Transcriptome analysis revealed the drought-responsive genes in Tibetan hulless barley.

Xingquan Zeng,Yawei Tang,Zexiu Wei,Tashi Nyima,Qijun Xu,Lijun Bai,Hongjun Yuan,Yulin Wang

doi:10.1186/s12864-016-2685-3

Abstract

BackgroundHulless barley, also called naked barley, is an important cereal crop worldwide, serving as a healthy food both for human consumption and animal feed. Nevertheless, it often suffered from drought stress during its growth and development, resulting in a drastic reduction in barley yields. Therefore, study on molecular mechanism of hulless barley drought-tolerance is very important for increasing barley production. To investigate molecular mechanism of barley drought-resistance, this study examined co-regulated mRNAs that show a change in expression pattern under early well water, later water deficit and finally water recovery treatments, and to identify mRNAs specific to water limiting conditions.ResultsTotal of 853 differentially expressed genes (DEGs) were detected and categorized into nine clusters, in which VI and VIII were apparently up-regulated under low relative soil moisture content (RSMC) level. The majority of genes in these two clusters was relevant to abiotic stress responses in abscisic acid (ABA) dependent and independent signaling pathway, including NCED, PYR/PYL/RCAR, SnRK2, ABF, MYB/MYC, AP2/ERF family, LEA and DHN. In contrast, genes within clusters II and IV were generally down-regulated under water stress; cluster IX genes were up-regulated during water recovery response to both low and high RSMC levels. Genes in implicated in tetrapyrrole binding, photosystem and photosynthetic membrane were the most affected in cluster IX.ConclusionTaken together, our findings indicate that the responses of hulless barley to drought stress shows differences in the pathways and genes activated. Furthermore, all these genes displayed different sensitivities to soil water deficit and might be profitable for future drought tolerance improvement in barley and other crops.Electronic supplementary materialThe online version of this article (doi:10.1186/s12864-016-2685-3) contains supplementary material, which is available to authorized users.

Highlights

Hulless barley, called naked barley, is an important cereal crop worldwide, serving as a healthy food both for human consumption and animal feed
Analysis of transcriptome-seq data In the present study, cDNA libraries were constructed from leaves harvested at eight days after drought stress and during rehydration with three biological replicates, and sequenced using the Illumina HiSeqTM 2000 platform
In summary, this study provided a comprehensive analysis of drought-responsive genes and transcriptome expression profiles of Tibetan hulless barley leaves by combined DGE, RNA-seq, and computational approaches

Summary

Introduction

Called naked barley, is an important cereal crop worldwide, serving as a healthy food both for human consumption and animal feed. It often suffered from drought stress during its growth and development, resulting in a drastic reduction in barley yields. With caryopses that thresh free from the pales, hulless (naked) barley provides an attractive advantage for the human consumption [1]. It is cultivated in the valleys and in the higher land on Tibet. ABA treatment influences the expression of drought response genes [19]

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Conclusion