Signaling in Plants. Series: Plant Cell Monographs, Vol. 16, Munnik T.(Ed.), Springer-Verlag, Heidelberg, Germany, pp185-199.
9. Munnik T. (2014) PI-PLC: Phosphoinositide-phospholipase C in plant signaling. In: Phospholipases in Plant Signaling. Wang X. (Ed.), Signaling and Communication in Plants 20, Springer-Verlag, Berlin Heidelberg. pp 27-54.
Phospholipid signalling; Signal transduction; Membrane trafficking; Stress signalling (cold, heat, drought, salt, pathogen); biochemistry; cell biology; molecular biology; genetics, physiology
• British Council Fellowship (1994)
• EMBO short-term Fellowship (1997)
• PULS Fellowship (1998-2001)
• KNAW (Dutch Royal Society of Sciences) Fellowship (2000-2005)
• VIDI fellowship for innovative research (2005-2010)
• ECHO grant (2007)
• VPP grant (2011)
• NPST grant (2012)
• NWO-DBT grant (2015-2020)
• ECHO grant (2018-2021)
• IXA grant (2018)
Publications: (see All Publications)
• Number of publications in international refereed scientific journals according to WoS: 117
• Contributions to books:
- 2 books (Ed. 2010; Ed. 2013, both Springer);
- 7 chapters
• Number of citations according to WoS: 7921; average citations: 67; H-index: 54
• Lecturer at various International Advanced Courses (e.g. ICRO; FEBS, EPS, UNMP, TWAS)
• Coordinator and teacher of various BSc, MSc and PhD courses (molecular cell biology, biochemistry, cellular physiology, plant-abiotic stress)
• >145 Invited seminars at (inter)national universities, conferences and symposia, world wide (see below).
• Organiser of internal seminars for SILS, Green Life Sciences, and Plant Sciences at the University of Amsterdam
• Conference chair of numerous national- and international conferences
• Organiser and chair of Gordon Research Conference (GRC) Salt and Water Stress 2012, Hong Kong, China.
Currently, there are no vacancies
(e.g. FEBS, EMBO, Marie Curie) - please contact: t.munnik @ uva.nl
Phosphatidic acid (PA) and polyphosphoinositides (PPIs) are minor phospholipids in biological membranes that function as cellular signalling molecules at very low concentrations. Their turnover is much faster than of structural phospholipids and levels quickly change in response to biotic- (pathogens) and abiotic- (salt, cold, heat, drought) stresses. How this is regulated and where this occurs in the cell (e.g. plasma membrane, ER, Golgi) or in the whole plant (e.g. root, stem, stomata) has our particular interest. The genome of the model plant system Arabidopsis thaliana, encodes genes for various lipid kinases, phosphatases and phospholipases, and by using T-DNA insertion knock-out mutants, overexpression lines, and FP fusions, we are pinpointing their individual contribution in stress and/or development. Over the years we constructed various lipid biosensor lines, which are plants expressing specific lipid-binding domains that are fused to a fluorescent protein that are used to study the dynamics of lipid-second messengers in living cells. Personal felowships or students can be involved in any of the projects.
Teun Munnik (PI)
Ringo van Wijk (Lab manager)
Xavier Zarza (Post-doc)
Femke de Jong (Post-doc)
Steven Arisz (senior Post-doc)
Max van Hooren (PhD student)
Ruud Korver (PhD student)
Safrina Ahmad (PhD student)
Jack Dickenson (MSc student)
Eveline Bosman (BSc student)
Michael Mishkind (permanent guest)
Essam Darwish (guest)
Nazish Annum (guest)
Laura Zonia (Washington University in St. Louis, MO, USA)
Aleksandra Haduch (PhD student, Poland)
Wendy Roels (Naktuinbouw)
Dörte Klaus (PD, Toulouse, F)
Christiane Unger (MSc, Halle, Germany)
Alan Musgrave (UvA, retired)
Ana Laxalt (PI, Mar del Plata, Argentina)
Bas ter Riet (Enza Zaden, Enkhuizen, NL)
Harold Meijer (WUR, Wageningen, NL)
