title: Small RNA and PARE sequencing in flower bud reveal the involvement of sRNAs in endodormancy release of Japanese pear (Pyrus pyrifolia 'Kosui').
abstract: BACKGROUND
  In woody perennial plants, including deciduous fruit trees, such as pear, endodormancy is a strategy for surviving the cold winter. A better understanding of the mechanism underlying the endodormancy phase transition is necessary for developing countermeasures against the effects of global warming. In this study, we analyzed the sRNAome of Japanese pear flower buds in endodormant and ecodormant stages over two seasons by implementing of RNA-seq and degradome-sequencing.
  
  
  RESULTS
  We identified 137 conserved or less conserved miRNAs and 50 pear-specific miRNAs. However, none of the conserved microRNAs or pear-specific miRNAs was differentially expressed between endodormancy and ecodormancy stages. On the contrast, 1540 of 218,050 loci that produced sRNAs were differentially expressed between endodormancy and ecodormancy, suggesting their potential roles on the phase transition from endodormancy to ecodomancy. We also characterized a multifunctional miRNA precursor MIR168, which produces two functional miR168 transcripts, namely miR168.1 and miR168.2; cleavage events were predominantly mediated by the non-conserved variant miR168.2 rather than the conserved variant miR168.1. Finally, we showed that a TAS3 trans-acting siRNA triggered phased siRNA within the ORF of one of its target genes, AUXIN RESPONSE FACTOR 4, via the analysis of phased siRNA loci, indicating that siRNAs are able to trigger phased siRNAs in pear.
  
  
  CONCLUSIONS
  We analyzed the sRNAome of pear flower bud during dormant phase transition. Our work described the sRNA profiles of pear winter buds during dormant phase transition, showing that dormancy release is a highly coordinated physiological process involving the regulation of sRNAs.
authors.affiliation: NARO Institute of Fruit Tree Science, Tsukuba, Ibaraki, 305-8605, Japan. songlingbai@zju.edu.cn.|Department of Horticulture, The State Agricultural Ministry's Key Laboratory of Horticultural Plant Growth, Development & Quality Improvement, Zhejiang University, Hangzhou, Zhejiang Province, 310058, China. songlingbai@zju.edu.cn.
authors.forename: Songling
authors.initials: S
authors.lastname: Bai
authors.affiliation: NARO Institute of Fruit Tree Science, Tsukuba, Ibaraki, 305-8605, Japan.|Present address: Graduate School of Horticulture, Chiba University, Matsudo-shi, Chiba, 271-8510, Japan.
authors.forename: Takanori
authors.initials: T
authors.lastname: Saito
authors.affiliation: NARO Institute of Fruit Tree Science, Tsukuba, Ibaraki, 305-8605, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Ito
authors.affiliation: NARO Institute of Fruit Tree Science, Tsukuba, Ibaraki, 305-8605, Japan.
authors.forename: Pham Anh
authors.initials: PA
authors.lastname: Tuan
authors.affiliation: Department of Horticulture, The State Agricultural Ministry's Key Laboratory of Horticultural Plant Growth, Development & Quality Improvement, Zhejiang University, Hangzhou, Zhejiang Province, 310058, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Department of Horticulture, The State Agricultural Ministry's Key Laboratory of Horticultural Plant Growth, Development & Quality Improvement, Zhejiang University, Hangzhou, Zhejiang Province, 310058, China.
authors.forename: Yuanwen
authors.initials: Y
authors.lastname: Teng
authors.affiliation: NARO Institute of Fruit Tree Science, Tsukuba, Ibaraki, 305-8605, Japan. takaya@affrc.go.jp.
authors.forename: Takaya
authors.initials: T
authors.lastname: Moriguchi
mesh_terms: D035264:Flowers / Q000235:genetics* / Q000254:growth & development; D018506:Gene Expression Regulation, Plant; D059014:High-Throughput Nucleotide Sequencing; D035683:MicroRNAs / Q000235:genetics*; D057445:Plant Dormancy / Q000235:genetics*; D031989:Pyrus / Q000235:genetics* / Q000254:growth & development; D018749:RNA, Plant / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics; D017423:Sequence Analysis, RNA
chemical_list: D035683:MicroRNAs; D018749:RNA, Plant; D034741:RNA, Small Interfering
keywords: Endodormancy; Flower bud; Japanese pear; PARE-seq; Small RNA; sRNA-seq