Gene Silencing of Argonaute5 Negatively Affects the Establishment of the Legume-Rhizobia Symbiosis

Authors

Maria del Rocio Reyero-Saavedra, Universidad Nacional Autonoma de MexicoFollow
Zhenzhen Qiao, University of OklahomaFollow
Maria del Socorro Sanchez-Correa, Universidad Nacional Autonoma de MexicoFollow
M. Enrique Diaz-Pineda, Universidad Nacional Autonoma de MexicoFollow
Jose L. Reyes, Universidad Nacional Autónoma de MéxicoFollow
Alejandra A. Covarrubias, Universidad Nacional Autónoma de MéxicoFollow
Marc Libault, University of OklahomaFollow
Oswaldo Valdes-Lopez, Universidad Nacional Autónoma de MexicoFollow

ORCID IDs

0000-0001-5129-9741

Date of this Version

2017

Citation

Genes 2017, 8, 352

Comments

© 2017 by the authors.

Open access

doi:10.3390/genes8120352

Abstract

The establishment of the symbiosis between legumes and nitrogen-fixing rhizobia is finely regulated at the transcriptional, posttranscriptional and posttranslational levels. Argonaute5 (AGO5), a protein involved in RNA silencing, can bind both viral RNAs and microRNAs to control plant-microbe interactions and plant physiology. For instance, AGO5 regulates the systemic resistance of Arabidopsis against Potato Virus X as well as the pigmentation of soybean (Glycine max) seeds. Here, we show that AGO5 is also playing a central role in legume nodulation based on its preferential expression in common bean (Phaseolus vulgaris) and soybean roots and nodules. We also report that the expression of AGO5 is induced after 1 h of inoculation with rhizobia. Down-regulation of AGO5 gene in P. vulgaris and G. max causes diminished root hair curling, reduces nodule formation and interferes with the induction of three critical symbiotic genes: Nuclear Factor Y-B (NF-YB), Nodule Inception (NIN) and Flotillin2 (FLOT2). Our findings provide evidence that the common bean and soybean AGO5 genes play an essential role in the establishment of the symbiosis with rhizobia.