Professor Mark Fricker

Fellow by Special Election, Plant Sciences

I started as an undergraduate reading Botany at Pembroke in 1981, followed by a PhD in Stirling on stomatal physiology with Colin Willmer in 1984, a post-doc in Edinburgh with Tony Trewavas on calcium signalling, before returning to Pembroke as a Fellow of Pembroke in 1989. I served as Senior Tutor from 200-2003 and Academic Director from 2008-2015. I am now back doing research in the Plant Sciences Department.

Research interests

A summary of our research interests is given below. More information can be found on:






Fricker, M.D., Heaton, L.L.M., Jones, N., Obara, B., Schwarzlander, M. and Meyer, A. (2017) Quantitation of ER structure and function. Methods in Molecular Biology , 1691:43-66. Doi: 10.1007/978-1-4939-7389-7_5



De Col, V., P. Fuchs, T. Nietzel, M. Elsässer, C. P. Voon, A. Candeo, I. Seeliger, M. D. Fricker, C. Grefen, I. M. Møller, A. Bassi, B. L. Lim, M. Zancani, A. J. Meyer, A. Costa, S. Wagner and M. Schwarzländer (2017). ATP sensing in living plant cells reveals tissue gradients and stress dynamics of energy physiology. eLife 6: e26770. Doi: 10.7554/eLife.26770



Fricker, M.D., Heaton, L.L.M, Jones, N.S., and Boddy, L. (2017). The mycelium as a network. Microbiol. Spectrum, 5: FUNK-0033-2017. Doi:10.1128/microbiolspec.FUNK-0033-2017



Fricker, M.D., Akita, D., Heaton, L.L.M., Jones, N., Obara, B. and Nakagaki, T. (2017) Automated analysis of Physarum network structure and dynamics. J. Phys. D: Appl. Phys. 50, 254005. Doi:10.1088/1361-6463/aa72b9



Garagounis, C, Kostaki, K.-I., Hawkins, T.J., Cummins, I, Fricker, M.D., Hussey, P.J., Hetherington, A.M. and Sweetlove, L.S. (2017) Microcompartmentation of cytosolic aldolase in Arabidopsis by interaction with the actin cytoskeleton. J. Exp. Bot. 68, 885-898. Doi: 10.1093/jxb/erx015






Chan, A, Marimar, B.C., Townlet, H., Fricker, M.D. and Thompson, I. (2016) Effective delivery of volatile biocides employing mesoporous silicates for treating biofilms. J. Roy. Soc. Interface (14,126: 20160650). Doi: 10.1098/rsif.2016.0650



Akita, D., Kunita,I., Fricker, M.D., Kuroda, S., Sato, K. and Nakagaki, T. (2016) Models for Murray’s Law. J. Phys. D: Appl. Phys. 50, 024001. Doi: 10.1088/1361-6463/50/2/024001



Breeze, E., Dzimitrowicz, N., Kriechbaumer, V. Brooks, R., Botchway, S.W.,  Brady, J.P., Hawes, C., Dixon, A., Schnell, J.R., Fricker, M.D. and Frigerio, L. (2016) A C-terminal amphipathic helix is necessary for the in vivo tubule-shaping function of a plant reticulon. PNAS Doi: 10.1073/pnas.1605434113



Lee, C., Maksaev, G., Jensen, G., Murcha, M., Wilson, M., Fricker, M., Hell, R., Haswell, E., Millar, A.H., Sweetlove, L. (2016) MSL1 is a mechanosensitive ion channel that dissipates mitochondrial membrane potential and maintains redox homeostasis in mitochondria during abiotic stress. Plant J. Doi: 10.1111/tpj.13301



Fricker, M.D., Heaton, L., Jones, N., Nakagaki, T., Akita, D. and Obara, B. (2016) Automated analysis of Physarum network structure and dynamics. Proc. PhysNet. Doi: 10.4108/eai.3-12-2015.2262482



Fricker, M.D., Moger, J., LittleJohn, G.R. and Deeks, M. (2016). Making microscopy count: quantitative light microscopy of dynamic processes in living plants. J. Microsc. 263, 181-191. Doi: 10.1111/jmi.12403



Kirchhelle, C., Chow, C.-M., Foucart, C., Neto, H., Stierhof, Y.-D., Kalde, M., Walton, C., Fricker, M.D., Smith, R.S., Jérusalem, A., Irani, N., and Moore, I., (2016) The specification of geometric edges by a plant Rab GTPase is an essential cell-patterning principle during organogenesis in Arabidopsis. Developmental Cell 36, 386–400. Doi: 10.1016/j.devcel.2016.01.020



Lee, S.H., Fricker, M.D. and Porter, M.A. (2016) Mesoscale analyses of fungal networks as an approach to quantifying phenotypic traits. Journal of Complex Networks. doi: 10.1093/comnet/cnv034



Fuchs, R. Kopischke, M., Klapprodt, C. Hause, G., Meyer, A., Schwarzländer, M. Fricker, M.D. and Lipka, V. (2016) Immobilized subpopulations of leaf epidermal mitochondria mediate PEN2-dependent pathogen entry control in Arabidopsis. Plant Cell, 28, 130-145 Doi: 10.1105/tpc.15.00887



Fricker, M.D. (2016) Quantitative Redox Imaging Software. Anti-oxidant and Redox Signalling 24, 752-762. Doi: 10.1089/ars.2015.6390