Christa Testerink (Prof. Plant Physiology, WUR)
Wessel van Leeuwen (Hazera Seeds, NL)
Rafa Tobeña (Madrid, Spain)
Gert-Jan de Boer (Enza Zaden, Enkhuizen, NL)
John van Himbergen (VROM)
Diewertje van der Does (UU, Utrecht, NL)
Saskia van Wees (UU, Utrecht, NL)
Fabio Formiggini (Italy)
Gaby Gonorazky (Uni of Mar del Plata, Argentina)
Martine den Hartog (Covidien, Amsterdam)
Arnold van der Luit (Oncodesign, France)
Bastiaan Bargmann (CA, USA)
Bas van Schooten (NWO)
Essam Darwish (Uni. Cairo, Egypt)
Joop Vermeer (Prof. Plant Cell Biology, Uni of Zürich, Switzerland)
Muhammad Shahbaz (Prof. Uni of Faisalabad, Pakistan)
Qianqian Zhang (Nikon, Shanghai, China)
Jessica Meyer (technician WUR)
Martine den Hartog
Julian C. Verdonk
Steven A. Arisz
Bas ter Riet
Diewertje van der Does
Jacco van Rheenen
Carlos Jr. Rubio 'Chucho'
Mark aan 't Goor
Martijn van Ophem
Rui Alvez (Erasmus student)
Babette Vlieger (BSc student)
Ludo Cialdella (BSc student)
Dr. Michael Mishkind (NSF, VA, USA)
Dr. Ana Laxalt (Mar del Plata, Argentina)
Dr. Joachim Goedhart (WU, Wageningen)
Dr. Dorus Gadella (WU, Wageningen)
Dr. Bas Tomassen (Erasmus Rotterdam, NL)
Dr. Katie Anne Wilkins (Birmingham, UK)
Dr. Anne Sophie Leprince (Paris, France)
Dr. Noam Reznik (Tel Aviv, Israel)
Dr. Magdalena Wierzchowiecka (Poland)
MSc. Özgecan Tanyolaç (Izmir, Turkey)
MSc. Maria Alejandra Schlöffel (University of Tübingen, Germany)
Dr. Bojan Gujas (ETH, Zürich, Switzerland)
Dr. Necla Pehlivan (Turkey)
Dr. Theodora Farmaki, (Thessaloniki, Greece)
Dr. Wojciech Rymaszewski (Warsaw, Poland)
Dr. Hui-fen Kuo (Academia Sinica, Taiwan)
MSc. Kelly Stecker (University of Wisconsin, USA)
Dr. Muhammad Jamil (WUR)
MSc Madiha Butt (Faisalabad, Pakistan)
Dr. Tomoko Hirano (Kyoto Prefectural University, Japan)
Dr. Jyothilakshmi Vadassery (Max Planck, Germany)
MSc. Dominik Novák (Palacky University, Olomouc, Czech Republic)
Dorus Gadella (SILS, UvA, NL)
Nullin Divecha (Manchester, UK)
Mats Ellerström (Göteborg University, Sweden)
Takashi Aoyama (Kyoto University, Japan)
Erik Nielsen (Michigan, US)
Ana Laxalt (University of Mar del Plata, Argentina)
Charles Brearley (Norwich, UK)
Chris de Koster (SILS, UvA, NL)
Ingo Heilmann (Halle, Germany)
Robin Irvine (Cambridge, UK, retired)
Laura de la Canal (Mar del Plata, Argentina)
Nick Ktistakis (Cambridge, UK)
Ralf Oelmüller (Jena, Germany)
Jack Vossen (WUR, Wageningen, NL)
Dierk Scheel (Halle, Germany)
Dorothea Bartels (Bonn, Germany)
George Carman (Rutgers, NJ, US)
Laci Bögre (London, UK)
Claudia Jonak (Vienna, Austria)
Susanne Hoffmann-Benning (Michigan, US)
Pavla Binarova (Prague, Czech Republic)
Ingo Heilmann (Halle, Germany)
Jörg Kudla (Münster, Germany)
Bert de Boer (VU, Amsterdam)
Silke Robatzek (Münich, Germany)
Mariusz Pietruszka (University of Silesia, Poland)
Antonio Fernandez Tiburcio (Barcelona, Spain)
Noni Franklin-Tong (University of Birmingham, UK)
Edgar Kooijman (Kent, USA)
Aviah Zilberstein (Tel Aviv, Israel)
İsmail Türkan (Izmir, Turkey)
Pia Harryson (Stockholm, Sweden)
Tzyy-Jen Chiou (Academia Sinica, Taiwan)
Libo Shan (Texas A&M University, US)
Ping He (Texas A&M University, US)
Glenda Gillaspy (Virginia Tech, US)
Yee-yung Charng (Academia Sinica, Taiwan)
Taijoon Chung (Pusan National University, Republic of Korea)
Jenny Russinova (VIB, Ghent University, Belgium)
Gabriel Schaaf (University of Bonn, Germany)
Luis Lopez-Molina (University of Geneva, Switzerland)
Antia Rodriguez-Villalon (ETH, Zürich, Sitzerland)
Christian S. Hardtke (Lausanne, Sitzerland)
Niko Geldner (Uni Lausanne, Sitzerland)
Joop Vermeer (Uni Zürich, Sitzerland)
Wybren Jan Buma (HIMS,Molecular photonics UvA)
Jan van Maarseveen (HIMS, Organisc chemistry, UvA)
Jiri Friml (IST Austria)