Genome-Wide Identification and Characterization of Salinity Stress-Responsive miRNAs in Wild Emmer Wheat (Triticum turgidum ssp. dicoccoides).

Kewei Feng,Pingchuan Deng,Mengxing Wang,Weining Song,Licao Cui,Xiaojun Nie

doi:10.3390/genes8060156

Abstract

MicroRNAs (miRNAs) are a class of endogenous small noncoding RNAs which regulate diverse molecular and biochemical processes at a post-transcriptional level in plants. As the ancestor of domesticated wheat, wild emmer wheat (Triticum turgidum ssp. dicoccoides) has great genetic potential for wheat improvement. However, little is known about miRNAs and their functions on salinity stress in wild emmer. To obtain more information on miRNAs in wild emmer, we systematically investigated and characterized the salinity-responsive miRNAs using deep sequencing technology. A total of 88 conserved and 124 novel miRNAs were identified, of which 50 were proven to be salinity-responsive miRNAs, with 32 significantly up-regulated and 18 down-regulated. miR172b and miR1120a, as well as mi393a, were the most significantly differently expressed. Targets of these miRNAs were computationally predicted, then Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis found that the targets of salinity-responsive miRNAs were enriched in transcription factors and stress-related proteins. Finally, we investigated the expression profiles of seven miRNAs ranging between salt-tolerant and sensitive genotypes, and found that they played critical roles in salinity tolerance in wild emmer. Our results systematically identified the salinity-responsive miRNAs in wild emmer, not only enriching the miRNA resource but also laying the foundation for further study on the biological functions and evolution of miRNAs in wild wheat and beyond.

Highlights

Wheat is one of the most important crops around the world, with about 620 Mt of production annually, and it provides more than 20% of total human food calories [1]
To gain insight into the role of miRNAs playing in salinity stress tolerance in wild emmer wheat, we identified and characterized the salinity responsive miRNAs through high-throughput sequencing combined with bioinformatic analysis
Many studies have suggested that a lot genes are involved in response to salinity stress and exhibit different patterns of expression which of genes are involved in response to salinity stress and exhibit different patterns of expression which may be regulated at the post-transcriptional level by miRNA in plants

Summary

Introduction

Wheat is one of the most important crops around the world, with about 620 Mt of production annually, and it provides more than 20% of total human food calories [1] Abiotic stresses such as drought and salinity shed a significantly negative impact on wheat production and these negative effects are gradually increasing due to declining water supply, land degradation and climate change [2]. Extensive studies have been conducted to identify and characterize the genes and regulators involved in the biological process and the metabolic network of salinity stress response, which provided some clues for the mechanism as well as the resource for genetic improvement of crop salt tolerance [8]. Less is known about the regulatory network controlling the salt response and tolerance

Methods

Results

Discussion

Conclusion