title: Virus-mediated efficient induction of epigenetic modifications of endogenous genes with phenotypic changes in plants.
abstract: Gene silencing through transcriptional repression can be induced by targeting double-stranded RNA (dsRNA) to a gene promoter. It has been reported that a transgene was silenced by targeting dsRNA to the promoter, and the silenced state was inherited to the progeny plant even after removal of the silencing inducer from cells. In contrast, no plant has been produced that harbors silenced endogenous gene after removal of promoter-targeting dsRNA. Here, we show that heritable gene silencing can be induced by targeting dsRNA to the endogenous gene promoters in petunia and tomato plants, using the Cucumber mosaic virus (CMV)-based vector. We found that efficient silencing of endogenous genes depends on the function of the 2b protein encoded in the vector virus, which has the ability to facilitate epigenetic modifications through the transport of short interfering RNA to nucleus. Bisulfite sequencing analyses on the targeted promoter in the virus-infected and its progeny plants revealed that cytosine methylation was found not only at CG or CNG but also at CNN sites. The observed inheritance of asymmetric DNA methylation is quite unique, suggesting that plants have a mechanism to maintain even asymmetric methylation. This CMV-based gene silencing system provides a useful tool to artificially modify DNA methylation in plant genomes and elucidate the mechanism for epigenetic controls.
authors.affiliation: Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Kanazawa
authors.affiliation: Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan.
authors.forename: Jun-Ichi
authors.initials: JI
authors.lastname: Inaba
authors.affiliation: Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan.
authors.forename: Hanako
authors.initials: H
authors.lastname: Shimura
authors.affiliation: Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan.
authors.forename: Shungo
authors.initials: S
authors.lastname: Otagaki
authors.affiliation: Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan.
authors.forename: Sayuri
authors.initials: S
authors.lastname: Tsukahara
authors.affiliation: Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Matsuzawa
authors.affiliation: Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan.
authors.forename: Bo Min
authors.initials: BM
authors.lastname: Kim
authors.affiliation: Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan.
authors.forename: Kazunori
authors.initials: K
authors.lastname: Goto
authors.affiliation: Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan.
authors.forename: Chikara
authors.initials: C
authors.lastname: Masuta
mesh_terms: D017799:Cucumovirus / Q000235:genetics*; D019175:DNA Methylation; D035264:Flowers / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D020868:Gene Silencing / Q000502:physiology*; D005822:Genetic Vectors / Q000235:genetics*; D032306:Petunia / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D011058:Pollen / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D012330:RNA, Double-Stranded / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics
chemical_list: D012330:RNA, Double-Stranded; D034741:RNA, Small Interfering