Wagner, S., Behera, S., De Bortoli, S., Logan, D., Fuchs, P., Carraretto, L., Teardo, E., Cendron, L., Nietzel, T., Füßl, M., Doccula, F., Navazio, L., Fricker, M., Van Aken, O., Finkemeier, I., Meyer, A., Szabo, I., Costa, A., and Schwarzländer, M. (2015) AtMICU choreographs mitochondrial Ca2+ dynamics in Arabidopsis. Plant Cell 27, 3190-3212. Doi: 10.1105/tpc.15.00509



Heaton, L.L.M., Jones, N.S. and Fricker, M.D. (2015) Energetic constraints on saprotrophic fungal growth determine life history strategies. American Naturalist 187 E27-E40. Doi: 10.1086/684392



Wagner, S., Nietzel, T., Aller, I., Costa, A., Fricker, M.D., Meyer, A.J. and Schwarzländer, M. (2015) Analysis of plant mitochondrial function using fluorescent protein sensors. Methods in Molecular Biology 1305, 241-252. Doi:






Schwarzländer, M., Wagner, S., Ermakova, Y. G., Belousov, V. V., Radi, R., Beckman, J. S., Murphy, M. P. (2014). The 'mitoflash' probe cpYFP does not respond to superoxide. Nature, 514(7523), E12-E14. Doi:10.1038/nature13858



Lichius, A., Goryachev, A. B., Fricker, M. D., Obara, B., Castro-Longoria, E., & Read, N. D. (2014). CDC-42 and RAC-1 regulate opposite chemotropisms in Neurospora crassa. J. Cell Science, 127, 1953-1965. Doi:10.1242/jcs.141630



Littlejohn, G. R., Mansfield, J. C., Christmas, J. T., Witterick, E., Fricker, M. D., Grant, M. R., Love, J. (2014). An update: improvements in imaging perfluorocarbon-mounted plant leaves with implications for studies of plant pathology, physiology, development and cell biology. Frontiers in Plant Science, 5, 140. Doi:10.3389/fpls.2014.00140



Samalova, M., Meyer, A. J., Gurr, S. J., & Fricker, M. D. (2014). Robust anti-oxidant defences in the rice blast fungus Magnaporthe oryzae confer tolerance to the host oxidative burst. New Phytol, 201, 556-573. Doi:10.1111/nph.12530



Darrah, P. R., & Fricker, M. D. (2014). Foraging by a wood-decomposing fungus is ecologically adaptive. Environ. Microbiol., 16, 118-129. Doi:10.1111/1462-2920.12216






Samalova, M., Johnson, J., Illes, M., Kelly, S., Fricker, M., & Gurr, S. (2013). Nitric oxide generated by the rice blast fungus Magnaporthe oryzae drives plant infection. New Phytol, 197, 207-222. Doi:10.1111/j.1469-8137.2012.04368.x



Kunita, I., Yoshihara, K., Tero, A., Ito, K., Lee, C.-F., Fricker, M.D. and Nakagaki, T. (2013) Adaptive path-finding and transport network formation by the amoeba-like organism Physarum. In Proc. Info.Comm. Tech., 6, 14-29. Doi: 10.1007/978-4-431-54394-7_2






Simonin, A., Palma-Guerrero, J., Fricker, M., & Louise Glass, N. (2012). Physiological significance of network organization in fungi. Eukaryotic Cell, 11, 1345-1352. Doi:10.1128/EC.00213-12



Yasumura, Y., Pierik, R., Fricker, M. D., Voesenek, L. A., & Harberd, N. P. (2012). Studies of Physcomitrella patens reveal that ethylene-mediated submergence responses arose relatively early in land-plant evolution. Plant J, 72, 947-959. Doi:10.1111/tpj.12005



Onnela, J. -P., Fenn, D. J., Reid, S., Porter, M. A., Mucha, P. J., Fricker, M. D.,Jones, N. S. (2012). Taxonomies of networks from community structure. Physical Review E, 86, 036104. Doi:10.1103/PhysRevE.86.036104



Schwarzländer, M., Murphy, M. P., Duchen, M. R., Logan, D. C., Fricker, M. D., Halestrap, A. P., Sweetlove, L. J. (2012). Mitochondrial 'flashes': a radical concept repHined. Trends Cell Biol, 22, 503-508. Doi:10.1016/j.tcb.2012.07.007



Heaton, L. L., López, E., Maini, P. K., Fricker, M. D., & Jones, N. S. (2012). Advection, diffusion, and delivery over a network. Phys Rev E, 86, 021905. Doi:



Obara, B., Grau, V., & Fricker, M. D. (2012). A bioimage informatics approach to automatically extract complex fungal networks. Bioinformatics, 28, 2374-2381. Doi:10.1093/bioinformatics/bts364



Schwarzländer, M., Logan, D. C., Johnston, I. G., Jones, N. S., Meyer, A. J., Fricker, M. D.,Sweetlove, L. J. (2012). Pulsing of membrane potential in individual mitochondria: a stress-induced mechanism to regulate respiratory bioenergetics in Arabidopsis. Plant Cell, 24, 1188-1201. Doi:10.1105/tpc.112.096438



Obara, B., Fricker, M., Gavaghan, D., & Grau, V. (2012). Contrast-independent curvilinear structure detection in biomedical images. IEEE Trans Image Process, 21, 2572-2581. Doi:10.1109/TIP.2012.2185938



Au, K. K. C., Pérez-Gõmez, J., Neto, H., Neto, H., Müller, C., Meyer, A. J.,Moore, I. (2012). A perturbation in glutathione biosynthesis disrupts endoplasmic reticulum morphology and secretory membrane traffic in Arabidopsis thaliana. Plant Journal, 71, 881-894. Doi:10.1111/j.1365-313X.2012.05022.x



