Phospholipid Signalling in Plant Stress & Development

Plants cannot run away! Instead, over millions of years of evolution, they have developed smart strategies  to quickly respond and deal with the sudden changes in their environment. Such changes are experienced as stress, which can be of biotic- (e.g. pathogens, herbivores) or abiotic nature (e.g. cold, heat, salinity, drought). Our main focus is to understand the molecular mechanism by which plant cells sense these stress signals, how these signals are intracellularly transduced, and  how they are eventually converted into appropriate cellular responses that allow the plant to deal with the stress. We are specifically interested in the signal transduction of temperature stress (cold, heat), water stress (drought, salinity and hypoosmotic stress), and during plant-microbe interactions.

RESEARCH

Research in the lab of Plant Cell Biology is focussed on the role of phospholipids in Stress Signalling & Development. Especially, lipid second messengers 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 common lipidomic analyses. Nonetheless, these minor signalling lipids can easily be picked up by ³²P_i-labelling (see TECHNIQUES) because their turnover is much faster than structural phospholipids and because they are synthesised via lipid kinases that use ATP, which is one of the first compounds labelled. Key players involved in PA and PPI metabolism are depicted in the scheme above. Routinely, this involves PLC-and PLD signalling cascades and a variety of lipid and inositolphosphate kinases. Note that PA can be generated through both PLC- and PLD pathways, which likely occurs at different cellular- and subcellular locations and in response to different stimuli, and resulting in different outputs.

TECHNIQUES

³²P_i-labelling and TLC

Phospholipids are routinely analysed using in vivo  ³²P-orthophosphate (³²P_i)-labelling. In general, cells-, seedlings- or tissues like  leaf discs are used, and labelling times vary from min to hrs or 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 use  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. We have found 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 (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 'flowering plants' contain 30- 100- fold lower levels of PIP₂ than Chlamydomonas or animal cells. This discrepancy has major consequences for the interpretation of lipid signalling in plants and what PLC takes as substrate in vivo (see ref. 70).

'Differential labelling protocol': distinguishing between DGK- and PLD-generated PA

Since both PLD and DGK can generate PA as second messenger, it is crucial to be able to ditinguish between both pathways. Moreover, PA can also be intermediate in the synthesis of structural phospholipids via acylation of lyso-PA. To distinguish between these PA pools, we have setup a Differential Labellling protocol. It uses the fact that for PA to become radioactive, one only needs relative short labelling incubation times for the DGK and long for the PLD. This is because DGK requires ATP to make PA and this is one of the first components to become labelled when cells are incubatred with ³²P_i, while PLD requires  a ³²P-labelled structural lipid like PE to generate ³²P-PA and this takes hours of metabolic labelling (see top panels). Moreover, using the transphosphatidylation assay, one can check after how long labelling, the structural lipid pool is able to generate a radioactive PA and PBut.

In the pannels below show the practice for Chlamydomonas cells that were metabolically labelled with ³²P_i for the times indicated, and were subsequently treated for 1 min with buffere alone  (control; panel A, B) or with a stimulus (in this case  1 µM mastoparan in buffer (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, DGPP. The point is that all cells were treated for the same time period (1 min) but that the PBut only became radioactive when its substrate (i.e. PE) started to be labelled (>40min). The same would hold for the PA that would be generated through PLD. In contrast, when PA was generated via DGK, then the label would come from ATP, and since this compound  is labelled within sec, an increased radioactive PA response could be witnessed if a DGK was involved. Since PA kinase also uses ATP, a similar response in DGPP can be expected (panel D). Since the specific radioactivity of ³²P-ATP decreases over time, the 1-min response decreases concomitantly.  The combined assay  is a relative measure and provides evidence  for PA coming through DGK- and/or PLD pathways. See details in Arisz et al. , 2009 (Ref 68, 84) and  in response to cold stress (ref 80).

Visualizing Lipid Signalling using Lipid Biosensors

Using Fluorescent-Protein (FP) fusions of specific lipid-binding domains, stably expressed in tobacco BY-2 cells and Arabidopsis, we have generated various lipid biosensor lines tthat can be used to topographically visualize where certain lipids are localised and/or 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). Yvon Jaillais' lab  (Lyon) recently characterized FP-sensors for PA and PS. In general, all biosensor lines are publically available.

Arabidopsis T-DNA insertion mutants

Using T-DNA insertion mutants, evidence for the participation of individual PLC, PLD and DGK in stress signalling- & 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 many of them, we have  mutants, which we are happy to share.

Below,  an example of reduced salt tolerance for 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)

LIPID SIGNALLING DURING PLANT STRESS & DEVELOPMENT

Role of Phospholipids in Membrane Trafficking

Polyphosphoinositides play distinct roles in membrane trafficking. This is examplified during cell divison, where PI3P, PI4P and PI(4,5)P₂ exhibit distinct patterns when the new plasma membrane and cell wall that seperate the mother cell into two daughter cells, and 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 expanding cell plate (A).  

