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Plant function and evolutionary biology
REVIEW

Transcriptional snapshots provide insights into the molecular basis of arbuscular mycorrhiza in the model legume Medicago truncatula

Natalija Hohnjec A B , Kolja Henckel C , Thomas Bekel C , Jerome Gouzy D , Michael Dondrup B C , Alexander Goesmann C and Helge Küster A B E
+ Author Affiliations
- Author Affiliations

A Institute for Genome Research, Center for Biotechnology (CeBiTec), Bielefeld University, D-33594 Bielefeld, Germany.

B International Graduate School in Bioinformatics and Genome Research, Center for Biotechnology (CeBiTec), Bielefeld University, D-33594 Bielefeld, Germany.

C Bioinformatics Resource Facility, Center for Biotechnology (CeBiTec), Bielefeld University, D-33594 Bielefeld, Germany.

D Laboratoire des Interactions Plantes Micro-organismes LIPM, Chemin de Borde-Rouge–Auzeville, BP 52627, 31326 Castanet Tolosan, Cedex, France.

E Corresponding author. Email: Helge.Kuester@Genetik.Uni-Bielefeld.DE

F This paper originates from a presentation at the Third International Conference on Legume Genomics and Genetics, Brisbane, Queensland, Australia, April 2006.

Functional Plant Biology 33(8) 737-748 https://doi.org/10.1071/FP06079
Submitted: 5 April 2006  Accepted: 15 June 2006   Published: 2 August 2006

Abstract

The arbuscular mycorrhizal (AM) association between terrestrial plants and soil fungi of the phylum Glomeromycota is the most widespread beneficial plant–microbe interaction on earth. In the course of the symbiosis, fungal hyphae colonise plant roots and supply limiting nutrients, in particular phosphorus, in exchange for carbon compounds. Owing to the obligate biotrophy of mycorrhizal fungi and the lack of genetic systems to study them, targeted molecular studies on AM symbioses proved to be difficult. With the emergence of plant genomics and the selection of suitable models, an application of untargeted expression profiling experiments became possible. In the model legume Medicago truncatula, high-throughput expressed sequence tag (EST)-sequencing in conjunction with in silico and experimental transcriptome profiling provided transcriptional snapshots that together defined the global genetic program activated during AM. Owing to an asynchronous development of the symbiosis, several hundred genes found to be activated during the symbiosis cannot be easily correlated with symbiotic structures, but the expression of selected genes has been extended to the cellular level to correlate gene expression with specific stages of AM development. These approaches identified marker genes for the AM symbiosis and provided the first insights into the molecular basis of gene expression regulation during AM.

Keywords: arbuscule-specific genes, EST-sequencing, expression databases, Glomus spp., in silico transcriptome profiling, microarray-based transcriptome profiling, TIGR M. truncatula Gene Index.


Acknowledgments

This work was supported by the Deutsche Forschungsgemeinschaft SPP 1084 ‘Mykorrhiza’ as well as by the European Union projects MEDICAGO (QLG-CT2000–00676) and GRAIN LEGUMES (FOOD-CT-2004–506223). HK, MD and NH acknowledge financial support by the International Graduate School in Bioinformatics and Genome Research. The work of AG and TB was funded by the Bundesministerium für Bildung und Forschung (BMBF 0313105).


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