title: A mobile signal transported over a long distance induces systemic transcriptional gene silencing in a grafted partner.
abstract: Transcriptional gene silencing (TGS) can be induced by promoter-targeted small interfering RNA (siRNA). Long-distance transmission of TGS by viral infection in plants has been reported. However, systemic TGS has not been observed in the case of using an inverted repeat transgene as the silencing trigger. Here it is reported that a mobile signal, presumably the siRNA, produced from a hairpin structure transgene controlled by a companion cell-specific promoter can also induce transmissible TGS in both a modified agroinfiltration and a grafting system. Although the transmissible TGS occurred only in cells located in the vicinity of a leaf vein in the scion, very strong silencing was observed in the root system, especially the lateral roots, including the root apical meristem. The transmissible TGS was maintained through tissue culture and subsequently inherited by the progeny. The results suggest the potential application of mobile promoter-targeting siRNA in horticulture for improvement of plant cultivars by grafting.
authors.affiliation: Faculty of Agriculture and Life Science, Hirosaki University, Hirosaki 036-8561, Japan.
authors.forename: Songling
authors.initials: S
authors.lastname: Bai
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kasai
authors.forename: Kaori
authors.initials: K
authors.lastname: Yamada
authors.forename: Tianzhong
authors.initials: T
authors.lastname: Li
authors.forename: Takeo
authors.initials: T
authors.lastname: Harada
mesh_terms: D060054:Agrobacterium / Q000378:metabolism; D019175:DNA Methylation; D018506:Gene Expression Regulation, Plant; D020868:Gene Silencing; D049452:Green Fluorescent Proteins / Q000378:metabolism; D018515:Plant Leaves / Q000235:genetics; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic / Q000235:genetics; D034741:RNA, Small Interfering / Q000378:metabolism; D012038:Regeneration / Q000502:physiology; D015398:Signal Transduction / Q000235:genetics*; D014026:Nicotiana / Q000235:genetics*; D014158:Transcription, Genetic
chemical_list: D034741:RNA, Small Interfering; D049452:Green Fluorescent Proteins