Temperature Stress

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   rapidly produce PA and PIP₂. Using a biosensor, we found that the heat-induced PIP₂ is localized at the plasma membrane, nuclear envelope, nucleolus and at punctate cytoplasmic structures ( see below). Increases in 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 heat-induced results in large part from the activation of PLD rather than the sequential action of PLC and DGK. ³²P-Pulse-labelling analysis revealed that the PIP₂ response is due to activation of a PIPK rather than the inhibition of a lipase or PIP₂ phosphatase (see ref 64, 69). Using T-DNA insertion mutants,. we are currenly identifying which of the 11 PIP5Ks and which of the 12 PLDs are involved. This work highly involves Michael Mishkind (NSF).

Osmotic Stress

Osmotic stress responses not only involves salinity and drought but also hypotonic stress . Using ³²P_i-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 lipid biosensors but also by HPLC analysis, using a strong anion-exchanger after deacylation, which generates 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 the isoenzymes and genes are involved (63; Zarza et al., In prep). 

Plant Defence

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 the natural pathogen Hyaloperonospora parasitica , the causal agent of downy mildew. A DGK gene was found to be required for full resistance against virulent Pseudomonas and H. parasitica, while two PLD genes were found to be involved in the resistance against avirulent Pseudomonas (unpublished)

Pollen Tube Growth

Work from Dr. Laura Zonia has focussed 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. Several key 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. Common themes emerging across these information cascades are osmoregulation and cell volume status. Further work confirmed that  many of these networks indeed converge at this point, where we revealed that transcellular hydrodynamic flux drives the growth of a pollen tube 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.

Signalling Enzymes: 

Diacylglycerol Kinase (DGK)

Accumulating evidence suggests that PA plays a pivotal role in the plant's response to environmental signals. Besides PLD, PA can also be generated by DGK. To establish which metabolic route is activated, a differential ³²P-labelling protocol can be used (see above). Based on this and on reverse-genetic approaches, DGK has taken center stage, next to PLD, as generator of PA in biotic- and abiotic-stress responses. The DAG substrate is generally thought to be derived from PLC activity. The model plant system Arabidopsis thaliana contains 7 DGKs, two of which, AtDGK1  and AtDGK2, resemble mammalian DGKε, encoding 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 been discovered to bind PA (Testerink and Munnik, 2011). Whether the PA comes from PLD or DGK often still remains to be elucidated. Cold stress, however,  rapidly triggers PA via DGK within minutes (ref 107). Freezing stress involves PLDs (see Xuemin Wang Lab).

Phospholipase D (PLD)

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.  

Phospholipase C (PLC) 

PI-PLCs have been classified into six subfamilies, β, γ, δ, ε, η and ζ, based on 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-like, which is the class that lacks the Pleckstrin Homology (PH) domain present in all other PI-PLCs. In mammalian cells, PLCζ is specifically expressed in sperm cells.

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 unclear but may involve Ca²⁺.

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.

PUBLICATIONS

Books

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, Germany. 

Plant Lipid Signaling Protocols. Munnik T . and Heilmann I. ( Eds.) 2013. Series: Methods in Molecular Biology 1009, Humana Press, NJ, USA. 305 p.

International (refereed) journals

• Number of publications in international refereed journals according to WoS: 119
• Number of citations according to WoS: 8400
• Average citations per item: 72
• H-index: 55 (June, 2019)

EXPERTISE:

Stress Signalling - Signal transduction - Phospholipid signalling - Membrane trafficking - Abiotic Stress (cold, heat, drought, salt) -  Biotic Stress (plant-pathogen) - Arabidopsis Development - Molecular Heaters

Cell Biology, Biochemistry, Plant Molecular Biology, Plant Physiology

SCIENTIFIC CAREER:

• Head a.i. Plant Cell Biology, Swammerdam Institute for Life Sciences, University of Amsterdam (2018-present).
• Associate Professor Plant Cell Biology, Swammerdam Institute for Life Sciences, University of Amsterdam (2016-present).
• Associate Editor Plant Physiology, section Signaling & Responses (2013 - present)
• Visiting Professor - Institute of Microbiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic, Pavla Binarova Lab (2007)
• Associate Professor Plant Physiology, Swammerdam Institute for Life Sciences, University of Amsterdam (2005-2016).
• Visiting Professor - Rutgers University, New Brunswick, NJ, USA. George Carman Lab (2002)
• Assistant Professor Plant Physiology, Swammerdam Institute for Life Sciences, University of Amsterdam (2000-2005).
• Post-doc  Alan Musgrave & Ben Cornelissen, Lipid Signalling in Plant-Pathogen Interactions (1997-2000).
• Post-doc  Vienna BioCenter, Austria - Heribert Hirt Lab, MAPK signalling. EMBO short-term fellowship (1997/1998)
• Ph.D ( cum laude; <3%) University of Amsterdam, Thesis: Phospholipid metabolism with respect to signal transduction in the green alga Chlamydomonas (1997)
• PhD student - Cambridge, UK - Robin Irvine Lab, Phosphoinositide signalling (1992/1994)
• PhD student - University of Amsterdam, The Netherlands, Alan Musgrave Lab, Chlamydomonas (1992-1997)
• Research Assistant - Agrotechnological Research Institute (ATO-DLO; Dr. Truus de Vrije), Wageningen, The Netherlands. Topic: Ethylene signalling in carnation flowers (1991-1992).
• Research Assistant - Institute for Molecular Cell Biology, University of Amsterdam. With Hans de Nobel & Frans Klis, Topic: Yeast cell wall assembly (1988-1990).
• BSc - Botany, University of Applied Sciences,  Amsterdam, The Netherlands (1988)

