title: Identification of aluminum-responsive microRNAs in Medicago truncatula by genome-wide high-throughput sequencing.
abstract: MicroRNAs (miRNAs) play important roles in response of plants to biotic and abiotic stresses. Aluminum (Al) toxicity is a major factor limiting plant growth in acidic soils. However, there has been limited report on the involvement of miRNAs in response of plants to toxic Al(3+). To identify Al(3+)-responsive miRNAs at whole-genome level, high-throughput sequencing technology was used to sequence libraries constructed from root apices of the model legume plant Medicago truncatula treated with and without Al(3+). High-throughput sequencing of the control and two Al(3+)-treated libraries led to generation of 17.1, 14.1 and 17.4 M primary reads, respectively. We identified 326 known miRNAs and 21 new miRNAs. Among the miRNAs, expression of 23 miRNAs was responsive to Al(3+), and the majority of Al(3+)-responsive mRNAs was down-regulated. We further classified the Al(3+)-responsive miRNAs into three groups based on their expression patterns: rapid-responsive, late-responsive and sustained-responsive miRNAs. The majority of Al(3+)-responsive miRNAs belonged to the 'rapid-responsive' category, i.e. they were responsive to short-term, but not long-term Al(3+) treatment. The Al(3+)-responsive miRNAs were also verified by quantitative real-time PCR. The potential targets of the 21 new miRNAs were predicted to be involved in diverse cellular processes in plants, and their potential roles in Al(3+)-induced inhibition of root growth were discussed. These findings provide valuable information for functional characterization of miRNAs in Al(3+) toxicity and tolerance.
authors: State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, The Chinese Academy of Sciences, Beijing 100093, People's Republic of China.
authors: Lei
authors: L
authors: Chen
authors: Tianzuo
authors: T
authors: Wang
authors: Mingui
authors: M
authors: Zhao
authors: Qiuying
authors: Q
authors: Tian
authors: Wen-Hao
authors: WH
authors: Zhang
mesh_terms: D000535:Aluminum / Q000378:metabolism; D000077410:Aluminum Chloride; D017607:Aluminum Compounds / Q000494:pharmacology*; D002712:Chlorides / Q000494:pharmacology*; D018506:Gene Expression Regulation, Plant; D015723:Gene Library; D018745:Genome, Plant; D059014:High-Throughput Nucleotide Sequencing / Q000379:methods; D046913:Medicago truncatula / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D035683:MicroRNAs / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D009690:Nucleic Acid Conformation; D018517:Plant Roots / Q000187:drug effects / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D012322:RNA Precursors / Q000235:genetics / Q000378:metabolism; D018749:RNA, Plant / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D017607:Aluminum Compounds; D002712:Chlorides; D035683:MicroRNAs; D012322:RNA Precursors; D018749:RNA, Plant; D000077410:Aluminum Chloride; D000535:Aluminum