Heaton, L., Obara, B., Obara, B., Grau, V., Grau, V., Grau, V.,Fricker, M. D. (2012). Analysis of fungal networks. Fungal Biology Reviews, 26, 12-29. Doi:10.1016/j.fbr.2012.02.001



Obara, B., Obara, B., Fricker, M., Grau, V., & Grau, V. (2012). Coherence enhancing diffusion filtering based on the Phase Congruency Tensor. Proceedings - International Symposium on Biomedical Imaging, 202-205. Doi:10.1109/ISBI.2012.6235519



Obara, B., Obara, B., Fricker, M., Grau, V., Grau, V., & Grau, V. (2012). Contrast independent detection of branching points in network-like structures. Progress in Biomedical Optics and Imaging - Proceedings of SPIE, 8314. Doi:10.1117/12.910575



Obara, B., Obara, B., Fricker, M., Grau, V., & Grau, V. (2012). Local phase approaches to extract biomedical networks. Proceedings - International Symposium on Biomedical Imaging, 1796-1799. Doi:10.1109/ISBI.2012.6235931






Schwarzländer, M., Logan, D.C., Fricker, M.D., & Sweetlove, L.J. (2011). The circularly permuted yellow fluorescent protein cpYFP that has been used as a superoxide probe is highly responsive to pH but not superoxide in mitochondria: implications for the existence of superoxide 'flashes'. Biochem J, 437, 381-387. Doi:10.1042/BJ20110883



Smith, D.M.D., Onnela, J.P., Onnela, J.P., Lee, C.F., Fricker, M.D.,Johnson, N.F. (2011). Network automata: Coupling structure and function in dynamic networks. Advances in Complex Systems, 14, 317-339. Doi:10.1142/S0219525911003050






Heaton, L.L., López, E., Maini, P.K., Fricker, M.D., & Jones, N.S. (2010). Growth-induced mass flows in fungal networks. Proc Roy Soc B Biol Sci, 277, 3265-3274. Doi:10.1098/rspb.2010.0735



Boddy, L., Wood, J., Redman, E., Hynes, J., & Fricker, M. D. (2010). Fungal network responses to grazing. Fungal Genet Biol, 47, 522-530. Doi:10.1016/j.fgb.2010.01.006



Tero, A., Takagi, S., Saigusa, T., Ito, K., Bebber, D. P., Fricker, M. D.,Nakagaki, T. (2010). Rules for biologically inspired adaptive network design. Science, 327, 439-442. Doi:10.1126/science.1177894






Hafke, J. B., Furch, A. C., Fricker, M. D., & van Bel, A. J. (2009). Forisome dispersion in Vicia faba is triggered by Ca2+ hotspots created by concerted action of diverse Ca2+ channels in sieve elements. Plant Signal Behav, 4, 968-972. Doi: 10.4161/psb.4.10.9671



Furch, A. C., van Bel, A. J., Fricker, M. D., Felle, H. H., Fuchs, M., & Hafke, J. B. (2009). Sieve element Ca2+ channels as relay stations between remote stimuli and sieve tube occlusion in Vicia faba. Plant Cell, 21, 2118-2132. Doi:10.1105/tpc.108.063107



Marty, L., Siala, W., Schwarzländer, M., Fricker, M. D., Wirtz, M., Sweetlove, L. J.,Hell, R. (2009). The NADPH-dependent thioredoxin system constitutes a functional backup for cytosolic glutathione reductase in Arabidopsis. PNAS, 106, 9109-9114. Doi:10.1073/pnas.0900206106



Schwarzländer, M., Fricker, M. D., & Sweetlove, L. J. (2009). Monitoring the in vivo redox state of plant mitochondria: effect of respiratory inhibitors, abiotic stress and assessment of recovery from oxidative challenge. Biochim Biophys Acta, 1787, 468-475. Doi:10.1016/j.bbabio.2009.01.020



Lehmann, M., Schwarzländer, M., Obata, T., Sirikantaramas, S., Burow, M., Olsen, C. E.,Laxa, M. (2009). The metabolic response of Arabidopsis roots to oxidative stress is distinct from that of heterotrophic cells in culture and highlights a complex relationship between the levels of transcripts, metabolites, and flux. Mol Plant, 2, 390-406. Doi:10.1093/mp/ssn080



Boddy, L., Hynes, J., Bebber, D. P., & Fricker, M. D. (2009). Saprotrophic cord systems: Dispersal mechanisms in space and time. Mycoscience, 50, 9-19. Doi:10.1007/s10267-008-0450-4



Fricker, M.D. Boddy, L. Nakagaki, T. Bebber, D.P. (2009) Adaptive biological networks. In Adaptive Networks: Theory, Models and Applications. Eds T. Gross and H. Sayama, Pp 51-70. Doi: 10.1007/978-3-642-01284-6_4






Ingle, R. A., Fricker, M. D., & Smith, J. A. (2008). Evidence for nickel/proton antiport activity at the tonoplast of the hyperaccumulator plant Alyssum lesbiacum. Plant Biol (Stuttg), 10, 746-753. Doi:10.1111/j.1438-8677.2008.00080.x



Rotheray, T. D., Jones, T. H., Fricker, M. D., & Boddy, L. (2008). Grazing alters network architecture during interspecific mycelial interactions. Fungal Ecology, 1, 124-132. Doi:10.1016/j.funeco.2008.12.001



