title: High-throughput sequencing and degradome analysis reveal altered expression of miRNAs and their targets in a male-sterile cybrid pummelo (Citrus grandis).
abstract: G1 + HBP is a male sterile cybrid line with nuclear genome from Hirado Buntan pummelo (C. grandis Osbeck) (HBP) and mitochondrial genome from "Guoqing No.1" (G1, Satsuma mandarin), which provides a good opportunity to study male sterility and nuclear-cytoplasmic cross talk in citrus. High-throughput sRNA and degradome sequencing were applied to identify miRNAs and their targets in G1 + HBP and its fertile type HBP during reproductive development.
  
  
  
  A total of 184 known miRNAs, 22 novel miRNAs and 86 target genes were identified. Some of the targets are transcription factors involved in floral development, such as auxin response factors (ARFs), SQUAMOSA promoter binding protein box (SBP-box), MYB, basic region-leucine zipper (bZIP), APETALA2 (AP2) and transport inhibitor response 1 (TIR1). Eight target genes were confirmed to be sliced by corresponding miRNAs using 5' RACE technology. Based on the sequencing abundance, 42 differentially expressed miRNAs between sterile line G1 + HBP and fertile line HBP were identified. Differential expression of miRNAs and their target genes between two lines was validated by quantitative RT-PCR, and reciprocal expression patterns between some miRNAs and their targets were demonstrated. The regulatory mechanism of miR167a was investigated by yeast one-hybrid and dual-luciferase assays that one dehydrate responsive element binding (DREB) transcription factor binds to miR167a promoter and transcriptionally repress miR167 expression.
  
  
  
  Our study reveals the altered expression of miRNAs and their target genes in a male sterile line of pummelo and highlights that miRNA regulatory network may be involved in floral bud development and cytoplasmic male sterility in citrus.
authors: Key Laboratory of Horticultural Plant Biology of Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China.
authors: Yan-Ni
authors: YN
authors: Fang
authors: Key Laboratory of Horticultural Plant Biology of Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China.
authors: Bei-Bei
authors: BB
authors: Zheng
authors: Key Laboratory of Horticultural Plant Biology of Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China.
authors: Lun
authors: L
authors: Wang
authors: Key Laboratory of Horticultural Plant Biology of Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China.
authors: Wei
authors: W
authors: Yang
authors: Key Laboratory of Horticultural Plant Biology of Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China.
authors: Xiao-Meng
authors: XM
authors: Wu
authors: Key Laboratory of Horticultural Plant Biology of Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China.
authors: Qiang
authors: Q
authors: Xu
authors: Key Laboratory of Horticultural Plant Biology of Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China. guoww@mail.hzau.edu.cn.
authors: Wen-Wu
authors: WW
authors: Guo
mesh_terms: D002874:Chromosome Mapping; D032461:Chromosomes, Plant; D002957:Citrus / Q000235:genetics*; D016000:Cluster Analysis; D019295:Computational Biology / Q000379:methods; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D035683:MicroRNAs / Q000235:genetics*; D010641:Phenotype; D051479:Plant Infertility / Q000235:genetics*; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D034622:RNA Interference; D012333:RNA, Messenger / Q000235:genetics*; D014157:Transcription Factors / Q000378:metabolism
chemical_list: D035683:MicroRNAs; D012333:RNA, Messenger; D014157:Transcription Factors
keywords: CMS; Citrus; Degradome; High-throughput sRNA sequencing; miRNA