SCIENTIFIC SERVICES:

• Associate Editor Plant Physiology,  section Signaling & Response (2012-present)
• Referee for: Nature, Nature Cell Biol, Nature Immunol, Science, PNAS, Current Biology, J. Biol. Chem., Biochem. J, FEBS. Lett, Plant Cell, Curr. Opin. Plant Biol, Trends Plant Sci, PLoS One, Plant Physiol, Plant J, Plant Mol. Biol, New Phytol, J. Exp. Bot, Plant Cell Environ, Plant Cell Physiol, eLife.
• Evaluation panels: NWO-ALW (panel member MtC; VIDI), NWO-CW (panel member ECHO, TOP), ERC (EU), USDA (US), NIH (US), BBSRC (UK), CNRS (Fr), ISF (Isr) AACF (Can) DFG (Ger).
• PhD thesis committees: 30
• Member-, secretary- and chair of the NWO-CW study group, Lipids & Membranes (2005-2008)
• Expert Evaluator ERC >2014

AWARDS/PRIZES/GRANTS

•   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)

•   EU-FET grant (2019)

OUTPUT

Publications: (see All Publications)

•   Number of publications in international refereed scientific journals according to WoS: 119

•   Contributions to books:

      - 2 books (Ed. 2010; Ed. 2013, both Springer);

      - 7 chapters

•   Number of citations according to WoS: >8400; average citations: 72; H-index: 55

Scientific teaching:

•   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)

Outreach activities:

•   >150 Invited seminars at (inter)national universities, conferences and symposia, world wide (see below).

•   Organiser of seminars for SILS, University of Amsterdam

•   Organiser of Plant & Green Life Science seminars at SILS, GLS, University of Amsterdam

•   Conference chair at various national- and international conferences

•   Organiser & chair of Gordon Research Conference (GRC)  Salt and Water Stress 2012, Hong Kong, China.

•   Co-organiser of the 15th World Conference of Parasitic Plants (WCPP2019), Amsterdam, The Netherlands.

•   Organiser of the 10th ESPL,  European Symposium on Plant Lipids (2021), Amsterdam, The Netherlands.

Invited Lectures

2020    

• Phospholipid Signalling in Plant Stress, Defence, and Development. IRTG seminar series University of Göttingen, Jan 30-31, Göttingen, Germany.
• Abiotic-stress induced lipid signals. 6th International Conference on Plant Abiotic Stress Tolerance, Feb 21-22, Vienna Austria

2019

• Role for PIP2 in Plant Heat Stress Tolerance. GRC on  Plant Lipids - Structure, Metabolism & Function. Jan 27-Feb 1, Galveston, Texas, USA.
• Minor lipids with Major impact in Plant Stress Signalling and Development. Invited seminar Texas A&M University, Feb 6, College Station, TX, USA 
• Molecular heaters. Kick-off Meeting EU-FET network BoostCrop, Feb 14, Amsterdam The Netherlands.
• Inositol Phospholipids: Lubrigating Membrane Traffic and Transport in Plant Stress and Development. Keynote lecture. International Workshop on Plant Membrane Biology, session Membrane organisation, Organelles and Signalling. July 7-12 July, Glasgow, UK.
• Molecular Heaters in Plant Biology. EU-FET BoostCrop Meeting, Nov 5-7, University of Warrick, Warrick, UK.
• Phospholipid Signalling in Plant Stress & Development. Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Cientificas-Universidad Politecnica de Valencia, Nov 13, Valencia, Spain.
• Molecular Heaters. Presentation IXAnext project, IXA UvA-HvA, Nov 22, Amsterdam, Netherlands.

2018

• Lipids: Building plant tolerance to environmental stress. Plantum Matchmaking, Sept 20, De Meern, The Netherlands
• PIP₂ Signalling in Plants. Invited seminar Eidgenössische Technische Hochschule (ETH) Zürich, Feb 22, Zürich, Switzerland. 
• Phospholipid Signalling in Plant Stress & Development. Syngenta, Feb 27, Stein, Switzerland. 
• Phosphoinositide Signalling in Plant Stress & Development. University of London,Royal Halloway, April 30, London, UK.
• Osmotic Stress Triggers PIP₂Signalling. Gordon Research Conference on Salt & Water Stress in Plants. June 3-8, Waterville Valley, NH, USA.
• Heat Stress-Activated Lipid Signalling. Biannual International Plant Thermomorphogenesis Meeting, 27‐29 August, Utrecht, The Netherlands.
• Signalling through membranes. Chemical Ecology Amsterdam Symposium, Nov 5, Amsterdam, The Netherlands

2017

• New Roles for PLC in Plant Stress & Development. GRC on  Plant Lipids: Structure, Metabolism & Function. Jan 29-Feb 3, Galveston, Texas, USA.
• Lipid signals greasing stress- and developmental responses in plants. Invited seminar, University of Geneva, March 22, Geneva, Switzerland.
• New Roles for PPIs  in Plant Development and Stress Signalling. The Yucatan Center for Scientific Research (CICY), June 12-14, Merida, Mexico.
• Phospholipid Signaling in Plant Stress & Development. Plant Biology 2017 (ASPB), June 24-28, Honalulu, Hawaii, USA.
• PIP₂ Signalling in Plants. Invited seminar ETH Zürich, Oct 26, Zürich, Switzerland.

