Molecular Plant-Microbe Interactions (2013) 26, 1004-1015

M. Carmen Cañizares, Rosa Lozano-Durán, Tomás Canto, Eduardo R. Bejarano, David M. Bisaro, Jesús Navas-Castillo and Enrique Moriones (2013)
Effects of the crinivirus coat protein-interacting plant protein SAHH on post-transcriptional RNA silencing and its suppression
Molecular Plant-Microbe Interactions 26 (9), 1004-1015
Abstract: In plants, post-transcriptional gene silencing (PTGS) is a sequence-specific mechanism of RNA degradation induced by double-stranded RNA (dsRNA), which is processed into small interfering RNAs (siRNAs). siRNAs are methylated and, thereby, stabilized by the activity of the S-adenosylmethionine-dependent RNA methyltransferase HEN1. PTGS is amplified by host-encoded RNA-dependent RNA polymerases (RDR), which generate dsRNA that is processed into secondary siRNAs. To counteract this RNA silencing-mediated response of the host, plant viruses express proteins with silencing suppression activity. Here, we report that the coat protein (CP) of crinivirus (family Closteroviridae, genus Crinivirus) Tomato chlorosis virus, a known suppressor of silencing, interacts with S-adenosylhomocysteine hydrolase (SAHH), a plant protein essential for sustaining the methyl cycle and S-adenosylmethionine-dependent methyltransferase activity. Our results show that, by contributing to an increased accumulation of secondary siRNAs generated by the action of RDR6, SAHH enhances local RNA silencing. Although downregulation of SAHH prevents local silencing, it enhances the spread of systemic silencing. Our results also show that SAHH is important in the suppression of local RNA silencing not only by the crinivirus Tomato chlorosis virus CP but also by the multifunctional helper component-proteinase of the potyvirus Potato virus Y.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Tomas Canto, Jesús Navas-Castillo, Eduardo R. Bejarano

Research topic(s) for pests/diseases/weeds:
resistance/tolerance/defence of host
molecular biology - genes

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Tomato chlorosis virus