title: Specific down-regulation of PAL genes by artificial microRNAs in Populus trichocarpa.
abstract: Artificial microRNAs (amiRNAs) are similar to microRNAs (miRNAs) in that they are able to reduce the abundance of specific transcripts in plants by RNA-Induced Silencing Complex (RISC)-mediated cleavage and degradation, but differ in that they are designed for specific targets. The long generation times of forest trees have limited the discovery of mutations by conventional genetics. AmiRNAs can create gene-specific transcript reduction in transgenic trees in a single generation and may have broad application for functional genomics of trees. In this paper, we describe the specific down-regulation of multiple genes in the phenylalanine ammonia-lyase (PAL) gene family of Populus trichocarpa using amiRNA sequences incorporated in a P. trichocarpa miRNA-producing precursor, ptc-MIR408. Two different amiRNA constructs were designed to specifically down-regulate two different subsets of PAL genes, revealing differential regulation within the gene family. Down-regulation of subset A (PAL2, PAL4 and PAL5) by amiRNA-palA led to an increase in transcript abundance of subset B (PAL1 and PAL3). The reciprocal effect was not observed.
authors: Forest Biotechnology Group, Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, NC 27695, USA. rshi@ncsu.edu
authors: Rui
authors: R
authors: Shi
authors: Chenmin
authors: C
authors: Yang
authors: Shanfa
authors: S
authors: Lu
authors: Ronald
authors: R
authors: Sederoff
authors: Vincent L
authors: VL
authors: Chiang
mesh_terms: D001483:Base Sequence; D017931:DNA Primers; D015536:Down-Regulation; D017343:Genes, Plant; D035683:MicroRNAs / Q000502:physiology*; D009154:Mutation; D032107:Populus / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012689:Sequence Homology, Nucleic Acid
chemical_list: D017931:DNA Primers; D035683:MicroRNAs