library_construction_protocol: 12-day-old seedlings of AGO1 truncation mutants in the ago1-36 background were ground to a fine powder in liquid nitrogen and subjected to RNA extraction using TRI Reagent, small RNAs of 18-40 nucleotides (nt) were isolated from total RNA resolved on 15% urea-PAGE gels. 12-day-old Arabidopsis seedling of  AGO1::HA-AGO1 del 1-90AA in the ago1-36 background, AGO1::HA-AGO1 del 91-189AA and  AGO1::HA-AGO1 del 1-189AA in the ago1-36 /+  backgrounds were collected and ground into powder in liquid nitrogen then subjected to immunoprecipitation using HA antibody (sigma H3663). Small RNA library was constructed using NEBNext Multiplex Small RNA Library Prep Set for Illumina (E7300).