Fig. 3.

VasiRNAs are biologically active. (A) Length distribution and abundance (reads per million of total reads) of the small RNAs derived from the 1,172 RDR1 target genes, rRNAs, and tasiRNAs found in AGO1 and AGO2 complexes coimmunoprecipitated (IP) from WT plants after mock or CMV-∆2b infection. (B−D) Northern blot analyses of the accumulation of the large and small RNAs in WT and mutant plants after inoculation with buffer (mock), CMV, and/or CMV-∆2b. LHCB1.3 was examined as the RDR1 target gene in C and D whereas five additional target genes (membrane related protein CP5; AT5G20700; HSP70-1, heat shock protein 70–1; RBCS-1A, Rubisco small subunit 1A; RCA, Rubisco activase) were analyzed in B. Methylene blue staining of 25S rRNA and Northern blot detection of Tubulin beta 2 (TUB2) mRNA, viral siRNAs, miR167, and U6 RNA were shown as controls. All of the mutant alleles (dcl2-1, dcl4-2, and ago2-1) used were null alleles except for ago1-27, which is hypomorphic because AGO1 is indispensable for development.