MtHAP2-1 is a key transcriptional regulator of symbiotic nodule development regulated by microRNA169 in Medicago truncatula
Abstract
In the model legume Medicago truncatula, we identified a new transcription factor of the CCAAT-binding family, MtHAP2-1, for which RNA interference (RNAi) and in situ hybridization experiments indicate a key role during nodule development, possibly by controlling nodule meristem function. We could also show that MtHAP2-1 is regulated by microRNA169, whose overexpression leads to the same nodule developmental block as MtHAP2-1 RNAi constructs. The complementary expression pattern of miR169 and MtHAP2-1 and the phenotype of miR169-resistant MtHAP2-1 nodules strongly suggest, in addition, that the miR169-mediated restriction of MtHAP2-1 expression to the nodule meristematic zone is essential for the differentiation of nodule cells.
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Footnotes
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↵3 Corresponding authors.
↵3 E-MAIL aniebel{at}toulouse.inra.fr; FAX 33-5-61285061.
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↵4 E-MAIL martin.crespi{at}isv.cnrs-gif.fr; FAX 33-1-69823695.
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Supplemental material is available at http://www.genesdev.org.
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Article is online at http://www.genesdev.org/cgi/doi/10.1101/gad.402806
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- Received July 24, 2006.
- Accepted September 25, 2006.
- Copyright © 2006, Cold Spring Harbor Laboratory Press