People

Professor Karl Oparka

Location: Rutherford 107E

Telephone: +44 (0) 131 650 7256

Group members: Karen Bell (Research Assistant), Dr. Christophe Lacomme, Dr. Jens Tilsner, Olga Linnik (PhD student), Jessica Fitzgibbon (PhD student)

C.V.

Year	Description
2005-present	Head of Institute of Molecular Plant Sciences, Regius Chair of Plant Science, Fellow of The Royal Society of Edinburgh
1994-2005	Scottish Crop Research Institute: Head of Cell Biology
2002-2005	Individual Merit Promotion (band 2)
1994-2002	Individual Merit Promotion (band 3)
1989-1994	Principal Scientific Officer
1979-1983	Durham University, Senior Research Associate
1976-1979	Aberdeen University PhD
1972-1976	Aberdeen University BSc. Hons (I) in Botany

Research groupings

No details available

Teaching

I teach on the 4th year Plant Science Honours programme, on the 3rd year Plant Physiology Course and on the second-year course 'The Dynamic Cell'

Research interests

Our research examines the structure/function relationships of plasmodesmata (PD) and the basic mechanisms by which macromolecules pass between higher plant cells. Recent work has focussed on the formation of primary and secondary PD, and in the development of novel approaches for studying PD dynamics non-invasively. My group also researches the mechanisms by which plant-viral genomes pass between cells, with emphasis on the movement of the filamentous viruses potato virus X (PVX) and tobacco mosaic virus (TMV). Specific emphasis is placed on the role of viral movement proteins in facilitating the passage of viral genomes through PD. Additional interests include studies of the movement of non-cell autonomous plant proteins, and the isolation of novel protein components from PD using proteomics and viral-vector based technologies. The group also studies the long-distance movement of macromolecules in plants with emphasis on the nature and regulation of phloem unloading in sink organs such as developing roots and storage organs. We are also interested in the biotechnological uses of viral vectors as protein delivery vehicles in plants.

To increase our understanding of the control of cell-to-cell transport in plants, we use a diversity of approaches that encompass molecular biology, cell biology, plant virology and confocal imaging. Recently we have exploring a wide range of novel imaging approaches, based on fluorescent reporter technologies, to track RNA and protein movement within living plant cells. These include the use of a novel fluorescent reporter, iLOV, derived by molecular evolution from a plant phototropin (collaboration with Dr. John Christie, University of Glasgow), the development of an in vivo reporter of viral RNA based on the RNA-binding protein, Pumilio, and the use of direct RNA labelling protocols coupled to microinjection. In current work, we are exploring the use of novel photactivatable flouresecent reporters,coupled to photoactivation localisation microscopy (PALM; collaboration with Dr. Cristina Flors, School of Chemistry, University of Edinburgh) to conduct super-resolution studies of PD development and virus cell-to-cell movement.


Phloem unloading of GFP in a developing lateral root of A. thaliana. The GFP was expressed in leaves under the companion cell-specific promoter SUC2 and subsequently transported to roots. An unloading zone develops at the base of the lateral root connecting it to central phloem of the stele (see Stadler et al., 2005; Plant J. 41, 319).	Association of the tobacco mosaic virus (TMV) movement protein (red) with the microtubule cytoskeleton (green) in infected epidermal cells (see Gillespie et al. 2002; Plant Cell 14, 1207).

Surface view of plasmodesmata in the basal wall of a tobacco trichome cell, imaged using field emission scanning electron microscopy (FESEM). For details see Faulkner et al. (2008).	Plasmodesmata expressing a movement protein-GFP fusion protein (green) in the basal cell wall (stained blue with Calcofluor) of a tobacco leaf trichome (see Faulkner et al. 2008)

Viral RNA (green) of tobacco mosaic virus imaged in a single leaf epidermal cell using the RNA-binding protein, Pumilio, coupled to bimolecular fluorescence complementation (BiFC). For details see Tilsner et al. (2009).	Extensive cell-to-cell movement of tobacco mosaic virus (TMV) expressing the fluorescent reporter DsRed after injection into a single trichome cell. The initially infected cell was co-injected with free GFP (green) which remains confined to the injected cell. Chlorophyll autofluorscence from mesophyll cells is shown in blue.

