Genome-Wide Identification of RNA Silencing-Related Genes and Their Expressional Analysis in Response to Heat Stress in Barley (Hordeum vulgare L.).

Éva Hamar,Henrik Mihály Szaker,György Szittya,András Kis,János Taller,Péter Gyula,Ágnes Dalmadi,Tibor Csorba,Fabio Miloro,Zoltán Havelda

doi:10.3390/biom10060929

Abstract

Barley (Hordeum vulgare L.) is an economically important crop cultivated in temperate climates all over the world. Adverse environmental factors negatively affect its survival and productivity. RNA silencing is a conserved pathway involved in the regulation of growth, development and stress responses. The key components of RNA silencing are the Dicer-like proteins (DCLs), Argonautes (AGOs) and RNA-dependent RNA polymerases (RDRs). Despite its economic importance, there is no available comprehensive report on barley RNA silencing machinery and its regulation. In this study, we in silico identified five DCL (HvDCL), eleven AGO (HvAGO) and seven RDR (HvRDR) genes in the barley genome. Genomic localization, phylogenetic analysis, domain organization and functional/catalytic motif identification were also performed. To understand the regulation of RNA silencing, we experimentally analysed the transcriptional changes in response to moderate, persistent or gradient heat stress treatments: transcriptional accumulation of siRNA- but not miRNA-based silencing factor was consistently detected. These results suggest that RNA silencing is dynamically regulated and may be involved in the coordination of development and environmental adaptation in barley. In summary, our work provides information about barley RNA silencing components and will be a ground for the selection of candidate factors and in-depth functional/mechanistic analyses.

Highlights

Barley (Hordeum vulgare L.) is the fourth most important crop in the world in terms of cultivated area (50 MHa) and grain yield produced (140 Mt) [1]
According to Hidden Markov-model (HMM) profile analysis, a total number of five HvDCLs, eleven HvAGOs and seven HvRDR genes were predicted in the barley genome
H. vulgare silencing components were named based on the closest relative in A. thaliana, or monocot species O. sativa and Z. mays (Figure 1)

Summary

Introduction

Barley (Hordeum vulgare L.) is the fourth most important crop in the world in terms of cultivated area (50 MHa) and grain yield produced (140 Mt) [1]. Barley grain has a high nutritional component content [2] and is used as a human food and animal feed. Beyond the obvious economic importance, studying barley is useful for understanding and increasing crop resilience. Relatively tolerant to abiotic stresses among cereal crops, heat stress during reproductive phase negatively affects barley grain yield and quality [6,7]. Barley genetic variation may be employed for the development of efficient strategies to enhance its productivity under diverse climatic conditions. Germplasm availability and expansion may be critical for the sustained high yield of crops under climate change and global warming conditions

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Discussion

Conclusion