Research Article miR319, miR390, and miR393 Are Involved in Aluminum Response in Flax (Linum usitatissimum L.) Alexey A. Dmitriev, 1 Anna V. Kudryavtseva, 1 Nadezhda L. Bolsheva, 1 Alexander V. Zyablitsin, 1 Tatiana A. Rozhmina, 1,2 Natalya V. Kishlyan, 2 George S. Krasnov, 1 Anna S. Speranskaya, 1,3 Anastasia A. Krinitsina, 3 Asiya F. Sadritdinova, 1 Anastasiya V. Snezhkina, 1 Maria S. Fedorova, 1 Olga Yu. Yurkevich, 1 Olga V. Muravenko, 1 Maxim S. Belenikin, 1,3 and Nataliya V. Melnikova 1 1 Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow 119991, Russia 2 All-Russian Research Institute for Flax, Torzhok 172002, Russia 3 Faculty of Biology, Lomonosov Moscow State University, Moscow 119991, Russia Correspondence should be addressed to Nataliya V. Melnikova; mnv-4529264@yandex.ru Received 23 September 2016; Revised 6 January 2017; Accepted 29 January 2017; Published 19 February 2017 Academic Editor: Xiaobai Li Copyright © 2017 Alexey A. Dmitriev et al. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Acid soils limit agricultural production worldwide. Major reason of crop losses in acid soils is the toxicity of aluminum (Al). In the present work, we investigated expression alterations of microRNAs in fax (Linum usitatissimum L.) plants under Al stress. Flax seedlings of resistant (TMP1919 and G1071/4 k) and sensitive (Lira and G1071/4 o) to Al cultivars and lines were exposed to AlCl 3 solution for 4 and 24 hours. Twelve small RNA libraries were constructed and sequenced using Illumina platform. In total, 97 microRNAs from 18 conserved families were identifed. miR319, miR390, and miR393 revealed expression alterations associated with Al treatment of fax plants. Moreover, for miR390 and miR393, the alterations were distinct in sensitive and resistant to Al genotypes. Expression level changes of miR319 and miR390 were confrmed using qPCR analysis. In fax, potential targets of miR319 are TCPs, miR390–TAS3 and GRF5, and miR393–AFB2-coding transcripts. TCPs, TAS3, GRF5, and AFB2 participate in regulation of plant growth and development. Te involvement of miR319, miR390, and miR393 in response to Al stress in fax was shown here for the frst time. We speculate that these microRNAs play an important role in Al response via regulation of growth processes in fax plants. 1. Introduction Acid soils result in decrease of agricultural production all over the world [1]. Toxicity of aluminum (Al) is a major reason of crop losses in acid soils [2]. Diferent mechanisms of plant response to Al stress were identifed: organic acid exudation by roots to chelate Al ions in soil, detoxifcation of Al in plants via chelation or transportation into the vacuole, modifcations of cell wall to alter Al binding with its components, and so forth [3–5]. MicroRNA (miRNA) negatively regulates gene expres- sion and in this way controls numerous biological processes in plants [6], including stress response [7–9]. Gene expression regulation via miRNA was revealed as one of the mechanisms of response to Al in diferent plant species [10–12]. However, there is no data on involvement of miRNAs in response to Al stress in important agricultural plant, fax (Linum usitatissimum L.). Flax fber is utilized in textile industry; fax seeds are used for production of oil, linoleum, food, and pharmaceutical products [13–15]. Flax genetics and epigenetics are in the focus of research interest [16–20]. In the previous works on fax, the involvement of miRNAs in response to saline and alkaline stresses [21] and excessive or defcient nutrition [22–24] was shown. Hindawi BioMed Research International Volume 2017, Article ID 4975146, 6 pages https://doi.org/10.1155/2017/4975146