Schwarzländer, M., Fricker, M. D., Müller, C., Marty, L., Brach, T., Novak, J.,Meyer, A. J. (2008). Confocal imaging of glutathione redox potential in living plant cells. J Microsc, 231, 299-316. Doi:10.1111/j.1365-2818.2008.02030.x



Fricker, M. D., Lee, J. A., Bebber, D. P., Tlalka, M., Hynes, J., Darrah, P. R., Boddy, L. (2008). Imaging complex nutrient dynamics in mycelial networks. J Microsc, 231, 317-331. Doi:10.1111/j.1365-2818.2008.02043.x



Tlalka, M., Bebber, D. P., Darrah, P. R., Watkinson, S. C., & Fricker, M. D. (2008). Quantifying dynamic resource allocation illuminates foraging strategy in Phanerochaete velutina. Fungal Genet Biol, 45, 1111-1121. Doi:10.1016/j.fgb.2008.03.015



Morgan, M. J., Lehmann, M., Schwarzländer, M., Baxter, C. J., Sienkiewicz-Porzucek, A., Williams, T. C.,Finkemeier, I. (2008). Decrease in manganese superoxide dismutase leads to reduced root growth and affects tricarboxylic acid cycle flux and mitochondrial redox homeostasis. Plant Physiol, 147, 101-114.Doi:10.1104/pp.107.113613



Tlalka, M., Fricker, M., & Watkinson, S. (2008). Imaging of long-distance alpha-aminoisobutyric acid translocation dynamics during resource capture by Serpula lacrymans. Appl Environ Microbiol, 74, 2700-2708. Doi:10.1128/AEM.02765-07



Samalova, M., Fricker, M., & Moore, I. (2008). Quantitative and qualitative analysis of plant membrane traffic using fluorescent proteins. Methods Cell Biol, 85, 353-380. Doi:10.1016/S0091-679X(08)85015-7



Meyer, A.J. and Fricker, M.D. (2008). Imaging thiol-based redox processes in live cells. In: Sulfur Metabolism in Phototropic Organisms. Ed: C. Dahl, R. Hell, D. Knaff, T. Leustek. pp. 483–501. ISBN: 1402068638, 9781402068638



Fricker, M.D., Bebber, D.P. and Boddy, L. (2008) Mycelial networks: structure and dynamics. In: Ecology of saprotrophic basiodiomycetes. Eds L. Boddy, J.C. Franklin and P. van West. Pp 3-18. Doi:






Tlalka, M., Bebber, D. P., Darrah, P. R., Watkinson, S. C., & Fricker, M. D. (2007). Emergence of self-organised oscillatory domains in fungal mycelia. Fungal Genet Biol, 44, 1085-1095. Doi:10.1016/j.fgb.2007.02.013



Fricker, M. D., Tlalka, M., Bebber, D., Takagi, S., Watkinson, S. C., & Darrah, P. R. (2007). Fourier-based spatial mapping of oscillatory phenomena in fungi. Fungal Genet Biol, 44, 1077-1084. Doi:10.1016/j.fgb.2007.02.012



Bebber, D. P., Hynes, J., Darrah, P. R., Boddy, L., & Fricker, M. D. (2007). Biological solutions to transport network design. Proc Roy Soc Biol Sci, 274, 2307-2315. Doi:10.1098/rspb.2007.0459



Fricker, M.D., Boddy, L. and Bebber, D.P. (2007) Network organisation of mycelial fungi. In: The Mycota. Vol VIII, Biology of the Fungal Cell (2nd Ed). Eds R.J. Howard and N.A.R. Gow. 2nd ed., 341 Doi:






Libourel, I. G., van Bodegom, P. M., Fricker, M. D., & Ratcliffe, R. G. (2006). Nitrite reduces cytoplasmic acidosis under anoxia. Plant Physiol, 142, 1710-1717. Doi:10.1104/pp.106.088898



Samalova, M., Fricker, M., & Moore, I. (2006). Ratiometric fluorescence-imaging assays of plant membrane traffic using polyproteins. Traffic, 7, 1701-1723. Doi:10.1111/j.1600-0854.2006.00502.x



Bebber, D.P., Tlalka, M., Hynes, J., Darrah, P.R., Ashford, A., Watkinson, S.C., Boddy, L., and Fricker, M.D. (2006). Imaging complex nutrient dynamics in mycelial networks. In: G.M. Gadd (Ed). Fungi in the Environment. Cambridge University Press, Cambridge. ISBN: 1139462105, 9781139462105



Watkinson, S.C., Bebber, D., Darrah, P.R., Fricker, M.D.,Tlalka, M. & Boddy, L. (2006) The role of wood decay fungi in the carbon and nitrogen dynamics of the forest floor. In: Gadd, G.M. (ed.) Fungi in Biogeochemical Cycles. Cambridge University Press, Cambridge. ISBN 1107320747, 9781107320741



Jarrett, T. C., Ashton, D. J., Fricker, M., & Johnson, N. F. (2006). Interplay between function and structure in complex networks. Phys Rev E, 74, 026116. Doi:



Darrah, P. R., Tlalka, M., Ashford, A., Watkinson, S. C., & Fricker, M. D. (2006). The vacuole system is a significant intracellular pathway for longitudinal solute transport in basidiomycete fungi. Eukaryot Cell, 5, 1111-1125. Doi:10.1128/EC.00026-06



Fricker, M., Runions, J., & Moore, I. (2006). Quantitative fluorescence microscopy: from art to science. Annu Rev Plant Biol, 57, 79-107. Doi:10.1146/annurev.arplant.57.032905.105239



Boddy, L., Tordoff, G.M., Wood, J., Hynes, J., Bebber, D., Jones, T.H. and Fricker, M.D. (2006). Mycelial foraging strategies of saprotrophic cord-forming basidiomycetes. In: 8th International Mycological Congress Proceedings, ed. W. Meyer & C. Pearce. Medimond, Italy. Pp. 13-20.






