RETRACTED: Small RNA duplexes function as mobile silencing signals between plant cells.
In the plant RNA interference (RNAi) pathway, 21-nucleotide duplexes of small interfering RNA (siRNA) are processed from longer double-stranded RNA precursors by the RNaseIII Dicer-like 4 (DCL4). Single-stranded siRNAs then guide Argonaute 1 (AGO1) to execute posttranscriptional silencing of complementary target RNAs. RNAi is not cell-autonomous in higher plants, but the nature of the mobile nucleic acid(s) signal remains unknown. Using cell-specific rescue of DCL4 function and cell-specific inhibition of RNAi movement, we genetically establish that exogenous and endogenous siRNAs, as opposed to their precursor molecules, act as mobile silencing signals between plant cells. We further demonstrate physical movement of mechanically delivered, labeled siRNA duplexes that functionally recapitulate transgenic RNAi spread. Cell-to-cell movement is unlikely to involve AGO1-bound siRNA single strands, but instead likely involves siRNA duplexes.
Dunoyer
Patrice
P
Institut de Biologie Moléculaire des Plantes du CNRS, Université de Strasbourg 12 rue du Général Zimmer, 67084 Strasbourg cedex, France. patrice.dunoyer@ibmp-ulp.u-strasbg.fr
Schott
Gregory
G
Himber
Christophe
C
Meyer
Denise
D
Takeda
Atsushi
A
Carrington
James C
JC
Voinnet
Olivier
O
D017360:Arabidopsis / Q000166:cytology* / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D060565:Argonaute Proteins; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000235:genetics; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D018515:Plant Leaves / Q000166:cytology / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified; D034622:RNA Interference; D012322:RNA Precursors / Q000378:metabolism; D012330:RNA, Double-Stranded / Q000235:genetics / Q000378:metabolism; D018749:RNA, Plant / Q000235:genetics / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism*; D043244:Ribonuclease III / Q000235:genetics / Q000378:metabolism; D014170:Transformation, Genetic
C117457:AGO1 protein, Arabidopsis; D029681:Arabidopsis Proteins; D060565:Argonaute Proteins; D004268:DNA-Binding Proteins; C109765:ETT protein, Arabidopsis; D009687:Nuclear Proteins; D012322:RNA Precursors; D012330:RNA, Double-Stranded; D018749:RNA, Plant; D034741:RNA, Small Interfering; D049452:Green Fluorescent Proteins; C504982:DCL4 protein, Arabidopsis; D043244:Ribonuclease III