Apple chlorotic leaf spot virus 50 kDa movement protein acts as a suppressor of systemic silencing without interfering with local silencing in Nicotiana benthamiana.
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.
Yaegashi
Hajime
H
The United Graduate School of Agricultural Sciences, Iwate University, Morioka 020-8550, Japan.
Takahashi
Tsubasa
T
The 21st Century Center of Excellence Program, Iwate University, Morioka 020-8550, Japan.
Isogai
Masamichi
M
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.
Kobori
Takashi
T
Kyoto Prefectural Institute of Agricultural Biotechnology, Soraku-gun, Kyoto 619-0244, Japan.
Ohki
Satoshi
S
Graduate School of Life and Environmental Sciences, University of Osaka Prefecture, Sakai 599-8531, Japan.
Yoshikawa
Nobu
N
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.
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
D008164:Luminescent Proteins; D053830:Plant Viral Movement Proteins; D014764:Viral Proteins