title: Genome-wide identification of different dormant Medicago sativa L. MicroRNAs in response to fall dormancy.
abstract: BACKGROUND
  MicroRNAs (miRNAs) are a class of regulatory small RNAs (sRNAs) that regulate gene post-transcriptional expression in plants and animals. High-throughput sequencing technology is capable of identifying small RNAs in plant species. Alfalfa (Medicago sativa L.) is one of the most widely cultivated perennial forage legumes worldwide, and fall dormancy is an adaptive characteristic related to the biomass production and winter survival in alfalfa. Here, we applied high-throughput sRNA sequencing to identify some miRNAs that were responsive to fall dormancy in standard variety (Maverick and CUF101) of alfalfa.
  
  
  RESULTS
  Four sRNA libraries were generated and sequenced from alfalfa leaves in two typical varieties at distinct seasons. Through integrative analysis, we identified 51 novel miRNA candidates of 206 families. Additionally, we identified 28 miRNAs associated with fall dormancy in standard variety (Maverick and CUF101), including 20 known miRNAs and eight novel miRNAs. Both high-throughput sequencing and RT-qPCR confirmed that eight known miRNA members were up-regulated and six known miRNA members were down-regulated in response to fall dormancy in standard variety (Maverick and CUF101). Among the 51 novel miRNA candidates, five miRNAs were up-regulated and three miRNAs were down-regulated in response to fall dormancy in standard variety (Maverick and CUF101), and five of them were confirmed by Northern blot analysis.
  
  
  CONCLUSIONS
  We identified 20 known miRNAs and eight new miRNA candidates that were responsive to fall dormancy in standard variety (Maverick and CUF101) by high-throughput sequencing of small RNAs from Medicago sativa. Our data provide a useful resource for investigating miRNA-mediated regulatory mechanisms of fall dormancy in alfalfa, and these findings are important for our understanding of the roles played by miRNAs in the response of plants to abiotic stress in general and fall dormancy in alfalfa.
authors.affiliation: College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, China.
authors.forename: Wenna
authors.initials: W
authors.lastname: Fan
authors.affiliation: College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, China.
authors.forename: Senhao
authors.initials: S
authors.lastname: Zhang
authors.affiliation: College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, China.
authors.forename: Hongqi
authors.initials: H
authors.lastname: Du
authors.affiliation: College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, China.
authors.forename: Xiaoge
authors.initials: X
authors.lastname: Sun
authors.affiliation: College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, China.
authors.forename: Yinghua
authors.initials: Y
authors.lastname: Shi
authors.affiliation: College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, China.
authors.forename: Chengzhang
authors.initials: C
authors.lastname: Wang
mesh_terms: D015870:Gene Expression; D018506:Gene Expression Regulation, Plant; D018745:Genome, Plant; D000455:Medicago sativa / Q000235:genetics* / Q000254:growth & development; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D058977:Molecular Sequence Annotation; D057445:Plant Dormancy / Q000235:genetics*; D018515:Plant Leaves / Q000235:genetics* / Q000254:growth & development; D018749:RNA, Plant / Q000235:genetics* / Q000378:metabolism; D012621:Seasons; D017423:Sequence Analysis, RNA
chemical_list: D035683:MicroRNAs; D018749:RNA, Plant