title: RNA silencing systems and their relevance to plant development.
abstract: RNA silencing refers to a broad range of phenomena sharing the common feature that large, double-stranded RNAs or stem-loop precursors are processed to ca. 21-26 nucleotide small RNAs, which then guide the cleavage of cognate RNAs, block productive translation of these RNAs, or induce methylation of specific target DNAs. Although the core mechanisms are evolutionarily conserved, epigenetic maintenance of silencing by amplification of small RNAs and the elaboration of mobile, RNA-based silencing signals occur predominantly in plants. Plant RNA silencing systems are organized into a network with shared components and overlapping functions. MicroRNAs, and probably trans-acting small RNAs, help regulate development at the posttranscriptional level. Small interfering RNAs associated with transgene- and virus-induced silencing function primarily in defending against foreign nucleic acids. Another system, which is concerned with RNA-directed methylation of DNA repeats, seems to have roles in epigenetic silencing of certain transposable elements and genes under their control.
authors.affiliation: Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, CH-4058, Basel, Switzerland. meins@fmi.ch
authors.forename: Frederick
authors.initials: F
authors.lastname: Meins
authors.forename: Azeddine
authors.initials: A
authors.lastname: Si-Ammour
authors.forename: Todd
authors.initials: T
authors.lastname: Blevins
mesh_terms: D019175:DNA Methylation; D020868:Gene Silencing; D008957:Models, Genetic; D063245:Plant Development; D010944:Plants / Q000235:genetics*; D034622:RNA Interference; D018749:RNA, Plant / Q000235:genetics*; D034741:RNA, Small Interfering / Q000235:genetics / Q000502:physiology
chemical_list: D018749:RNA, Plant; D034741:RNA, Small Interfering