Fard Ehsan Mohseni, Bakhshi Behnam, Farsi Mohammad, Kakhki Amin Mirshamsi, Nikpay Nava, Ebrahimi Mohammad Ali, Mardi Mohsen, Salekdeh Ghasem Hosseini
Department of Systems Biology, Agricultural Biotechnology Research Institute of Iran, Agricultural Research, Education, and Extension Organization, Karaj, Tehran, Iran.
Mol Biosyst. 2017 Oct 24;13(11):2289-2302. doi: 10.1039/c7mb00298j.
MicroRNAs (miRNAs) are small endogenous regulatory RNAs that are involved in a variety of biological processes related to proliferation, development, and response to biotic and abiotic stresses. miRNA profiles of rice (Oryza sativa L. cv. IR64.) leaves in a partial root zone drying (PRD) system were analysed using a high-throughput sequencing approach to identify miRNAs associated with drought signalling. The treatments performed in this study were as follows: well-watered ("wet" roots, WW), wherein both halves of the pot were watered daily; drought ("dry" roots, DD), wherein water was withheld from both halves of the pot; and well-watered/drought ("wet" and "dry" roots, WD), wherein one half of each pot was watered daily, the same as in WW, and water was withheld from the other part, the same as in DD. High-throughput sequencing enabled us to detect novel miRNAs and study the differential expression of known miRNAs. A total of 209 novel miRNAs were detected in this study. Differential miRNA profiling of the DD, WD and WW conditions showed differential expression of 159 miRNAs, among which 83, 44 and 32 miRNAs showed differential expression under both DD and WD conditions. The detection of putative targets of the differentially expressed miRNAs and investigation of their functions showed that most of these genes encode transcription factors involved in growth and development, leaf morphology, regulation of hormonal homeostasis, and stress response. The most important differences between the DD and WD conditions involved regulation of the levels of hormones such as auxin, cytokinin, abscisic acid, and jasmonic acid and also regulation of phosphor homeostasis. Overall, differentially expressed miRNAs under WD conditions were found to differ from those under DD conditions, with such differences playing a role in adaptation and inducing the normal condition. The mechanisms involved in regulating hormonal homeostasis and involved in energy production and consumption were found to be the most important regulatory pathways distinguishing the DD and WD conditions.
微小RNA（miRNA）是一类内源性小调节RNA，参与多种与增殖、发育以及对生物和非生物胁迫的响应相关的生物学过程。利用高通量测序方法分析了部分根区干燥（PRD）系统中水稻（Oryza sativa L. cv. IR64.）叶片的miRNA谱，以鉴定与干旱信号相关的miRNA。本研究进行的处理如下：充分浇水（“湿”根，WW），即花盆的两半每天都浇水；干旱（“干”根，DD），即花盆的两半都不浇水；充分浇水/干旱（“湿”和“干”根，WD），即每个花盆的一半每天浇水，与WW相同，另一半不浇水，与DD相同。高通量测序使我们能够检测新的miRNA并研究已知miRNA的差异表达。本研究共检测到209个新的miRNA。DD、WD和WW条件下的差异miRNA谱显示159个miRNA存在差异表达，其中83、44和32个miRNA在DD和WD条件下均表现出差异表达。对差异表达miRNA的假定靶标的检测及其功能研究表明，这些基因中的大多数编码参与生长发育、叶片形态、激素稳态调节和应激反应的转录因子。DD和WD条件之间最重要的差异涉及生长素、细胞分裂素、脱落酸和茉莉酸等激素水平的调节以及磷稳态的调节。总体而言，发现WD条件下差异表达的miRNA与DD条件下的不同，这些差异在适应和诱导正常状态中发挥作用。调节激素稳态以及能量产生和消耗所涉及的机制被发现是区分DD和WD条件的最重要调节途径。