2016

• Phospholipid signalling in plant stress & development. Invited seminar. University of Ghent, Feb 10, Ghent, Belgium.
• Phospholipid signals in plant stress and development. Invited seminar Institute for Bioscience and Biotechnology Research, Department of Plant Sciences and Landscape Architecture, University of Maryland, March 31, Rockville, MD, USA.
• Phosphoinositides - lipid signals in plant stress and development. Invited seminar, University of Lausanne. Juli 15, Lausanne, Switzerland.

2015

• Shining light on 'plant PLC signalling' Gordon Research Conference (GRC) on Plant Lipids: Structure, Metabolism, and Function, Feb 1-6, Galveston, TX, USA.
• Lipid Signals at Work. Texas A&M University, Feb 6, College Station, TX, USA
• Phospholipids in plant stress signalling and development. Feb 9, University of Arizona, Tempe, AZ, USA.
• Polyphosphoinositide signaling in plant stress & development. Invited speaker at 3rd SPOT-ITN conference on "Stress Biology and Crop Fertility", March 18 - 22, Sorrento, Italy.
• Phospholipid signalling in plant stress & development. Invited seminar. Shanghai Center for Plant Stress Biology (PSC). May 12, Shanghai, China.
• Phospholipid signalling in plant stress & development. Invited seminar. Shanghai Institute of Plant Physiology and Ecology (SIPPE), Chinese Academy of Science (CAS), May 13, Shanghai, China.
• Phospholipid signalling in plant stress & development. Invited seminar. College of Life Science, Nanjing Agricultural University, May 15, Nanjing, China.
• Green Light for Lipid Second Messengers in Plants. Invited speaker at Biochemical Society/FEBS Signalling 2015 - Cellular functions of phosphoinositides and inositol phosphates. Sept 1-4, Robinson College, Cambridge, UK.
• Phospholipid Signaling in Plant Stress & development. Invited seminar. UNAM, Oct 19, Mexico City, Mexico.
• Phospholipid Signaling in Plant Stress & development. Invited seminar. Universidad Autónoma de Nuevo León, Oct 20-21, Nuevo León, Monterrey, Mexico.
• Green Light for Lipid Second Messengers in Signalling Stress & Development. Centro de Investigacion Cientifica de Yucatan (CICY), Oct 23, Merida, Mexico.
• Phospholipid-based Signalling in Plant Stress & Development. Invited speaker. 6^th International Singapore Lipid Symposium (Nov 30-Dec 2) and 6^th Asian Symposium on Plant Lipids, Dec 2-4, Singapore.

2014

• Phospholipid signals in plant stress and development. Invited seminar at Centre of the Region Hana for Biotechnological and Agricultural Research, Palacky University Olomouc, March 25, Olomouc, Czech Republic.
• Polyphosphoinositides – molecular beacons in plant membranes. Invited seminar, Academy of Sciences of the Czech Republic. March 27, Prague, Czech Republic.
• Phospholipid signalling in salt- and water stress. COST FA0901 Conference: Putting Halophytes to Work - From Genes to Ecosystems, April 9-10, Coimbra, Portugal.
• Role of polyphosphoinositides in auxin signalling. Auxentric 2014 – 3^rd International Meeting on Early Auxin Research. May 23-25, Norwich, UK.
• Salt stress triggers distinct PI4P- and PI(4,5)P₂ responses at the plasma membrane of Arabidopsis thaliana. Gordon Research Conference on Salt & Water Stress in Plants. Aug 3-8, Newry, ME, USA.
• Polyphosphoinositide signalling in plants. University of Barcelona. Sept 5, Barcelona, Spain.
• Phospholipid signaling in plant stress & development. Invited seminar at section Molecular Physiology of Plants and Micro-organisms, Catholic University of Leuven, Nov 19, Leuven, Belgium.
• PIP₂ Signaling in Plant Stress and Development. Invited seminar at Institute of Life Sciences, Université Catolique de Louvain (UCL), Nov 20, Louvain-la-Neuve, Belgium. 

2013

• Visualizing phospholipid signals in plants. Gordon Research Conference (GRC) on Plant Lipids: Structure Metabolism and Function. Jan 26 - Feb 1, Galveston, TX, USA.
• Lipid Signals at Work. Invited seminar. Julius-von-Sachs-Institut für Biowissenschaften, University of Würzburg, May 27, Würzburg, Germany
• PLC meets Auxin: New data on an old Story. Auxin Sailing 2013, June 7-9, Leiden, The Netherlands.
• Phospholipid signals in plant stress and development. Invited seminar. The Sainsbury Laboratory, June 21, Norwich, UK.
• Stress-activated, phospholipid-based signaling pathways in plants. Plenary speaker, 54^th International Conference on the Biochemistry of Lipids (ICBL): Linking Transcription to Physiology in Lipidomics, Sept 17-21, Bari, Italy.
• Phospholipid signals in plant stress & development. Invited seminar Agrobios, Sept 23, Metaponto, Italy.

