RT Journal Article
SR Electronic
T1 A hormone-activated mobile RNAi pathway defends plant stem cells from virus infection
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2022.12.18.520928
DO 10.1101/2022.12.18.520928
A1 Marco Incarbone
A1 Gabriele Bradamante
A1 Florian Pruckner
A1 Tobias Wegscheider
A1 Wilfried Rozhon
A1 Vu Nguyen
A1 Ruben Gutzat
A1 Thomas Lendl
A1 Stuart MacFarlane
A1 Michael Nodine
A1 Ortrun Mittelsten Scheid
YR 2022
UL http://biorxiv.org/content/early/2022/12/19/2022.12.18.520928.abstract
AB Stem cells are essential for the development and organ regeneration of multicellular organisms, so their infection by pathogenic viruses must be prevented. Accordingly, mammalian stem cells are highly resistant to viral infection due to dedicated antiviral pathways including RNA interference (RNAi) (1, 2). In plants, a small group of stem cells harbored within the shoot apical meristem (SAM) generates all postembryonic above-ground tissues, including the germline cells. Many viruses do not proliferate in these cells, yet the molecular bases of this exclusion remain only partially understood (3, 4). Here we show that a plant-encoded RNA-dependent RNA polymerase, after activation by the plant hormone salicylic acid, amplifies antiviral RNAi in infected tissues. This provides stem cells with RNA-based virus sequence information, which prevents virus proliferation. Furthermore, we find RNAi to be necessary for stem cell exclusion of several unrelated RNA viruses, despite their ability to efficiently suppress RNAi in the rest of the plant. This work elucidates a molecular pathway of great biological and economic relevance and lays the foundations for our future understanding of the unique systems underlying stem cell immunity.Competing Interest StatementThe authors have declared no competing interest.