here - First Legume Society Conference (LSC1)

Book of Abstracts First Legume Society Conference 2013: A Legume Odyssey Novi Sad, Serbia, 9-11 May 2013
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Role of the arbuscular mycorrhizal symbiosis on S-uptake and S-starvation resistance in
Medicago truncatula
D Wipf 1 , K Gallardo 2 , L Casieri 1
1 UMR1347 INRA/Agrosup/Université de Bourgogne Agroécologie, Pôle Interactions Plantes-Microorganismes
- ERL 6300 CNRS, Dijon Cedex, France
2 UMR1347 INRA/Agrosup/Université de Bourgogne Agroécologie, Pôle GEAPSI, Dijon, France
Due to its key role in the biosynthesis of many S-containing compounds, sulphur is a
macronutrient essential for plant growth, development, and response to various abiotic and biotic
stresses. Sulphate represents a very small portion of soil S pull and it’s the only form that plant
roots can take up and mobilize through H + -dependent co-transport processes implying sulphate
transporters. Unlike the other organically bound forms of S, sulphate is normally leached from
soils due to its solubility in water, thus reducing its availability to plants. Although our knowledge
of plant sulphate transporters has been growing significantly in the last decades, little is still
known about the effect of the arbuscular mycorrhiza (AM) interaction on S-uptake and S-stress
resistance. For this reason our studies focused on the mycorrhizal interaction between the
leguminous model plant Medicago truncatula and the arbuscular mycorrhizal fungus Rhizophagus
intraradices (ex Glomus intraradices). Carbon, nitrogen and sulphur measurements in different plant
tissues and expression analysis of genes encoding putative Medicago sulphate transporters
(MtSULTRs) were performed to better understand the beneficial effects of mycorrhizal
interaction at different sulphate concentrations. The putative effects of mycorrhizal interaction
were also assessed on seed weight and quality through protein content and 1-D gel analyses.
Among the 8 putative MtSULTRs in-silico identified; some of them were differentially
transcribed in roots and leaves due to sulphate concentration and/or upon mycorrhization,
potentially defining a switch between direct (DP) and mycorrhizal (MP) sulphate uptake
pathways.
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