Medicago truncatula, a model plant for studying the molecular genetics of theRhizobium-legume symbiosis


Medicago truncatula has all the characteristics required for a concerted analysis of nitrogen-fixing symbiosis withRhizobium using the tools of molecular biology, cellular biology and genetics.M. truncatula is a diploid and autogamous plant has a relatively small genome, and preliminary molecular analysis suggests that allelic heterozygosity is minimal compared with the cross-fertilising tetraploid alfalfa (Medicago sativa). TheM. truncatula cultivar Jemalong is nodulated by theRhizobium meliloti strain 2011, which has already served to define many of the bacterial genes involved in symbiosis with alfalfa. A genotype of Jemalong has been identified which can be regenerated after transformation byAgrobacterium, thus allowing the analysis ofin-vitro-modified genes in an homologous transgenic system. Finally, by virtue of the diploid, self-fertilising and genetically homogeneous character ofM. truncatula, it should be relatively straightforward to screen for recessive mutations in symbiotic genes, to carry out genetic analysis, and to construct an RFLP map for this plant.

This is a preview of subscription content, log in to check access.



restriction fragment length polymorphism


  1. Agarwal, K. and P.K. Gupta, 1983. Cytological studies in the genusMedicago Linn. Cytologia 48:781–793.

    Google Scholar 

  2. Amor, R.L. 1965. Barrel medic (Medicago tribuloïdes Desr.) in the Australian wheat belt. J. Aust. Inst. Agric. Sci. 31:25–35.

    Google Scholar 

  3. Barker, D.G., P. Gallusci, V. Lullien, H. Khan, M. Ghérardi and T. Huguet. 1988. Identification of two groups of leghemoglobin genes in alfalfa (Medicago sativa) and a study of their expression during root nodule development. Plant Mol. Biol. 11:761–772.

    Article  CAS  Google Scholar 

  4. Bennett, M.D. and J.B. Smith. 1976. Nuclear DNA amounts in angiosperms. Phil. Trans. Roy. Soc. Lond. 274:224–274.

    Google Scholar 

  5. Bennett, M.D., J.B. Smith and J.S. Heslop-Harrison. 1982. Nuclear DNA amounts in angiosperms. Proc. R. Soc. London B 216:179–199.

    CAS  Article  Google Scholar 

  6. Bonierbale, M.W., R.L. Plaisted and S.D. Tanksley. 1988. RFLP maps based on a common set of clones reveal modes of chromosomal evolution in potato and tomato. Genetics 120:1095–1103.

    PubMed  Google Scholar 

  7. Crawford, E.J., A.W.H. Lake and K.G. Boyce. 1989. Breeding annualMedicago species for semi-arid conditions in Southern Australia. Adv. Agron. 42:399–437.

    Article  Google Scholar 

  8. Deak, M., G.B. Kiss, C. Koncz and D. Dudits. 1986. Transformation ofMedicago byAgrobacterium-mediated gene transfer. Plant Cell Rep. 5:97–100.

    Article  CAS  Google Scholar 

  9. Delauney, A.J. and D.P.S. Verma. 1988. Cloned nodulin genes for symbiotic nitrogen fixation. Plant Mol. Biol. Rep. 6:279–285.

    CAS  Google Scholar 

  10. Essad, S. 1987. Sur la relation prossible d'une unité de variation saltatoire de l'ADN nucléaire, le nucléon, et des chromosomes B dans le genreMedicago L. C.R. Acad. Sci. Paris 305 série III:307–310.

    Google Scholar 

  11. Essad S. 1988. Mise en évidence de variations saltatoire de l'ADN nucléaire dans et entre les espèces du genreMedicago L. Genome 30:825–834.

    Google Scholar 

  12. Franssen, H.J., J-P. Nap, T. Cloudemans, W. Stiekema, H. van Dam, F. Govers, J. Louwerse, A. van Kammen and T. Bisseling. 1987. Characterisation of cDNA for nodulin-75 of soybean: A gene product involved in early stages of root nodule development. Proc. Natl. Acad. Sci. USA 84:4495–4499.