Watkinson, S. C., Boddy, L., Burton, K., Darrah, P. R., Eastwood, D., Fricker, M. D.,Tlalka, M. (2005). New approaches to investigating the function of mycelial networks. Mycologist, 19, 11-17. Doi:10.1017/S0269915XO5001023






Meskauskas, A., Fricker, M. D., & Moore, D. (2004). Simulating colonial growth of fungi with the Neighbour-Sensing model of hyphal growth. Mycol Res, 108, 1241-1256. Doi:






Hartmann, T. N., Fricker, M. D., Rennenberg, H., & Meyer, A. J. (2003). Cell-specific measurement of cytosolic glutathione in poplar leaves. Plant Cell Environ, 26, 965-975. Doi: 10.1046/j.1365-3040.2003.01031.x



Tlalka, M., Hensman, D., Darrah, P. R., Watkinson, S. C., & Fricker, M. D. (2003). Noncircadian oscillations in amino acid transport have complementary profiles in assimilatory and foraging hyphae of Phanerochaete velutina. New Phytologist, 158, 325-335. Doi:10.1046/j.1469-8137.2003.00737.x






Meyer, A. J., & Fricker, M. D. (2002). Control of demand-driven biosynthesis of glutathione in green Arabidopsis suspension culture cells. Plant Physiol, 130, 1927-1937. Doi:10.1104/pp.008243



Brandizzi, F., Fricker, M., & Hawes, C. (2002). A greener world: the revolution in plant bioimaging. Nat Rev Mol Cell Biol, 3, 520-530. Doi: 10.1038/nrm861



Tlalka, M., Watkinson, S. C., Darrah, P. R., & Fricker, M. D. (2002). Continuous imaging of amino-acid translocation in intact mycelia of Phanerochaete velutina reveals rapid, pulsatile fluxes. New Phytologist, 153, 173-184. Doi:10.1046/j.0028-646X.2001.00288.x






Meyer, A. J., May, M. J., & Fricker, M. (2001). Quantitative in vivo measurement of glutathione in Arabidopsis cells. Plant J, 27, 67-78. Doi:



Fricker, M. D., & Meyer, A. J. (2001). Confocal imaging of metabolism in vivo: pitfalls and possibilities. J Exp Bot, 52, 631-640. Doi:



Fricker, M.D., Parsons, A., Tlalka, M., Blancaflor, E., Gilroy, S., Meyer, A. and Plieth, C. (2001) Fluorescent probes for living plant cells. In: Plant Cell Biology: A Practical Approach. 2nd Ed. Ed C. Hawes and B. Satiat-Jeunemaitre. Pp 35-84.






Gutiérrez-Alcalá, G., Gotor, C., Meyer, A. J., Fricker, M., Vega, J. M., & Romero, L. C. (2000). Glutathione biosynthesis in Arabidopsis trichome cells. PNAS, 97, 11108-11113. Doi: 10.1073/pnas.190334497



Meyer, A. J., & Fricker, M. D. (2000). Direct measurement of glutathione in epidermal cells of intact Arabidopsis roots by two-photon laser scanning microscopy. J Microsc, 198, 174-181. Doi: doi:10.1046/j.1365-2818.2000.00696.x"



Fricker, M. D., May, M., Meyer, A. J., Sheard, N., & White, N. S. (2000). Measurement of glutathione levels in intact roots of Arabidopsis. J Microsc, 198, 162-173. Doi: doi:10.1046/j.1365-2818.2000.00696.x



Fricker, M.D., May, M., White, N.S. and Meyer, A. (2000) Modelling GSH pathways from in vivo imaging. In: Sulfur Nutrition and Sulfur Assimilation in Higher Plants. Ed. C. Brunold, H. Rennenberg, L.J. De Kok, I. Stulen and J.-C. Davidan. Paul Haupt Publishers, Berne. Pp 353-354.



Meyer, A.J. and Fricker, M.D. (2000) Quantitative imaging of glutathione in live cells by laser scanning microscopy. In: Sulfur Nutrition and Sulfur Assimilation in Higher Plants. Ed. C. Brunold, H. Rennenberg, L.J. De Kok, I. Stulen and J.-C. Davidan. Paul Haupt Publishers, Berne. Pp 351-352.






Tlałka, M., Runquist, M., Runquist, M., & Fricker, M. (1999). Light perception and the role of the xanthophyll cycle in blue-light-dependent chloroplast movements in Lemna trisulca L. Plant Journal, 20, 447-459. Doi:10.1046/j.1365-313X.1999.00614.x



Tlałka, M., & Fricker, M. (1999). The role of calcium in blue-light-dependent chloroplast movement in Lemna trisulca L. Plant Journal, 20, 461-473. Doi:10.1046/j.1365-313X.1999.00621.x



Fricker, M.D. and Oparka, K.J. (1999) Imaging techniques in plant transport: Meeting review. J. Exp. Bot. 50 1089-1100. URL:




Fricker, M.D., Plieth, C., Knight, H., Blancaflor, E., Knight, M.R., White, N.S., and Gilroy, S. (1999) Fluorescent and luminescent techniques to probe ion activities in living plant cells. In: Fluorescent and luminescent probes. 2nd Ed. Ed. W.T. Mason. Pp 569-596. Doi: 10.1016/B978-012447836-7/50044-0







