John Innes Centre

Prof Allan Downie

Lab Pages

Lab MembersExpand lab members list

Related links

Curriculum Vitae

  • 1971 BSc University of Strathclyde
  • 1974 PhD University of Dundee
  • 1975 Postdoctoral Fellow. Radiation biology and Biophysics, University of Rochester, New York
  • 1976 Research Fellow; John Curtin School of Medical Research, Australian National University
  • 1981 Project Leader, John Innes Institute
  • 1985 Project Leader, CSIRO Division of Plant Industry, Canberra Australia
  • 1988-present Project leader John Innes Centre
  • 1999-present Honorary Professor, University of East Anglia, UK
  • 2006-present Chair of Faculty
  • 2006-present Member of Central Management Board John Innes Centre

Allan Downie

Project Leader

Molecular Microbiology

Contact details

allan.downie@bbsrc.ac.uk

Research interests

Rhizobium attachment to and infection of legume roots

Symbiotic nitrogen fixation on legume roots requires the attachment of rhizobia to roots and root hairs. This is required for the induction of nodule morphogenesis and the root infection events that lead to the infection of the root nodules in which the bacteria fix nitrogen and make it available to the plants. My group is investigating the role and interplay between (a) quorum-sensing (population-density-dependent) regulation of gene expression, (b) surface polysaccharides and (c) secreted proteins, during surface attachment of Rhizobium leguminosarum biovar viciae, focussing on attachment to root hairs.  

Calcium signalling in legume roots during nodulation

Rhizobia attached to root hairs produce nodulation (Nod) factors that induce a calcium influx at the tip of legume root hairs and then calcium oscillations (called calcium spiking) around the nuclear region of these cells. In collaboration with Giles Oldroyd we are analysing how the perception of Nod-factors is coupled to the induction of early nodulation genes in legumes. This has involved identification of legume nodulation genes some of which are required for induction of the calcium signals whereas others integrate the calcium signals leading to gene expression.

Selected Publications

Edwards A., Frederix M., Wisniewski-Dyé F., Jones J., Zorreguieta A., Downie J. A. (2009)
The cin and rai quorum-sensing regulatory systems in Rhizobium leguminosarum are coordinated by ExpR and CinS, a small regulatory protein coexpressed with CinI.
Journal of Bacteriology 191 (9) 3059-3067
DOI:10.1128/JB.01650-08
Krehenbrink M., Downie J. A. (2008)
Identification of protein secretion systems and novel secreted proteins in Rhizobium leguminosarum bv. viciae
BMC Genomics 9 article 55
Oldroyd G. E., Downie J. A. (2008)
Coordinating nodule morphogenesis with rhizobial infection in legumes.
Annual Review of Plant Biology 59 519-546
DOI:10.1146/annurev.arplant.59.032607.092839

Recent Publications

Downie J. A. (2010)
The roles of extracellular proteins, polysaccharides and signals in the interactions of rhizobia with legume roots.
FEMS Microbiology Reviews 34 (2) 150-170
DOI:10.1111/j.1574-6976.2009.00205.x
Hazledine S., Sun J., Wysham D., Downie J. A., Oldroyd G. E., Morris R. J. (2009)
Nonlinear time series analysis of nodulation factor induced calcium oscillations: evidence for deterministic chaos?
PLoS One 4 (8) e6637
DOI:10.1371/journal.pone.0006637
Hirsch S., Kim J., Muńoz A., Heckmann A. B., Downie J. A., Oldroyd G. E. (2009)
GRAS proteins form a DNA binding complex to induce gene expression during nodulation signaling in Medicago truncatula
Plant Cell 21 (2) 545-557
DOI:10.1105/tpc.108.064501
Kiss E., Olah B., Kalo P., Morales M., Heckmann A. B., Borbola A., Lozsa A., Kontar K., Middleton P., Downie J. A., Oldroyd G. E., Endre G. (2009)
LIN, a novel type of U-box/WD40 protein, controls early infection by rhizobia in legumes.
Plant Physiology 151 (3) 1239-1249
DOI:10.1104/pp.109.143933
Talukdar T., Gorecka K. M., de Carvalho-Niebel F., Downie J. A., Cullimore J., Pikula S. (2009)
Annexins - calcium- and membrane-binding proteins in the plant kingdom. Potential role in nodulation and mycorrhization in Medicago truncatula
Acta Biochimica Polonica 56 (2) 199-210
Yokota K., Fukai E., Madsen L. H., Jurkiewicz A., Rueda P., Radutoiu S., Held M., Hossain M. S., Szczyglowski K., Morieri G., Oldroyd G. E., Downie J. A., Nielsen M. W., Rusek A. M., Sato S., Tabata S., James E. K., Oyaizu H., Sandal N., Stougaard J. (2009)
Rearrangement of actin cytoskeleton mediates invasion of Lotus japonicus roots by Mesorhizobium loti
Plant Cell 21 (1) 267-84
DOI:10.1105/tpc.108.063693
Downie J. A., Gonzalez J. E. (2008)
Cell-to-cell communication in rhizobia: quorum sensing and plant signalling
Chemical Communication Among Bacteria
ASM Press
(chapter unknown) 213-232
Fox M. A., Karunakaran R., Leonard M. E., Mouhsine B., Williams A., East A. K., Downie J. A., Poole P. S. (2008)
Characterization of the quaternary amine transporters of Rhizobium leguminosarum bv. viciae 3841.
FEMS Microbiology Letters 287 (2) 212-220
DOI:10.1111/j.1574-6968.2008.01307.x
Hernández-González I., Meakin G., Walker A. W., Hynes M. F., Young J. P., Downie J. A., Romero D., Johnston A. W., Dávila G., Parkhill J., González V., Crossman L. C., Castillo-Ramírez S., McAnnula C., Lozano L., Vernikos G. S., Acosta J. L., Ghazoui Z. F. (2008)
A common genomic framework for a diverse assembly of plasmids in the symbiotic nitrogen fixing bacteria.
PLoS ONE 3 (7) e2567
DOI:10.1371/journal.pone.0002567
Kosuta S., Hazledine S., Sun J., Miwa H., Morris R. J., Downie J. A., Oldroyd G. E. (2008)
Differential and chaotic calcium signatures in the symbiosis signaling pathway of legumes.
Proceedings of the National Academy of Sciences USA 105 (28) 9823-8
DOI:10.1073/pnas.0803499105
Williams A., Wilkinson A., Krehenbrink M., Russo D. M., Zorreguieta A., Downie J. A. (2008)
Glucomannan-mediated attachment of Rhizobium leguminosarum to pea root hairs is required for competitive nodule infection.
Journal of Bacteriology 190 (13) 4706-4715
DOI:10.1128/JB.01694-07