An inhibitor of viral RNA replication is encoded by a plant resistance gene.
The tomato Tm-1 gene confers resistance to tomato mosaic virus (ToMV). Here, we report that the extracts of Tm-1 tomato cells (GCR237) have properties that inhibit the in vitro RNA replication of WT ToMV more strongly than that of the Tm-1-resistance-breaking mutant of ToMV, LT1. We purified this inhibitory activity and identified a polypeptide of approximately 80 kDa (p80(GCR237)) using LC-tandem MS. The amino acid sequence of p80(GCR237) had no similarity to any characterized proteins. The p80(GCR237) gene cosegregated with Tm-1; transgenic expression of p80(GCR237) conferred resistance to ToMV within tomato plants; and the knockdown of p80(GCR237) sensitized Tm-1 tomato plants to ToMV, indicating that Tm-1 encodes p80(GCR237) itself. We further show that in vitro-synthesized Tm-1 (p80(GCR237)) protein binds to the replication proteins of WT ToMV and inhibits their function at a step before, but not after, the viral replication complex is formed on the membrane surfaces. Such binding was not observed for the replication proteins of LT1. These results suggest that Tm-1 (p80(GCR237)) inhibits the replication of WT ToMV RNA through binding to the replication proteins.
Ishibashi
Kazuhiro
K
Division of Plant Sciences, National Institute of Agrobiological Sciences, Tsukuba 305-8602, Japan. ishika32@affrc.go.jp
Masuda
Kiyoshi
K
Naito
Satoshi
S
Meshi
Tetsuo
T
Ishikawa
Masayuki
M
D002457:Cell Extracts; D002460:Cell Line; D017343:Genes, Plant / Q000235:genetics*; D018551:Solanum lycopersicum / Q000235:genetics* / Q000378:metabolism / Q000821:virology*; D008969:Molecular Sequence Data; D010935:Plant Diseases / Q000235:genetics* / Q000821:virology*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D012367:RNA, Viral / Q000096:biosynthesis* / Q000235:genetics; D014779:Virus Replication / Q000235:genetics*
D002457:Cell Extracts; D010940:Plant Proteins; D012367:RNA, Viral
Plant Cell. 1993 Aug;5(8):913-920
12271089
Annu Rev Phytopathol. 2005;43:581-621
16078896
Theor Appl Genet. 1990 Nov;80(5):602-8
24221065
Plant Cell. 2000 Apr;12(4):569-82
10760245
Plant J. 2002 Sep;31(6):777-86
12220268
J Gen Virol. 1976 Aug;32(2):311-4
14223
Virology. 2005 Nov 10;342(1):150-8
16122776
Arch Virol. 2007;152(5):903-14
17238011
Virology. 1991 Jul;183(1):106-13
2053275
J Virol. 1996 Sep;70(9):6227-34
8709249
J Virol. 1993 Sep;67(9):5328-38
8350399
Plant J. 1998 Jan;13(2):211-9
9680977
Genes Cells. 2007 Feb;12(2):133-42
17295834
Proc Natl Acad Sci U S A. 2004 Feb 17;101(7):1863-7
14769932
EMBO J. 2003 Jan 15;22(2):344-53
12514140
J Biochem. 1984 Dec;96(6):1915-23
6549393
Plant Cell. 1999 May;11(5):781-92
10330465
J Mol Biol. 2002 Aug 30;321(5):741-65
12206759
Virology. 1987 Dec;161(2):527-32
3686829
J Gen Virol. 1997 Feb;78 ( Pt 2):461-4
9018069
Mol Gen Genet. 1991 Nov;230(1-2):33-8
1745239
EMBO J. 1988 Jun;7(6):1575-81
16453849
Genetics. 1992 Dec;132(4):1141-60
1360934
Virology. 1991 Jul;183(1):99-105
2053299
Plant Cell Physiol. 2006 Mar;47(3):426-31
16381658
Mol Plant Pathol. 2004 May 1;5(3):223-33
20565612
Theor Appl Genet. 1996 Feb;92(2):151-6
24166161
Proc Natl Acad Sci U S A. 2000 Jan 4;97(1):489-94
10618445
Plant J. 1998 Apr;14(2):177-86
9628015
Proc Natl Acad Sci U S A. 2007 Feb 27;104(9):3129-34
17360619
J Virol. 2006 Sep;80(17):8459-68
16912296
J Virol. 2007 Mar;81(6):2584-91
17108048