2012

• Visualizing phospholipid signals during plant stress and development. Winter Conference POSTECH, Pohang University of Science and Technology, January 12-13, Pohang, South-Korea.
• Phospholipid Signalling in Plant Defence. BARD Workshop on Plant Innate Immunity/Effector Biology. Feb 5-8, Tel Aviv, Israel.
• Visualizing Phospholipid Signalling in Plant Stress and Development. Invited seminar. Hebrew University of Jerusalem. Feb 9, Rehovot, Israel.
• Polyphosphoinositide signalling in plants. Invited lecture. University of Lausanne. April 12, Lausanne, Switzerland.
• Phospholipid signals in plant stress & development. Invitedlecture. University of Zurich. April 13, Zurich, Switzerland.
• Polyamines trigger two distinct phospholipid signalling pathways in Arabidopsis. EPS Theme Symposium, April 26, Utrecht, The Netherlands.
• Phospholipid Signalling in Plant Stress & Development. Agricultural Biotechnology Research Center (ABRC) at Academia Sinica, June 22, Taipei, Taiwan.
• Gordon Research Conference (GRC) on Salt & Water Stress in Plants. June 24-29, Hong Kong. China.
• Lipid Signalling in Plant Stress and Development. 21^st National Biology Congress, Sept 3-7, Izmir, Turkey.

2011

• Phospholipid-based signalling. Invited seminar, University of Birmingham, May 31, Birmingham, UK.
• Phospholipid-basedsignalling during plant stress and development. Plant Science Student Conference (PSSC). June 14-17, Halle/Saale, Germany.
• Integration of abiotic and biotic stress responses: phospholipid signalling modules in plants. Annual Meeting of the Society for Experimental Biology (SEB). July 1-4, Glasgow, UK.
• Visualizing Phospholipid Signalling Pathways during Plant Stress and Development. Cell Signalling Networks, 13^th IUBMB Conference, Oct 22-27, Merida, Mexico.
• Phospholipid Signalling in Plant Stress and Development.Invited seminar CICY, Yucatan Center for Scientific Research, Oct 29, Merida, Mexico.
• Integration of Abiotic Stress Responses: Phospholipid Signalling Modules in Plants. 4^th International INPAS meeting on Salt & Drought Stress in Plants. Nov 18-19, Limasol, Cyprus. 

2010

• Phospholipid metabolism in plant stress and development. Plant Abiotic Stress – from Signalling to Crop Improvement. April 22-24, Valencia, Spain.
• Signaling pathways in osmotic stress. Gordon Research Conference (GRC) on Salt & Water Stress in Plants. June 13-18, Les Diablerets, Switzerland.
• Phospholipid signalling in plants. Invited lecture. University of Lausanne. June 19, Lausanne, Switzerland.
• Polyphosphoinositides in membrane trafficking during plant stress and development. EPS workshop - 'Endomembranes in plants'. July 2, Amsterdam, The Netherlands.
• Phospholipid metabolism in plant stressanddevelopment. Keynote lecture at the 19^th International Symposium on Plant Lipids (ISPL2010). July 11-16, Cairns, Australia.
• Learning the lipid language of plant signalling, Frontiers in Genomics - Seminar I, National University of México (UNAM). Nov 22, Cuernavaca, Mexico.
• Phospholipid signalling in plant stress and development. Frontiers in Genomics - Seminar II, Center for Genomic Sciences (CCG), Institute of Biotechnology (IBT), National University of México (UNAM). Nov 23, Cuernavaca, Mexico. 

2009

• Phospholipid-based signal transduction. Invited seminar, University of Münster. Jan, 27, Münster, Germany.
• Phospholipid signalling in plant stress and development. Invited seminar, Michigan State University. Jan 29, Ann Arbor, MI, USA.
• Phosphatidic acid signaling in plants. Gordon Research Conference (GRC) on Plant Lipids. Feb 1-6, Galveston, Texas, USA.
• Green light for phospholipid signals. Invited seminar, Universität Bonn. March 11, Bonn, Germany.
• Phospholipid signalling in plant stress and development.Invited seminar, Max Planck Institute for Chemical Ecology. April 1, Jena, Germany.
• Phospholipids in plant stress signalling and development. Invited seminar, Leibniz Instituteof Plant Biochemistry (IPB), Halle University. April 3, Halle, Germany.
• Phosphoinositide signalling in plant stress signalling and development. COST Meeting Plant Abiotic Stress - From signaling to development. May 14-17, Tartu, Estonia.
• Phospholipid signalling in plant stress and development. Invited seminar, Dec 17, Fribourg, Zwitzerland. 

