title: Apple chlorotic leaf spot virus 50 kDa movement protein acts as a suppressor of systemic silencing without interfering with local silencing in Nicotiana benthamiana.
abstract: Apple chlorotic leaf spot virus (ACLSV) is the type species of the genus Trichovirus and its single-stranded, plus-sense RNA genome encodes a 216 kDa protein (P216) involved in replication, a 50 kDa movement protein (P50) and a 21 kDa coat protein (CP). In this study, it was investigated whether these proteins might have RNA silencing-suppressor activities by Agrobacterium-mediated transient assay in the green fluorescent protein-expressing Nicotiana benthamiana line 16c. The results indicated that none of these proteins could suppress local silencing in infiltrated leaves. However, systemic silencing in upper leaves induced by both single- and double-stranded RNA could be suppressed by P50, but not by a frame-shift mutant of P50, P216 or CP. Moreover, when P50 was expressed separately from where silencing signals were generated in a leaf, systemic silencing in upper leaves was inhibited. Collectively, our data indicate that P50 acts as a suppressor of systemic silencing without interfering with local silencing, probably by inhibiting the movement of silencing signals.
authors.affiliation: The United Graduate School of Agricultural Sciences, Iwate University, Morioka 020-8550, Japan.
authors.forename: Hajime
authors.initials: H
authors.lastname: Yaegashi
authors.affiliation: The 21st Century Center of Excellence Program, Iwate University, Morioka 020-8550, Japan.
authors.forename: Tsubasa
authors.initials: T
authors.lastname: Takahashi
authors.affiliation: Plant Pathology Laboratory, Faculty of Agriculture, Iwate University, Morioka 020-8550, Japan.|The United Graduate School of Agricultural Sciences, Iwate University, Morioka 020-8550, Japan.
authors.forename: Masamichi
authors.initials: M
authors.lastname: Isogai
authors.affiliation: Kyoto Prefectural Institute of Agricultural Biotechnology, Soraku-gun, Kyoto 619-0244, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Kobori
authors.affiliation: Graduate School of Life and Environmental Sciences, University of Osaka Prefecture, Sakai 599-8531, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Ohki
authors.affiliation: Plant Pathology Laboratory, Faculty of Agriculture, Iwate University, Morioka 020-8550, Japan.|The 21st Century Center of Excellence Program, Iwate University, Morioka 020-8550, Japan.|The United Graduate School of Agricultural Sciences, Iwate University, Morioka 020-8550, Japan.
authors.forename: Nobu
authors.initials: N
authors.lastname: Yoshikawa
mesh_terms: D052677:Flexiviridae / Q000737:chemistry*; D008164:Luminescent Proteins / Q000032:analysis; D053830:Plant Viral Movement Proteins / Q000502:physiology*; D037941:Silencer Elements, Transcriptional / Q000502:physiology*; D013329:Structure-Activity Relationship; D014026:Nicotiana / Q000821:virology; D014764:Viral Proteins / Q000502:physiology
chemical_list: D008164:Luminescent Proteins; D053830:Plant Viral Movement Proteins; D014764:Viral Proteins