pubmed.ncbi.nlm.nih.gov

Salicylic acid-mediated and RNA-silencing defense mechanisms cooperate in the restriction of systemic spread of plum pox virus in tobacco - PubMed

Salicylic acid-mediated and RNA-silencing defense mechanisms cooperate in the restriction of systemic spread of plum pox virus in tobacco

Josefa M Alamillo et al. Plant J. 2006 Oct.

Free article

Abstract

Plum pox virus (PPV) is able to replicate in inoculated leaves of Nicotiana tabacum, but is defective in systemic movement in this host. However, PPV produces a systemic infection in transgenic tobacco expressing the silencing suppressor P1/HC-Pro from tobacco etch virus (TEV). In this work we show that PPV is able to move to upper non-inoculated leaves of tobacco plants expressing bacterial salicylate hydroxylase (NahG) that degrades salicylic acid (SA). Replication and accumulation of PPV is higher in the locally infected leaves of plants deficient in SA or expressing TEV P1/HC-Pro silencing suppressor. Accumulation of viral derived small RNAs was reduced in the NahG transgenic plants, suggesting that SA might act as an enhancer of the RNA-silencing antiviral defense in tobacco. Besides, expression of SA-mediated defense transcripts, such as those of pathogenesis-related (PR) proteins PR-1 and PR-2 or alternative oxidase-1, as well as that of the putative RNA-dependent RNA polymerase NtRDR1, is induced in response to PPV infection, and the expression patterns of these defense transcripts are altered in the TEV P1/HC-Pro transgenic plants. Long-distance movement of PPV is highly enhanced in NahG x P1/HC-Pro double-transgenic plants and systemic symptoms in these plants reveal that the expression of an RNA-silencing suppressor and the lack of SA produce additive but distinct effects. Our results suggest that SA might act as an enhancer of the RNA-silencing antiviral defense in tobacco, and that silencing suppressors, such as P1/HC-Pro, also alter the SA-mediated defense. Both an RNA-silencing and an SA-mediated defense mechanism could act together to limit PPV infection.

PubMed Disclaimer

Cited by

Recovery of Nicotiana benthamiana plants from a necrotic response induced by a nepovirus is associated with RNA silencing but not with reduced virus titer.
Jovel J, Walker M, Sanfaçon H. Jovel J, et al. J Virol. 2007 Nov;81(22):12285-97. doi: 10.1128/JVI.01192-07. Epub 2007 Aug 29. J Virol. 2007. PMID: 17728227 Free PMC article.
Global Transcriptomic Changes Induced by Infection of Cucumber (Cucumis sativus L.) with Mild and Severe Variants of Hop Stunt Viroid.
Xia C, Li S, Hou W, Fan Z, Xiao H, Lu M, Sano T, Zhang Z. Xia C, et al. Front Microbiol. 2017 Dec 12;8:2427. doi: 10.3389/fmicb.2017.02427. eCollection 2017. Front Microbiol. 2017. PMID: 29312160 Free PMC article.
Transcriptional and post-transcriptional regulation of RNAi-related gene expression during plant-virus interactions.
Gong Q, Wang Y, Jin Z, Hong Y, Liu Y. Gong Q, et al. Stress Biol. 2022 Aug 19;2(1):33. doi: 10.1007/s44154-022-00057-y. Stress Biol. 2022. PMID: 37676459 Free PMC article. Review.
The P25 protein of potato virus X (PVX) is the main pathogenicity determinant responsible for systemic necrosis in PVX-associated synergisms.
Aguilar E, Almendral D, Allende L, Pacheco R, Chung BN, Canto T, Tenllado F. Aguilar E, et al. J Virol. 2015 Feb;89(4):2090-103. doi: 10.1128/JVI.02896-14. Epub 2014 Dec 3. J Virol. 2015. PMID: 25473046 Free PMC article.
Modulation of host plant immunity by Tobamovirus proteins.
Conti G, Rodriguez MC, Venturuzzi AL, Asurmendi S. Conti G, et al. Ann Bot. 2017 Mar 1;119(5):737-747. doi: 10.1093/aob/mcw216. Ann Bot. 2017. PMID: 27941090 Free PMC article. Review.

Salicylic acid-mediated and RNA-silencing defense mechanisms cooperate in the restriction of systemic spread of plum pox virus in tobacco - PubMed