Doe, C. L., Wang, G., Chow, C., Fricker, M. D., Singh, P. B., & Mellor, E. J. (1998). The fission yeast chromo domain encoding gene chp1+ is required for chromosome segregation and shows a genetic interaction with alpha-tubulin. Nucleic Acids Res, 26, 4222-4229. Doi:






Fricker, M. D., White, N. S., & Obermeyer, G. (1997). pH gradients are not associated with tip growth in pollen tubes of Lilium longiflorum. J Cell Sci, 110, 1729-1740. URL:



Sánchez-Fernández, R., Fricker, M., Corben, L. B., White, N. S., Sheard, N., Leaver, C. J.,May, M. J. (1997). Cell proliferation and hair tip growth in the Arabidopsis root are under mechanistically different forms of redox control. PNAS, 94, 2745-2750. Doi:10.1073/pnas.94.6.2745



Errington, R. J., Fricker, M. D., Wood, J. L., Hall, A. C., & White, N. S. (1997). Four-dimensional imaging of living chondrocytes in cartilage using confocal microscopy: a pragmatic approach. Am J Physiol, 272, C1040-C1051. URL:



Fricker, M., Hollinshead, M., White, N., & Vaux, D. (1997). Interphase nuclei of many mammalian cell types contain deep, dynamic, tubular membrane-bound invaginations of the nuclear envelope. J Cell Biol, 136, 531-544. Doi: 10.1083/jcb.136.3.531



Fricker, M.D., Errington, R.J., Wood, J.L., Tlalka, M., May, M. and White, N.S. (1997) Quantitative confocal fluorescence measurements in living tissues. In: Signal Transduction - Single Cell Research. Ed. B. Van Duijn. and A. Wiltnik. Springer-Verlag, Heidelberg. 413-445. Doi:



White, N.S., Errington, R.J., Fricker, M.D. and Wood, J.L. (1997) Multidimensional fluorescence microscopy: optical distortions in quantitative imaging of biological specimens. In: Fluorescence Microscopy and Fluorescent Probes. Plenum Press. Doi:






Willmer, C.M. and Fricker, M.D. (1996) Stomata. 2nd Ed.  ISBN: 0412574306, 9780412574306



White, N. S., Errington, R. J., Fricker, M. D., & Wood, J. L. (1996). Aberration control in quantitative imaging of botanical specimens by multidimensional fluorescence microscopy. Journal of Microscopy, 181, 99-116. Doi:10.1046/j.1365-2818.1996.113392.x






Napier, R., Trueman, S., Henderson, J., Boyce, J., Hawes, C., Fricker, M.,Venis, M. (1995). Purification, sequencing and functions of calreticulin from maize. J. Exp.Botany, 46, 1603-1613. Doi:10.1093/jxb/46.10.1603






Boyce, J. M., Coates, D., Fricker, M. D., & Evans, D. E. (1994). Genomic sequence of a calnexin homolog from Arabidopsis thaliana. Plant Physiol, 106, 1691. URL:



Larin, Z., Fricker, M. D., Maher, E., Ishikawa-Brush, Y., & Southern, E. M. (1994). Fluorescence in situ hybridisation of multiple probes on a single microscope slide. Nucleic Acids Res, 22, 3689-3692. Doi:



Allan, A. C., Fricker, M. D., Ward, J. L., Beale, M. H., & Trewavas, A. J. (1994). Two transduction pathways mediate rapid effects of abscisic acid in Commelina guard cells. Plant Cell, 6, 1319-1328. Doi:10.1105/tpc.6.9.1319



Larin, Z., Fricker, M. D., & Tyler-Smith, C. (1994). De novo formation of several features of a centromere following introduction of a Y alphoid YAC into mammalian cells. Hum Mol Genet, 3, 689-695. Doi:



Fricker, M.D., White, N.S., Thiel, G., Millner, P., and Blatt, M.R. (1994) Peptides derived from the auxin binding protein elevate Ca2+ and pH in stomatal guard cells of Vicia: A confocal fluorescence ratio imaging study. In: Membrane Transport in Plants and fungi: Molecular Mechanisms and Contol. Eds. M.R. Blatt, R.A. Leigh and D. Sanders. SEB Symposium Series 48 215-228.



Fricker, MD, Tlalka, M, Ermantraut, J, Obermeyer, G, Dewey, M, Gurr, S, Patrick, J, White, NS. (1994) Confocal fluorescence ratio imaging of ion activities in plant cells Scanning Microscopy. 8, 391-405.






Thiel, G., Blatt, M. R., Fricker, M. D., White, I. R., & Millner, P. (1993). Modulation of K+ channels in Vicia stomatal guard cells by peptide homologs to the auxin-binding protein C terminus. PNAS, 90, 11493-11497. Doi: doi:10.1073/pnas.90.24.11493



Fricker, M.D. Blatt, M.R. and White, N.S. (1993) Confocal fluorescence ratio imaging of pH in plant cells. In: Biotechnology Applications of Microinjection, Microscopic Imaging and Fluorescence. Eds. P. Bach, C.H. Reynolds, J.M. Clark, P.L. Poole and J. Mottley Plenum Press. Pp 151-162. Doi:



Fricker, M.D., Tester, M. and Gilroy, S. (1993) Fluorescent and luminescent techniques to probe plant cell activity. In W.T. Mason and G. Relf, Eds, Fluorescent Probes for Biological Activity of Living Cells - A Practical guide. Academic Press. Pp 360-377.