Representative publications

Brandizzi, F., Pinto da Silva, L., Batoko, H., Boevink, P., Evans, D., Oparka, K.J., Denecke, J., Hawes, C. (2003) ER quality control can lead to retrograde transport from the ER lumen to the cytosol and the nucleoplasm in plants. The Plant Journal 34, 269-281
Roberts, A.G., Oparka, K.J. (2003) Plasmodesmata and the control of symplastic transport. Plant, Cell and Environment 26, 103-124
Taliansky, M., Roberts, I.M., Kalinina, N., Ryabov, E.V., Raj, S.K., Robinson, D.J., Oparka, K.J. (2003) An umbraviral protein, involved in long-distance RNA movement, binds viral RNA and forms unique protective ribonucleoprotein complexes. Journal of Virology 77, 3031-3040
Wright, K.M., Roberts, A.G., Sauer, N., Oparka, K.J. (2003) Analysis of phloem loading capacity in leaves of tobacco expressing the SUC2 promoter. Plant Physiology 131, 1555-1565
Medina-Escobar, N., Haupt, S., Boevink, P., Chapman, S., Oparka, K.J. (2003) High-throughput viral expression of cDNA-GFP fusions reveals novel subcellular addresses and identifies unique proteins that interact with plasmodesmata. Plant Cell 15, 1507-1523
Complainville, A., Brocard, L., Roberts, I., Dax, E., Sauer, N., Kondrosi, A., Wolf, S., Oparka, K.J., Crespi, M. (2003). Nodule initiation involves creation of a new symplasmic field in specific root cells of Medicago ssp. Plant Cell 15, 2778-2791
Oparka, K.J. (2004) Getting the message across - how do plant cells exchange macromolecular complexes? Trends in Plants Science 9, 33-41
Stadler, R., Wright, K.M., Lauterbach, C., Ammon, G., Gahrtz, M., Feuerstein, A., Oparka, K.J., Sauer, N. (2004) Transgenic expression of GFP-fusions in Arabidopsis reveals extensive non-specific protein trafficking between companion cells and sieve elements, and identifies a novel post-phloem domain in roots. Plant Journal 41, 319-331
Haupt, S., Cowan, G., Ziegler, A., Oparka, K.J., Torrance, L. (2004). Two movement proteins of a plant virus traffic in the endocytic recycling pathway. Plant Cell 17, 164-187
Valentine, T., Shaw, J., Blok, V., Phillips, M., Oparka, K.J., Lacomme, C. (2004) Efficient virus induced gene silencing in roots using a modified tobacco rattle virus vector. Plant Physiology 136, 3999-40009
Boevink, P., Oparka, K.J. (2005) Viral-host interactions during movement processes. Review. Plant Physiology 138, 1815-1821
Chapman, S., Oparka, K.J. Roberts, A.G. (2005) New tools for in vivo fluorescence tagging. Current Opinion in Plant Biology 8, 565-573 (eds. K. Oparka and P. Zambryski)
Latijnhouwers, M, Hawes, C., Carvalho, C., Oparka, K.J. Gillingham, A., Boevink, P. (2006) An Arabidopsis GRIP domain protein locates to the trans Golgi and binds the small GTPase ARL1. Plant Journal 44, 459-570
Martens, H., Roberts, A.G., Oparka, K.J., Schulz. A (2006) Quantification of plasmodesmatal ER coupling between sieve elements and companion cells using fluorescence redistribution after photobleaching (FRAP). Plant Physiology 142, 471-480
Wright, K.M., Wood, N., Chapman, S., Roberts, A.G., Oparka, K.J. (2007) Plasmodesmatal targeting of the TMV movement protein is energy dependent and requires the actin-ER network - evidence from FRAP. Traffic 8, 21-31
Valentine, T.A., Randall, E., Wypijewski, K., Chapman, S., Jones, J., Oparka, K.J. (2007)
Delivery of macromolecules to plant parasitic nematodes using a tobacco rattle virus vector. Plant Biotechnology Journal 5, 827-834
Silady, R.A., Ehrhardt, D.W., Jackson, K., Faulkner, C., Oparka, K.J., Somerville, C.R. (2008)
The GRV2/RME-8 protein of Arabidopsis functions in the late endocytic pathway and is required for vacuolar membrane flow. Plant Journal 53, 29-41
Faulkner, C., Jackson, K., Jeffree, C., Oparka, K.J. (2008) Peeking into pit fields - a multiple twinning model of secondary plasmodesmata formation in tobacco. Plant Cell, 20, 1504-1518
Chapman, S., Faulkner, C., Roberts, A.G., Oparka, K.J., Christie, J. (2008) The photoreversible fluorescent protein, iLOV, outperforms GFP as a reporter of plant virus infection. Proceedings of the National Academy of Sciences, USA 105, 20038-20043
Tilsner, J., Linnik, O., Bell, K., Lacomme, C., Oparka, K.J. (2009) Imaging viral genomes in plant cells using a Pumilio-based reporter. Plant Journal 57, 758-770
Christensen, N., Tilsner, J., Bell, K., Lacomme, C., Oparka. K.J. (2009) Live-cell imaging of tobacco mosaic virus (TMV) RNA reveals that the 5’ cap is required for virion attachment to the actin/ER network during early infection. Traffic (In press)
Christensen, N., Faulkner, C., Oparka, K.J. (2009) Evidence for unidirectional flow through plasmodesmata. Plant Physiology (In Press).

This article was published on Feb 8, 2012