Involved in transcriptional gene silencing (TGS). Component of the RISC complex that associate with the small interfering RNA (siRNA) pathway involved in direct cytosine methylation at endogenous DNA repeats. Required for the accumulation of specific siRNAs derived from transgene and heterochromatin-related endogenous loci. Involved in RNA-directed DNA methylation (RdDM) at specific endogenous loci. Probably not required for the accumulation of siRNAs derived from transgene inverted repeats that induce post-transcriptional gene silencing (PTGS). Associates mainly with small RNAs of 24 nucleotide in length and preferentially recruits small RNAs with a 5' terminal adenosine. Targeted by turnip yellows virus (TuYV) protein P0 (via F-box-like domain) for probable proteasome degradation and thereby inactivating AGO6 function in RNA silencing. Expressed in roots, cotyledons and shoot meristematic region. Belongs to the argonaute family. Ago subfamily.