Fricker, M. D., & White, N. S. (1992). Wavelength considerations in confocal microscopy of botanical specimens. J. Microscopy, 166(1), 29-42. Doi: 10.1111/j.1365-2818.1992.tb01505.x



Fricker, M.D. and White, N.S. (1992) Application of confocal microscopy and three-dimensional image analysis to plant and microbial cells. Binary 4 44-49.






Hodick, D., Gilroy, S., Fricker, M., & Trewavas, A. (1991). Cytosolic Ca2+-concentrations and distributions in rhizoids of Chara fragilis desv. determined by ratio analysis of the fluorescent-probe indo-1. Botanica Acta, 104, 222-228. Doi: 10.1111/j.1438-8677.1991.tb00221.x



Fricker, M. D., Grantz, D. A., & Willmer, C. M. (1991). Stomatal responses measured using a viscous flow (liquid) porometer. J. Exp. Bot., 42, 747-755. Doi:10.1093/jxb/42.6.747



Gilroy, S., Fricker, M. D., Read, N. D., & Trewavas, A. J. (1991). Role of calcium in signal transduction of Commelina guard cells. Plant Cell, 3, 333-344. Doi:10.1105/tpc.3.4.333



Fricker, M.D., Gilroy, S.G., Read, N.D. and Trewavas, A.J. (1991) Visualisation and measurement of the calcium message in guard cells. In: Molecular Biology of Plant Development. Eds: G.I. Jenkins and W. Schuch. SEB Symposium Series, 44, 177-190.



Gilroy, S., Fricker, M.D., Read, N.D. and Trewavas, A.J. (1991) The role of Ca2+ and ABA in the regulation of stomatal aperture. In: Progress in Plant Growth Regulation. Eds. C.M. Karssen, L.C. Van Loon and D. Vreugdenhil. Current Plant Science and Biotechnology in Agriculture, 13, 105-115. Kluwer Academic Publishers. Dordrecht.



White, N.S., Bennett, S.T., Kenton, A.Y., Callimassia, M.A. and Fricker, M.D. (1991) Characterising plant chromosomes and their 3-D organisation using CLSM. Scanning 13, 228-229.



White, N.S., Fricker, M.D. and Shotton, D.M. (1991) Quantitative visualisation of 3D biological CLSM images. Scanning 13, 51-53.






Fricker, M., & Willmer, C. (1990). Nitrate-sensitive ATPase activity and proton pumping in guard cell protoplasts of Commelina. J. Exp. Bot, 41, 193-198. Doi:10.1093/jxb/41.2.193



Bennett, S.T., Fricker, M.D., Bennett, M.D. and White, N.S. (1990) The 3-D localization of chromosomes using confocal microscopy. Trans. Royal Microscopical Soc. 1, 441-444.



Fricker, M.D., Gilroy, S.G. and Trewavas, A.J. (1990). Signal transduction in plant cells and the calcium message. In: Signal Perception and Transduction in Higher Plants. NATO AS1 Series, 47, pp 89-102. Eds R. Ranjeva and A.M. Boudet. Springer-Verlag Berlin Heidelberg.



Fricker, M.D. and White, N.S. (1990) Volume measurement of guard cell vacuoles during stomatal movements using confocal microscopy. Trans. Royal Microscopical Soc. 1, 345-348.



Gilroy, S., Fricker, M.D., Read, N.D. and Trewavas, A.J. (1990) Fluorescence ratio imaging and photometry of calcium in living plant cells. Trans. Royal Microscopical Soc. 1, 475-478.






Gilroy, S.G., Fricker, M.D., Blowers, D., Harvey, H.J., Collinge, M. and Trewavas, A.J. (1989) Calcium channels, cytosol calcium and plasma membrane phosphorylation: an integrated calcium stat system. In: Plant Membrane Transport: The Current Position. Pp 215-224. Eds J. Dainty, M.I. DeMichelis, E. Marre and F. Rasi-Caldogno. Elsevier. Amsterdam.






Fricker, M., & Willmer, C. (1987). Vanadate sensitive ATPase and phosphatase-activity in guard-cell protoplasts of Commelina. J. Exp. Bot, 38, 642-648. Doi:10.1093/jxb/38.4.642


Biological Network analysis

We have pioneered network analysis of foraging basidiomycete fungi growing in unconstrained microcosms (Bebber et al. 2007a; Bebber et al. 2007b; Boddy et al. 2009; Boddy et al. 2010; Fricker et al. 2008a; Fricker et al. 2007; Fricker et al. 2008b; Heaton et al. 2010; Rotheray et al. 2008). We have shown using graph-theoretic analysis of digitised networks, that these indeterminate, de-centralized systems can yield adaptive networks with both high transport capacity and robustness to damage, but at a relatively low cost, through a 'Darwinian' process of selective reinforcement of key transport pathways and recycling of redundant routes (Bebber et al. 2007a). Furthermore, fungal networks are able to dynamically modify link strengths and local connectivity when subject to experimental attack to readjust the balance between transport capacity, robustness to damage and resource allocation, resulting in increased resilience as the environment becomes more challenging (Boddy et al. 2010; Rotheray et al. 2008).

Currently network extraction is a laborious manual exercise. We have recently developed high-throughput, automated imaging, visualisation and network analysis protocols to extract biological network organisation using Phase Congruency Tensors (PCTs) to specifically enhance curvi-linear features in the image (Obara, 2012a-c). This approach can rapidly extract networks with 106 links in a few minutes with high fidelity.

