%0 Journal Article %T Profile of small interfering RNAs from cotton plants infected with the polerovirus Cotton leafroll dwarf virus %A Tatiane F Silva %A Elisson AC Romanel %A Roberto RS Andrade %A Laurent Farinelli %A Magne £¿ster£¿s %A C¨¦cile Deluen %A R¨¦gis L Corr¨ºa %A Carlos EG Schrago %A Maite FS Vaslin %J BMC Molecular Biology %D 2011 %I BioMed Central %R 10.1186/1471-2199-12-40 %X Deep sequencing of small RNAs (sRNAs) from leaves of CLRDV-infected cotton plants revealed that the vsRNAs were 21- to 24-nucleotides (nt) long and that their sequences matched the viral genome, with higher frequencies of matches in the 3- region. There were equivalent amounts of sense and antisense vsRNAs, and the 22-nt class of small RNAs was predominant. During infection, cotton Dcl transcripts appeared to be up-regulated, while Dcl2 appeared to be down-regulated.This is the first report on the profile of sRNAs in a plant infected with a virus from the family Luteoviridae. Our sequence data strongly suggest that virus-derived double-stranded RNA functions as one of the main precursors of vsRNAs. Judging by the profiled size classes, all cotton DCLs might be working to silence the virus. The possible causes for the unexpectedly high accumulation of 22-nt vsRNAs are discussed. CLRDV is the causal agent of Cotton blue disease, which occurs worldwide. Our results are an important contribution for understanding the molecular mechanisms involved in this and related diseases.The RNA silencing pathway controls important biological processes in plants, including regulation of gene expression during development, heterochromatin formation, hormone signaling, metabolic processes, and stress responses, as well as being an important antiviral defense mechanism [1]. In plants, antiviral silencing can be triggered by the presence of viral double-stranded RNAs (dsRNA), which are generated by the viral RNA polymerase as an intermediate in genomic replication and transcription, or are predicted to form as secondary structures along single stranded viral genomic RNA (ssRNA) [2]. Both structures are recognized by Dicer-like (DCL) ribonucleases and are processed into virus-derived small interfering RNAs (vsRNAs) that vary in length from 21 to 24 nucleotides (nt) [3-5]. These vsRNAs are then loaded into Argonaute (AGO)-containing complexes known as RNA-induced silencing complexes (RISC %U http://www.biomedcentral.com/1471-2199/12/40