Plant virus-mediated induction of miR168 is associated with repression of ARGONAUTE1 accumulation.
Virus infections induce the expression of ARGONAUTE1 (AGO1) mRNA and in parallel enhance the accumulation of miR168 (regulator of AGO1 mRNA). Here, we show that in virus-infected plants the enhanced expression of AGO1 mRNA is not accompanied by increased AGO1 protein accumulation. We also show that the induction of AGO1 mRNA level is a part of the host defence reaction, whereas the induction of miR168, which overlaps spatially with virus-occupied sectors, is mediated mainly by the Tombusvirus p19 RNA-silencing suppressor. The absence of p19 results in the elimination of miR168 induction and accompanied with the enhanced accumulation of AGO1 protein. In transient expression study, p19 mediates the induction of miR168 and the down-regulation of endogenous AGO1 level. P19 is not able to efficiently bind miR168 in virus-infected plants, indicating that this activity is uncoupled from the small RNA-binding capacity of p19. Our results imply that plant viruses can inhibit the translational capacity of AGO1 mRNA by modulating the endogenous miR168 level to alleviate the anti-viral function of AGO1 protein.
Várallyay
Eva
E
Agricultural Biotechnology Center, Plant Virology and Bioinformatics Group, Gödöllő, Hungary.
Válóczi
Anna
A
Agyi
Akos
A
Burgyán
József
J
Havelda
Zoltán
Z
D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism / Q000821:virology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D060565:Argonaute Proteins; D015536:Down-Regulation; D018506:Gene Expression Regulation, Plant; D018551:Solanum lycopersicum / Q000235:genetics / Q000378:metabolism / Q000821:virology; D046913:Medicago truncatula / Q000235:genetics / Q000378:metabolism / Q000821:virology; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D018749:RNA, Plant / Q000235:genetics / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D014026:Nicotiana / Q000235:genetics / Q000378:metabolism / Q000821:virology; D017864:Tombusvirus / Q000235:genetics / Q000378:metabolism*
C117457:AGO1 protein, Arabidopsis; D029681:Arabidopsis Proteins; D060565:Argonaute Proteins; D035683:MicroRNAs; D012333:RNA, Messenger; D018749:RNA, Plant; D034741:RNA, Small Interfering
Cell. 2008 Apr 4;133(1):116-27
18342361
Curr Opin Plant Biol. 2008 Oct;11(5):560-6
18691933
Cell. 2007 Aug 10;130(3):413-26
17693253
Plant J. 2006 Jul;47(1):140-51
16824182
Mol Cell. 2006 Apr 7;22(1):129-36
16600876
Nat Protoc. 2008;3(2):190-6
18274520
Plant Cell. 1995 Aug;7(8):1157-72
7549478
Plant Cell. 2004 May;16(5):1235-50
15084715
Proc Natl Acad Sci U S A. 2005 Aug 16;102(33):11928-33
16081530
Curr Biol. 2007 Sep 18;17(18):1615-21
17869109
Science. 2004 Mar 26;303(5666):2022-5
12893888
Plant Cell. 2002 Mar;14(3):629-39
11910010
Mol Cell. 2004 Jul 23;15(2):173-83
15260969
Cell. 2009 Feb 20;136(4):669-87
19239888
J Virol. 2000 Dec;74(23):10873-81
11069981
Plant Cell. 2009 Jun;21(6):1762-8
19531599
Plant Cell. 2007 May;19(5):1549-64
17513503
Mol Plant Microbe Interact. 2002 Mar;15(3):193-202
11952121
Plant Cell. 2002 Feb;14(2):359-72
11884680
Plant Cell. 2003 Nov;15(11):2730-41
14555699
Science. 2004 Nov 5;306(5698):1046-8
15528448
J Virol. 2007 Nov;81(21):11768-80
17715232
J Virol. 2005 Jan;79(1):450-7
15596838
EMBO Rep. 2009 May;10(5):521-6
19343050
Curr Biol. 2007 Sep 18;17(18):1609-14
17869110
Nat Genet. 2007 Aug;39(8):1033-7
17643101
Plant J. 2009 Jun;58(6):940-51
19220787
Mol Plant Microbe Interact. 2002 Mar;15(3):269-80
11952130
EMBO J. 2003 Feb 3;22(3):633-40
12554663
Trends Plant Sci. 2008 Jul;13(7):375-82
18550416
Plant J. 2010 May;62(3):463-72
20128884
Mol Cell. 2005 Aug 5;19(3):421-8
16061187
Plant Mol Biol. 2008 Jul;67(4):403-17
18392778
J Virol. 2006 Jun;80(12):5747-56
16731914
Proc Natl Acad Sci U S A. 2006 Feb 7;103(6):1994-9
16446454
Genes Dev. 2006 Dec 1;20(23):3255-68
17158744
J Virol. 2007 Apr;81(8):3797-806
17267504
PLoS One. 2009 Jul 30;4(7):e6442
19649244
Genes Dev. 2004 May 15;18(10):1187-97
15131082
Plant J. 2008 Jul;55(2):278-88
18397378
Dev Cell. 2003 Feb;4(2):205-17
12586064
Proc Natl Acad Sci U S A. 2007 Jul 17;104(29):12157-62
17615233
PLoS Genet. 2009 Sep;5(9):e1000646
19763164
Science. 2008 May 30;320(5880):1185-90
18483398
EMBO J. 2004 Feb 25;23(4):876-84
14976549
Plant Cell. 1998 Jun;10(6):937-46
9634582
Methods Mol Biol. 2008;451:69-79
18370248
EMBO J. 2006 Jun 21;25(12):2768-80
16724105
Cell. 2002 Aug 23;110(4):513-20
12202040
Plant J. 2010 May;62(3):454-62
20128885
J Virol. 2005 Jun;79(12):7812-8
15919934
EMBO J. 2002 Jun 17;21(12):3070-80
12065420
Trends Plant Sci. 2008 Jul;13(7):359-67
18501664
BMC Plant Biol. 2009 Dec 30;9:152
20042107
Proc Natl Acad Sci U S A. 2008 Sep 23;105(38):14732-7
18799732
EMBO J. 1998 Mar 16;17(6):1799-809
9501101
Cell. 2003 Dec 26;115(7):799-811
14697199