2008

• Phospholipid signalling in plant stress. Invited seminar, University of Tübingen. Jan 7, Tübingen, Germany.
• PLD Signalling in tomato. Invited seminar, Institute for Experimental Botany. Czechoslovak Academy of Sciences. Feb 15, Prague, Czech Republic.
• Phospholipid signalling in plant stress and development. Invited seminar, Université Catholique de Louvain. March 14, Louvain-la-Neuve, Belgium.
• Phospholipid-signalling events during abiotic stress. COST Meeting. April 10-13, Matera, Italy.
• Phospholipid signalling events during plant-microbe interactions. The German researchcouncil (DFG) Priority Program 'Microbial Reprogramming of Plant Cell Development'. April 16-18, Bad Honnef, Germany.
• Phospholipid signalling in and cytoskeletal control. Annual meeting of the European Cytoskeleton Club. May 14-16, Vranovská Ves, Moravia, Czech Republic.
• Phospholipid signalling in plant stress and development. ¹⁸th International Symposium on Plant Lipids (ISPL2008). July 20-25, Bordeaux, France.
• Visualizing osmotic stress-induced phospholipid signals. Gordon Research Conference (GRC) on Salt & Water Stress in Plants. Sept 7-12, Big Sky, Montana, USA.
• Phospholipid signalling in plants.Invited seminar, Stockholm University. Oct 21, Stockholm, Sweden.
• Lipid signalling in plant Stress and development. Faculty Symposium Swedish University of Agricultural Sciences (SLU), Uppsala BioCenter. Oct 22, Uppsala, Sweden.
• Phospholipid signalling in plant stress and development. International Symposium in Commemoration of 150^th BirthAnniversary of Sir J.C. Bose and the Birth Centenary of Prof. SM Sircar: "A Journey from Plant Physiology to Plant Biology". Nov 24-28, Kolkata, India.

2007

• Phospholipid signalling in plants - 'Seeing is believing'. 3rd European Symposium on Plant Lipids. April 1-4, York, UK.
• Lipid signalling. 3^rd International Symposium on Plant Neurobiology (ISPN). May 14-18, štrbské Pleso, Slovakia.
• Lipid signals in plant defense. XIII International Congress of the International Society for Molecular Plant-Microbes Interaction (IS-MPMI). July 21-27, Sorrento, Italy.
• Lipid signalling in response to stress. Third meeting of the Polish Society of Plant Experimental Biology, Aug 26-30, Warsaw, Poland.
• Lipidomics in Plant Cell Signalling. 4^th GERLI Lipidomics Meeting (Groupe d'Etude et de Recherche en Lipidomique). Oct 9-11, Toulouse, France.
• Plant phospholipid signalling. Invited seminar, INRA-CNRS. Oct 11, Castanet-Tolosan, France.
• Phospholipid signalling gets the green light. Invited seminar, University of Würzburg. Nov 22, Würzburg, Germany.
• Visualizing phospholipid-based signalling events in plant cells. Invited seminar, Academy of Sciences of the Czech Republic. Dec 10, Prague, Czech Republic.

2006

• How do lipids signal? Symposium on 'Signal Transduction in Plants', Research School Experimental Plant Sciences (EPS). Feb 2, Amsterdam, the Netherlands.
• Symposium on 'Order and Disorder(s) of Cell Lipids', Netherlands Society for Biochemistry and Molecular Biology. May 19, Utrecht, The Netherlands.
• PA, an emerging lipid second messenger in plant-stress responses. ¹⁵th FESPB (Federation of European Societies of Plant Biology). July 17-21, Lyon, France.
• Crosstalk between different stress pathways. Gordon Research Conference (GRC) on Salt & Water Stress in Plants. Sept 3-8, Oxford, UK.  

2005

• "Cracking the green paradigm": Functional coding of lipid signals in plant stress responses, Montagskolloquium, University of Freiburg. Jan 24, Freiburg, Germany.
• Water-stress activated phospholipid signalling pathways. International Conference on Biotechnology for Salinity & Drought Tolerance in Plants. March 28-31, Islamabad, Pakistan.
• Phosphatidic acid signalling in plant stress. 2^nd International Conference on Stress signals and cellular responses. March 31-April 2, Halle, Germany.
• Diacylglycerol kinase and phosphatidic acid signalling in plants. DGK-day, Dutch Cancer Institute (NKI). Oct 6, Amsterdam, the Netherlands.
• Osmotic stress triggering multiple lipid signaling responses. Invited seminar, University of Connecticut. Oct 25, Storrs, CT, USA.
• Stress-activated PA Signalling. International Conference on Plant Lipid-Mediated Signaling. Oct 26-29, Raleigh, NC, USA.
• Plant phospholipid signalling - What's cooking? University of North Carolina. Nov 1, Chapel Hill, NC, USA.
• Learning the lipid language in plant signalling. TWAS Course on Signal Transduction in Plants, University of Mar del Plata. Nov 24, Mar del Plata, Argentina.
• PA signalling and stress signal integration. TWAS Course on Signal Transduction in Plants, University of Mar del Plata. Nov 25, Mar del Plata, Argentina.
• Phospholipid signalling in plants - What's cooking? University of Mar del Plata. Dec 1, Mar del Plata, Argentina.
• Phospholipid-based signallingin plants. 10^th Congress of the Panamerican Association of Biochemistry and Molecular Biology (PABMB). Dec 3-6, 2005, Pinamar, Argentina. 

