Four plant Dicers mediate viral small RNA biogenesis and DNA virus induced silencing.

ABSTRACT: Like other eukaryotes, plants use DICER-LIKE (DCL) proteins as the central enzymes of RNA silencing, which regulates gene expression and mediates defense against viruses. But why do plants like Arabidopsis express four DCLs, a diversity unmatched by other kingdoms? Here we show that two nuclear DNA viruses (geminivirus CaLCuV and pararetrovirus CaMV) and a cytoplasmic RNA tobamovirus ORMV are differentially targeted by subsets of DCLs. DNA virus-derived small interfering RNAs (siRNAs) of specific size classes (21, 22 and 24 nt) are produced by all four DCLs, including DCL1, known to process microRNA precursors. Specifically, DCL1 generates 21 nt siRNAs from the CaMV leader region. In contrast, RNA virus infection is mainly affected by DCL4. While the four DCLs are partially redundant for C

SUBMITTER: Blevins T 

PROVIDER: S-EPMC1669714 | biostudies-literature | 2006

REPOSITORIES: biostudies-literature