Elucidating the Functional Role of Predicted miRNAs in Post-Transcriptional Gene Regulation Along with Symbiosis in Medicago truncatula

Background: Non-coding RNAs (ncRNAs) are important regulators of gene expression. MicroRNAs (miRNAs) are small ncRNAs, which inhibit translational and post-transcriptional processes, whereas long ncRNAs regulate both transcriptional and post-transcriptional gene expression. Medicago truncatula is a well-known model plant for studying legume biology. Despite its importance in nitrogen fixation, little information is available about Medicago ncRNAs that play an important role in symbiosis.

Objective: This study aims to predict the miRNAs and their targets from the genome of M. truncatula and elucidate their roles in symbiosis and transcriptional regulation.

Methods: We have developed a computational method to identify miRNAs in M. truncatula. In addition, we have also predicted the targets of these miRNAs involved in various biological processes and established an interaction model for symbiosis.

Results: We have predicted 186 miRNAs, of which 165 are novel. Additionally, 770 proteins targeted by these miRNAs are also predicted. We show that 51 of these novel miRNAs target 282 lncRNAs. The symbiosis-related gene regulation is explored through analyzing the interactions between predicted miRNAs and their nodulin target proteins.

Conclusion: Knowledge gained from this study will enhance our understanding of the nitrogenfixing ability of this important model plant, which in turn will improve soil fertility.