2004

• Stress-activated phospholipid signaling. Keystone Symposium on Plant Responses to Abiotic Stress. Feb 19-24, Santa Fe, NM, USA.
• Phospholipid signals in biotic- and abiotic-stress signalling. CRISP meeting, Feb 27 - March 1, Radstadt, Austria.
• Phospholipid signalling in plants. Annual Meeting Dutch Experimental Plant Sciences. April 4-5, 2004, Lunteren, the Netherlands.
• Osmotic stress-activated phospholipid signalling. Gordon Research Conference (GRC) on Salt & Water Stress In Plants. June 13-18, Hong Kong, China.
• Phospholipid signalling pathways in abiotic and biotic stress. 2nd European Plant Science Organization (EPSO) Conference. Oct. 10-14, Ischia, Italy. 

2003

• Challenging phospholipid signalling in plants. Invited seminar, University of Dundee. March 12, Dundee, Scotland, UK.
• Phospholipid-based signal transduction. Invited seminar, Free University Amsterdam, April 28, Amsterdam, The Netherlands.
• Phospholipid metabolism and signalling in plants. Invited seminar, Academic Medical Center (AMC). May 20, Amsterdam, Netherlands.
• Challenging phospholipid signalling in plants, 1^st EuroFed Symposium on Plant Lipids. Sept 10-13, Aachen, Germany.
• Phospholipid signalling in plant stress. Invited seminar, Leipzig Instituteof Plant Biochemistry. Oct 23, Halle, Germany. 

2002

• Phospholipid-based signal transduction pathways in plants. Centro de Investigacion Cientifica de Yucatan (CICY). March 15, Merida, Mexico.
• Phospholipid-based signal transduction pathways in plants. NJAES Distinghuished Seminar Series Agricultural and Environmental Genomics, Rutgers University, March 20, New Brunswick, NJ, USA.
• Phospholipid-based signal transduction in plants. Seminar series Plant Cell Biology, University of Wageningen, May 17, Wageningen, The Netherlands.
• Phospholipid signalling in plants. Invited seminar, Royal Holloway, University of London. Nov 11, Egham,UK.
• Phospholipid-basedsignalling in plants. Botanisches Kolloquium, University of Hamburg. Dec 18, Hamburg, Germany. 

2001

• Phospholipid-based signalling in plants. Invited seminar, John Innes Centre, The Sainsburry Lab. Feb. 13, Norwich, UK.
• Phospholipid-based signalling triggered upon plant stress. International Conference on Stress Signals and Stress Proteins. March 15-17, Halle,Germany.
• Phospholipid-derived second messengers in plants -Differences and similarities. FEBS Advanced Course: Lipid-mediated signalling in cellular functions. June 23, Santa Maria Imbaro, Italy.
• Phospholipid signalling in plants - Current status and perspectives. FEBS Advanced Course: Lipid-mediated signalling in cellular functions. June 25, Santa Maria Imbaro, Italy.
• Osmotic stress activates distinct MAPK and lipid signalling in plants. 27^th Meeting of the Federation of European Biochemical Societies (FEBS). June 30 - July 5, Lisbon, Portugal.
• Phospholipid signalling. International Training Course ICRO, Signalling to Growth and Cell Division in Arabidopsis. July 19-27, London, UK.

  2000

• Phospholipid-based signal transduction mechanisms in plant cells. Biologisches Kollo-quium, Rheinische-Friedrich-Wilhelms-Universität Bonn. Jan 10, Bonn, Germany.
• Osmotic stress activates distinct MAPK- and lipid signalling pathways in plants. Keystone symposium on Cell Activation and Signal Transduction: Lipid Second Messengers IV. Feb 5-10, Taos, New Mexico, USA.
• Phospholipid-based signal transduction mechanisms in plant cells. Biochemistry Seminar, Kansas State University. Feb 14, Manhattan, Kansas, USA.
• Phospholipid signalling. International Cell Research Organization (ICRO) - Training Course on 'Signalling to growth and cell division in Arabidopsis'. July 19-21, London, UK.
• Osmotic Stress Activates Distinct MAPK- and Lipid Signalling Pathways in Plants. Gordon Research Conferen (GRC) on Salt & Water Stress in Plants. August 20-25, Tilton, NH, USA.

1999

• Signal transduction pathways using lipids. Invited seminar, University of Vienna. Jan 22, Vienna, Austria
• Phospholipid metabolism and cell signalling in Chlamydomonas. Invited seminar, University of Cologne. Jan 26, Cologne, Germany.
• Phospholipid-based signalling pathways in plant cells. Invited seminar, Max-Planck-Institut für Züchtungsforschung. Jan 27, Cologne, Germany.
• Phospholipid based-signalling mechanisms. International EPS Summer School on 'Signalling in plant development and defence'. July 21-23, Wageningen, The Netherlands.
• Osmotic stress triggers distinct phospholipid-based signalling pathways in plant cells. International Conference on Cellular Responses to Oxidative and Osmotic Stress. Aug 28 - Sept 1, Egmond aan Zee, The Netherlands.

