Work from a collaboration with Xia Li’s lab at Huazhong Agricultural University (China) has just been published online in Molecular Plant. Congratulations to Xia’s team and Chao Su from our lab!
Here, we report that the microRNA172c (miR172c) activates soybean (Glycine max) Rhizobia-Induced CLE1 (GmRIC1) and GmRIC2 by removing the transcriptional repression of these genes by soybean Nodule Number Control 1 (NNC1), thereby activating the AON pathway. NNC1 interacts with GmNINa, the soybean ortholog of Lotus NODULE INCEPTION (NIN) and hampers its transcriptional activation of GmRIC1 and GmRIC2. Importantly, GmNINa acts as a transcriptional activator of miR172c. Intriguingly, NNC1 can transcriptionally repress miR172c expression, introducing a novel negative feedback loop into the NNC1 regulatory network. Moreover, GmNINa interacts with NNC1 and can relieve the NNC1-mediated repression of miR172c transcription. Thus, the GmNINa/miR172c/NNC1 network is a master switch that coordinately regulates and optimizes NF and AON signaling, supporting the balance between nodulation and AON in soybean.
Molecular Plant (2019); https://doi.org/10.1016/j.molp.2019.06.002