    PubMed  Article  CAS  Google Scholar 

  13. Gresshoff, P.M., D.A. Day, A.C. Delves, A.P. Mathews, J.E. Olsson, G. Dean Price, K.A. Schuller and B.J. Carroll 1986. Plant host genetics of nodulation and symbiotic nitrogen fixation in pea and soybean. In:Nitrogen Fixation Research Progress. (eds. H.J. Evans, P.J. Bottomley, W.E. Newton), pp 19–25, Nijhoff, Amsterdam.

    Google Scholar 

  14. Jorgensen, J.E., J. Stougaard, A. Marcker, and K.A. Marcker. 1988. Root nodule specific gene regulation: Analysis of the soybean nodulin N23 gene promoter in heterologous symbiotic systems. Nucl. Acids Res. 16:39–50.

    PubMed  Article  CAS  Google Scholar 

  15. Lesins, K.A. and I. Lesins. 1979. GenusMedicago (Leguminosae): A taxogenetic study. Dr. W. Junk, The Hague.

    Google Scholar 

  16. Long, S.R. 1989.Rhizobium-legume nodulation: Life together in the underground. Cell 56:203–214.

    PubMed  Article  CAS  Google Scholar 

  17. Lullien, V., D.G. Barker, P. de Lajudie and T. Huguet. 1987. Plant gene expression in effective and ineffective root nodules of alfalfa (Medicago sativa). Plant Mol. Biol. 9:469–478.

    Article  CAS  Google Scholar 

  18. Meyerowitz, E.M. and R.E. Pruitt. 1985.Arabidopsis thaliana and plant molecular genetics. Science 229:1214–1218.

    Article  CAS  PubMed  Google Scholar 

  19. Nolan, K.E., R.J. Rose and J.R. Gorst. 1989. Regeneration ofMedicago truncatula from tissue culture: Increased somatic embryogenesis using explants from regenerated plants. Plant Cell Rep. 8:278–281.

    Article  Google Scholar 

  20. Petit, A., J. Stougaard, A. Kühle, K.A. Marcker and J. Tempé. 1987. Transformation and regeneration of the legumeLotus corniculatus: A system for molecular studies of symbiotic nitrogen fixation. Mol. Gen. Genet. 207:245–250.

    Article  CAS  Google Scholar 

  21. Rosenberg, C., P. Boistard, J. Dénarié, F. Casse-Delbart. 1981. Genes controlling early and late functions in symbiosis are located on a megaplasmid inRhizobium meliloti. Mol. Gen. Genet. 184:326–333.

    PubMed  CAS  Google Scholar 

  22. Spano, L., D. Mariotti, M. Pezzotti, F. Damiani and S. Arcioni. 1987. Hairy root transformation in alfalfa (Medicago sativa L.). Theor. Appl. Genet. 73:523–530.

    Article  CAS  Google Scholar 

  23. Sukhapinda, K., R. Spivey and E.A. Shahin. 1987. Ri-plasmid as a helper for introducing vector DNA into alfalfa plants. Plant Mol. Biol. 8:209–216.

    Article  CAS  Google Scholar 

  24. Verma, D.P.S. and K. Nadler. 1984. Legume-Rhizobium symbiosis: Host's point of view. In:Genes Involved in Microbe-Plant Interactions. Plant Gene Research Vol.1. (eds D.P.S. Verma and T. Hohn), pp 57–93 Springer-Verlag Wien New York.

    Google Scholar 

Download references

Author information



Rights and permissions

Reprints and Permissions

About this article

Cite this article

Barker, D.G., Bianchi, S., Blondon, F. et al. Medicago truncatula, a model plant for studying the molecular genetics of theRhizobium-legume symbiosis. Plant Mol Biol Rep 8, 40–49 (1990).

Download citation


  • symbiotic nitrogen fixation
  • legume
  • Medicago truncatula