The underlying mechanisms leading to the emergence of adaptive behaviour in macroscopic mycelial networks are unknown. However, models based on growth-induced mass flow through the experimentally determined macroscopic networks provide a high level of explanatory power for the transport of added radiolabel (Heaton et al. 2010; Heaton et al. 2012). We infer that bio-physical hydraulic coupling and internal flows observed in macroscopic networks may act as the central mechanism enabling coordinated growth across the complete range of scales in networked organisms.

Slime Mold Networks

The work on fungal networks has also led to collaboration with Toshiyuki Nakagaki and his team in Hakodate to understand network formation in the acellular slime mold Physarum polycephalum. We have recently shown that it can form networks with comparable efficiency, fault tolerance, and cost to those of real-world infrastructure networks such as the Tokyo rail system (Tero et al. 2010), which was awarded an IgNobel prize in 2010. The core mechanisms needed for adaptive network formation can be captured in a biologically inspired mathematical model that may be useful to guide network construction in other domains.

Signal transduction

We have a long track record in the development and application of imaging techniques to map redox homeostasis and signalling plant and fungal systems (Moore et al., 2006; Brandizzi et al,. 2002). We developed a system for quantitative imaging of total cytoplasmic glutathione (GSH) in vivo following GST-catalysed conjugation to monochlorobimane (MCB) to give a fluorescent glutathione-bimane (GSB) adduct. This has allowed measurement of concentrations of GSH in defined cell types in intact tissues, to dissect the control of GSH synthesis and to analyse activities of GSH-based xenobiotic detoxification pathways in intact tissues with sub-cellular resolution. The imaging assay is technically complex (Fricker et al., 2000; Meyer and Fricker, 2000; Meyer et al., 2001), but now successfully applied to GSH measurements in several different types of tissues including roots (Sanchez-Fernandez et al., 1997; Fricker et al., 2001), trichomes (Gutiérrez-Alcalá et al 2000), suspension culture cells (Meyer and Fricker, 2002), and mesophyll, epidermal and guard cells of wild type and transgenic poplar over-expressing g-ECS (Hartmann et al 2003), mutants in ER morphology (Au et al., 2012), and most recently pathogenic fungi (Samalova et al., unpub.). This work has now been combined with in vivo redox imaging with using ratiometric roGFP1 and roGFP2 (Schwarzlander et al., 2008; Marty et al., 2009) and application of these probes to measure mitochondrial redox state under a range of stress conditions (Lehmann et al., 2008; Schwarzlander et al., 2009) and in mutants deficient in MnSOD (Morgan et al 2008). We have also shown that cpYFP does not act as a reporter for superoxide, but behaves as an effective pH indicator in vivo, and reveals the presence of transient alkalinisation events associated with flickering in mitochondrial membrane potential (Schwarzlander et al. 2011; 2012). Most recently, we have started to move these approaches across to the pathogenic rice last fungus, Magnaporthe oryzae, coupling the redox and ROS probes with nitric oxide measurements.

Links to videos
nph12530-sup-0002-VideoS1.wmv video/wmv 1036K Video S1 Measurement of the redox potential of the glutathione pool in Magnaporthe oryzae germlings using recombinant Grx1-roGFP2.
nph12530-sup-0003-VideoS2.wmv video/wmv 396K Video S2 Measurement of reactive oxygen species (ROS) using 2′,7′-dichlorodihydrofluorescein diacetate (H2DCFDA) in developing spores and during appressorium formation inMagnaporthe oryzae.
nph12530-sup-0004-VideoS3.wmv video/wmv 1513K Video S3 Simultaneous measurement of mitochondrial membrane potential, reactive oxygen species (ROS) and Grx1-roGFP2 ratio in a swelling germ tube of Magnaporthe oryzae.
nph12530-sup-0005-VideoS4.wmv video/wmv 1763K Video S4 Simultaneous measurement of mitochondrial membrane potential, reactive oxygen species (ROS) and Grx1-roGFP2 ratio in a developing appressorium of Magnaporthe oryzae.
nph12530-sup-0006-VideoS5.wmv video/wmv 1317K Video S5 Formation of glutathione-bimane and subsequent vacuolar sequestration in a developing germling ofMagnaporthe oryzae.
nph12530-sup-0007-VideoS6.wmv video/wmv 1122K Video S6 Animated three-dimensional projections of vacuolar segmentation in spores of Magnaporthe oryzae during the early stages of germination.
nph12530-sup-0008-VideoS7.wmv video/wmv 1286K Video S7 Animated three-dimensional projections of Grx1-roGFP2 fluorescence expressed in Magnaporthe oryzae, and the corresponding ratio images, 16 or 24 h after inoculation on a susceptible rice variety, CO39.
nph12530-sup-0009-VideoS8.wmv video/wmv 9489K Video S8 Animated three-dimensional projections of Grx1-roGFP2 fluorescence expressed in Magnaporthe oryzae, and the corresponding ratio images, 48 h after inoculation on a susceptible rice variety, CO39.
nph12530-sup-0010-VideoS9.wmv video/wmv 1427K Video S9 Animated three-dimensional projections of Grx1-roGFP2 fluorescence expressed in Magnaporthe oryzae, and the corresponding ratio images, 16 or 24 h after inoculation on a resistant rice variety, IR68.
nph12530-sup-0011-VideoS10.wmv video/wmv 7403K Video S10 Animated three-dimensional projections of Grx1-roGFP2 fluorescence expressed in Magnaporthe oryzae, and the corresponding ratio images, 48 h after inoculation on a resistant rice variety, IR68.

Slime Moulds to run the railways? - Oxford Abridged Short Talks