title: Differential microRNA Analysis of Glandular Trichomes and Young Leaves in Xanthium strumarium L. Reveals Their Putative Roles in Regulating Terpenoid Biosynthesis.
abstract: The medicinal plant Xanthium strumarium L. (X. strumarium) is covered with glandular trichomes, which are the sites for synthesizing pharmacologically active terpenoids such as xanthatin. MicroRNAs (miRNAs) are a class of 21-24 nucleotide (nt) non-coding RNAs, most of which are identified as regulators of plant growth development. Identification of miRNAs involved in the biosynthesis of plant secondary metabolites remains limited. In this study, high-throughput Illumina sequencing, combined with target gene prediction, was performed to discover novel and conserved miRNAs with potential roles in regulating terpenoid biosynthesis in X. strumarium glandular trichomes. Two small RNA libraries from leaves and glandular trichomes of X. strumarium were established. In total, 1,185 conserved miRNAs and 37 novel miRNAs were identified, with 494 conserved miRNAs and 18 novel miRNAs being differentially expressed between the two tissue sources. Based on the X. strumarium transcriptome data that we recently constructed, 3,307 annotated mRNA transcripts were identified as putative targets of the differentially expressed miRNAs. KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway analysis suggested that some of the differentially expressed miRNAs, including miR6435, miR5021 and miR1134, might be involved in terpenoid biosynthesis in the X. strumarium glandular trichomes. This study provides the first comprehensive analysis of miRNAs in X. strumarium, which forms the basis for further understanding of miRNA-based regulation on terpenoid biosynthesis.
authors.affiliation: CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, China, 430074; Graduate University of Chinese Academy of Sciences, Beijing, China, 100049.
authors.forename: Rongyan
authors.initials: R
authors.lastname: Fan
authors.affiliation: CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, China, 430074; Graduate University of Chinese Academy of Sciences, Beijing, China, 100049.
authors.forename: Yuanjun
authors.initials: Y
authors.lastname: Li
authors.affiliation: CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, China, 430074.
authors.forename: Changfu
authors.initials: C
authors.lastname: Li
authors.affiliation: CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, China, 430074.
authors.forename: Yansheng
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D017124:Conserved Sequence / Q000235:genetics; D018506:Gene Expression Regulation, Plant / Q000502:physiology; D063990:Gene Ontology; D059014:High-Throughput Nucleotide Sequencing; D035683:MicroRNAs / Q000032:analysis / Q000235:genetics / Q000502:physiology*; D018515:Plant Leaves / Q000737:chemistry / Q000378:metabolism*; D018749:RNA, Plant / Q000032:analysis / Q000235:genetics / Q000502:physiology; D013729:Terpenes / Q000032:analysis / Q000378:metabolism*; D064201:Trichomes / Q000737:chemistry / Q000378:metabolism*; D031210:Xanthium / Q000235:genetics / Q000378:metabolism* / Q000502:physiology
chemical_list: D035683:MicroRNAs; D018749:RNA, Plant; D013729:Terpenes