title: Genome-wide analysis reveals dynamic changes in expression of microRNAs during vascular cambium development in Chinese fir, Cunninghamia lanceolata.
abstract: MicroRNAs (miRNAs) are small noncoding regulatory RNAs that play key roles in the process of plant development. To date, extensive studies of miRNAs have been performed in a few model plants, but few efforts have focused on small RNAs (sRNAs) in conifers because of the lack of reference sequences for their enormous genomes. In this study, Solexa sequencing of three sRNA libraries obtained from dormant, reactivating, and active vascular cambium in Chinese ﬁr (Cunninghamia lanceolata) using tangential cryosectioning identified 20 known miRNA families and 18 novel potential miRNAs, of which nine novel miRNA precursors were validated by RT-PCR and sequencing. More than half of these novel miRNAs displayed stage-specific expression patterns in the vascular cambium. Furthermore, analysing the 103 miRNAs and their predicted targets indicated that about 70% appeared to negatively regulate their targets, of which two target genes involved in the regulation of cambial cell division were validated via RNA ligase-mediated rapid amplification of 5'-cDNA ends (RLM 5'-RACE) and transient co-expression in Nicotiana benthamiana leaves. Interestingly, miRNA156 and miRNA172 may regulate the phase transition in vascular cambium from dormancy to active growth. These results provide new insights into the important regulatory functions of miRNAs in vascular cambium development and wood formation in conifers.
authors: College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China College of Life Sciences, Henan Normal University, Xinxiang 453007, China Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
authors: Zongbo
authors: Z
authors: Qiu
authors: College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China.
authors: Xiaojuan
authors: X
authors: Li
authors: College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China.
authors: Yuanyuan
authors: Y
authors: Zhao
authors: College of Life Sciences, Henan Normal University, Xinxiang 453007, China.
authors: Manman
authors: M
authors: Zhang
authors: College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China.
authors: Yinglang
authors: Y
authors: Wan
authors: College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China.
authors: Dechang
authors: D
authors: Cao
authors: Medicinal Plant Cultivation Research Centre, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100193, China.
authors: Shanfa
authors: S
authors: Lu
authors: College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China linjinxing@bjfu.edu.cn.
authors: Jinxing
authors: J
authors: Lin
mesh_terms: D001483:Base Sequence; D058506:Cambium / Q000235:genetics / Q000254:growth & development; D032486:Cunninghamia / Q000235:genetics* / Q000254:growth & development; D015870:Gene Expression; D018506:Gene Expression Regulation, Plant; D015723:Gene Library; D059014:High-Throughput Nucleotide Sequencing; D035683:MicroRNAs / Q000737:chemistry / Q000235:genetics*; D008969:Molecular Sequence Data; D009928:Organ Specificity; D010802:Phylogeny; D018515:Plant Leaves / Q000235:genetics / Q000254:growth & development; D018749:RNA, Plant / Q000737:chemistry / Q000235:genetics; D058727:RNA, Small Untranslated / Q000737:chemistry / Q000235:genetics; D017423:Sequence Analysis, RNA; D014026:Nicotiana / Q000235:genetics / Q000254:growth & development
chemical_list: D035683:MicroRNAs; D018749:RNA, Plant; D058727:RNA, Small Untranslated
keywords: Chinese fir (Cunninghamia lanceolata); high-throughput small RNA sequencing; microRNA; vascular cambium; wood formation.