Ane Sesma

Project Leader

Disease and Stress Biology

Contact details

ane.sesma@bbsrc.ac.uk

Research interests

Magnaporthe oryzae (rice blast fungus) causes disease in a wide variety of grasses including rice, wheat and barley. The process of infection on leaves by M. oryzae has been extensively studied. It can also infect roots under laboratory conditions by producing fungal structures typical of root-infecting pathogens including microsclerotia, runner hyphae and hyphopodia.

The main goal of our group is the characterisation of the molecular basis of organ-specific pathogenic mechanisms governing M. oryzae plant infection. The comparative analysis of these two pathways of plant attack (via leaves or roots) by M. oryzae will provide insights into the evolutionary potential of intractable soil-borne pathogens of the Magnaporthaceae family such as the economically significant fungus Gaeumannomyces graminis (the causal agent of take-all disease) and the turfgrass pathogen Magnaporthe poae.

Organ-specific infection mechanisms

The recognition of plant cell surfaces (leaves/roots) leads to the development of different infection structures (appressoria or hyphopodia) before fungal penetration. It is not known if the hyphopodium is an intermediate step that takes place before the formation of a mature appressorium or is an independent developmental process.

We have observed that hydrophilic polystyrene is able to induce M. oryzae to form hyphopodia-like structures which then go on to differentiate into hyphae with the bulbous and filamentous growth typical of that observed on roots. Several approaches including lectin cytochemistry, gene expression analysis of infection-related genes and well characterised mutants were used for a detailed analysis of this morphogenetic development. Our results reveal genetic commonalities between appressorium and hyphopodium differentiation suggesting that hyphopodia could represent primitive appressoria, and so hyphopodium formation is likely to be an intermediate step before mature appressorium development.

Post-transcriptional gene regulation mechanisms

Little is known about post-transcriptional gene regulation mechanisms that control fungal plant infection. We are investigating the role of a RNA-binding protein required for the maturation and transport of mRNA precursors implicated in the synthesis of secondary metabolites (often called natural products) and infection-related development. This research will help us to understand the link between natural products and cell differentiation processes in fungi.

Fungal effectors

Fungal secreted proteins are known to manipulate and alter the physiology and immune response of host plants during fungal infection. We are initiating studies on fungal effectors and their involvement during fungal plant colonisation by looking at the role of potentially secreted fungal proteins conferring organ specificity for fungal infection.

Selected Publications

S.L. Tucker, Maria Besi, R. Galhano, Marina Franceschetti, S. Goetz, S. Lenhert, A. Osbourn and A. Sesma (2010). Common Genetic Pathways Regulate Organ-Specific Infection-related Development in the Rice Blast Fungus. Plant Cell, vol. 22, p.1-20.

Fredrik Jernerén, Ane Sesma, Marina Francheschetti, Mats Hamberg, and Ernst H. Oliw. Gene Deletion of 7,8-Linoleate Diol Synthase of the Rice Blast Fungus. STUDIES ON PATHOGENICITY, STEREOCHEMISTRY, AND OXYGENATION MECHANISMS (2010). Journal of Biological Chemistry, vol. 285 (8), p. 5308-5316.

Besi, M., Tucker, S. L. & Sesma, A. (2008). Magnaporthe and its relatives. Encyclopedia of Life Sciences DOI:10.1002/9780470015902.a0021311. (review article)

S. Lenhert, A. Sesma, M. Hirtz, L. Chi, H. Fuchs, H.P. Wiesmann, A.E. Osbourn and B.M. Moerschbacher. Capillary Induced Contact Guidance (2007). Langmuir, vol. 23 (20), p. 10216 - 10223.

S. Güimil, H-S Chang, T. Zhu, A. Sesma, A. Osbourn, C. Roux, V. Ioannidis, E.J. Oakeley, M. Docquier, P. Descombes, S.P. Briggs and U. Paszkowski. "Comparative transcriptomics of rice reveals an ancient pattern of response to microbial colonization". Proceedings of the National Academy of Sciences USA (2005), vol. 102 (22), p. 8066-8070.

A. Sesma and Anne E. Osbourn. "The rice leaf blast pathogen undergoes developmental processes typical of root-infecting fungi". Nature (2004), vol. 431, p. 582-586.

Recent Publications

Jernerén F., Sesma A., Franceschetti M., Hamberg M., Oliw E. H. (2010)
Gene deletion of 7,8-linoleate diol synthase of the rice blast fungus: studies on pathogenicity, stereochemistry, and oxygenation mechanisms.
Journal of Biological Chemistry 285 (8) 5308-16
DOI:10.1074/jbc.M109.062810

Tucker S. L., Besi M., Galhano R., Franceschetti M., Goetz S., Lenhert S., Osbourn A., Sesma A. (2010)
Common genetic pathways regulate organ-specific infective behaviour in the rice blast fungus
Plant Cell 22 (3) 953-972

Besi M., Tucker S. L., Sesma A. (2008)
Magnaporthe and its relatives
Encyclopedia of Life Sciences
Wiley
E-pub
DOI:10.1002/9780470015902.a0021311

Lab Pages

Lab Members