Expression profiling in Medicago truncatula identifies more than 750 genes differentially expressed during nodulation, including many potential regulators of the symbiotic program.
In this study, we describe a large-scale expression-profiling approach to identify genes differentially regulated during the symbiotic interaction between the model legume Medicago truncatula and the nitrogen-fixing bacterium Sinorhizobium meliloti. Macro- and microarrays containing about 6,000 probes were generated on the basis of three cDNA libraries dedicated to the study of root symbiotic interactions. The experiments performed on wild-type and symbiotic mutant material led us to identify a set of 756 genes either up- or down-regulated at different stages of the nodulation process. Among these, 41 known nodulation marker genes were up-regulated as expected, suggesting that we have identified hundreds of new nodulation marker genes. We discuss the possible involvement of this wide range of genes in various aspects of the symbiotic interaction, such as bacterial infection, nodule formation and functioning, and defense responses. Importantly, we found at least 13 genes that are good candidates to play a role in the regulation of the symbiotic program. This represents substantial progress toward a better understanding of this complex developmental program.
Laboratoire des Interactions Plantes Micro-Organismes, Institut National de la Recherche Agronomique-Centre National de la Recherche Scientifique, 31326 Castanet Tolosan cedex, France.
Fikri
F
El Yahyaoui
Helge
H
Küster
Besma
B
Ben Amor
Natalija
N
Hohnjec
Alfred
A
Pühler
Anke
A
Becker
Jérôme
J
Gouzy
Tatiana
T
Vernié
Clare
C
Gough
Andreas
A
Niebel
Laurence
L
Godiard
Pascal
P
Gamas
D001692:Biological Transport; D002473:Cell Wall / Q000378:metabolism; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D046913:Medicago truncatula / Q000235:genetics* / Q000378:metabolism / Q000382:microbiology; D009586:Nitrogen Fixation; D020411:Oligonucleotide Array Sequence Analysis; D010940:Plant Proteins / Q000378:metabolism; D018517:Plant Roots / Q000378:metabolism; D040901:Proteomics; D015398:Signal Transduction; D016962:Sinorhizobium meliloti / Q000502:physiology; D013559:Symbiosis / Q000502:physiology; D014158:Transcription, Genetic
D010940:Plant Proteins