1998

• Phospholipid-derived second messengers in plant cells. IMCB seminar, University of Amsterdam. March April 8, Amsterdam, the Netherlands.
• KCl activates different lipid-derived signalling pathways in Chlamydomonas moewusii. 8^th International Conference on the Cell and Molecular Biology of Chlamydomonas. June 2-7, Tahoe City, CA, USA

1997

• Lipid signals meet MAPK. Invited seminar, University of Vienna. Dec 17, Vienna, Austria

1995

• G-protein activated PA formation is generated via PLC and PLD and attenuated by PA kinase: Formation of the novel phospholipid, diacylglycerolpyrophosphate. Annual SON-CW Meeting, Lipids & Biomembranes. March 13-14, Lunteren, The Netherlands.
• Phospholipid-derived second messengers in Chlamydomonas eugametos. Euroconference Experimental Biology of Chlamydomonas. March 29-31, Amsterdam, The Netherlands.
• Phospholipid-derived signals in Chlamydomonas eugametos. Annual SLW Meeting, Experimental Plant Sciences. April 24-25, Lunteren, The Netherlands.
• Phospholipase C and phospholipase D signalling in the green alga Chlamydomonas. 2^nd UK Phospholipid Signalling Meeting. Sept28, Cambridge, UK.

  1994

• Phospholipase C and phospholipase D signaling in Chlamydomonas eugametos. SLW meeting, Molecular Cell Biology of Plants. Nov 4, Wageningen, The Netherlands.
• PLC- and PLD signaling in Chlamydomonas eugametos gametes. 8^th Kölner Algentag,nov 6-8, Cologne, Germany.
• Signs of phospholipase C, phospholipase D and phosphoinositide 3-kinase signalling in Chlamydomonas. Sixth International Conference on the Cell and Molecular Biology of Chlamydomonas. May 17-22, Tahoe City, CA, USA. 

1993

• Signs of a PI 3-kinase signalling pathway in Chlamydomonas. European Chlamydomonas Conference. May 23-26 may, Amsterdam, The Netherlands.

Vacancies

Currently, no vacancies

For personal fellowship applications:

(e.g. FEBS, EMBO, Marie Curie, etc) - please contact:  t.munnik @ uva.nl

Fellowships/Internships

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.

Tools & Expertise :

• Plant physiology, e.g. root development, lateral root formation, root zones; root hairs; pollen tubes; biotic- (PAMPs, Pseudomonas) & abiotic stress (i.e. cold, freezing, heat, salt, hyperosmotic, hyoosmotic, drought).
• Cell biology  (lipid biosensors, FP-tagged kinases, -lipases; PIP2- and PA- targets, phosphomimetics) 
• Lipid biochemistry (TLC, HPLC, GC, liposomes, Fat blots; Radiolabelling, e.g. ³²P/³³P/¹⁴C/³H-Ins
• Protein Biochemistry (enzyme kinetics, lipid targets, lipid binding;  SDS-PAGE, Western blot, IP, Mass Spec)
• Confocal Imaging (lipid biosensors; reporter lines; FP-tagged proteins; endocytosis; exocytosis; membrane trafficking)
• Plant Molecular Biology (cloning; promoter analysis, fusion proteins, gene silencing, overexpression; T-DNA-insertion mutants; q/RT-PCR, RNA-Seq; crossing)

SILS - Plant Cell Biology

Teun Munnik (PI) 

Ing. Ringo van Wijk (Lab manager)   

Dr. Xavier Zarza (Post-doc)  

Dr. Femke de Jong (Post-doc)  

Dr. Steven Arisz (senior Post-doc)  

Drs. Max van Hooren (PhD student)

Ms Hui Sheng (PhD student)

Mrs. Safrina Ahmad  (PhD student) 

Drs. Xandra Schrama (technician)

Drs. Floris Stevens (technician)

Drs. Stella Prelovšek (technician)

Dr. Michael Mishkind (permanent guest) 

Dr. Leonardo Hinojosa (guest)

Ex-group members

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)

Nazish Annum (Agricultural Biotechnogy Division, National Institute for Biotechnology and Genetic Enginering, Faisalabad, Pakistan)

Ruud Korver  (ENZA) 

Mhyrte Praat (Utrecht University)

Ex-undergraduate students

Wladimir Tameling  

Martine den Hartog  

Julian C. Verdonk  

Steven A. Arisz  

Bas ter Riet  

Elske Schouten  

Diewertje van der Does  

Monique Raats  

Tamara Chessa  

Jacco van Rheenen  

Nathalie Verhoef  

Tessa Nauta  

Thanh Le

Maarten Reitsema 

Jiorgos Kourelis 

Carlos Jr. Rubio 'Chucho'

Mark aan 't Goor 

Matthew Lefebvre 

Ruy Kortbeek 

Mart Lamers 

Max Stam

Kinwai Fung

Milan Plasmeijer 

Martijn van Ophem

Floris Stevens

Rui Alvez (Erasmus student)

Babette Vlieger (BSc student)

Ludo Cialdella (BSc student) 

Jack Dickenson (MSc student)

Eveline Bosman (BSc student)

Valerie de Ridder (BSc student)

Willard Bout

Guests

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)

Dr. 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)

Collaborating Labs 

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)   

Gertjan Kramer (SILS, UvA, NL) 

Harro Bouwmeester (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)

Gerard van der Linden (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)  

Jörg Kudla (Münster, Germany) 

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)