ViPS Invited Seminar December 2017

Jens Stougaard, University of Aarhus, Denmark

Date: 13th December 2017

Time: 13:15

Title: Signals and receptors involved in endosymbiosis

Location: Biocentre 2, seminar room 1015, Viikinkaari 5

Host: Alan Schulman

Abstract: My research activities have for most of my career had a strong focus and legumes and their interaction with microorganisms.  Legumes form endosymbioses with rhizobia and arbuscular mycorrhizal fungi, host endophytes, support a rhizosphere community and like other plants they are attacked by pathogens. One of the features enabling legumes to distinguish between these very different microbes appears to be a large family of LysM receptor kinases monitoring microbial signals. LysM receptor kinases have been shown to play a crucial role for perception of rhizobial Nod factors while others have not been studied. The function of some of these receptors in perception of signal molecules including lipochito-oligosaccharides, exopolysaccharides and chitin derived signal molecules and in plant-microbe interaction will be presented together with the genetic and biochemical methods used for functional studies. Biochemical approaches for detailed characterization of ligand – LysM receptor interactions will be presented and a model for legume recognition of rhizobial bacteria and pathogens will be discussed.

Jens Stougaard is Professor of Molecular Biology and Genetics at Aarhus University and Director of the Centre for Carbohydrate Recognition and Signalling (CARB). Jens Stougaard leads a group studying plant genes regulating the development of nitrogen fixing root nodules and mycorrhiza formation in legumes. Currently the perception mechanisms for the bacterial Nod-factor and exopolysaccharide signal molecules, the function of receptors involved and the downstream signal transduction cascades are in focus. The plant model system used for this research is Lotus japonicus that form determinate root nodules. Lotus japonicus is also used for investigating the long-range signalling integrating root nodule development into the general developmental program of the plant. Genetics, genomics and biochemical methods are used to identify and characterise components of regulatory circuits including hormone regulation of nodule organogenesis and rhizobial infection. In order to improve the genetic analysis, a large-scale insertion population based on the germ-line specific activity of the LORE1 retroelement has been established and made available to the community as a resource for reverse genetics in plants.

More recently a more strategic research project aiming to develop genomics-based breeding of Vicia faba (faba bean) has been initiated with collaborators from Denmark, UK, Finland and Canada. The idea is to build a consortium of Northern hemisphere players, NORFAB (NORthern FABa) with the critical mass and key expertise required to develop sophisticated genomics-based plant breeding methods and provide access to germplasm with the relevant genetic diversity. NORFAB aims to improve the yield and quality of faba bean seeds to a level making faba bean a competitive protein crop for cultivation on arable farmland under northern European and Canadian/US northern prairie conditions. NORFAB will establish genomics and genetics and use new genotyping and phenotyping methodologies to develop this orphan crop.

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Relevant publications:

Bozsoki Z, Cheng J, Feng F, Gysel K, Vinther M, Andersen KR, Oldroyd G, Blaise M, Radutoiu S, Stougaard J. Receptor-mediated chitin perception in legume roots is functionally separable from Nod factor perception. Proc Natl Acad Sci U S A. 2017 Sep 19;114(38):E8118-E8127. doi: 10.1073/pnas.1706795114.

Kawaharada Y, Nielsen MW, Kelly S, James EK, Andersen KR, Rasmussen SR, Füchtbauer W, Madsen LH, Heckmann AB, Radutoiu S, Stougaard J. Differential regulation of the Epr3 receptor coordinates membrane-restricted rhizobial colonization of root nodule primordia. Nat Commun. 2017 Feb 23;8:14534. doi: 10.1038/ncomms14534.

Kawaharada Y, Kelly S, Nielsen MW, Hjuler CT, Gysel K, Muszyński A, Carlson RW, Thygesen MB, Sandal N, Asmussen MH, Vinther M, Andersen SU, Krusell L, Thirup S, Jensen KJ, Ronson CW, Blaise M, Radutoiu S, Stougaard J. Receptor-mediated exopolysaccharide perception controls bacterial infection. Nature. 2015 Jul 16;523(7560):308-12. doi: 10.1038/nature14611.

Broghammer A, Krusell L, Blaise M, Sauer J, Sullivan JT, Maolanon N, Vinther M, Lorentzen A, Madsen EB, Jensen KJ, Roepstorff P, Thirup S, Ronson CW, Thygesen MB, Stougaard J. Legume receptors perceive the rhizobial lipochitin oligosaccharide signal molecules by direct binding. Proc Natl Acad Sci U S A. 2012 Aug 21;109(34):13859-64. doi: 10.1073/pnas.1205171109.

Madsen LH, Tirichine L, Jurkiewicz A, Sullivan JT, Heckmann AB, Bek AS, Ronson CW, James EK, Stougaard J. The molecular network governing nodule organogenesis and infection in the model legume Lotus japonicus. Nat Commun. 2010 Apr 12;1:10. doi: 10.1038/ncomms1009