ORIGINAL ARTICLE miRNA-based drought regulation in wheat Guray Akdogan 1 & Ebru Derelli Tufekci 1,2 & Serkan Uranbey 1 & Turgay Unver 2 Received: 2 March 2015 /Revised: 20 June 2015 /Accepted: 23 June 2015 # Springer-Verlag Berlin Heidelberg 2015 Abstract MicroRNAs (miRNAs) are a class of small non- coding regulatory RNAs that regulate gene expression by guiding target mRNA cleavage or translational inhibition. Drought is a common environmental stress influencing crop growth and development. To date, it has been reported that a number of plant miRNA are involved in drought stress re- sponse. In this study, we comparatively investigated drought stress-responsive miRNAs in the root and leaf of bread wheat (Triticum aestivum cv. Sivas 111/33) by miRNA microarray screening. miRNA microarray analysis showed that 285 miRNAs (207 upregulated and 78 downregulated) and 244 miRNAs (115 upregulated and 129 downregulated) were dif- ferentially expressed in leaf and root tissues, respectively. Among the differentially expressed miRNAs, 23 miRNAs were only expressed in the leaf and 26 miRNAs were only expressed in the root of wheat growth under drought stress. Upon drought treatment, expression of miR159, miR160, miR166, miR169, miR172, miR395, miR396, miR408, miR472, miR477, miR482, miR1858, miR2118, and miR5049 were found to be significantly differentiated in bread wheat. The regulatory network analysis showed that miR395 has connections with a number of target transcripts, and miR159 and miR319 share a number of target genes. Drought-tolerant and drought-sensitive wheat cultivars showed altered expression pattern upon drought stress in terms of investigated miRNA and their target transcript ex- pression level. Keywords Drought stress . microRNA . Microarray . Triticum aestivum Introduction Hexaploid bread wheat (Triticum aestivum L., AABBDD, 2n=42) is one of the main staple crops. Together with maize and rice, wheat provides >60 % of the average daily diet for humans (faostat.fao.org). Crop species including wheat are challenged by several biotic and abiotic factors affecting ag- ronomic production (Xin et al. 2010; Pandey et al. 2014). Moreover, several abiotic stress factors such as droughts, floods, and salinity become more common as a result of global climate change (Shanker et al. 2014). Drought negatively affects vegetative and reproductive plant development causing severe reductions in plant produc- tivity. Additionally, it can cause a series of physiological and biochemical changes in plants (Wu et al. 2014; Li et al. 2015; Zhang 2015). To cope with the challenging aspects of drought, plants use several mechanisms and produce response at phys- iological and molecular levels (Shiriga et al. 2014). Plant microRNAs (miRNAs) are a highly conserved class of small (21–24 nucleotides), non-coding RNAs that regulate gene expression by post-transcriptional degradation or trans- lational repression (Liu et al. 2008; Unver et al. 2009; Eldem et al. 2013; Zhang 2015). miRNAs have emerged as important players in post-transcriptional gene regulation. After discovery of miRNAs as a post-transcriptional regulator, it has led to the understanding of the expression behavior of Electronic supplementary material The online version of this article (doi:10.1007/s10142-015-0452-1) contains supplementary material, which is available to authorized users. * Turgay Unver turgayunver@gmail.com 1 Department of Field Crops, Faculty of Agriculture, Ankara University, 06110 Ankara, Turkey 2 Department of Biology, Faculty of Science, Çankırı Karatekin University, 18100 Çankırı, Turkey Funct Integr Genomics DOI 10.1007/s10142-015-0452-1